IN THIS CHAPTER
Seeing how age impacts pregnancy
Meeting the challenge of multiple births
Having second babies — and third, fourth, fifth …
Being part of a thoroughly modern family
Preparing older children for the new arrival
No two pregnancies are exactly alike. If you’re like most women, you figure out pretty early in the game that your experience is different in some way from every friend and relative you talk to. You’re not as nauseous as your sister was during the first three months — or your morning sickness is 20 times worse than your best friend’s. You feel comfortable exercising throughout your pregnancy, although your cousin Jennifer was put on bed rest. Plenty of variation occurs within the boundaries of what’s considered to be a “normal” pregnancy. But some special kinds of pregnancies come with their own particular characteristics and challenges. This chapter focuses on them.
Figuring Out How Age Matters
Whether you’re a prospective father or mother, age can make a difference. Special problems and issues arise for men and women in their late 30s and older. Teen moms also face unique challenges. This section covers these challenges.
Over-30-something moms
Long gone are the days when almost all pregnant women were in their early 20s (and many were in their teens). Now, a greater number of women postpone having families until they’ve not only finished their education but also had time to become established in their careers. These days, too, divorce is more common, and many women find themselves having children with a second husband — often when they’re well into their 30s or 40s (and sometimes 50s).
How old is too old? The answer used to be when you reach menopause — or even some years earlier — when your body no longer produces healthy eggs that can be fertilized to become embryos. But today, because of advances in assisted reproductive technologies like in vitro fertilization (IVF), which may use eggs donated by another woman, even women who are past the age of menopause can become pregnant. Also, over the last few years, there have been incredible advances in egg freezing, so even if you aren’t ready to have children, eggs can be frozen and stored until the time is right.
Today, a more useful question is “At what age do you need to watch out for special problems?” And here, the answer is more specific. Any woman who is at least 35 years old during her pregnancy falls into the medical category of advanced maternal age, or AMA. (An impersonal term, to be sure, but perhaps less insulting than the alternatives that are also used: older gravida, mature gravida, and the particularly unfortunate elderly gravida.) The reason for singling out older mothers with any special term at all is that the incidence of certain chromosomal abnormalities increases with advancing maternal age. At age 35, the risks begin to increase significantly, as shown in Figure 1-1.
Source: Data of Hook (1981) and Hook et al. (1983). Because sample size for some intervals is relatively small, confidence limits are sometimes relatively large. Nonetheless, these figures are suitable for genetic counseling. *Excluded for ages 20–32 (data not available).
FIGURE 1-1: As maternal age rises, so do the risks of chromosomal abnormalities.
Doctors formerly concluded that at age 35, the risk of the fetus carrying some chromosomal abnormality was great enough to equal the risk of pregnancy loss after undergoing amniocentesis (about 0.5 percent at that time, although now the risks are thought to be much lower, 1/300 to 1/500 or even lower). Genetic testing — either amniocentesis or chorionic villus sampling — was routinely offered for pregnant women older than 35 in the United States. Some practitioners still adhere to the traditional age-35 dictum, but the American Congress of Obstetricians and Gynecologists now recommends women of all ages be offered the option of screening for Down syndrome — either by nuchal translucency screening, chorionic villus sampling, or amniocentesis (see Book 2, Chapters 1 and 2).
Recently, noninvasive prenatal screening (NIPS, or noninvasive prenatal testing, NIPT) has become available for women 35 and older. This actually identifies fetal DNA in Mom’s blood and has a high detection rate for Down syndrome and disorders involving an extra chromosome 13 or 18. This can also tell the sex of the baby. It’s important to remember that NIPS is still a screening test and not a definitive test. Currently, the test isn’t available to women carrying multiple gestations, although research over the next few years may determine its utility in these situations.
The good news is that except for this increase in certain chromosomal abnormalities, babies born to women older than 35, or even older than 40, are as likely as any other babies to be healthy. The moms themselves do stand a higher-than-average risk of developing preeclampsia or gestational diabetes (see Book 6, Chapters 2 and 3), and they stand an increased risk of delivering early or needing a cesarean delivery. Additionally, and for reasons not quite understood, women over age 35, and especially over age 40, are at a higher risk for stillbirth. Some doctors recommend closer surveillance in the last month of pregnancy and even earlier delivery at about 39 weeks. Still, these risks aren’t terribly high. Naturally, an older woman’s experience with pregnancy depends to a large extent on her underlying health. If a woman is 48 years old or even 50 but she’s in excellent health, she’s likely to do extremely well.
A WORD ABOUT ALTERNATIVE CONCEPTIONS
Thanks to assisted-reproductive technologies, more and more women older than 40 are becoming pregnant, some even with twins or triplets. Although many of these women conceive with their own eggs, many others conceive with someone else’s. These women have unique issues to deal with, including what to tell their future children, friends, and family. Some, when they’re pregnant, experience internal conflicts about the baby’s genetic identity; they worry about the fact that their baby is biologically related to someone else and what that may mean. But often, these concerns disappear when the woman begins to feel her baby moving around inside her — and if not then, as soon as the baby is born.
Parents — even parents of children conceived the old-fashioned way — often discover after they meet their new baby in person that each child’s identity is unique and that the exact genetic ancestry doesn’t matter nearly as much as they thought it would. So it makes sense that women who’ve had children conceived with donor eggs typically find that, after only a few days of caring for the new baby, they feel every bit as maternal as any biological mother would. The same is true of fathers of children who’ve been conceived with donor sperm. As the number of people having children with donated eggs or sperm grows, the whole experience is likely to become more comfortable for everyone involved.
Not-so-young dads
As mentioned earlier, pregnancies in older women call for some special scrutiny because of the increased risk of genetic complications. To some extent, pregnancies involving older dads should likewise be singled out for observation. There’s no absolute age cutoff for “advanced paternal age,” but many people use 45 or 50 (although some argue it should be 35, just as it is for women).
Whereas for women the main genetic risk is having a fetus with a chromosomal abnormality (most commonly an extra chromosome), for men the risk is spontaneous gene mutations in the sperm, which can lead to a child with an autosomal dominant disorder, such as achondroplasia (a type of dwarfism) or neurofibromatosis. It only requires an abnormal gene from one parent to cause this kind of problem. (In so-called recessive genetic disorders — cystic fibrosis and sickle-cell anemia, for example — both parents must provide an abnormal gene for the problem to occur.) Autosomal dominant disorders are very rare, however, and many are impossible to test for, which is why no routine testing exists for advanced paternal age. Also, some studies suggest a slightly higher risk of autism with older dads, but again, the exact age at which this risk increases isn’t quite clear, and it’s still an unusual factor in this disorder.
Very young moms
Pregnancy in teenage women raises a different set of concerns. Although this age group doesn’t sustain any increase in chromosomal abnormalities, these women may experience a higher incidence of some birth defects. Because teenage moms tend to have less-than-optimal nutritional habits, they also experience a higher incidence of low-birth-weight babies. Teenage moms are also at a higher risk of developing preeclampsia, are more likely to deliver by cesarean delivery, and are less likely to breastfeed. Due to their unique situation, young moms need special guidance and counseling. If you’re a teenage mom, make sure you receive adequate prenatal care, follow a healthy diet, and consider the benefits of breastfeeding (see Book 5, Chapter 1).
Having Twins or More
Having twins may seem simple — to someone who’s never faced the reality of it. It’s either “double the pleasure” or a living nightmare (twice the work and only half the sleep). Twins are complicated, as any mother of twins can tell you — for hours and hours, if you’re willing to listen. A sizable part of having twins, triplets, or more is the experience of pregnancy.
If you’re having triplets or more, what applies to twins generally applies to triplets (and more), only to a much greater extent.
Although the vast majority of twin pregnancies proceed smoothly and result in the birth of two beautiful, healthy babies, some risks are involved for both the fetuses and the mom. As a result, most practitioners want women who are pregnant with twins to have checkups more frequently than other moms, and they may schedule plenty of extra ultrasound exams.
Ethnic background and family history can increase your chances of having twins; certain women are constitutionally more likely to ovulate more than one egg in a cycle. If twins occur in your family, let your practitioner know.
This section takes a closer look at several questions and issues you may have if you’re pregnant with twins.
THE ODDS (AND ODDITIES) OF HAVING TWINS, TRIPLETS, OR MORE
The number of twins conceived is much larger than the number of twins who are actually born. Many pregnancies that begin as twin pregnancies end as single births because one of the fetuses never develops. In many cases, one of the fetuses disappears before the pregnancy is even diagnosed (the so-called vanishing twin). The incidence of twin births is usually estimated to be close to 3 percent of all births. However, the incidence is rising, mainly due to the increasing use of fertility techniques.
The incidence of spontaneous triplets is much rarer — about 1 in 7,000. Spontaneous quadruplets or more are exceedingly rare. However, with the increasing use of infertility treatments, the incidence of triplets has increased tenfold over the past few decades. Fortunately, though, the rate of increase is slowing because of refinements in infertility treatments.
Looking at types of multiples
Twins can be either identical or fraternal. These old-fashioned terms don’t completely describe how twins occur.
· Identical twins look very much alike and are always the same sex. They come from a single embryo, meaning they’re a product of the union of one egg and one sperm. (In other words, they’re monozygotic — they come from the same zygote.) They have exactly the same genes as each other, which explains their resemblance. In the United States, roughly one-third of all twins are identical. An egg can split into three, leading to identical triplets, but it’s very unusual.
· A woman conceives fraternal twins when she ovulates more than one egg, two different sperm fertilize two eggs, and the resulting zygotes implant in her uterus at the same time. These twins — who arise from two zygotes and are thus dizygotic twins — don’t share an identical set of genes. Instead, their genetic makeup is as similar as that of any pair of children born of the same parents. They’re just born at the same time. They can be the same sex, or they can be of opposite sexes. Roughly two-thirds of all twins conceived spontaneously in the United States are fraternal. If three eggs are fertilized, the result is fraternal triplets. A triplet pregnancy can also consist of two fetuses that are monozygotic and one from a second fertilized egg — leading to two babies who are identical and one who’s fraternal.
The chances that a woman will have identical twins increases after she reaches the age of 35. The chances a woman will have fraternal twins (because she ovulates more than one egg in any given month), on the other hand, rise until about the age of 35 and then drop off. Some families have more than their statistical share of fraternal twins. Some women are predisposed to ovulating more than one egg at a time, and that can lead to fraternal twins. If a woman has a history of twinning on her mother’s side, she may stand a higher chance of twinning. Fraternal twinning also becomes more likely when a woman takes fertility drugs, because these medications boost her chances of ovulating more than one egg. Of course, a woman who takes fertility drugs can still produce an egg that gets fertilized and then splits in two to form identical twins.
Determining whether multiples are identical or fraternal
Many women who are pregnant with twins ask their doctor or sonographer during an ultrasound exam whether her twins are fraternal or identical. In some cases, the technician or your doctor can tell: If the babies are two different sexes, they’re fraternal. If they’re the same sex, they may be fraternal or identical. If they’re the same sex or if the fetuses’ sexes aren’t yet visible, other findings on ultrasound can suggest whether the twins are identical:
· An egg that splits very early after fertilization, within the first two or three days, results in two embryos that have separate placentas and separate amniotic sacs. This situation is called diamniotic/dichorionic (see Figure 1-2a). On ultrasound, they look no different from fraternal twins who come from two separately fertilized eggs. So with twins who have separate placentas and are of the same sex, it’s impossible to tell on ultrasound if they’re identical or fraternal.
· If an egg splits between the third and eighth day after fertilization, the resulting twins are in two separate amniotic sacs but share a single placenta (see Figure 1-2b). Your doctor may use the term diamniotic/monochorionic to describe this situation. If, on ultrasound, your doctor or sonographer can see that a set of twins shares a single placenta, chances are they’re identical. (Keep in mind, though, that sometimes determining whether there’s one placenta or two that are very close together is difficult on ultrasound.) The thickness of the membrane separating the sacs gives another clue — with two separate placentas, a thick membrane separates the two sacs, whereas with one placenta, the membrane is very thin.
· An egg that splits sometime between 8 and 13 days after fertilization results in twins that not only share a placenta but also are in a single amniotic sac (see Figure 1-2c). Twins like these are called monoamniotic/monochorionic. If your doctor does an ultrasound examination and sees twins sharing the same amniotic sac, she can be sure that they’re identical. This is pretty rare (1 percent of all twins, or 1 in 60,000 pregnancies).
· An egg that splits after the 13th day of gestation results in conjoined or “Siamese” twins, which are exceedingly rare.
Illustration by Kathryn Born, MA
FIGURE 1-2: Your practitioner can often tell which type of twins you’re having by viewing the placenta(s) and amniotic sac(s) during an ultrasound exam.
An expert sonographer can use subtle signs to help differentiate the various types of twins, although sometimes it still may be hard to be certain. The sonographer establishes whether the twins have two separate placentas and, of less importance, whether they’re actually fraternal or identical. Establishing the type of placentation (monochorionic or dichorionic) is easier in the first trimester than in the second or third trimester.
Because different types of twins are associated with different problems and risks, trying to figure out which type of twinning is present is important. If the ultrasound signs are ambiguous and the medical situation suggests that determining the type of twinning is especially important, special tests can be performed to answer this question. These tests are called zygosity studies and require an invasive procedure, such as amniocentesis, chorionic villus sampling (CVS), or fetal blood sampling (see Book 2, Chapter 2).
Screening for Down syndrome in pregnancies with twins or more
For many years, the most common way of screening pregnancies for Down syndrome was by measuring different markers in the mother’s blood at 16 weeks of pregnancy (see Book 2, Chapter 2). The accuracy of this test with twins is fair, but with triplets or more, it doesn’t help at all. The newer method of Down syndrome screening in the first trimester (nuchal translucency; see Book 2, Chapter 1) appears to work pretty well for moms with multiple gestations because the doctor can obtain a nuchal-translucency measurement for each fetus, thus determining each fetus’s individual risk of having Down syndrome.
Using the nuchal translucency and Mom’s blood markers, doctors can detect about 70 to 75 percent of all cases of Down syndrome in twins. This is a little lower than the detection rate in single fetuses but still pretty good. With triplets or more, using the nuchal-translucency measurement alone tends to be the most helpful approach, because it’s difficult to determine how to use the mother’s blood markers in this situation.
Conducting genetic testing in pregnancies with twins or more
Chorionic villus sampling and amniocentesis are a little trickier with twins or more. The two main challenges are to make sure each fetus is sampled separately and that none of the tissue taken from one fetus contaminates the tissue taken from the other. In the case of identical twins, this issue isn’t as critical, because the fetuses have the same genetic makeup. If you find a genetic abnormality (or lack of any genetic abnormalities) in one, the same is almost always true for the other. With fraternal twins, triplets, or more, testing each one separately is critical.
Amniocentesis
Amniocentesis (see Book 2, Chapter 2) is the most common way to do genetic testing in multifetal pregnancies. This method requires inserting a separate needle into the uterus for each fetus being tested. Of course, the amniocentesis is done under ultrasound guidance. After the doctor removes some fluid from the first fetus’s amniotic sac, she may leave the needle in place to inject a harmless organic blue dye (called indigo carmine) into that fetus’s amniotic sac. (Don’t worry — you won’t give birth to a Smurf. This blue dye is absorbed over time.) Then, if the fluid from the second needle comes out clear (not blue), the doctor knows that she has sampled the second sac. If you’re carrying more than two fetuses, the doctor adds a few drops of blue dye to each consecutive sac after she taps it.
PATIENTS WANT TO KNOW …
Q: “Is doing an amniocentesis or CVS for twin or triplet pregnancies riskier than for singleton pregnancies?”
A: Although scientists have conducted little research on this question, it appears the chances of complications aren’t substantially greater in multifetal pregnancies if the person performing the procedure is experienced in doing it with mothers carrying twins or more.
Chorionic villus sampling
Chorionic villus sampling, or CVS (see Book 2, Chapter 1), can be somewhat complicated in multifetal pregnancies, but experienced doctors can usually handle the job. In some cases, the placentas are positioned in such a way that CVS is technically impossible. In these cases, the mother has the option of having an amniocentesis a little later in the pregnancy, at about 15 to 18 weeks (rather than 10 to 12 weeks for CVS).
Keeping track of which baby is which
Your doctor designates your babies before birth as Twin A and Twin B (or Triplets A, B, and C). These designations enable your doctor to communicate to you and others (nurses and other medical personnel) which baby is which and to follow the progress of each baby separately and consistently throughout the pregnancy. By convention, the fetus closest to the cervix (the opening to the womb) is designated as Twin A (or Triplet A). This baby is usually born first. In a triplet pregnancy, the highest triplet (closest to your chest) is designated as Triplet C. (Some patients come up with their own clever names.)
Living day-to-day during a multiple pregnancy
If you’re pregnant with multiples, don’t ignore everything else written in this book. In many ways, your pregnancy proceeds like any other. The difference, as you may already know, is that your experience is more intense in various ways: You grow a larger belly more quickly, your nausea may be worse, your amniocentesis (if you have one) is a bit more complicated (as described earlier in this chapter), and the birth may take longer. With triplets or more, these physical changes and symptoms are even more exaggerated. In addition, certain complications are more frequent in multiples than in singletons. The following list describes many of the ways your experience may be somewhat different:
· Activity: In the old days, doctors recommended women with twins be placed on bed rest beginning at 24 to 28 weeks. However, data shows women placed on bed rest appear to be no less likely than others to experience preterm delivery or have babies of low birth weight. Whether you need to reduce your activity depends on your prior obstetrical history as well as on how smoothly your pregnancy goes from week to week. If you develop preterm labor or have problems with fetal growth, your doctor may recommend you take it easy. With triplets or more, the benefit is unclear, but many obstetricians routinely recommend bed rest starting in the second trimester.
· Diet: Many experts recommend women carrying twins consume an extra 300 calories a day above what is required for a singleton (in other words, an extra 600 calories per day above their pre-pregnancy intake). For triplets and more, no consensus exists, but obviously your food intake should be somewhat greater.
· Iron and folic acid: Women carrying twins, triplets, or more stand a greater chance of developing anemia, which is due to dilutional anemia (see Book 1, Chapter 3) as well as greater demands for iron and folic acid. Doctors recommend supplemental iron and folic acid for women carrying two or more fetuses.
· Nausea: Most women carrying two or more fetuses definitely have more nausea and vomiting in early pregnancy than women with only one. This nausea may be related to higher levels of hCG (a pregnancy hormone) circulating through the bloodstream. The good news is that nausea and vomiting for mothers of multiples, as for mothers of single babies, usually goes away by the end of the first trimester.
· Prenatal doctor visits: Your practitioner is likely to follow pretty much the same routine she uses for mothers of single babies. That is, you have your blood pressure, weight, and urine checked at each visit.
But because you have more than one fetus, your practitioner may ask you to come in more frequently. Some practitioners perform routine pelvic exams to make sure your cervix isn’t dilating prematurely; others may suggest your cervix be checked with an ultrasound exam. On the other hand, if you don’t have any preterm labor symptoms, your doctor may decide you don’t need these extra exams. (See the later section “Monitoring for preterm labor in twins” for details.)
· Ultrasound examinations: Most practitioners suggest that mothers of twins or more have ultrasound examinations every four to six weeks throughout their pregnancy in order to check fetal growth. If you have any problems, these exams may need to be more frequent.
With more than one fetus, your doctor can’t use fundal height measurements to evaluate the growth. And because women with twins, triplets, or more are at a higher risk of having problems with fetal growth (see the “Intrauterine growth restriction” section later in this chapter), these periodic ultrasound exams are very important. Some doctors also monitor the cervix every two weeks by transvaginal ultrasound during the second trimester to look for an increased risk of preterm birth. (For more on this, see the later section “Monitoring for preterm labor in twins.”)
· Weight gain: The average weight gain for a twin pregnancy is 35 to 45 pounds (15 to 20 kg). But the exact amount you gain depends on your pre-pregnancy weight. The Institute of Medicine recommends that mothers with twin pregnancies gain about 1 pound per week during the second and third trimesters.
Recent studies show that you can achieve the optimal growth rates by taking into account your body mass index (see Book 1, Chapter 3) prior to pregnancy and show that weight gain in the first two trimesters may be especially important. Doctors recommend weight gains of 45 to 50 pounds (20 to 23 kg) by 34 weeks for triplets and more than 50 pounds (23 kg) for quadruplets.
· Delivery: If you’re carrying dichorionic twins and everything is going smoothly, many practitioners recommend delivery by 38 weeks, 0 days to 38 weeks, 6 days because this has the best outcome for your babies. If you’re carrying uncomplicated monochorionic twins, doctors recommend delivery earlier, somewhere between 34 weeks, 0 days and 37 weeks, 6 days.
Going through labor and delivery
Although some studies have suggested that in very specific situations and with very strict criteria, vaginal delivery of a triplet pregnancy may be possible, almost all triplets are delivered by cesarean. This section on birth positions and delivery is addressed to women carrying twins.
Often, pregnancy goes smoothly for mothers of twins, but labor and delivery can still be complex. For this reason, women carrying more than one fetus should deliver in a hospital, where extra personnel are present to handle any complications that may arise.
Assuming the babies are full-term, your babies can be in different positions. Basically, their positions fall into one of three possibilities:
· Both fetuses can be head-down (vertex), as they are in about 45 percent of twin pregnancies (see Figure 1-3a). Vaginal delivery is successful 60 to 70 percent of the time when the babies are in this position.
· The first fetus can be head-down and the second not (see Figure 1-3b), as is the case about 35 percent of the time, making a cesarean delivery more likely unless your practitioner can turn the second baby to a head-down position. Whether trying to manipulate the baby in this way makes sense is a matter of some debate among practitioners. Your doctor’s choice of trying to turn the baby around or delivering the baby breech depends on her training, experience, and professional bias.
· The first fetus can be breech or transverse (lying horizontally across the uterus), and the second can be breech, head-down, or transverse. This positioning occurs about 20 percent of the time (see Figure 1-3c).
Illustration by Kathryn Born, MA
FIGURE 1-3: Three possible positions of twins before delivery.
With any of these combinations of positions, if the babies are preterm, the options may be different. In any case, discuss the possibilities with your doctor before the time of delivery.
Covering special issues for moms with multiples
If you’re pregnant with twins or triplets (or more), your doctor puts you under closer surveillance because the risk of certain complications is greater in multifetal pregnancies. The following topics are some of the things she’s watching out for.
Don’t let this list scare you. Just be aware of potential problems so that if they develop, you and your practitioner can recognize them early and manage them appropriately.
Preterm delivery
The biggest risk you face in carrying more than one baby is that you may have preterm labor and delivery. The average length of pregnancy for a singleton is 40 weeks, but for a twin pregnancy, it’s only about 36 weeks; for triplets, 33 to 34 weeks; and for quadruplets, about 31 weeks. A pregnancy is full-term if it lasts 37 weeks or more. Preterm delivery is technically between 24 and 37 weeks, but most babies born at 35 or 36 weeks are generally as healthy as babies delivered after 37 weeks.
About 80 percent of mothers carrying triplets and 40 percent of those with twins experience preterm labor, but not all deliver early. (See details about preterm labor and delivery in Book 6, Chapter 2.)
Chromosomal abnormalities
When you have more than one fetus and they aren’t identical, the chances that either one of them has a genetic abnormality are somewhat higher. After all, each baby has its own individual risk of some abnormality, and the risks add up. Mothers of single babies are considered to be of advanced maternal age (AMA) at 35, as described earlier in this chapter, but in twin pregnancies derived from two separate eggs, AMA may be as early as 33, and for triplets, 31 or 32. This all becomes relevant for women considering the genetic testing mentioned earlier.
Diabetes
Because the incidence of gestational diabetes is higher with twins or more, many practitioners recommend all women carrying more than one fetus be screened for this condition. (See Book 6, Chapter 3.)
Hypertension and preeclampsia
Hypertension (high blood pressure) is more common in multifetal pregnancies. The risk is proportional to the number of fetuses present. Some women develop hypertension alone, without other symptoms or other physical signs. Others develop a condition unique to pregnancy called preeclampsia, which involves high blood pressure in association with spilling protein in the urine (proteinuria), or if proteinuria is absent, the presence of some other abnormalities (see the description of preeclampsia in Book 6, Chapter 2). Forty percent of mothers carrying twins and 60 percent or more carrying triplets develop some form of hypertension during pregnancy. For this reason, your practitioner keeps a close eye on your blood pressure.
Intrauterine growth restriction
Problems with fetal growth occur in anywhere from 15 to 50 percent of all twins. The problem is even more common in triplets and in fetuses that share the same placenta. In the case of a single placenta, the blood may not be distributed equally, which may cause one twin to get more nutrients than the other. In multiples that have different placentas, growth restriction can result when one placenta is implanted in a more favorable position within the uterus and therefore provides better nourishment than the other. Your doctor is likely to schedule periodic ultrasound exams during your pregnancy to check that both (or all three) fetuses are growing properly.
Twin-twin transfusion syndrome
Twin-twin transfusion syndrome is specific to twins who share a single placenta. In some cases, the single placenta contains blood vessels that interconnect between the two fetuses. This connection enables the two fetuses to exchange blood — and allows the blood to become distributed unequally. The fetus who gets more blood grows bigger and produces extra amniotic fluid, whereas the one who gets less blood may suffer impaired growth and have significantly decreased amniotic fluid in his or her sac. This situation can be very serious, but fortunately, it affects only 10 to 15 percent of monochorionic twins.
Multifetal pregnancy reduction
Some doctors perform the multifetal pregnancy reduction procedure to decrease the number of fetuses a woman is carrying in order to improve the chances that she delivers healthy babies. Doctors more commonly use it in women who have at least three viable fetuses resulting from fertility treatments because of the high risk of preterm delivery if they try to carry all the fetuses. Also, some women carrying twins want to reduce their pregnancy to a singleton, and this is becoming increasingly common. Usually a maternal–fetal medicine specialist performs a multifetal pregnancy reduction between 10 and 13 weeks in a special center. The risk involved is acceptably low when an experienced physician specifically trained in this procedure performs it. The important thing is to find out about all possible options so you have as much information as possible to make the best decision for you.
Selective termination
A selective termination procedure can be used in a multifetal pregnancy to terminate one of the fetuses when that fetus has a significant abnormality. A maternal–fetal medicine specialist can perform this procedure if the fetuses have separate placentas so that the medication used can’t cross over and affect the normal fetus. In the case of identical twins who share a single amniotic sac, some other options are available (ask your doctor). In the latter case, only a few centers in the United States perform this procedure.
Monitoring for preterm labor in twins
Doctors aren’t sure what exactly causes labor to start in any pregnancy, but it has something to do with how distended the uterus is. With twins, the uterus becomes larger much earlier than it does with a single fetus, so the risk of going into labor early — as well as delivering early — is increased. As mentioned earlier, the average gestational age when a single fetus delivers is 40 weeks. The average gestational age for the delivery of twins is 36 weeks.
Doctors have come up with ways to try to prevent premature births in twin gestations. Some approaches include putting in a cervical cerclage (a stitch sewn into the cervix to try to keep it closed) and using progesterone to keep the uterus from contracting. Unfortunately, neither of these two treatments has been shown to change the rate of premature delivery in twins.
Although no surefire treatments exist to prevent premature birth in twins, doctors have focused on trying to come up with strategies to predict which patients with twins are at the highest risk for delivering early. If your risk is high, your doctor may decide to admit you to the hospital for more intensive observation and to make sure you don’t have preterm labor that is unrecognized. Your doctor may also give you steroid shots between weeks 24 and 34 to help your babies’ lungs mature sooner in the event that you do deliver early.
Two factors that are indicators of early delivery can be examined via transvaginal ultrasound:
· The length of the cervix: The cervix usually gets progressively shorter prior to delivery. Cervical length measurements are most helpful in twins between 16 and 24 weeks of pregnancy, but sometimes they’re continued after that time if the situation warrants.
· Whether the cervix is dilating: Early dilation is sometimes called funneling because the cervix looks like a funnel on ultrasound.
The frequency of the measurements depends on your own situation, but they’re typically taken about every two weeks. If your cervix is long and not dilated, your chances of a premature delivery are low. If it’s short or showing signs of early dilation, your doctor will probably step up the frequency of your visits or even admit you to the hospital.
Another test to predict the likelihood of delivering early involves determining the level of fetal fibronectin (see Book 6, Chapter 2). This substance is found in vaginal secretions obtained by using a special swab. Fetal fibronectin levels are higher in women with twins who are at an increased risk for early delivery. Even if your cervix is closed and you aren’t in premature labor, if your fetal fibronectin test is positive, your doctor may decide to give you steroids.
Getting Pregnant Again
Doctors and parents haven’t come to a consensus on the optimal time to get pregnant again. Probably the most important consideration is your overall health. If you can get back to your pre-pregnancy or ideal body weight quickly after you deliver, and if you can replenish any lost nutrients and vitamins (particularly folate, iron, and calcium) from your last pregnancy, you can probably consider getting pregnant again fairly soon — in about 12 to 18 months. A recent large study showed getting pregnant again in less than 18 months was associated with an increased risk of adverse pregnancy outcomes. If you’ve had a complicated pregnancy, a difficult delivery, or excessive loss of blood, wait until you’re in better shape before trying again.
Also ask yourself what you consider to be the ideal age difference in your children. Some people feel having children close in age is better. That way, the older child doesn’t have so many years to settle into the role of only child and therefore may not feel so jealous when the new baby comes. Others feel spacing the children further apart so that the older child is mature enough to handle the introduction of a new sibling is better. Most important is how you and your partner feel and how ready you are to take on another child. The decision may involve emotional and financial issues as well as physical ones. Ask yourself whether you can handle the pressure and the expense and can do the work that having another child takes.
Realizing how each pregnancy differs
Naturally, any mother compares her second pregnancy with her first, but every pregnancy is different. If your last pregnancy went smoothly, you may think any little thing out of the ordinary that happens in the next pregnancy is a signal that things aren’t going well. By the same token, if your first pregnancy was difficult, you needn’t assume the same complications are going to happen again. And no matter what anybody tells you, remember that different symptoms don’t mean the second baby will be a different sex from your first child.
These are some of the ways in which you may experience pregnancy differently the second (or third or fourth) time around:
· Many women feel that they’re showing sooner or are at least more bloated and distended. This condition may be because their abdominal muscles have been stretched by their previous pregnancy and are now more lax.
· Many women find that nausea isn’t as severe as it was the first time around, and others find that it’s worse.
· You can usually identify fetal movement earlier.
· Labor is usually shorter, and delivery is easier.
· Many women find they feel Braxton-Hicks contractions earlier and more frequently than with their first child. (See Book 2, Chapter 3 for more on Braxton-Hicks contractions.)
· Most women are less anxious the second time around.
One thing remains the same: As hard as it may be to believe, you will love your second child as much as your first.
In their third pregnancy, many women commonly experience a special kind of worry: They feel that because their first two pregnancies were healthy and problem-free, the third one’s bound to have complications. Many feel that they were lucky twice in a row and that going for a third time is pushing their luck. If you feel this way, believe us, you aren’t alone. Keep in mind the chances of trouble aren’t inherently greater in a third pregnancy, even if the first two went smoothly.
Giving birth after a prior cesarean delivery
If you’ve had a cesarean delivery and you get pregnant again, you may wonder whether you can deliver vaginally this time or need another cesarean. To some extent, the answer depends on which of the following kinds of cesarean you had:
· Low transverse: Most cesarean deliveries are done through a low-transverse incision (across the floor in the lower part of the uterus) — see Figure 1-4a. Women who have this kind of incision usually can deliver vaginally in a subsequent pregnancy as long as they have no other complicating factors. The risk of uterine rupture is lowest with this kind of incision.
· Classical: If you have what’s known as a classical cesarean, in which a vertical incision is made in the upper portion of the uterus (see Figure 1-4b), don’t try to have a vaginal delivery in a subsequent pregnancy, because this type of incision is more likely to rupture. Vertical incisions are sometimes performed in cases of very preterm birth or placenta previa (see Book 6, Chapter 2) or when the mother’s uterus is an abnormal shape or has large fibroids.
· Low vertical: A low-vertical incision (see Figure 1-4c) is performed less frequently than a low-transverse incision, but it does enable the mother to attempt labor and delivery in a subsequent pregnancy.
Illustration by Kathryn Born, MA
FIGURE 1-4: Various kinds of uterine incisions.
The incision made on your skin doesn’t reflect the type of incision on your uterus. In other words, you may have a transverse incision on your skin (a bikini cut) but still have a vertical incision on your uterus.
Doctors used to think that after a woman had a cesarean delivery, all her babies would have to be delivered the same way and that trying a vaginal delivery risked the uterus rupturing through the old cesarean scar. But studies have demonstrated that the risk of such a rupture is quite low — less than 1 percent. Discuss the issues of uterine rupture with your doctor. Other recent studies show that 70 percent of the time, women can successfully deliver a baby vaginally after they’ve had a cesarean.
Of course, the likelihood of success depends to some extent on why a cesarean was performed in the first place. If your doctor performed it because the baby was breech, the chances that the next baby can be delivered vaginally are nearly 90 percent. If the cesarean was performed because the baby was too large to fit through the mother’s pelvis, the chances of a future vaginal delivery fall to 50 to 60 percent. Some smaller hospitals are unable to offer VBAC (vaginal birth after cesarean) to their patients because they don’t have the capacity to meet the special requirements needed to do so (like 24/7 availability of an anesthesiologist).
Why would you want to deliver your next baby vaginally? The main benefit is that if you’re successful, your recovery is much shorter. Another potential benefit from a vaginal birth is that it’s often associated with less postpartum pain. However, although most patients find the pain associated with vaginal birth to be less than that associated with cesarean delivery, some vaginal births have painful complications of their own. See Book 2, Chapter 7 for more information.
Other benefits of a vaginal birth include the following:
· A lower risk of the kind of complications associated with abdominal surgery, including
· Anesthesia problems
· Inadvertent injury to adjacent organs
· Infection
· Possible blood clots from being immobile for a longer period of time
· For some women, a psychological benefit from experiencing a vaginal birth
· A shorter hospital stay
· The possibility, indicated by some studies, that the baby clears her secretions more efficiently if born vaginally
However, you do have some risk: If you try labor and then end up with another cesarean, studies show that the complication rate is higher than if you went straight to a repeat cesarean without labor. Additionally, your recovery may be longer than if you had elected to have a repeat cesarean.
If You’re a Nontraditional Family
Single women and gay or lesbian couples bearing children are becoming more and more common. If you fall into one of these categories, discussing your situation with your practitioner is important. Don’t worry that your doctor may judge or ridicule you. Practitioners are trained to be sensitive to all patients’ needs, and you’re no different. If your practitioner does seem to have a problem with your situation, move on to someone who’s more understanding — the sooner, the better.
In many single-mother and lesbian pregnancies, the father of the baby isn’t physically present. Still, try to have information about the father’s family history and ethnicity so you and your practitioner can go over any genetic implications (see Book 2, Chapter 1).
If the father isn’t going to be around for the whole process, build your own support network. If you’re a single mom, you may choose one or more people (family members or close friends) to share your pregnancy, labor, and delivery. If you’re part of a lesbian couple, the nonpregnant partner can assume the primary support role. If the father is a male friend, include him as support. No matter the case, having your support people accompany you to any prenatal visits or prenatal classes and having them around for the labor and delivery process is completely appropriate.
Preparing Your Child (or Children) for a New Arrival
Many parents look forward to having a second child specifically because they want to provide a sibling for the first one. But your first child may not easily understand this reasoning. She may feel completely content about being the only child, and it may be months or years before the first one appreciates the second one. For those of you who are having your second child — or third or fourth (or more!) — the following sections offer a few ideas about how to help prepare the older one(s) for the new arrival. Many hospitals now offer sibling classes to help your child acclimate. Contact the hospital in which you plan to deliver for information.
Explaining pregnancy
The ease or difficulty you may have introducing a new baby sister or brother depends quite a bit on how old the elder sibling is. Explaining a new baby to a 15-year-old is easy; getting the concept across to a 15-month-old can be tricky. And the challenge begins at the time you tell the first child that you’re pregnant. A 2-year-old has little concept of time and may not understand that Mom is pregnant for months before the baby comes. She may be frustrated the baby can’t come immediately. So delay telling a very young child about your pregnancy until the second or third trimester, unless you don’t mind being hounded every day about when the new baby is coming.
If your child is old enough — at least 2 or 3 years old — you may want to bring her along to prenatal doctor visits, ultrasound examinations, or shopping trips for baby items. (While you’re doing that shopping, consider getting a small present for your child so she doesn’t feel neglected.) A child who is old enough may also like to join in discussions about what to name the new baby.
If you anticipate moving your child to a new room or having her graduate from a crib to a bed, make the change before the baby is born. This change allows your older child to have a chance to acclimate so she doesn’t associate the new situation directly with the new baby’s arrival.
As you near the end of your pregnancy, don’t be surprised if your child starts to act up or becomes unusually clingy and dependent. Many children get a sense that things are about to change when they see their mother getting physically bigger or when they overhear conversations about the impending arrival. During this time, be supportive and loving. Include your child in the preparations as much as possible. And remember that although having a new sibling affects almost all children in certain predictable ways, each child is unique, and how yours reacts depends in large part on her personality.
Making babysitting arrangements for your delivery
Obviously, you need to plan on having someone take care of your child when you and your partner go to deliver the new baby. If your delivery is scheduled (that is, you’re having a planned cesarean or an elective induction), making arrangements is relatively easy. But most women don’t know exactly when the big moment will arrive. And you still need to be ready beforehand.
If you go into labor spontaneously in the middle of the night, you want your child to be prepared in advance for what will happen and who will show up to take care of her while you’re gone. Reassure your child you will be okay and that she can come to see you and the new baby in the hospital very soon. If possible, phone your child at home while you’re in the hospital to tell her that you’re doing well, especially if your labor is unusually long. Many hospitals now have special sibling visiting hours, and you may want to check out the details ahead of time.
Pack a couple of gifts to take with you to the hospital — one for your child to give to the new baby and one for the baby to give to the child.
Coming home
During the first few days that the new siblings live together, you may be amazed at how well-adjusted, happy, and excited your older child is. Part of this attitude is genuine enthusiasm. But keep in mind that part of it may also be your older child’s attempt to share the limelight with the new baby. Some children have a short period of difficulty coping; others do fine at first but develop longer-lasting sibling rivalry.
Don’t be surprised if your child begins to regress in terms of some developmental milestones. A previously potty-trained child may resort to bed-wetting, for example. Or a child may resume thumb-sucking or have difficulty sleeping. You may notice your older child gets especially jealous while you’re breastfeeding. During this period, understand your child may need extra reassurance that you still love her and the new baby hasn’t replaced her in your heart at all.
Explain that your heart is big enough to love more than one child. If possible, allow your elder child to help care for the baby. How much “help” your child is capable of providing depends on her age, but even small children can fetch a diaper if you need one or help give the baby a bath. Don’t be surprised if at times your child expresses aggression toward you or the baby. Usually, these acts of aggression are harmless, but during this early stage of adjustment, don’t leave your child alone with the baby unsupervised. She may not realize certain ways of handling the baby may be harmful.
Several months may pass before your older child feels secure, but eventually most children do deal with the change successfully. Quite often friends, neighbors, and family shower the new baby with gifts. Again, having a stash of inexpensive new toys for your older child to prevent excessive jealousy may be a good idea. It’s also a good idea to occasionally spend some one-on-one time with the older child to maintain your special bond with one another. With extra love and understanding, you can help your child through what can be a difficult period.