Sure, those last preggo weeks can be plenty uncomfortable, but keeping your little bun in the oven all the way to 40 weeks may make a whopping difference in your child's health. The latest studies indicate that babies born at 37 and 38 weeks, once considered full term, are more likely to have breathing problems, low blood sugar, and other issues that could send them to the neonatal intensive care unit.
The research was so compelling that it spurred the American Congress of Obstetricians and Gynecologists (ACOG) last year to revise its definition of full term to those infants who are born after 39 weeks. "We're recognizing that the last few weeks matter," explains Michael Gravett, M.D., scientific director of the Global Alliance to Prevent Prematurity and Stillbirth, an initiative of Seattle Children's Hospital. "Babies born at 39 weeks have fewer immediate problems versus those born at 37 and 38 weeks. And down the road, they do better on tests of intelligence and gross motor skills."
The exact cause of preterm labor remains a mystery, but these smart strategies will increase your chances of making it to that magical date.
Eat real food Put down that bag of chips! Your craving for junk food may be intense, but evidence continues to mount that eating a balanced diet of real foods may reduce your risk of preterm labor. A recent study of 66,000 pregnant Scandinavian women found that those who consumed a diet of fresh and raw veggies, whole-grain cereals, fruit and berries, lean poultry and fish, and lots of water were significantly less likely to have a premature delivery than moms-to-be on a Western diet that included more processed foods.
Although the study didn't directly prove that unhealthy eating habits cause preterm births, it added to the evidence linking the two, notes Edward McCabe, M.D., Ph.D., chief medical officer of the March of Dimes. "It's one more reason to avoid fast food, junk food, processed food, and sugary drinks," Dr. McCabe says.
Nosh often Your baby doesn't just need nutrients -- he needs them delivered frequently. Researchers have found that skipping meals and going for long periods without food increases your chance of early labor. Your best course of action: Eat at least five times a day. (Aim for three meals and two or three healthy snacks.) Eating frequent smaller meals may also reduce nausea and heartburn.
Do a smell check You may love the scent of your shampoo, but many beauty products with "fragrance" listed on the label contain phthalates, a class of hormone-mimicking chemicals that have been linked to preterm labor. A study in JAMA Pediatrics found that pregnant women with higher levels of phthalates in their urine were two to five times more likely to deliver preterm than those with lower levels. The study makes a case for using products that are phthalate free, says principal investigator John Meeker, Sc.D., of the University of Michigan in Ann Arbor.
Six types of phthalates, also called plasticizers, are banned from toys, but they're still found in building materials like pipes, vinyl flooring and wallpaper, food packaging, and personal-care products. Avoid plastics with recycling code No. 3. Perfume and toiletries are a trickier issue because manufacturers aren't required to list phthalates on the label. Dr. Meeker recommends looking for products that say "fragrance free," "no synthetic fragrance," or "phthalate free" to lower your risk of exposure. Or download the free Skin Deep app from the Environmental Working Group and use it to scan bar codes for ingredients and a safety rating before you buy.
Be good to your gums Chronic gum disease is a serious risk factor for preterm birth, though doctors aren't sure why, says Louis Muglia, M.D., director of the Center for Prevention of Preterm Birth at Cincinnati Children's Hospital. Pregnant women should brush and floss after meals and visit the dentist for regular cleaning. And don't forget mouthwash. Another study found that using an alcohol-free antimicrobial mouth rinse could cut women's risk of early labor by about three-quarters.
Go when you gotta go You're running to the bathroom constantly, so you may be tempted to sometimes hold it. Don't. You may trigger a urinary tract infection (UTI), a bacterial infection that can spread to your kidneys and jump-start labor. (Ward off UTIs by drinking plenty of fluids, wiping front to back, and fully emptying your bladder.) What's more, pregnant women may not experience the burning pain during urination that's a typical UTI symptom, so watch for foul-smelling, cloudy, or bloody urine. Your care provider will also test your urine during checkups. If bacteria turn up, a course of antibiotics usually clears up the problem and reduces your risk.
Measure up A short cervix is probably the most powerful predictor of preterm birth among first-time moms. Your cervix, which is like a doorway from the uterus to the vagina, gets shorter as your due date approaches. But if it shortens too soon, you're five or six times more likely to have a premature birth. A transvaginal ultrasound between 18 and 24 weeks is the best way to measure your cervix.
ACOG says it's reasonable for doctors to have all their patients measured, but some ob-gyns evaluate cervical length only in women whom they consider to be high risk, so ask your doctor about it. If your cervix does come up short, your doctor can prescribe progesterone treatments, which can reduce the likelihood of preterm labor by about 40 percent.
Steer clear of all smoke You may already know that smoking doubles your risk of preterm birth, but exposure to secondhand smoke can also up your chance of having a preemie. And you'd be wise to avoid the fumes from third-hand smoke too. "Third-hand smoke is when you enter a room or a car and you can tell someone was smoking in there," says Dr. McCabe. "The smoke leaves a residue that contains lead, arsenic, and other toxins." The same goes for e-cigs. Manufacturers claim they are healthier, but e-cigs still contain nicotine, which can be dangerous to a fetus, he notes. "We also know that preterm births go down after smoke-free legislation is enacted." Studies in the U.S. and Europe show that when a community makes this change, hospitalization for preterm births, on average, can drop by as much as 10 percent in just one year.
Fight off infections Your immune system is weaker when you're pregnant because your body is focused on growing a baby, and infections have been known to kick-start labor, so it's important to do everything you can to stay healthy. Wash your hands frequently, avoid people who are sick, and call your doctor right away if you run a fever.
Be sure to get a flu shot, too, says Siobhan Dolan, M.D., medical advisor for the March of Dimes and coauthor of Healthy Mom, Healthy Baby. It's safe and effective, and studies have found that your baby will be bigger and less likely to be born prematurely than the babies of moms who weren't vaccinated. Plus, your baby will be less likely to catch the virus after he's born, because you'll pass on your protective antibodies to him.
Get the right dose of D There's new evidence that women who don't get enough vitamin D are significantly more likely to develop preeclampsia and to go into early labor. Scientists believe the nutrient, which your body naturally makes in response to sunlight, helps fight infections that lead to prematurity.
Most prenatal vitamins contain 400 IU per tablet, but that may not be enough for many women. Dr. Gravett recommends asking your doctor to test your vitamin D level, especially if you're a vegetarian, have limited exposure to the sun, or have dark skin. If the test shows your level is low, he recommends an additional vitamin D supplement. ACOG says that 1,000 to 2,000 IU a day is safe for pregnant women, but the latest research has persuaded some doctors, including Dr. Gravett, to recommend even higher daily doses. One large study found that pregnant woman who took 4,000 IU of vitamin D per day significantly reduced their risk of giving birth prematurely.
Don't skimp on DHA Another nutrient that may prolong your pregnancy is DHA, an omega-3 fatty acid that helps your baby's brain and eyes develop. Studies have found that DHA supplements can increase the average length of gestation by three to six days and significantly reduce your risk of delivering before 34 weeks. The best way to get DHA is from fish. Eat at least 8 but no more than 12 ounces per week of low-mercury fish like salmon, herring, freshwater trout, and sardines, or up to 6 ounces per week of chunk light canned tuna. (Avoid higher-mercury albacore, also called chunk white.) You can also find DHA in walnuts, some vegetable oils (canola, soybean, olive), and foods labeled DHA-fortified. If you don't eat a lot of these foods, ask your doctor about a daily supplement of at least 200 milligrams of DHA.
Originally published in the March 2015 issue of American Baby magazine.