Bundles of joy just keep getting bigger. The March of Dimes reports that in the United States alone, twin births jumped 70 percent between 1980 and 2004. The rate of "higher order multiples" -- doctorspeak for triplets, quadruplets, quintuplets, and so on -- quadrupled between 1980 and 1998. Talk about a baby boom! The rate of multiple births appears to be leveling off in recent years, but still, more than 3 percent of babies in the U.S. are born in sets of two or more.
The surge in multiple births is easy to explain. Many women are waiting until their 30s and 40s to start families, and women over 30 conceive multiple babies more often than younger women, according to the March of Dimes. Older women are also more likely to undergo infertility treatments -- pills, shots, and surgical procedures -- that increase the odds several eggs will be fertilized at the same time. This means that with the help of techniques such as in vitro fertilization, some women who couldn't conceive even one child on their own end up with two, three, four, or more during one pregnancy.
It's no secret that more babies require extra work. Just getting them into car seats and taking them to the grocery store will be a challenge. But before moms and dads start worrying about such details, they need to manage the actual pregnancy. Multiple babies need special care long before they're born. If you're carrying more than one baby, you'll have to do what you can to give your children the best possible start.
What are the risks of multiple births?
Babies in overcrowded wombs are often born before they're due. According to the March of Dimes, more than 50 percent of all twins, and over 90 percent of all triplets are born prematurely, or earlier than 38 weeks. For quadruplets and quintuplets, premature birth is a near certainty. The average gestation for quadruplets is only 29 weeks.
Just like any other baby born early, premature multiples often face many health challenges. They are usually undersized (less than five and a half pounds), underdeveloped, and ill-prepared for life on the outside. They may need to spend weeks or sometimes months in the neonatal intensive care unit before they're ready to go home. The more mature your baby is at birth, the less likely he will be to have problems. Babies born after 34 weeks usually do very well, while babies born at 26 to 29 weeks generally have only mild or moderate problems.
Low birthweight babies, especially those born earlier than 32 weeks and weighing less than three and a half pounds, are at greater risk for complications such as infection or lasting disabilities such as cerebral palsy. And though most premature babies born after 26 weeks do survive, premature birth is still the leading cause of death among newborns, according to Seminars in Perinatology.
Even when multiples make it to full term, they tend to be smaller than babies born singly. (Doctors call these "singletons.") Low birthweight babies have more health problems and may need extra care in the hospital and at home. In extreme cases, small babies can develop the same disabilities that afflict very premature babies.
Identical twins face another possible hazard. According to the March of Dimes, about 20 percent of identical twins develop a complication known as twin-to-twin transfusion syndrome. The condition occurs when blood flows from one baby to another through their shared placenta. As a result, one twin may receive too much blood while the other receives too little. The condition can be fatal for both babies if it's not treated promptly.
Multiple pregnancies can also be hard on the mother. Each additional baby raises the risk of preeclampsia (marked by high blood pressure during pregnancy) and gestational diabetes, so health-care providers recommend additional prenatal visits for women expecting multiples.
Are multiple pregnancies especially risky for older women?
Thankfully, no. A recent National Institutes of Health study of 147,400 twin pregnancies and 5,015 triplet pregnancies found that babies born to women over 35 fared as well as those born to younger women. Specifically, multiples born to older women were no more likely to be born prematurely, to be extremely small, or to die soon after delivery than those of younger women. Researchers chalk up much of the success of older mothers to better-than-average prenatal care. Fertility treatments also helped improve the odds. Women who conceive with medical assistance -- as many older women do -- are very unlikely to carry identical twins. As a result, very few of them ever face the danger of twin transfusion syndrome, a disorder in which identical twins become ill after getting a disproportionate share of blood through the placenta.
What can I do to reduce the risks?
- Get good prenatal care. Regular prenatal care is crucial to the success of any pregnancy. And as the number of babies in the womb increases, so do the risks. Doctors can monitor, treat, or even prevent conditions that often threaten multiple pregnancies, such as high blood pressure and diabetes. As a result, prenatal care greatly lowers the risk of premature birth. If a woman is carrying twins, her doctor can run tests to check for twin transfusion syndrome. In many cases, the babies can be saved with prompt treatment.
- A woman carrying multiple babies should become very familiar with her doctor. According to the March of Dimes, most doctors recommend twice-monthly visits during the second trimester, and at least a weekly visit during the third trimester. Women with conditions such as high blood pressure or diabetes may need more frequent visits.
- Maintain a healthy lifestyle. Regular prenatal care isn't the only way to lower the odds of a premature birth. Mothers can do their part by avoiding cigarettes, alcohol, and street drugs. Cutting back on stress, getting screened for common vaginal infections (like bacterial vaginosis), and getting regular exercise may also help.
- Eat well. This is no time to start skimping on meals. According to the March of Dimes, women who are pregnant with multiples should aim for a steady, healthy weight gain. Women carrying multiples should take in about 300 more calories a day than women carrying one baby (a total of 2,700 to 2,800 calories a day).
- A weight gain of at least 24 pounds in the first 24 weeks greatly reduces the risk that twins will be born too small or too early. Women who were at a healthy weight to start with should try to add a total of about 35 to 45 pounds in a twin pregnancy. (If you're underweight or overweight, your doctor may set different goals.) Triplets typically call for a gain of 50 to 60 pounds.
Of course, there's more to healthy eating than simply packing on the pounds. Mothers should also strive to give their babies the nutrition they need to grow. A well-balanced diet is an excellent start. Many women also take vitamin and mineral supplements on the advice of their doctors. Two nutrients in particular -- folic acid and iron -- are crucial for a healthy pregnancy; your prenatal vitamin should contain at least 30 milligrams of iron. Talk to your doctor about the supplements and dosages that are right for you.
What about bed rest?
In the not-so-distant past, women who carried multiple babies could almost always look forward to a long sentence of bed rest. Doctors once assumed that bed rest would reduce a woman's chance of going into labor too early, but the practice is falling out of favor. According to a report in Nursing Research, routine bed rest has never been shown to prevent premature births. In fact, some studies suggest that bed rest may actually INCREASE the risk of premature birth for healthy women carrying twins.
In short, the value of routine bed rest for women carrying multiples is uncertain. If your doctor recommends bed rest, ask him or her to explain the potential benefits. If you're not satisfied with the answer, you may want to seek a second opinion.
All parents-to-be are bursting with questions, and extra babies only add to the uncertainty. Your medical team can give you the answers you need to make your pregnancy as safe and smooth as possible. As for handling those future trips to the grocery store, complete with shoppers cooing at your brood, you're on your own.
March of Dimes. Multiples: Twins, triplets, and beyond. http//www.marchofdimes.com/professionals/14332_4545.asp
Blondel B and M Kaminski. Trend in the occurrence, determinants, and consequences of multiple births. Seminars in Perinatology. August, 2002. 26(4):239-249.
Robinson JN. The epidemiology of premature labor. Seminars in Perinatology. August, 2001. 25(4): 204-214.
National Institutes of Health. NIH news release: Multiples born to older moms fare same as or better than those born to younger moms. September, 2002.
Crowther CA. Hospitalization and bed rest for multiple pregnancy. Cochrane Database System Review. 2001.
Maloni JA et al. Dysphoria among high-risk pregnant women hospitalized on bed rest: a longitudinal study. Nursing Research. 2002. 51:92-99.