Mayo Clinic Guide to a Healthy Pregnancy: From Doctors Who Are Parents, Too!

CHAPTER 9. Month 6: Weeks 21 to 24

It’s now pretty evident to everyone that I’m pregnant. I didn’t like it when people weren’t sure if I was pregnant or just “packin’ on the pounds.” It’s always been important to me to look good and stay in shape, so I’m trying to eat decent and exercise and not gain too much weight. Some days go better than others. I think the fact that I feel better now helps. I’m starting to get really excited, and I wonder a lot about what the baby will look like. I’m thinking it’s going to be a blonde-haired, blue-eyed girl! — Tessa

Two down and one to go — almost! This month marks the last full month of your second trimester. That means you’re almost two-thirds of the way there. As has been the case the previous couple of months, growth is now occurring at a more rapid pace. In fact, if your little girl or boy was born at the end of this month, he or she would have about a 50 percent chance of survival, and the odds get better with each passing week.


While most of baby’s organs are structurally developed or nearing development, baby is still quite small. But by the end of this month, he or she will finally pass the 1-pound mark!

Week 21 This week baby begins toabsorb small amounts of sugar from the amniotic fluid he or she swallows during the day. These sugars pass through your baby’s digestive system, which is now developed enough to handle them. Any processing of the sugars, however, is only done as practice. Baby is still completely dependent on the placenta for his or her nourishment.

Also this week, your baby’s bone marrow starts to make blood cells. The bone marrow works along with the liver and spleen, which have been responsible, up to this point, for making blood cells.

Week 22 The senses of taste and touch advance this week. Taste buds are starting to form on your baby’s tongue, and his or her brain and nerve endings are now mature enough to process the sensation of touch. If you could sneak a peek at your baby this week, you might see him or her experimenting with this newfound sense of touch — feeling his or her face, sucking a thumb or touching other body parts.

Your baby’s reproductive system is continuing to develop, too. If you’re having a boy, this week his testes begin to descend from the abdomen down to the scrotum. If you’re having a girl, her uterus and ovaries are now in place, and her vagina is developed. Your baby girl has already made all of the eggs she’ll need for her own reproductive life.

By 22 weeks into your pregnancy, baby is about 7½ inches long from head to rump, and weighs about 1 pound.

Week 23 During week 23 baby’s lungs develop rapidly, beginning preparation for life on the outside. The lungs are beginning to produce a substance that lines the air sacs called surfactant. This substance allows the air sacs to inflate easily. It also keeps them from collapsing and sticking together when they deflate.

If your baby was born before this time, the lungs would have had no chance of working. Now it’s possible that the lungs could function to some degree outside the womb. However, your baby would need a lot more surfactant to handle breathing air without help.

In addition, the blood vessels in your baby’s lungs are growing and developing in preparation for breathing. He or she is making breathing movements, but these are just trial runs. Your baby is still receiving oxygen through your placenta. There’s no air in the lungs until after birth.

Although your baby now looks like a baby, he or she is still slender and delicate looking, with little body fat and thin, nearly translucent skin. Later in your pregnancy, when fat production catches up to skin production, your baby will grow into this skin and will look more like an infant.

Babies born at 23 weeks can sometimes survive if they receive the appropriate medical care in a neonatal intensive care unit. But complications are common and usually serious. On the bright side, the long-term outlook for premature babies is improving each year as knowledge in the field of neonatal medicine continues to expand. But there’s no doubt that at this age, baby is far better off staying in the uterus, if at all possible.

Week 24 This week your baby is beginning to get a sense of whether he or she is upside-down or right side up inside your amniotic sac. That’s because your baby’s inner ear, which controls balance in the body, is now developed.

By the 24th week of your pregnancy, your baby is 8½ inches long and weighs about 1½ pounds. Babies born at 24 weeks have a greater than 50-50 chance of survival, and the odds get better with every passing week. Still, complications are frequent and serious.


One thing you may notice this month is that baby’s first kicks are a far cry from the fluttery, butterflies-in-the-stomach movements of last month.

What’s happening and where During the first five months of your preg-nancy, the level of the hormone progesterone was slightly higher than the level of estrogen. This month your estrogen level is catching up. At 21 or 22 weeks, the two hormones will be at about the same level.

Your heart and circulatory system Your blood pressure will probably continue to stay lower than normal this month. After your 24th week, it should return to where it was before you were pregnant. This is because your body continues to make more blood this month, filling your very relaxed blood vessels. Production of red blood cells should be catching up to production of plasma.

You may continue to experience nasal congestion, nosebleeds and bleeding gums, due to increased blood flow to your nasal passages and gums.

Your respiratory system To accommodate your increasing lung capacity, your rib cage is enlarging. By the time your baby is born, the distance around your rib cage will have expanded by 2 to 3 inches. After your child is born, it will return to its pre-pregnancy size.

Baby is also pushing up on your diaphragm. However, the expansion of your chest diameter has more than compensated for this compression. You may still breathe slightly faster, but any shortness of breath has probably lessened.

Breasts Your breasts may now be ready to produce milk. You may see tiny droplets of watery or yellowish fluid appearing on your nipples, even this early. This early milk is called colostrum and is loaded with active, infection-fighting antibodies from your body. If you breast-feed, colostrum will be your baby’s food for the first few days after birth.

Blood vessels in your breasts continue to become more visible, too, showing through your skin as pink or blue lines.

Uterus This month, perhaps around your 22nd week of pregnancy, your uterus may begin practicing for labor and delivery. It starts exercising its muscle mass to build strength for the big job ahead. These warm-up contractions are called Braxton Hicks contractions. They’re occasional, painless contractions that feel like a squeezing sensation near the top of your uterus or in your lower abdomen and groin.

Braxton Hicks contractions are also called false labor. That’s because they’re very different from the contractions involved in true labor. Braxton Hicks contractions occur on an irregular schedule and vary in length and intensity. True labor contractions follow a pattern, growing longer, stronger and closer together.

That said, it can be easy to mistake Braxton Hicks contractions for the real thing. Contact your care provider if you’re having contractions that concern you, especially if they become painful or if you have more than six in an hour. The biggest difference between true labor and Braxton Hicks contractions is the effect on your cervix. With Braxton Hicks, your cervix doesn’t change. With true labor the cervix begins to open (dilate). You may need to see your care provider to determine whether the contractions are the real thing.

Urinary tract You continue to be at risk of developing a urinary tract infection. Slowed urine flow is caused by your growing uterus and flabbier muscle tone in the ureters, which carry urine from your kidneys to your bladder. If you think you may have a urinary tract infection, contact your care provider.

Bones, muscles and joints The ligaments supporting your abdomen continue to stretch, and the joints between your pelvic bones continue to soften and loosen in preparation for childbirth. In addition, your lower spine is curving backward to keep you from falling forward from the weight of your growing baby. Together, these changes can cause back and hip pain.

Vagina You may still experience thin, white vaginal discharge with little or no odor. If your vaginal discharge is greenish or yellowish, strong-smelling or accompanied by redness, itching or irritation of the vulva, you may have a vaginal infection. Contact your care provider.

Weight gain You’ll probably gain about a pound a week this month, for a total of about 4 pounds. You may gain 1½ pounds one week and only half a pound the next, but that’s not cause for concern. As long as your weight gain is remaining relatively stable, without any sudden increases or decreases, you’re doing great.


You may find (or your partner may tell you!) that your mood swings are improving. This may be because hormone production is occurring at a more even pace. You’re also becoming more accustomed to the changes occurring inside you. However, as your due date starts to loom a little closer, your mood swings may be replaced by fears.

Confronting your fears This month you may begin experiencing fears about the process of giving birth. In fact, you may have been having them for a while: “What if I don’t make it to the hospital in time? How will I cope with baring myself in front of strangers? What if I lose control during labor? What if there’s something wrong with the baby?”

Your partner is probably pondering some of these same questions. Often, parents-to-be have the same concerns as their partners but don’t admit it. Each may think he or she must be strong for the other. Your partner is probably also worried about something happening to you during labor and delivery.

Take time to sit down and make a list of your fears, and ask your partner to do the same. Then compare lists and share these concerns with your care provider. Sharing helps. When you share your fears, they have less power over you.

Being intimate If you’re like many women, you may be more interested in sex now than you were earlier in your pregnancy. You may even be more interested in sex now than you were before you became pregnant. This may be because you feel better, are sleeping better and you have more energy. Enjoy this feeling while it lasts — and before your baby arrives to put a significant crimp in your sex life. This heightened sexuality is by no means universal, and it’s possible you may not feel it at all. As you enter the final months of pregnancy, you may find your desire for sex waning again.


It’s a good idea to decide who you want to provide health care to your baby before your child is born. You’ll have someone you can call with any questions regarding newborn care — and most first-time parents have lots of questions. If you don’t already have a care provider in mind, ask for recommendations from friends or family members who have children. Your own care provider also may be an excellent referral source.

Types of providers Basically, three types of care providers are qualified to care for children: family physicians, pediatricians and pediatric nurse practitioners.

Family physicians Family physicians provide health care to people of all ages, including children. They are trained in adult and pediatric medicine. A family physician can see your child from babyhood all the way through adulthood. Family physicians take care of most medical problems. Also, if the rest of your family sees the same physician, your doctor will gain an overall perspective of your family. If you already have a family doctor you trust, ask whether he or she will see infants.

Pediatricians Many parents choose a pediatrician for their child’s health because caring for children is what a pediatrician is trained to do. Pediatricians specialize in the care of children from infancy through adolescence. After medical school, they go through a three-year residency program. Some pediatricians receive further training in subspecialties such as allergies, infectious disease, cardiology and psychiatry. A pediatrician can be particularly helpful if your child has a health condition or needs special medical attention.

Nurse practitioners Nurse practitioners are registered nurses with advanced training in a specialized area of medicine, such as pediatrics or family health. After nursing school, a nurse practitioner must go through a formal education program in his or her specialty field. A pediatric nurse practitioner focuses on caring for infants, children and teens. Most pediatric nurse practitioners can prescribe medications and order medical tests. They work closely with physicians and medical specialists.

Issues to consider No matter what type of provider you choose, it’s important that you feel comfortable with that person. You may wish to meet with several care providers before having your baby. Factors you may wish to explore include:

 What are the provider’s qualifications?

 How do you rate his or her bedside manner?

 Did the individual answer your questions to your satisfaction?

 How accessible is your care provider, either by phone or by appointment?

 If you’re in a managed care plan, is the provider part of the plan’s network?


By now, your visits are starting to get pretty routine, but that’s OK. Routine visits often mean everything is going well and progressing on schedule. As during your last visit, your care provider will likely check the size of your uterus by determining the fundal height — the distance from the top (fundus) of your uterus to your pubic bone. This month your fundal height will probably be about 21 to 24 centimeters — roughly equal to the number of weeks of your pregnancy.

In addition to performing the fundal height test, your care provider will likely check your weight and blood pressure and evaluate your baby’s heart rate. Your care provider may also ask you about any signs and symptoms you may be experiencing.


If this is your first pregnancy, you may get a little nervous — maybe even scared — when you start thinking ahead to labor and delivery. That’s natural. After all, you’ve never been through it before!

So how do you help calm those nerves? Go to class. If you haven’t signed up yet for childbirth classes, it’s a good time do so. Childbirth classes help you and your partner prepare for labor and childbirth. Such classes are available at most hospitals and birthing centers, so ask about them at one of your prenatal visits. Typically, the classes are offered as one- to two-hour sessions over the course of several weeks or as full-day sessions that take place over one or two weekends.

You’ll likely learn about signs of labor, pain relief options during labor, birthing positions, postnatal care and care of a newborn, including information on breast-feeding. At these classes you’ll also learn about what will happen to your body during labor and birth so that you feel positive rather than fearful. Especially if you’re a first-time parent, you may find that childbirth classes help calm your fears and answer many of your questions.

In addition, as part of your classes, you may be given a tour of the facility where you will have your baby, so when the big day arrives, you’ll know where to go and have a better idea of what will happen. You’ll also likely meet other expectant couples who have questions and concerns similar to yours, which can be comforting. If you plan to have a labor coach, such as your partner or another loved one, with you during labor and delivery, have him or her attend childbirth classes with you.

Different types Some childbirth education classes cover specific types of births, such as C-section birth, vaginal birth after C-section (VBAC) and multiple births. Refresher courses are also available for parents who simply want to review the basics.

Other classes are more general in nature, or they focus on specific methods of childbirth. For example:

 Lamaze. The goal of Lamaze is to increase confidence in your ability to give birth. Lamaze classes help you understand how to cope with pain in ways that both facilitate labor and promote comfort — including focused breathing, movement and massage. This method is based on the idea that a woman’s inner wisdom guides her through childbirth.

 Bradley. The Bradley Method emphasizes that birth is a natural process. You’re encouraged to trust your body, focusing on diet and exercise throughout pregnancy. You’re taught to manage labor through deep breathing, a variety of relaxation techniques, and the support of your partner or labor coach.

Many other classes borrow elements from these popular methods. In addition, you may find classes on alternative approaches to childbirth, including hypnotherapy and water birth.

What to look for Look for a class taught by a certified childbirth educator. This may be a nurse, midwife or other certified professional. The classes should be small — with no more than eight to 10 couples — to facilitate discussion and allow for personalized instruction. The classes should also be comprehensive, addressing all aspects of labor and delivery, as well as newborn care. Be sure to ask about the cost as well. Childbirth education classes are often recommended near the sixth or seventh month of pregnancy — but anytime before you go into labor is helpful.