Adolescent Health Care: A Practical Guide

Chapter 45

Barrier Contraceptives and Spermicides

Patricia A. Lohr

Spermicides are agents that kill sperms whereas barrier contraceptives block their movement toward the upper genital tract. Barrier contraceptives are available in a wide variety of designs, including the male and female condom, diaphragm, cervical cap, cervical shield, and sponge. Vaginal spermicides come in many forms such as foam, gel, cream, suppository, and film. In general, barrier methods and spermicides have higher failure rates but fewer systemic side effects than other modern contraceptive methods. Barrier methods also offer some reduction in the risk of sexually transmitted diseases (STDs). Many barrier contraceptives and all spermicides are available over the counter and improve adolescent access to birth control. The high typical-use failure rates of barrier methods and spermicides can be considerably lowered if they are used more consistently or in combination with other contraceptive methods.

Male Condoms

Condoms (Fig. 45.1) are the oldest method of male contraception and the second most popular reversible form of birth control in the United States (Mosher et al., 2004). Since the mid-1980s, condom use among teenage males has been increasing. The most recent data from the 2002 National Survey of Family Growth (NSFG) shows a continuation in this trend; 71% of teenage males reported condom use at sexual debut and an equal percentage reported condom use during the last episode of sexual intercourse (Abma et al., 2004). Trends differed by ethnicity and gender. Non-Hispanic black teens were more likely than other groups to report condom use at first sex, and Hispanic males were more likely to report no contraceptive use. Female teens report lower rates of male condom use than male teens; however, the number using condoms is also increasing. The percentage of female teenagers using a condom during their most recent sexual activity increased from 38% in 1995 to 54% in 2002.

Consistent condom utilization remains a problem for teenagers. In 1998, fewer than half (45%) of sexually experienced adolescent men used condoms consistently (Sonenstein et al., 1998). According to the 2002 NSFG data, the percentage of teenage males who reported using a condom every time they had intercourse over the preceding 12-month period was only 37% (Abma et al., 2004).

Condoms are very cost-effective for episodic intercourse, which is often found among teens. For long-term use, however, the condom's higher failure rate drives its overall cost much higher.

The human immunodeficiency virus (HIV) epidemic has heightened public awareness and acceptance of condoms. A significant degree of STD protection is afforded by latex and polyurethane condoms, which are impermeable to Chlamydia trachomatis, Neisseria gonorrhoeae, herpes simplex virus, cytomegalovirus, hepatitis B virus, and human papillomavirus (HPV). Millions of women use condoms in conjunction with other methods (e.g., sterilization, birth control pills, or spermicides) to capture this STD risk reduction benefit. Seventeen percent of adolescents combine the male condom with a female method of contraception for STD risk reduction and/or enhanced contraceptive efficacy (Sonenstein et al., 1998;Abma et al., 2004).

Uses of Male Condoms

Contraceptive Uses

  1. As a primary method of birth control, alone or in conjunction with a spermicide, a female barrier, hormonal method or intrauterine contraception
  2. As a backup method of contraception after a late start with a hormonal method (e.g., oral contraceptives, injections) or whenever two or more combined oral contraceptive pills or one progestin-only pill have been missed
  3. As a barrier contraceptive, used as part of the fertility awareness method (FAM) of contraception during vulnerable days of the woman's cycle

Noncontraceptive Uses

  1. To reduce transmission of STDs
  2. To blunt sensation, to treat premature ejaculation
  3. To reduce cervical antisperm antibody titers in women with associated infertility
  4. To reduce allergic reaction in women with sensitivity to sperm

Types of Male Condoms

The more than 100 brands of condoms available in the United States provide a wide range of choices in size, shape, thickness, lubricant, and design features intended

P.625


to enhance sensation and utilization. Three materials are used in manufacturing condoms: latex, lamb cecum (used to make natural membrane or “skin” condoms), and polyurethane. Condoms made from other synthetic materials are in development and testing. Latex condoms dominate the market (99%), whereas natural membrane and polyurethane condoms account for <1%. Condoms are available in several sizes, but most condoms are 170 mm long and 50 mm wide. The thickness ranges from 0.03 to 0.10 mm. Condom shapes vary (straight-sided, baggy, or contoured), as do their textures (smooth or ribbed). One experimental nonlatex design, the eZ·on condom, is a baggy sheath that is slipped on like a sock rather than rolled on. Condoms are lubricated by a wide range of materials such as silicones, spermicides, and water-based gels. Other features that are intended to make condoms more pleasurable to use include an array of colors, scents, and tastes.

 

FIGURE 45.1 The male condom—patient information sheet.

Some latex condoms are available with a spermicidal coating of nonoxynol-9. Spermicides may provide lubrication, but they do not contribute to STD risk reduction (Roddy et al., 1998) and existing data is very limited to support an added improvement in preventing pregnancy.

P.626


Spermicides may cause genital irritation, potentially leading to increased STDs and urinary tract infections (Handley et al., 2002). The spermicidal coating also drastically reduces the shelf life of latex condoms, from an average of 5 to 2 years. The current recommendations of the Centers for Disease Control and Prevention state that use of nonoxynol-9 lubricated condoms is preferable to not using a condom. However, given the option, use of condoms with nonoxynol-9 is not advocated because of their increased cost, shorter shelf life, association urinary tract infections in young women, and lack of apparent benefit when compared with other lubricated condoms (Workowski and Levine, 2002).

Polyurethane male condoms are nonbiodegradable and require less fastidious handling before use. They are not susceptible to damage by petroleum-based lubricants, lack the latex allergens, and do not have the unexpected taste or smell, occasionally associated with latex condoms, during oral-genital contact. Polyurethane itself is a stronger material than latex, but it lacks elasticity. With the exception of the experimental eZ·on condom, pregnancy rates in clinical trials were not higher in polyurethane condom users, but the slippage and breakage rates for the polyurethane condoms were four to eight times higher than for a standard latex condom (Frezieres et al., 1998; Steiner et al., 2003). The

P.627


higher breakage and slippage rates of polyurethane condoms may diminish some of their protective effect against STDs. Polyurethane male condoms may best be reserved for couples who cannot tolerate latex products.

Natural “skin” condoms afford almost equal pregnancy protection as latex or polyurethane condoms, but do not reduce STD risks. They are also significantly more expensive which may be a barrier to use by teens.

Mechanism of Action

Condoms are sheaths made of latex (rubber-based), polyurethane, or processed lamb cecum which fit over the penis and block transmission of semen.

Effectiveness

The male condom is the most effective barrier method available for pregnancy protection. The first-year failure rate for typical use of the latex male condom is 15%, and the failure rate for correct and consistent use is 2% (Trussell, 2004). Comparative trials of latex versus nonlatex condoms have confirmed higher breakage and slippage rates for nonlatex condoms during intercourse or withdrawal, but similar pregnancy rates (Gallo et al., 2003). Both latex and nonlatex condoms appear to have similar efficacy in preventing STDs. The most critical variable in predicting efficacy is consistent use, followed closely by proper technique. Condom quality has also improved dramatically in recent years. Research described in Consumer Reports found that 7 of 37 condom models failed routine testing in 1995, but by 1999 only 2 of 30 models failed those tests (Consumer's Union, 1995, 1999). The self-proclaimed “strength” and “contour” of the condom did not influence test scores.

Improving Condom Success

Dozens of excellent studies have been conducted to identify factors that predict consistent use of barrier methods, variables that would predict poor use, and ways to design interventions that might improve utilization. Most of this research has focused on the male condom. Given the vital role that barriers play in slowing the spread of STDs, answers to these questions are desperately needed. Unfortunately, studies show that solutions will not be easy to achieve.

There are profound differences in condom use by gender, with female adolescents reporting far less use of condoms than male adolescents (Brown et al., 1992; Ku et al., 1994; Abma et al., 2004). This may be due to the fact that female teens most commonly have older sexual partners and condom use by males tends to decrease with increasing age. Adolescent males appear to have greater knowledge about condom use and efficacy than females and may feel more comfortable obtaining condoms (Leland and Barth, 1992). Self-esteem may also play a role. Adolescent African-American females with higher self-esteem were found to be more likely to have positive attitudes toward condom use, feel more efficacious and less fearful about negotiating condom use, and perceived fewer barriers to using condoms (Salazar et al., 2005).

Many teens have misperceptions about condoms. Among 16,677 teens surveyed, approximately one third believed that condoms work just as well when Vaseline is used with them, and approximately one fifth believed that natural membrane condoms provide better protection against HIV than the latex condom (Crosby and Yarber, 2001). In addition, perception of knowledge about condoms among teens is not always associated with actual knowledge or use. In a longitudinal study of 404 virginal male adolescents who became sexually active during the study, those with low objective but high-perceived knowledge were approximately 3 times less likely to report using a condom at first intercourse (Rock et al., 2005).

Adolescents remain at high risk of STDs, particularly minority youth and young men who have sex with men (Centers for Disease Control and Prevention, 2003; Lightfoot et al., 2005). Youth who identify as bisexual appear to be at extremely high risk due to higher frequencies of multiple sexual partners, STDs, unprotected intercourse, and injection drug use (Goodenow et al., 2002). A perceived risk of STD or HIV infection is associated with higher condom use and also with intention to use condoms in the future (Brown et al., 1992;Donald et al., 1994; Orr and Langefeld, 1993). However, several studies show that many adolescents who are clearly at increased risk for STDs have little appreciation of their vulnerability (Rosenthal et al., 1994; O'Donnell et al., 1995). Teens with a history of a STD also do not appear to apply the factual knowledge gained from the prior experience to alter sexual behaviors, thereby providing an additional challenge to educational prevention efforts (DiClemente et al., 2002).

A common finding of virtually all studies is that condom use is increased when adolescents believe that their peers use condoms. Other factors that increase condom use are when teens believe that condoms can prevent STDs, when teens feel that they can talk to their partner about risks, when they have easy access to a supply of condoms, know how to use a condom, and carry condoms with them (Joffe and Radius, 1993; Schuster et al., 1998; DiIorio et al., 2001). Condom use is decreased when risky sexual behavior is just one of a cluster of risky health behaviors (e.g., smoking, substance abuse) or other lifestyle risks (e.g., violence). Substantial societal changes apparently are needed to address these issues. Putting condoms in open containers may be necessary to provide adolescent access to condoms, but it is clearly not sufficient to ensure their use.

For individual success in clinical practice, providers should be aware of condom misuse (Wood and Buckle, 1994) and should do the following:

  1. Teach the patient how best to use condoms (Fig. 45.1)
  2. Plan where to store condoms for ready access, privacy, and condom safety.
  3. Incorporate condom placement into the lovemaking process—when the penis is still somewhat flaccid, if possible, but certainly before any genital contact. The preejaculatory semen contains few sperm, but STD spread may occur early. Furthermore, a teen's ability to delay sexual activity to place the condom is markedly diminished after genital contact. Inexperienced youth benefit greatly from the opportunity to practice placing condoms on models or even over two fingers during office visits.
  4. Open the packaging carefully. Avoid using sharp objects. Any foil edges shearing across the condom may tear the late Between 24% and 65% of latex condom breakages occur before intercourse.
  5. P.628


Correctly place the condom. Judge which way the condom will unroll. Allow some slack at the top of condoms that have no reservoir tip; fit more snugly those with ejaculatory reservoirs once erection is complete. Squeeze the air out of the reservoir areas. Completely unroll the full length of the condom.

  1. Change condoms if different body orifices are penetrated. In particular, if a condom is used during anal or oral sex, it must be removed and replaced before vaginal penetration.
  2. Use only water-based lubricants or spermicides to reduce vaginal friction against the latex condom. Lubricant should be applied only to the external surface of the condom or to the vaginal area; lubricant should not be placed on the penis or on the inner surface of the condom, because that practice increases problems with slippage and breakage. Avoid petroleum-based products such as Vaseline, baby oils, and lotions. All vaginal antifungal treatments and some of the vaginal products for treatment of bacterial vaginosis also contain petroleum-based ingredients. Petroleum can react with the latex in seconds and undermine the strength of the condom; within 1 minute, microscopic tears may develop and become large enough to permit the passage of virus.
  3. After ejaculation, firmly grasp the rim of the condom at the base of the penis and carefully withdraw the unit while the penis is still firm. Any delays in removal can result in spillage and loss of protection.
  4. Inspect the condom for signs of breakage or spillage.
  5. Be prepared with fast-acting spermicide should the condom break or spill.
  6. Use emergency contraception as needed (see Chapter 46).
  7. Be responsive to patient complaints and apprehension
  8. For the young woman who is unsure that her partner will use condoms, role-play different scenarios with her until she believes she has the ability to discuss the issue with her partner and persuade him to use condoms. The same techniques are helpful to reduce STD risk for the receptive partner when men have sex with men.
  9. If the male partner complains of constriction or blunted sensation, recommend one of the following strategies:
  • Try a larger condom size.
  • Try a different condom style. Condoms with reservoirs at the side are available; these reduce glans pressure and purportedly enhance stimulation. Ribbed condoms are also designed to increase sensation.
  • Advise the couple to place a second, larger condom over the first one after the outer surface of the first condom has been well lubricated. The friction between the condoms may enhance penile sensation. It also reduces the impact of breakage problems.

Advantages

  1. Readily available: Condoms may be purchased in drug stores, by mail order on-line or through catalogs, and vending machines, or obtained in family planning or school clinics without prescription.
  2. Relatively inexpensive: Sometimes they are even available free from clinics. Male condoms cost $0.30 to $1.50 each. Frequent use raises the direct (out-of-pocket) costs and indirect (pregnancy-related) costs because of their moderately high failure rates.
  3. Portable: Condoms can easily be carried in a purse or other vehicle to be available whenever the need arises.
  4. Male participation: Although women purchase more than half of condoms, the sheaths are still used by men; men definitely benefit from detailed instructions.
  5. Visible proof of protection: Couples can get reasonably accurate feedback that protection was offered by observing the ejaculate contained in the condom.
  6. Significant reduction in risk of STDs, including HIV infection and cervical dysplasia: Transmission of bacterial STDs, such as chlamydia and gonorrhea, is markedly reduced by effective condom use (Cates and Holmes, 1996; Cates, 1997; d'Oro et al., 1994; Rosenberg et al., 1992). The impact that condom use has on the transmission of viral STDs depends on the site of infection. Studies consistently demonstrate that condoms provide important protection against HIV transmission. A meta-analysis of 25 studies of serodiscordant heterosexual couples found that condoms reduced transmission by 87% (range, 60%–90%). Consistent users had annual HIV seroconversion rates of 0.9%, compared with 6.8% for those who never used condoms (Davis and Weller, 1999). Consistent condom use also accelerates the regression of cervical and penile HPV-associated lesions and accelerates clearance of genital HPV infection in women (Holmes et al., 2004).

Disadvantages

  1. Requires placement with each act of intercourse
  2. May interrupt lovemaking
  3. Requires cooperation of male partner
  4. Carries a higher pregnancy rate than hormonal contraceptive methods or intrauterine contraception
  5. May diminish the pleasure of intercourse
  6. May blunt sensation for man; less “natural”
  7. May result in less vigorous intercourse due to fear that the condom may slip or break
  8. Requires prompt withdrawal after ejaculation, which may not permit sexual satisfaction of partner
  9. May increase vaginal irritation in women, especially those with inadequate lubrication
  10. Side effects (see subsequent text)

Side Effects of Male Condoms

Latex allergies are becoming more common in the United States; estimates are that latex allergies are found in 2% to 4% of couples using condoms. Among latex-exposed workers, the average may be as high as 18%. This number may be lower in the teen population with less previous exposure to latex. Polyurethane condoms are strongly recommended for latex-allergic couples, because the transition from mild reactions to anaphylaxis can develop rapidly. Some authors have suggested that the unsensitized partner could still use a latex condom if it is covered by a plastic condom. This strategy may reduce topical irritation, but the latex powder is a potent allergen and can induce severe, even life-threatening allergic reactions.

P.629


Future Developments

Condoms made of newer, nonlatex plastic materials, such as Tactylon, are in clinical trials and may be able to reduce the slippage and breakage problems associated with polyurethane (Callahan et al., 2000). A deproteinized latex condom (Manix Crystal) is available in France and other European countries and appears to be a safe alternative for latex-allergic individuals (Levy et al., 2001). Male condoms with new shapes (cap condoms) and different sized condoms (including snugger fit and custom-sized condoms) are increasingly available. The Unisex Condom, which can be used by either partner, is available in Canada and can be purchased through on-line condom distribution sites.

Female Condoms

The only female condom currently available in the United States is the FC Female Condom (formerly known as the Reality condom; Fig. 45.2). The device is a thin polyurethane sheath measuring 17 cm in length and 7.8 cm in width. It contains flexible polyurethane rings at each end. The inner ring is loose within the sheath. At the time of insertion, the inner ring is pivoted parallel to the axis of the vagina and is used to introduce the device through the introitus to the vault, just as a diaphragm is placed. After insertion, the inner ring is rotated at the top of the vault to stabilize the device during intercourse. The outer ring, which is fixed to the base of the device, remains outside the vagina. The female condom provides a barrier along the length of vagina and partially covers the introitus. It is lined internally with a silicone-based “dry” lubricant and may be combined with vaginal spermicides. The female condom should never be used with the latex male condom, because each device can compromise the integrity of the other.

Far fewer adolescents use the female condom than the male condom; only 1.7% report ever using the female condom (Abma et al., 2004). As with the male condom, adolescents appear to use the female condom inconsistently, often choosing to use a male condom instead—even when supplied with female condoms (Marshall et al., 2002). Among female teens with experience using the female condom, more than half found it to be an acceptable method and a very low percentage (4%) reported that they did not use the female condom because of embarrassment.

Efficacy

The female condom underwent 6-month clinical efficacy trials, during which time a 12.5% failure rate was observed in typical use in the United States. This rate has been annualized to a typical first-year failure rate of 21% (Trussell, 2004). Perfect-use rates are considerably lower (5%), reflecting perhaps the difficulty users experienced with this method. The female condom is impermeable to HIV and comparative studies of male and female condoms have found similar protection against STDs (Drew et al., 1990; French et al., 2003).

Advantages and Disadvantages

The female condom is available over the counter in single-size disposable units (Fig. 45.2); they are considerably more expensive than the male condom. The female condom causes no known adverse physical side effects. The polyurethane is not sensitive to petroleum-based products. However, its use may be challenging; even users who are experienced with diaphragm insertion may find the female condom difficult to insert. The package instructions say that correct placement may be difficult in the first or second attempt because of the device's lubrication. The female condom may be inserted up to 8 hours before intercourse to permit a relaxed insertion. The consumer is warned not to tear the sheath with fingernails or other sharp objects. During intercourse, the penis should be manually guided into the device. The couple is to remain attentive throughout coitus to the position of the outer ring to ensure that it does not ride up or get pushed into the vagina. The male partner must avoid excessive friction between his penis and the device, which could increase the breakage rate or cause inversion of the device on withdrawal. Additional lubrication applied within the condom can help reduce this risk and also reduces the noise the device may make during intercourse.

The relative complexity of the device and its low typical efficacy rate make the female condom a second choice after the male latex or polyurethane condom. However, the female condom may make an important contribution for women whose partners refuse to use male condoms. For adolescents, extensive education and hands-on practice may be needed to ensure correct use of the female condom. Emergency contraception should be offered in advance to all female condom users.

Future Developments

Female condoms made of latex (which is less expensive than polyurethane) are currently in development and testing. Models available in other countries include the Reddy female condom, which is latex and uses a soft, polyurethane sponge to hold it in place inside the vagina, and the Natural Sensation Panty Condom that is shaped and worn like a woman's panty with a built-in condom.

Diaphragm

The diaphragm (Fig. 45.3) is a dome-shaped latex device which, when introduced into the vagina, extends from the posterior fornix to the anterior vaginal wall to completely cover the cervix. The semirigid outer ring stabilizes the device in the upper vagina, and the dome holds spermicide directly against the cervix. As a mechanical barrier alone, the diaphragm has an unacceptably high failure rate; it is intended for use with contraceptive gel. The diaphragm must be professionally fitted and is available only by prescription.

Although not a commonly used method of contraception, there is a renewed interest in the diaphragm and other female barrier contraceptives that shield the cervix as a result of research indicating that they may be protective against the acquisition of HIV and other STDs (Moench et al., 2001). In addition, intensive research is being done to develop a vaginal microbicide (a topical product that protects against acquisition of HIV and other STDs) that may be used in conjunction with a diaphragm or similar vaginal device.

P.630

 

 

FIGURE 45.2 The female condom.

P.631


Types of Diaphragm

Diaphragms are available in sizes ranging from 50 to 105 mm in 5-mm increments and in four styles, which vary primarily by the construction of the rim or the seal.

  1. Arcing spring rim: A very sturdy rim that folds for insertion but springs open to stabilize the device's position within the vagina. It is designed for universal use, but is uniquely good for vaginas with limited muscle tone. There are two versions—one that folds only in one direction and another that is flexible in all directions. This latter design is the most popular style because of its ease of introduction. Most diaphragms currently used in the United States are versions of the arcing spring rim.
  2. Coil-spring rim: Sturdier rim that folds flat for insertion with no arc. It is suitable for a woman with average muscle tone and pubic arch angle. A plastic diaphragm introducer may be used, if needed.
  3. Flat-spring rim: Thin, delicate rim with gentle spring action that is more comfortable for women with firm vaginal wall tone. A plastic diaphragm introducer may be used.
  4. Wide-seal rim: Has a flexible flange attached to the inner edge of the rim to hold spermicide in place and to maintain a better seal. It has very limited availability and can be obtained only by direct order with arcing spring and coil-spring rims.
 

FIGURE 45.3 Sample instruction sheet for diaphragms. (Courtesy of Teenage Health Center, Children's Hospital of Los Angeles, Los Angeles, California.)

Contraindications to Use

  1. History of toxic shock syndrome
  2. Allergy to latex or spermicidal agents
  3. Recent pregnancy, before renormalization of anatomy
  4. Inability of patient to correctly insert and remove diaphragm

Effectiveness

The typical-use failure rate varies between 16% and 18%. The failure use with correct and consistent use is estimated

P.632


to be 6%. Women who are more successful users of diaphragms are usually older, are comfortable touching their genitals, and are able to anticipate coitus. However, adolescents certainly can be taught to use diaphragms effectively (Fig. 45.3).

Tips to Improve Success of Method

  1. Correct fitting of device (see later discussion)
  2. Detailed, hands-on instruction for patient education (see later discussion)
  3. Careful monitoring of diaphragm between uses to identify any defects (see later discussion)
  4. Careful selection of patient
  5. Offer only to motivated woman willing to touch her genitals and to use the device with everyact of intercourse
  6. Avoid offering to a woman with a markedly anteverted or retroverted uterus (diaphragm tends to dislodge)
  7. Discourage coital positions that compromise stability of diaphragm, particularly the female superior position

P.633


Correct Fitting of Diaphragm

A diaphragm must be fitted properly to be effective. The diagonal length of the vaginal canal from the posterior aspect of the symphysis pubis to the posterior vaginal fornix is measured during the bimanual examination. The second and third fingers are inserted deeply into the vagina until the tip of the middle finger touches the posterior vaginal wall; then the point at which the index finger touches the symphysis pubis is marked with the thumb. The hand is withdrawn and the diaphragm is placed on the tip of the third finger with the opposite rim in front of the thumb to measure the correct size. This is a first approximation, which requires reconfirmation through actual fitting. The diaphragm is inserted and checked. Then the next larger size is fitted. The correct size is one size smaller than the first one perceived by the patient. For example, starting at size 60 and increasing the sizes until the patient perceives pressure with a size 70 would suggest that a size 65 would be appropriate for her. This is confirmed by examining the

P.634


patient with the diaphragm in place. The diaphragm should touch the lateral vaginal walls, cover the cervix, and fit snugly between the posterior vaginal fornix and behind the symphysis pubis. A diaphragm that is too large may buckle and permit sperm to bypass the diaphragm. A diaphragm that is too small may slip out of place. The health care provider should appreciate that the adolescent may be tense during initial fitting, causing the fitting of a smaller diaphragm than would be required if the adolescent were relaxed.

Patient Education

Patient education programs should include the following.

  1. Demonstration of insertion and removal techniques: After being shown how to place the diaphragm, the teen should insert and remove it at least once in the office and have the placement checked by the provider.
  2. Detailed guidance about use of spermicide
  3. Coat the inner surface of the diaphragm with spermicidal gel. One application is effective for up to 6 hours.
  4. Add additional spermicide with the applicator if intercourse is delayed beyond 6 hours or if additional acts of coitus are anticipated. Additional doses must be placed into the vagina; the diaphragm should not be removed to add spermicide.
  5. Apply an extra dose immediately if the diaphragm is dislodged during intercourse, and consider using emergency contraception.
  6. Removal instructions
  7. Wait at least 6 hours after the last episode of coitus to remove the device.
  8. Remove before 24 hours of use to reduce the risk of toxic shock syndrome.
  9. Concrete instructions about cleaning and storage of device: Recommend washing device in soap and water, then soaking it in an alcohol solution (70% isopropanol or 80% ethanol) for at least 20 minutes after each application. Coat the device with cornstarch or another agent to prevent contamination or cracking, and store it in a dry container.
  10. Return for refitting of the diaphragm every 1 to 2 years, after every pregnancy, and after any 10% to 20% change in body weight.

Advantages

  1. The most effective of the female barrier methods available today
  2. Reduced risks of STDs, including HIV
  3. May be placed in anticipation of coitus

Disadvantages

  1. Requires professional sizing and is available only by prescription
  2. Requires motivation and extensive education for proper use
  3. Requires preparation and access to supplies; therefore, it may limit spontaneity and may not meet the impulsive needs of the adolescent
  4. May be considered messy, especially for multiple acts of intercourse
  5. Not an acceptable method if either partner is allergic to spermicide or latex
  6. There is a small risk of toxic shock syndrome associated with poorly timed or prolonged use
  7. The diaphragm increases the risk of cystitis by increasing the count of enteric organisms within the vagina

Future Developments

The SILCS intravaginal barrier is a one-size-fits-all diaphragm made of silicone that is entering phase II clinical trials. It is designed to be easier to use and intended for sale over the counter. The BufferGel Duet is a disposable, one-size-fits-all diaphragm made of dipped polyurethane that is in development. It will be marketed with prefilled BufferGel, a candidate microbicide and contraceptive.

Cervical Cap and Cervical Shield

The cervical cap and the cervical shield are cup-shaped devices made of silicone or latex, designed to cover the cervix and protect it from semen. Both are used with spermicide and provide contraceptive protection over multiple acts of intercourse for up to 48 hours without device removal. Each can be placed hours before coitus. The position should be reconfirmed before each coital act. The cap and the shield must be removed 48 hours after placement to reduce problems with odor and the possibility of toxic shock syndrome.

 

FIGURE 45.4 The FemCap. (Courtesy of FemCap, Inc., and Alfred Shihata, MD.)

The U.S. Food and Drug Administration (FDA) approved a silicone cervical cap, the FemCap, in 2003. It is shaped like a sailor's hat with a dome, rim, brim, and removal strap (Fig.45.4). The brim has a short side and long side, with the long side worn to the back of the vagina. The underside of the dome forms a bowl that covers the cervix. The brim forms a seal against the vaginal wall to hold the device in place. A small amount of spermicide is used in the bowl, spread on the outer brim, and placed in the groove between the dome and the brim. The FemCap comes in three sizes determined by the diameter of the inner rim. The smallest rim diameter (22 mm) is intended for nulliparous women, the medium (26 mm) cap is intended for women who have

P.635


been pregnant but have not had a vaginal delivery, and the largest (30 mm) is for women who have had a fullterm vaginal delivery. Although the sizing of the FemCap is determined by obstetric history, a clinician visit is required as the device can only be obtained with a prescription.

 

FIGURE 45.5 The Lea's Shield.

Lea's Shield is a reusable silicone cervical barrier that is held in place by its volume rather than its diameter (Fig. 45.5). The FDA approved it for use in 2002. The shield is oval in shape with a bowl that covers the cervix and fills the posterior fornix of the vagina, an anterior loop to aid in insertion and withdrawal, and a flat, tubular flutter valve leading from the inner surface of the bowl through to the convex side. This one-way valve prevents trapping of air between the cervix and the device after insertion and is intended to allow for egress of menstrual and other cervical secretions. Like the FemCap, the shield is held in place by the vaginal muscles rather than through suction. It is designed as a one-size-fits-all device but requires a clinician visit as it can only be obtained by prescription. The shield can be used with or without spermicide, although the addition of spermicide increases its contraceptive efficacy.

Contraindications for the cervical cap and shield include all those mentioned for the diaphragm. Cervical caps are not intended for use during menses. The shield may be used during menstruation, although none of the efficacy or safety trials included women who were menstruating.

Efficacy

The FemCap has been compared in a randomized trial with the diaphragm but was not found to be equivalent in efficacy (Mauck et al., 1999). Overall, the 6-month typical-use failure rate for the cap was 13.5% compared with 7.9% for diaphragm users. The differences between nulliparous and parous women in the FemCap group were not statistically significant (9.5% and 15.8%, p = 0.12). Extrapolating the 6-month unadjusted failure rate to 12 months gives a probability of 22.8 pregnancies per 100 women for the cap.

A 6-month efficacy trial of the Lea's Shield found a typical-use pregnancy rate of 8.7 per 100 women among those who used the device with spermicide (Mauck et al., 1996). There were no pregnancies among nulliparous women in this trial. The unadjusted typical-use failure rate for parous women was 11 per 100 women.

Fitting the Cervical Cap

Neither the FemCap nor Lea's Shield requires formal fitting, although a clinician visit is recommended to assure proper application and comfort with the devices.

Patient Education

Insertion of the FemCap

  1. Apply approximately ¼ teaspoon of spermicide in the bowl, spread a thin layer over the outer brim, and insert ½ teaspoon between the brim and the dome.
  2. Gently squeeze the cup and insert it into the vagina with the bowl facing upward and the longer brim entering first.
  3. Push the cap down toward the rectum and back as far as it can go.
  4. Check to make sure that the cap completely covers the cervix.

Removal of the FemCap

  1. To remove the cap, squat and bear down.
  2. Push the tip of a finger against the dome cap to break the suction.
  3. Grasp the removal strap with the tip of your finger and gently remove the device.
  4. Wash the cap thoroughly with a mild soap then rinse it with tap water. Allow the cap to air dry or gently pat it dry with a clean, soft towel and store.

Insertion of Lea's Shield

  1. Apply a small amount of spermicide in the bowl of the device.
  2. Gently squeeze the shield and insert into the vaginal bowl-first as high as it will go.
  3. Check to make sure that the entire cervix is covered by the bowl.

Removal of Lea's Shield

  1. Insert a finger into the vagina, grasp and twist the control loop to break the suction and gently remove.
  2. The shield should be washed thoroughly with mild liquid soap for approximately 2 minutes, dried, and then stored.

Advantages

  1. Effective for up to 48 hours; additional doses of spermicide are not required for multiple acts of intercourse
  2. May be placed early and is usually not detected by the partner
  3. May offer some reduction of STD risk, especially for cervical and upper genital tract infections

P.636


Disadvantages

  1. Requires a clinician visit to obtain a prescription
  2. Requires training in placement, removal, cleaning, and storage
  3. Replacement every 1 to 3 years; and refitting for the FemCap is needed after pregnancy
  4. May be difficult to insert or remove for some women

Contraceptive Sponge

After the introduction of the vaginal contraceptive sponge in 1983, it quickly became the leading female-controlled nonprescription contraceptive method. The manufacturer of sponges in the United States discontinued its production in early 1995 because the FDA found possible contamination along the production line, although the product was not compromised. The contraceptive sponge (Today Sponge) was brought back to the U.S. market in 2005.

The contraceptive sponge is made of pliable polyurethane foam that contains 1 gm of nonoxynol-9. A concave depression, or “dimple,” on one side fits against the cervix, and a woven polyester loop on the other side can be grasped for removal. After it is moistened with water, it is inserted into the vagina and is effective immediately. The sponge protects against pregnancy for 24 hours without the need to add spermicidal cream or jelly, regardless of the number of acts of intercourse. After intercourse the sponge must be left in place for 6 hours before is removed and discarded. Wearing the sponge for longer than 24 hours in not recommended because of the possible risk of toxic shock syndrome.

The sponge comes in one size and does not require fitting by a physician. It is relatively inexpensive ($10 for a package of three sponges) although the cost may be prohibitive for some adolescents. It is available without a prescription, can be inserted well before the onset of sexual activity, and is easy to use, making the contraceptive sponge well suited for adolescents.

Mechanism of Action

The primary contraceptive action of the sponge is provided by the spermicidal activity of nonoxynol-9, which is impregnated in the polyurethane foam. The sponge releases 125 to 150 mg of nonoxynol-9 slowly over a 24-hour period. The sponge also traps and absorbs semen and acts as a physical barrier between sperm and the cervical os.

Efficacy

The contraceptive sponge has different failure rates depending on the consistency of use and possibly parity. Overall, the typical-use failure rate of 16% in nulliparous women compared with 32% in parous women. Perfect use rates are 9% and 20%, respectively (Trussell, 2004). Observational data have suggested that parity may be less of a factor than motivation to use the sponge consistently when determining contraceptive efficacy of the sponge (Edelman and North, 1987).

Patient Education

Insertion

  1. Remove the sponge from its package and hold it with the “dimple” side facing up and the loop hanging down
  2. Moisten with approximately 2 tablespoons of water and squeeze the sponge a few times until it becomes sudsy
  3. Fold the sides of the sponge upward with a finger on each side to support it
  4. While in a standing, lying, or squatting position gently introduce the sponge into the vagina and using one or two fingers push the sponge upward as far as it will go
  5. Check the position of the sponge by running a finger around the edge of the sponge to make sure that the cervix is covered

Removal

  1. Wait 6 hours after the last act of intercourse before removing the sponge
  2. Insert one finger into the vagina until the loop is felt
  3. If the loop cannot be felt, bear down, lie on your back on the bed with your knees up against your chest, squat down in a low position, or sit on the toilet and tilt your pelvis forward (so that the small of your back is rounded) to bring the sponge closer to the vaginal opening
  4. Hook one finger into the loop then gently and slowly pull the sponge out
  5. Check to make sure the sponge is intact; if it is torn remove all pieces from the vagina
  6. Discard sponge

Contraindications

  1. History of toxic shock syndrome
  2. Allergy or sensitivity to polyurethane foam, nonoxynol-9, or metabisulfite (the preservative used in the sponge; women or partners with an allergy to sulfa should consult with a health care provider)
  3. The sponge is not recommended for use during menstruation

Advantages

  1. Lack of hormonal side effects or medical contraindications
  2. Allows for spontaneity after insertion; can be used over repeated acts of intercourse
  3. Available without a prescription or fitting by health care personnel; one size fits all
  4. Female-controlled method; does not require partner participation
  5. May be more comfortable to wear than other barrier methods such as the diaphragm
  6. Easy to use and not “messy”

Disadvantages

  1. Relatively high failure rate
  2. Teen must be comfortable touching genitals in order to insert device
  3. Spermicide may cause vaginal, vulvar, or penile irritation
  4. Sponge can become discolored or malodorous in the presence of vaginitis
  5. Can be difficult to remove

P.637


Side Effects

Approximately 4% of users will experience a sensitivity reaction to the sponge that can lead to itching, burning, redness, or a rash. Although this may be due to nonoxynol-9, other components of the sponge such as the preservative may be the source of the sensitivity reaction.

Future Developments

Two contraceptive sponges, Protectaid and Pharmatex, are available in Canada and Europe and may eventually be brought to the United States. Clinical trials of an additional contraceptive sponge, Avert, are planned.

Vaginal Spermicides

Vaginal spermicides are available in a wide array of delivery systems (Table 45.1). Spermicides can be used alone or in combination with barrier methods. They can play an important role in contraception for the adolescent, because they require neither a prescription nor a pelvic examination and are free from systemic side effects.

TABLE 45.1
Vaginal Spermicides

Base of Carrier

Onset of Action (min)

Duration of Action (min)

Concentration (%)

a Creams and gels are usually used in conjunction with diaphragms or cervical caps but may be used as single agents. Data from Hatcher RA, Trussell J, Stewart F, et al. Contraceptive technology, 17th rev. ed. New York: Ardent Media, 1998:358.

Aerosol foams

Immediate

60

 8–12

Creams and gelsa

Immediate

60

 2–5

Suppositories and tablets

10–15

60

 2.3–5.6

Film

15

60

28

Spermicides have been shown to have bactericidal and virucidal activity in vitro, but clinical data in vivo have failed to demonstrate any reduction in the risk of STD acquisition. Several studies of spermicide use in high-risk women have found that nonoxynol-9 does not reduce the risk of HIV or other STD transmission. There is no clear evidence that the risk of seroconversion is increased by the use of spermicides, although one case–control study of commercial sex workers in Africa found that multiple uses daily (>3.5) may increase the risk of HIV transmission (World Health Organization, 2002). Eleven percent of heterosexual adolescent males report experience with anal intercourse (Gates and Sonenstein, 2000). Although little has been documented about lubricant use among heterosexual couples who practice anal intercourse, a large proportion of men who have sex with men use lubricants during rectal intercourse, and 41% choose products that contain nonoxynol-9 (Gross et al., 1998). Lavage and biopsy studies of rectal epithelium exposed to nonoxynol-9 have demonstrated rapid epithelial sloughing with exposure of the underlying submucosa (Phillips et al., 2004). Because this damage may increase the risk of transmission of STDs, including HIV, the use of nonoxynol-9–containing products during anal intercourse should be discouraged.

Types of Spermicides

The various spermicidal preparations differ in their onset and duration of action and mode of application. Table 45.1 displays the more commonly used types of spermicidal products as well as the differences in the concentration of nonoxynol-9 in each formulation. In general, each agent is active for approximately 1 hour unless used with a diaphragm, cap, or shield. Foam, which is the most commonly used agent, is instantly effective. Suppositories and film require 10 to 15 minutes to melt and distribute over the cervix. Each type of suppository comes with complete and appropriate patient instructions for use. Encourage patients to choose a spermicidal agent with a use pattern that will work well for them.

Nonoxynol-9 is the active agent in all spermicides available in the United States. In other countries, agents such as octoxynol and benzalkonium chloride are also available as spermicides. However, benzalkonium has been shown to be irritating to vaginal epithelial cells and to reduce lactobacillus counts (Patton et al., 1999).

Efficacy

Typical first-year failure rates for spermicides used alone are estimated to be as high as 29% (Trussell, 2004). A randomized trial comparing three spermicidal gels containing different doses of nonoxynol-9 (52.5 mg, 100 mg, and 150 mg) with a spermicidal film and suppository (both containing 100 mg of nonoxynol-9) found 6-month failure rates that ranged from 10% to 22% (Raymond et al., 2004). The pregnancy risk was statistically higher in the gel containing 52.5 mg of nonoxynol-9, but there was no difference between any of the formulations containing 100 mg of nonoxynol-9. Correct and consistent use of spermicidal agents is estimated to reduce the pregnancy rate to 18%. In the trial described, perfect-use probabilities ranged from 5.1% to 15.7%. When used in conjunction with other methods, such as barriers and emergency contraception, the pregnancy rate drops.

Mechanism of Action

The components of spermicidal agents include an inert base (foam, cream, or jelly), which holds the spermicidal agent and blocks sperm from entering the cervical os. Spermicides destroy sperm by breaking down the outer cell membrane.

P.638


Contraindications

  1. Allergy or sensitivity to spermicidal agents or to the ingredients in the base
  2. Inability to use due to vaginal abnormalities or inability to master the insertion technique

Advantages

  1. No proven systemic side effects
  2. Readily available without prescription
  3. A fairly convenient, easy-to-learn method for teenagers
  4. May be used by women with or without involvement of partner
  5. May provide lubrication
  6. May be useful as a backup method for other contraceptives

Disadvantages

  1. Relatively high failure rate
  2. Considered messy by some teenagers (some forms)
  3. Must be used only a short time before intercourse is started
  4. Requires 10 to 15 minutes for activation (some formulations)
  5. Requires that woman be comfortable with touching her genitals
  6. Unpleasant taste if oral-genital sex is involved
  7. May cause a local allergic reaction

Future Developments

The need for vaginal agents that are contraceptive and protective against HIV and other STDs is increasingly compelling. Much of current research and development activity is centered on developing an agent with these properties.

Web Sites

For Teenagers and Parents Condoms

http://www.plannedparenthood.org/birth-controlpregnancy/birth-control/condom.htm. Planned Parenthood information sheet on condoms.

http://kidshealth.org/teen/sexual_health/contraception/contraception.html. Teen oriented Web site with information on condoms and other birth control methods.

http://www.condomania.com/. Information site and selection site for different types of condoms.

http://www.siecus.org/pubs/fact/fact0011.html. Siecus information sheet on condoms.

http://www.youngwomenshealth.org/femalebarrier1.html. Information from Boston Children's Hospital on female condoms.

Diaphragms, Cervical Caps, Cervical Shields

http://www.plannedparenthood.org/utah/diaphragm.htm. Planned Parenthood information sheet on diaphragms.

http://www.mayoclinic.com/health/birth-control/BI99999/PAGE=BI00009. Information sheet on diaphragms, cervical caps, and cervical shields from the Mayo Foundation for Medical Education and Research.

http://www.femcap.com/index.htm. Product Web site for the FemCap.

http://www.leasshield.com/index.htm. Product Web site for Lea's Shield®.

Contraceptive Sponge

http://www.mayoclinic.com/health/birth-control/BI99999/PAGE=BI00011. Information about the contraceptive sponge from the Mayo Foundation for Medical Education and Research.

http://www.todaysponge.com/. Product Web site with user and purchasing information.

Spermicides

http://www.sex-ed101.com/spermx.html. Sex Education 101 site with information on spermicides and many other issues.

http://www.fhi.org/en/. Family Health International Frequently Asked Questions on spermicides.

For Health Professionals

http://www.reproline.jhu.edu/english/1fp/1methods/1condom/condom.htm. Web site with presentation slides on condoms.

http://www.cervicalbarriers.org/. Informative Web site of The Cervical Barrier Advancement Society.

References and Additional Readings

Abma JC, Martinez GM, Mosher WD, et al. Teenagers in the United States: sexual activity, contraceptive use and childbearing, 2002. Vital Health Statistics, National Center for Health Statistics, 2004:23.

ACOG Committee Opinion. Condom availability for adolescents. Washington, DC: American College of Gynecologists and Obstetricians, 1995:154.

American Academy of Pediatrics. Condom availability for youth. Pediatrics 1995;95:281.

Brown LK, DiClemente RJ, Park T. Predictors of condom use in sexually active adolescents. J Adolesc Health 1992;13:651.

Callahan M, Mauck C, Taylor D, et al. Comparative evaluation of three Tactylon condoms and a latex condom during vaginal intercourse: breakage and slippage. Contraception2000;61:205.

Cates WC Jr. How much do condoms protect against sexually transmitted diseases. Int Plann Parenthood Fed Bull 1997;31:2.

Cates WC Jr, Holmes KK. Re: condom efficacy against gonorrhea and nongonococcal urethritis. Am J Epidemiol 1996;15:143.

Centers for Disease Control and Prevention. Trends in HIV-related sexual risk behaviors among high school students—selected U.S. cities, 1991–1997. JAMA 1999;282:228.

Centers for Disease Control and Prevention. Centers for Disease Control and Prevention: sexually transmitted disease surveillance, 2003. Atlanta, GA, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2003.

P.639

 

Consumer's Union. How reliable are condoms? Consum Rep 1995;60:320.

Consumer's Union. Condoms get better: tests of 30 models show far fewer failures than in past years. Consum Rep 1999;64:46.

Crosby RA, Yarber WL. Perceived versus actual knowledge about correct condom use among U.S. adolescents: results from a national study. J Adolesc Health Care 2001;28:415.

Davis KR, Weller SC. The effectiveness of condoms in reducing heterosexual transmission of HIV. Fam Plann Perspect 1999;31:272.

DiIorio C, Dudley WN, Kelly M, et al. Social cognitive correlates of sexual experience and condom use among 13- through 15-year old adolescents. J Adolesc Health Care2001;29:208.

DiClemente RJ, Wingood GM, Sionean C, et al. Association of adolescents' history of sexually transmitted disease (STD) and their current high-risk behavior and STD status: a case for intensifying clinic-based prevention efforts. Sex Transm Dis 2002;29:503.

Donald M, Lucke J, Dunne M, et al. Determinants of condom use by Australian secondary school students. J Adolesc Health 1994;15:503.

Drew WL, Blair M, Miner RC, et al. Evaluation of the virus permeability of a new condom for women. Sex Transm Dis 1990;17:110.

Edelman DA, North BB. Parity and the effectiveness of the Today contraceptive sponge. Adv Contracept 1987;3:327.

French PP, Latka M, Gollub EL, et al. Use-effectiveness of the female versus male condom in preventing sexually transmitted disease in women. Sex Transm Dis 2003;30:433.

Frezieres RG, Walsh TL, Nelson AL, et al. Breakage and acceptability of a polyurethane condom: a randomized controlled study. Fam Plann Perspect 1998;30:73.

Gallo MF, Grimes DA, Schulz KF. Nonlatex vs. latex male condoms for contraception: a systematic review of randomized controlled trials. Contraception 2003;68:319.

Gallo MF, Grimes DA, Schulz KF. Cervical cap versus diaphragm for contraception. Cochrane Database Syst Rev. 2002;(4):CD003551.

Gates GJ, Sonenstein FL. Heterosexual genital sexual activity among adolescent males: 1988 and 1995. Fam Plann Perspect 2000;32:295.

Goodenow C, Netherland J, Szalacha L. Related risk among adolescent males who have sex with males, females, or both: evidence from a statewide survey. Am J Public Health2002;92:203.

Gross SP, Buchbinder C, Celum P, et al. Rectal microbicides for U.S. gay men. Are clinical trials needed? Are they feasible? Sex Transm Dis 1998;25:296.

Handley MA, Reingold AL, Shiboski S, et al. Incidence of acute urinary tract infection in young women and use of male condoms with and without nonoxynol-9 spermicides.Epidemiology 2002;13:431.

Holmes KK, Levine R, Weaver M. Effectiveness of condoms in preventing sexually transmitted infections. Bull World Health Organ 2004;82:454.

Hufford D. Adolescents and condom use. Arch Pediatr Adolesc Med 1994;148:879.

Joffe A. Adolescents and condom use. Am J Dis Child 1993;147:746.

Joffe A, Radius SM. Self-efficacy and intent to use condoms among entering college freshmen. J Adolesc Health 1993;14:262.

Ku L, Sonenstein FL, Pleck JH. The dynamics of young men's condom use during and across relationships. Fam Plann Perspect 1994;26:246.

Leland NL, Barth RP. Gender differences in knowledge, intentions, and behaviors concerning pregnancy and sexually transmitted disease prevention among adolescents. J Adolesc Health 1992;13:589.

Levy DA, Moudiki P, Laynadier F. Deproteinised condoms are well tolerated by latex allergic patients. Sex Transm Infect 2001;77:202.

Lightfoot M, Song J, Rotherman-Borus MJ, et al. The influence of partner type and risk status on the sexual behavior of young men who have sex with men living with HIV/AIDS. J Acquir Immune Defic Syndr 2005;38:61.

Marshall S, Giblin P, Simpson P. at al Adolescent girls' perception and experiences with the reality female condom. J Adolesc Health Care 2002;31:5.

Mauck C, Callahan M, Wiener DH, et al. A comparitive study of the safety and efficacy of FemCap®, a new vaginal barrier contraceptive, and the Ortho All-Flex® diaphragm.Contraception 1999;60:71.

Mauck C, Glover LH, Miller E, et al. Lea's Shield® : a study of a the safety and efficacy of a new vaginal barrier contraceptive used with and without spermicide. Contraception1996;53:239.

Moench TR, Chipato T, Padian N. Preventing disease by protecting the cervix: the unexplored promise of internal vaginal barrier devices. AIDS 2001;15:1595.

Mosher WD, Martinez GM, Chandra A, et al. Use of contraception and use of family planning services in the United States, 1982–2002. Advance Data from Vital and Health Statistics, 2004:350.

O'Donnell L, Doval AS, Duran R, et al. Predictors of condom acquisition after an STD clinic visit. Fam Plann Perspect 1995;27:29.

d'Oro LC, Parazzini F, Naldi L, et al. Barrier methods of contraception, spermicides, and sexually transmitted diseases: a review. Genitourin Med 1994;70:410.

Orr DP, Langefeld CD. Factors associated with condom use by sexually active male adolescents at risk for sexually transmitted disease. Pediatrics 1993;91:873.

Patton DL, Kidder GG, Sweeney YC, et al. Effects of multiple applications of benzalkonium chloride and nonoxynol 9 on the vaginal epithelium in the pigtailed macaque (Macaca nemestrina). Am J Obstet Gynecol 1999;180:1080.

Phillips DM, Sudol KM, Taylor CL, et al. Lubricants containing N-9 may enhance rectal transmission of HIV and other STDs. Contraception 2004;70:107.

Raymond EG, Chen PL, Luoto J. Contraceptive effectiveness and safety of five nonoxynol-9 spermicides: a randomized trial. Obstet Gynecol 2004;103:430.

Rock EM, Ireland M, Resnick MD, et al. A rose by any other name? Objective knowledge, perceived knowledge, and adolescent male condom use. Pediatrics 2005;115:667.

Roddy RE, Cordero M, Ryan KA, et al. A randomized controlled trial comparing nonoxynol-9 lubricated condoms with silicone lubricated condoms for prophylaxis. Sex Transm Infect 1998;74:116.

Rosenberg MJ, Davidson AJ, Chen JH, et al. Barrier contraceptives and sexually transmitted diseases in women: a comparison of female-dependent methods and condoms. Am J Public Health 1992;82:669.

Rosenthal SL, Biro FM, Succop PA, et al. Reasons for condom utilization among high-risk adolescent girls. Clin Pediatr (Phila) 1994;33:706.

P.640

 

Salazar LF, Crosby RA, DiClemente RJ, et al. Self-esteem and theoretical mediators of safer sex among African American female adolescents: implications for sexual risk reduction interventions. Health Educ Behav 2005;32:413.

Santelli JS, Lindberg LD, Abma J, et al. Adolescent sexual behavior: estimates and trends from four nationally representative surveys. Fam Plann Perspect 2000;32:156.

Schuster MA, Bell RM, Berry SH, et al. Impact of a high school condom availability program on sexual attitudes and behaviors. Fam Plann Perspect 1998;30(2):67.

Sonenstein FL, Ku L, Lindberg LD, et al. Changes in sexual behavior and condom use among teenaged males: 1988 to 1995. Am J Public Health 1998;88:956.

Steiner MJ, Dominik R, Rountree R, et al. Contraceptive effectiveness of a polyurethane condom and a latex condom: a randomized controlled trial. Obstet Gynecol2003;101:539.

Trussell J. Contraceptive failure in the United States. Contraception 2004;70:89.

Workowski KA, Levine WC. Sexually transmitted disease treatment guidelines–2002. MMWR Recomm Rep 2002;51(RR-6):1.

World Health Organization. WHO/CONRAD technical consultation on nonoxynol-9, World Health Organization, Geneva, 9–10 October 2001: summary report. Reprod Health Matters2002;10:175.

Wood VD, Buckle RA. Condom misuse among adolescents. J Natl Med Assoc 1994;86:39.