Why It Pays to Wait for a Full-Term Baby Birth

You may be eager for the nine months to end, but a little patience can deliver big benefits.

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Mel Grego's doctor agreed to induce her at 38 weeks so that her baby would share a birthday with his father and grandmother. The mom from Hudson, Wisconsin, believed the date would bring her good fortune during the delivery. However, that didn't turn out to be the case. Grego ended up having an unplanned cesarean section, and her son developed a mild case of jaundice after he was born—a complication that sometimes occurs when a baby is born early. In fact, experts now believe that you should do everything in your power to make it to your due date, unless there's a medical reason to deliver your child sooner.

New research suggests that birthing a baby prior to 39 weeks puts him at higher risk for a range of health and developmental problems. "The evidence is so compelling that a growing number of American hospitals are launching programs to help prevent elective deliveries before 39 weeks of gestation," says Diane Ashton, M.D., deputy medical director of the March of Dimes. Learn more about the benefits of waiting from our experts.

What "Term" Means Now
For years, babies were considered term (what we often call full-term) between 37 and 41 weeks of pregnancy. Most physicians believed that major organ development was complete by 37 weeks and that babies simply packed on pounds during the last stretch of pregnancy. The latest research, however, has proved them wrong. "We now know that important organs, such as the lungs and the brain, are not fully developed until 39 weeks," says Jason K. Baxter, M.D., an ob-gyn who specializes in high-risk pregnancies at Thomas Jefferson University Hospital, in Philadelphia.

One study, for example, found that babies born by C-section before 39 weeks have more breathing difficulties than babies delivered by C-section after 39 weeks. Furthermore, babies delivered electively at 37 weeks are four times more likely to end up in the neonatal intensive care unit or have serious respiratory troubles than babies born at 39 weeks or later; babies who arrive at 38 weeks are twice as likely to have complications. As a result of these findings, experts now don't consider babies term until 39 weeks. Infants born during weeks 37 and 38 are considered early term.

Why Those Last Weeks Matter
You may be tempted to ask your doctor for an early induction because of swollen ankles or an aching back, but that final month is critical to your baby's good health. For starters, a compound in her lungs called surfactant, which enables her to breathe independently, continues to be produced in greater amounts during the last month of pregnancy and decreases her risk of developing breathing problems once she arrives.

Her liver is still undergoing changes that will enable it to properly filter toxins, such as jaundice-causing bilirubin, out of her body. Her skin is thickening and she is accumulating more body fat, which will help her to maintain her own body temperature after she's born. Brain development is still underway; at 35 weeks, for example, its volume is only about two thirds of what you'd expect at 39 to 40 weeks, says Dr. Ashton. Additionally, important brain and nerve connections are being made to help her suck, swallow, breathe, regulate her body temperature, and even sleep better once she's born.

How Sticking It Out Helps You
Avoiding medical interventions and allowing your body to go into labor naturally has major benefits for you too. You're more likely to have a smoother birth, explains Kathleen Simpson, Ph.D., a clinical nurse specialist at Mercy Hospital, in St. Louis. According to a study published in the American Journal of Obstetrics and Gynecology, the average labor time for first-time moms undergoing a planned induction was 14.5 hours, compared with ten or 11 hours for first-timers who went into labor on their own.

Artificially starting labor also increases your odds of having a C-section by 50 percent. In order to induce labor, medication is typically administered to soften the cervix and start contractions; a second drug, pitocin, can cause particularly intense contractions. If your cervix doesn't dilate all the way, or if your contractions aren't progressing, your doc will opt for a C-section. And while most C-sections today go off without a hitch, they're still considered major abdominal surgery.

Furthermore, letting your baby arrive when he's ready increases your chances of being able to bond with him as soon as he's born, rather than having to wait to hold him until after he's out of intensive care. Compared with the joy of having that first cuddle with your baby, the discomfort of those last few weeks is something you'll soon forget.

Originally published in the November 2012 issue of Parents magazine

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