Pregnancy ‘rules’: fact or fiction

What's a mom-to-be to do? Myths abound about what’s safe and what’s unsafe when you’re pregnant, and yesterday’s conventional wisdom is sometimes debunked by today’s science.

What’s a mom-to-be to do? Myths abound about what’s safe and what’s unsafe when you’re pregnant, and yesterday’s conventional wisdom is sometimes debunked by today’s science.To root out the truth behind seven widely repeated bits of advice, we asked two Saint Peter’s University Hospital physicians—Suzette Johnson, M.D., of Brunswick Hills Ob/Gyn in Hillsborough and East Brunswick; and Vincent F. Mileto, M.D., of Somerset Ob/Gyn Associates in Hillsborough and Bridgewater—to help us separate reality from myth.

“Pregnant women should never fly.”

Fiction. There’s no truth, our doctors report, to the notion that traveling at high altitudes puts too much pressure on the fetus and can cause premature labor. Pressurized cabins protect your baby—and you. “Pregnant women have been flying for years, and there are no good studies showing any danger,” says Dr. Johnson. “We tell patients that if they’re not high-risk and have no special problems they can travel on planes up to 36 weeks—four weeks short of full gestation.” But women who are experiencing bleeding, contractions or other complications should check with their doctor before flying, she adds.

If you plan to fly late in your pregnancy, you should be aware that some airlines have restrictions—it’s wise to check your carrier’s policy in advance. United Air Lines, for example, requires that women flying in their ninth month bring a note from their obstetrician with the due date and an assurance that it’s safe for them to fly.

Also, pregnancy’s high-estrogen state combined with sitting still for several hours does increase your chances of developing a blood clot. “On international flights or other longer trips, you really should get up and move around to keep the circulation in your legs going well,” warns Dr. Mileto.

“Pregnant women should never eat unpasteurized cheese.”

Fact. “These cheeses—such as brie, feta, camembert, Roquefort and goat cheese—can be a cause of severe infection that can potentially harm the fetus,” says Dr. Johnson. Made with raw milk, which may contain the bacterium listeria monocytogenes, they pose a risk of listeriosis, an infection that can cross the placenta and cause miscarriage, premature delivery or infant death. Because the pasteurization process kills listeria, pasteurized cheeses such as cheddar, mozzarella, cream cheese and cottage cheese are perfectly safe for pregnant women— and they’re excellent sources of calcium too.

Listeria can also be found in raw fruits and vegetables, so all produce should be properly washed before eating. Deli meats and hot dogs are also potential listeria carriers, but cooking kills the bacteria.

That said, Dr. Mileto adds a bit of perspective about probabilities. “It’s extremely unlikely that a woman would have a problem with this,” he says.

“Today’s advanced products make it safe to dye your hair while pregnant.”

Fiction. No such assurance can be given, our doctors say. While there is no solid evidence that hair dye is a danger (“You really can’t study these things on pregnant women, so you can’t definitively say,” says Dr. Mileto), they regard this one as a better-safe-than-sorry call.

If you must color your locks, choose nonpermanent dyes—natural vegetable preparations rather than chemical dyes, says Dr. Johnson. “We recommend at a minimum that women wait till after the first trimester to do any coloring of hair,” she adds, “because that’s the most crucial period, when the embryo is developing and all the cells are being differentiated into organs.”

Also, she says, check with your doctor before taking any topical medications any time in pregnancy.

“Pregnant women should completely avoid alcohol.”

Fact. “Fetal alcohol syndrome can cause mental retardation and developmental problems in your child, and there’s no evidence on how much alcohol it takes to cause it,” says Dr. Johnson. “So it’s best to avoid alcohol completely.”

But what if you have a margarita or two before learning you’re pregnant? Don’t fret too much, the doctors advise; in most cases, with limited amounts of alcohol, the baby should be fine. Still, there is a danger of pregnancy loss, so stop alcohol intake as soon as you get the news— or if you’re trying to become pregnant. Says Dr. Mileto: “If you don’t use alcohol, we know it didn’t hurt anything.”

“Coffee must be strictly shunned during pregnancy.”

Fiction. Some research has linked having more than three cups of coffee with a higher miscarriage risk, but other studies disagree. “I don’t think anyone, pregnant or not, should be having continuous caffeine through the day,” says Dr. Mileto. But for caffeine consumption in moms-to-be, both doctors counsel moderation, not avoidance.

“Stick with less than 10 ounces of caffeinated beverages a day,” says Dr. Johnson. That means just one cup of morning java if you’ll be having an afternoon cola— and skip one of those drinks if chocolate is your evening treat. Says the obstetrician: “Too much caffeine can increase the pulse rate, possibly causing palpitations.”

“Pregnant women should never take hot baths.”

Fiction. “Taking a sensibly hot bath is fine, but pregnant women are sensitive to heat, so I caution my patients to use common sense,” says Dr. Johnson. “For example, I don’t recommend sitting in a Jacuzzi because the temperature is too high.” But that advice applies for everyone, the doctor says: Sitting too long in a too-hot Jacuzzi could cause anyone to become overheated or pass out.

Dr. Mileto agrees that reasonably hot baths are not a problem. “True, one study showed that too high a body temperature for prolonged periods in very early pregnancy could harm development of the spinal cord,” he says. “But you’d have to be in a very hot bath to raise your temperature to those levels.”

Both obstetricians throw cold water on the idea that a warm bath will cause premature labor (it won’t) or make a mom-to-be unable to tell if her water has broken (that will be clear on leaving the tub).

“Pregnant women should not eat any fish.”

Fiction. “There are certain fish pregnant women should avoid because of the danger of mercury,” says Dr. Johnson. For instance, says the Food and Drug Administration, stay away from shark, swordfish, king mackerel or tilefish. (To learn more, log on to www.fda.gov and search “Seafood Advice for Pregnant Women.”)

But fish is a good source of omega-3 fatty acids, which help with fetal brain development, so smaller varieties like flute, flounder, tilapia and dark tuna are perfectly safe to consume. Dr. Johnson lets her patients have one can of tuna per week.