Joseph C. Gambone
Sexuality refers to how individuals express themselves as sexual beings. Physically, sexuality encompasses sexual intercourse and other forms of sexual contact. Often patients may have medical concerns about their sexual feelings and behavior and how these activities may affect or be affected by disease. Obstetrician-gynecologists should be familiar with the physiology of human sexual response and the types of sexual dysfunction that women may experience. Because female sexuality is most often expressed with another individual, usually male, it is important for healthcare professionals who take care of women to know the more important aspects of the male sexual response. The sociologic aspects of human sexuality and sexual behavior, such as cultural, ethical, moral, religious, or legal, are beyond the scope of this chapter.
Although sexuality and sexual expression rarely begins before puberty, gender identity is experienced much earlier, at about age 3 to 4 years. Children who are unable to identify with their assigned birth-gender have gender identity disorder (GID) and may develop transgender issues later in life. The diagnosis of GID can be made in an individual who has a strong and persistent cross-gender identity and a discomfort about the assigned gender.
During puberty, many teens begin exploring their bodies as well as experiencing sexual activity with others. Many teens, especially males, have early intercourse and are not well educated about contraception, the risks for pregnancy, or sexually transmitted infections (STIs). Young girls often have intercourse because of feelings of love, whereas boys are usually driven by curiosity. It is especially important for physicians to discuss sexuality with teens and to educate them about contraception and STI prevention. Teens are often apprehensive about discussing these issues and may fear parental discovery. They are usually more receptive to open-ended questions.
The early reproductive years are often the time when sexuality is explored and reproduction or its prevention becomes a priority. Infertility may be an issue in this age group, and many emotions may be evoked in infertile patients, often leading to sexual problems.
With increasing age and especially after menopause, the frequency and satisfaction with intercourse may decline. Decreased estrogen production causes progressive vaginal atrophy, which in turn leads to decreased vaginal lubrication, dyspareunia, and more difficulty in achieving orgasm. The decreased estrogen also decreases the acidity of the vaginal secretions, predisposing the woman to vaginal infections.
In many older couples, the frequency of intercourse declines because of the male partner’s inability to have erections. Illnesses or increased use of medications may also affect sexual functioning. A better understanding of the causes and more effective treatment for male erectile dysfunction are changing sexual behavior for many older individuals.
Variation in Sexual Expression
Human sexual expression is varied and often controversial. Health-care professionals must be knowledgeable and nonjudgmental about healthy and legal sexual expression and lifestyles to facilitate open and comfortable communication.
Heterosexuals are individuals who engage in sexual activity with the opposite sex. Most individuals engage in heterosexual behavior, which is considered “normal.” Homosexuals are those who engage in sexual activities with members of the same sex. Men who are homosexual are referred to as gay, whereas homosexual women are referred to as gay or lesbian. Although gay men tend to engage in more physical relationships and may have multiple partners, lesbians are generally inclined to be monogamous.
The reported incidence of homosexuality ranges from 6% to 20% in men and 3% to 18% in women. Several theories on homosexuality have been proposed, including a genetic predisposition, the maternal use of prenatal hormones, and other environmental factors. A multifactorial cause is likely.
Many homosexuals feel a need to conceal their sexuality for fear of loss of family, friends, or jobs. Familiarity with homosexuals has been shown to decrease the prejudice, and recently many homosexuals have “come out,” revealing their identities and expecting equal rights.
Bisexuals are those who engage in sexual activity with both men and women, either concomitantly or at different phases of their life. The reported incidence of bisexuality is 1% to 7% of men and 1% to 2% of women. Many individuals briefly explore same-sex activity at some time in their life but do not consider themselves bisexual.
Transgender or transsexual individuals are often confused with homosexuals. They have a strong belief from childhood that they were born into a body with the wrong sex. Most are heterosexual to their identified gender (i.e., men who believe they are women are attracted to men), and few are homosexual. Children with ambiguous genitalia who are assigned a particular gender may later show regret toward their assignment. Some experts recommend that these children be given a name that is appropriate to both genders to allow them to decide their gender for themselves later in life. Female-to-male transsexuals (FTM) are women that grow up as “tomboys” and often cross-dress. Male-to-female transsexuals (MTF) are men that grow up dressing as women. Transgender surgery is difficult to perform, especially FTM, and it is only performed in certain areas of the United States and the world. Box 27-1 lists some other variations in human sexual expression along with their definitions.
BOX 27-1 Other Forms of Sexual Expression and Their Definitions
Transvestism: Sexual excitement or gratification from wearing clothing of and enacting the opposite sex
Fetishism: Sexual excitement or gratification associated with an inanimate object (i.e., underwear) or body part (i.e., feet)
Pedophilia: Sexual excitement or gratification from children
Zoophilia: Sexual excitement or gratification through intercourse with animals
Exhibitionism: Sexual excitement or gratification from exposing one’s body, especially the genitals
Voyeurism: Sexual excitement or gratification from watching others
Masochism: Sexual excitement or gratification from enduring physical or physiologic pain; may be self-inflicted
Sadism: Sexual excitement or gratification from inflicting physical or physiologic pain onto others; also cruelty not associated with sexual behaviors
The process of sexual response was fully described by Masters and Johnson in 1966 based on extensive research. They delineated the female and male physical sexual response cycles. Although other modifications have been published, their version remains the classic description of human sexual response. The female cycle is divided into four phases, whereas in men, five phases are described. Generally, clitoral tissue is the most sexually sensitive anatomic area for women. Most women need to experience a caring relationship and nongenital physical stimulation before satisfactory sexual arousal can occur.
FEMALE SEXUAL RESPONSE CYCLE
The Excitement Phase
This phase starts with physical or psychological stimulation and may last minutes or hours. There is a sex flush, accompanied by erection of the nipples and engorgement of the breasts. A sex flush is an erythematous morbilliform skin change over the chest, neck, and face that occurs to a noticeable degree in 75% of women. In addition, the uterus elevates, and vaginal lubrication begins. The clitoris and labia enlarge, and the heart rate and blood pressure increase. Most muscles become tense (Figure 27-1A).
FIGURE 27-1 The four phases of the female sexual response cycle. A: The excitement phase. B: The plateau phase. C: The orgasmic phase. D: The resolution phase.
The Plateau Phase
During this phase, the breasts continue to enlarge, and the clitoris may elevate and retract under its hood. The Bartholin’s glands may secrete fluid near the vaginal opening, and there is tenting of the uterus to allow easier passage of sperm. The vagina and labia become more engorged, and there is increased blood pressure, heart rate, respiratory rate, and muscle tension (see Figure 27-1B).
The Orgasmic Phase
During this phase, there is release of sexual tension. The orgasmic phase is possible without actual physical stimulation. This phase is concentrated in the clitoris, vagina, and uterus. There is contraction of vaginal, uterine, lower abdominal, and anal muscles, usually 5 to 12 synchronized contractions 1 second apart. The first few contractions are the strongest and the closest together. Blood pressure, heart rate, and respiratory rate peak in this phase, and there is usually loss of voluntary muscle tone (e.g., most women curl their toes at orgasm). Women can have multiple orgasms before they enter the resolution phase (see Figure 27-1C).
The Resolution Phase
During this phase, the nipples and breasts decrease in size, and the vagina, clitoris, and uterus return to normal size and position. The sex flush disappears, and the blood pressure, heart rate, and respiratory rate also return to normal (see Figure 27-1D).
MALE SEXUAL RESPONSE CYCLE
The Excitement Phase
This phase begins with physical or psychological stimulation and may last minutes or hours. The nipples and penis become erect, and there is increased heart rate and blood pressure. The muscles become tense, and there is blood pooling in the extremities with vasocongestion in the penis and scrotum with testicular swelling and elevation (Figure 27-2A).
FIGURE 27-2 The five phases of the male sexual response cycle. A: The excitement phase. B: The plateau phase. C: The orgasmic phase. D: The resolution phase. E: The refractory phase (not illustrated).
The Plateau Phase
The testicles enlarge by 50%, and the prostate and penis also enlarge. There is increased blood flow, and the bulbourethral or Cowper’s gland secretes pre-ejaculatory fluid, which may contain sperm. There is increased blood pressure, heart rate, respiratory rate, and muscle tension. There is generally chest sex flushing (see Figure 27-2B).
The Orgasmic Phase
During the orgasmic phase, there is release of sexual tension; this phase is possible without actual physical stimulation. There are rhythmic contractions of the seminal vesicles, vas deferens, and prostate. The ejaculatory ducts push semen into the urethra, and ejaculation occurs with urethral contractions. The first few contractions are the strongest and the closest together. During this phase, the anal sphincter contracts. The point of imminence occurs a few seconds before ejaculation and refers to the point when a man knows an orgasm is inevitable (see Figure 27-2C).
The Resolution Phase
In the resolution phase, the genitals and penis decrease in size and return to a flaccid state. The testes descend, and the sex flush disappears. The blood pressure, heart rate, and respiratory rate return to normal (see Figure 27-2D).
The Refractory Phase
The refractory phase (not illustrated) occurs only in men. Because of this phase, men are not able to have multiple orgasms. During this phase, no amount of stimulation will cause another ejaculation. This phase lasts minutes in young men and hours to days in older men.
The similarity between the male and female cycles is apparent. Although the average time spent in each phase may differ (due primarily to learned behaviors), the elements of each cycle are the same. Because different neuronal circuits mediate each of these phases, sexual dysfunction may affect some phases without affecting the others.
The overall prevalence of sexual dysfunction is not known, but female sexual dysfunction is common. It has been estimated that one third of women experience decreased libido in situations in which the decrease is not desired. Comorbid conditions such as diabetes or obesity often play a causative role in sexual dysfunction, and not all women who lack interest in sexual activity are troubled by it.
EVALUATION OF SEXUAL FUNCTION
The assessment of sexual functioning should be an integral part of a complete medical evaluation, especially for the obstetrician-gynecologist. Skills for taking a sexual history are often overlooked in medical schools and sometimes ignored by physicians. It is more difficult to inquire about a patient’s sexuality if the physician is uncomfortable with the topic or is judgmental about sexual orientation. Clinicians may also be concerned about a patient’s answers, not knowing what to say or do if a history of sexual trauma is revealed. They may also feel untrained to deal with problems and solutions for sexual inadequacies. Often, they worry that the patients will misunderstand or be offended by the questions.
In taking a history, it is helpful to follow a routine pattern of questioning: (1) age of menarche, (2) menstrual patterns, (3) pregnancy history, (4) contraception use, (5) STI prevention, (6) sexual orientation, and (7) difficulties with sexual relations. Intimate partner violence and sexual abuse questions can then follow. Some sample questions may include the following:
• “Are you currently sexually active, and if so, with men, women, or both?”
• “Are you having any difficulties with sexual relations?”
• “Have you ever been in a situation in which you have experienced unwanted or harmful sexual activity?”
There are several factors that may affect taking a sexual history, including the physician’s own sexuality. A gay physician may be more thorough or may be afraid to inquire about a patient’s sexual orientation. At times, clinicians of both sexes may find themselves attracted to patients. In these instances, acceptance of the feelings as normal is appropriate, so long as behavior is unaffected and a professional relationship is maintained. Some patients may be seductive or even make sexual advances, but the physician must make it clear to the patient that the relationship is professional and not personal.
Appropriate boundaries of behavior during a physical examination must be maintained, and caution should be used with inappropriate language or overly friendly conversations. The patient may feel uncomfortable, especially with a doctor of the opposite sex, and fearful about potentially embarrassing discoveries, especially during the examination of the breasts and genitals. Drapes should be used to cover all the private body parts that are not being examined, and the physician should tell the patient what he or she is doing at all times. A nursing assistant or chaperone should be present during the examination.
FEMALE SEXUAL DYSFUNCTION
Sexual dysfunction is categorized by the Sexual Function Health Council of the American Foundation of Urologic Disease by failure of one or more of the phases of the sexual response cycle. Sexual dysfunction also includes pain disorders (Box 27-2).
BOX 27-2 American Foundation of Urologic Disease Consensus Classifi cation of Female Sexual Dysfunction
Sexual Desire/Interest Disorders∗
Hypoactive sexual desire disorder
Sexual aversion disorder
Sexual Arousal Disorder∗
Female sexual arousal disorder∗
Sexual Orgasmic Disorder∗
Sexual Pain Disorders∗
Other sexual pain disorder (genital pain from noncoital stimulation)
∗ Each disorder can be subtyped as lifelong vs acquired, generalized vs situational, and by origin (organic, psychogenic, mixed, or unknown).
Female sexual dysfunction is a common condition and often increases with age. Sexual dysfunction can be subdivided into three different categories, depending on whether it is primary (realistic sexual expectations have never been met under any circumstances), secondary (all phases have functioned in the past, but one or more no longer does), or situational (the response cycle functions under some circumstances, but not others). When a patient complains of hypoactive sexual desire, it is important to determine what her preferences are in contrast to those of her partner. A woman who desires intercourse twice a week may be perfectly normal but may not function well in a relationship in which her partner desires coitus daily. Sexual dysfunction can occur in homosexual or heterosexual relationships, or even in masturbatory situations.
ETIOLOGY OF SEXUAL DYSFUNCTION
As a general rule, primary problems are predominantly psychogenic and tend to be of longer duration. Secondary problems are often associated with the onset of a disease process or the use of a pharmacologic agent. If such an association cannot be established, deterioration in the patient’s relationship or some other chronologically related change in the patient’s life experience should be sought. It is important to consider psychological causes, such as depression or anxiety; organic causes, such as atherosclerosis, diabetes, or genital infections; and pharmacologic causes (Box 27-3). Factors initiating a problem may be different from those maintaining it. For example, drugs may precipitate a problem, but if anxiety and fear of failure sustain the difficulty, discontinuation of the drug alone may not rectify the problem.
BOX 27-3 Some Drugs that Can Diminish Sexual Functioning in Women
• Antihypertensive agents: reserpine, propranolol, methyldopa, atenolol, spironolactone
• Antidepressant medications: tricyclics or selective serotonin reuptake inhibitors
• Hypnotic agents: alcohol, barbiturates, tranquilizers, or diazepam
• Narcotics: heroin or methadone
• Antipsychotic agents: fluphenazine or chlorpromazine
• Stimulants: cocaine or amphetamines
• Hallucinogens: lysergic acid or mescaline
• Diuretics: acetazolamide
SEXUAL FUNCTION DISORDERS
Sexual Desire and Interest Disorders
Sexual desire appears to be an appetite similar to hunger, controlled by a dopamine-sensitive excitatory center, in balance with a serotonin (5-hydroxytryptamine)-sensitive inhibitory center. In both males and females, testosterone appears to be the hormone responsible for initially programming these centers during gestation and for maintaining their threshold of response. Stimulation and ablation experiments in cats and other mammalian species have located these centers within the limbic system, with significant nuclei in the hypothalamic and preoptic regions. For a woman, desire and interest in sexual activity result from a complex of both biologic and psychological inputs, including her feelings about her partner.
Disorders of sexual desire and interest include hypoactive sexual desire disorder and sexual aversion disorder. Lack of desire involves a decrease or absence of fantasy. Sexual aversion disorder may result from prior sex-associated trauma and personal aversion. Often in established relationships, decreased desire may result from sexual activity becoming too predictable and routine. Also, lack of privacy or external stresses, especially stress in the relationship, may initiate this disorder. Another important category of causes of hypoactive desire arises in the context of unrelated disease. Women may fear sex with a partner who has had a heart attack or may have decreased desire themselves following a mastectomy or hysterectomy.
Sexual arousal disorder is defined as the inability to attain or maintain sufficient sexual excitement, expressed as a lack of subjective excitement or somatic response such as genital lubrication. Estrogen is the hormone responsible for maintaining the vaginal epithelium and allowing transudation and lubrication to occur. Its deficiency (with breastfeeding or after menopause) is by far the most common cause of excitement phase dysfunction in women. Extragenital changes during the excitement phase include an increase in heart rate and blood pressure, enhanced muscle tension throughout the body, an increase in breast size, nipple erection, and engorgement of the surrounding areolae, and a sex flush. Some women do not recognize these symptoms as excitement and may experience difficulty and even failure on that basis.
During the orgasmic phase, a series of reflex clonic contractions of the levator sling and related genital musculature occur, mediated primarily by the sympathetic nervous system.
Orgasmic disorder is characterized by difficulty with or failure to attain orgasm following sufficient sexual stimulation and arousal. Anorgasmia may be situational. Many women experience orgasm only with manual or oral clitoral stimulation but not with penile thrusting alone. If they are willing to increase direct clitoral stimulation before, during, or after penile penetration, they may achieve a wholly satisfactory sexual adaptation. Women who have been orgasmic in the past but have lost that capacity should be screened for organic or pharmacologic causes, and changes in their relationship or relationships should be carefully explored.
Most women with primary anorgasmia have had minimal or no effective stimulation from self or partner. These patients should be encouraged to learn how to achieve orgasm through self-stimulation, and then to share this new information with their partners. Increasing the intensity of stimulation should increase the intensity of response.
Sexual Pain Disorders
Dyspareunia is genital pain associated with sexual intercourse. It is helpful to categorize dyspareunia into three groups for easier diagnosis and treatment: (1) pain with intromission (often due to vestibulitis, vaginismus, fissures, or other vulvar lesions); (2) mid-vaginal pain (often due to lack of lubrication, surgical scars, or urethral diverticulosis); and (3) deep-thrust dyspareunia (often due to endometriosis, interstitial cystitis, pelvic adhesions, or neoplasms).
Vaginismus is defined as severe pain or involuntary spasm of the distal vaginal and pelvic floor muscles during attempted penetration. Examination reveals no organic condition, but the pubococcygeal muscles are tight, and vaginal penetration by speculum or examining finger is painful and difficult, if not impossible. Often affected women harbor fantasies about the inadequacy of their vaginas to accommodate a speculum or penis and fear that penetration will damage them. These women respond remarkably well to education and reassurance. Others may have been traumatized by early sexual or other abuse and require more intensive psychological therapy. One important issue is whether they are motivated to participate with their partners in a stepwise desensitization program. This involves the slow, gentle vaginal insertion of dilators of gradually increasing size under the patient’s own control. Once sufficient progress has been made, the partner’s fingers and, ultimately, his penis may be substituted for the dilators. Alleviation of the problem is usually accomplished in 3 to 6 months.
Noncoital sexual pain disorder is pain that is induced by noncoital sexual stimulation.
MANAGEMENT OF SEXUAL DYSFUNCTION
Hormonal therapy is valuable in a limited number of situations. Estrogen (orally or vaginally) may improve desire, arousal, and orgasm by decreasing dyspareunia due to vaginal atrophy. Testosterone may improve desire and arousal but should be used only in hypoandrogenic women, especially after surgical menopause. Sildenafil (Viagra), used mostly in men with erectile dysfunction, inhibits cyclic guanosine monophosphate (cGMP) breakdown, therefore increasing clitoral and vaginal smooth muscle relaxation as well as improving lubrication. cGMP functions as a messenger in the nitric oxide–mediated relaxation of genital smooth muscle,. The use of sildenafil in women has not been as effective as in men.
A clitoral vacuum device (the EROS-CTD) has been approved by the U.S. Food and Drug Administration and is said to improve clitoral blood flow and engorgement. Fantasy therapy is helpful for hypoactive desire,and sensate-focusing therapy is helpful for excitement-phase defects.
As a group, orgasmic difficulties appear to respond to treatment most readily. For example, primary orgasmic difficulties may be resolved by means of guided masturbatory training and cognitive behavioral sex therapy. Secondary anorgasmia is more often associated with emotional or psychiatric disorders and relationship issues, so treatment is less effective. Excitement-phase dysfunctions do not have such positive outcomes, although problems with lubrication can nearly always be resolved satisfactorily. Lack of desire is the most resistant to treatment. Persons with little desire often have little internal motivation to seek more frequent sexual activity or to pursue help. Fewer than half of such patients show definite improvement. When the relationship is poor, behavioral approaches directed toward the sexual problem are rarely successful. Studies using medical and pharmacologic interventions for female arousal or orgasmic disorders, in contrast to those for erectile disorder and premature ejaculation in males, are still ongoing but show some promise.
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