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Separating Pregnancy Myths and Facts

and equal amounts of confusion.

"Some of that confusion is the result of new information that is continually coming to the forefront, but a lot of it is due to pregnancy myths that were popularized by certain books cautioning mothers to expect the worst, and that frightened a lot of women unnecessarily," says nurse midwife Jo Anne P. Davis, PhD, CNM, an instructor at NYU's College of Nursing in New York City.

But there are a few areas where we can help your pregnant body to do its job better, more efficiently, maybe more healthfully. And that is where separating the pregnancy myths from the facts can make a huge difference.

Pregnancy Diet Myths

Among the most popular -- and for some, the most daunting -- of all pregnancy myths are those related to daily diet. While it's vital to maintain a healthy diet, that's not always easy, particularly when we're unsure of exactly which foods we can and cannot have.

The good news: Whatever foods are healthy for mom are healthy for baby, says Peter Bernstein, MD, an obstetrician at Montefiore Medical Center in New York City. 

"Virtually all fruits and vegetables , whole grains, some diary, and most protein sources are good choices for mom and good choices for baby. There are really very few foods you need to avoid," says Bernstein.

Fish is among the foods that cause concern because of mercury, a metal that can be toxic to babies, children, and even adults.

The FDA suggests pregnant women not eat more than 12 ounces (two average-size servings) of fish per week. Allowable fish include canned light tuna, shrimp, salmon, pollack, or catfish. For albacore tuna (also known as "white" tuna), which has higher mercury content than canned light tuna, consumption should be limited to 6 ounces per week.

Fish to avoid include swordfish, shark, king mackerel, and tilefish, which contain high levels of mercury.

A report in the journal Science showed that when compared to wild salmon, farmed salmon contained significantly higher levels of contaminants linked to birth defects and developmental problems, including PCBs.

Though the report set off a panic alarm for many pregnant women, the PCB levels found in the farmed salmon were still lower than levels the FDA considers acceptable. The American College of Obstetricians and Gynecologists recommends following the FDA guidelines.

"The bottom line is that there does not appear to be enough evidence to suggest that there is any more risk to eating farmed compared to wild salmon. And the benefits to eating at least some fish on a regular basis probably outweigh any risk," says Bernstein.

Also, a large study published in the British medical journal Lancet in February 2007 showed that fish is an important food to include in the pregnancy diet . 

After looking at nearly 12,000 children, researchers found those whose mothers ate the most fish during pregnancy had a "higher intelligence quotient" than those whose mothers abstained from fish. The children of the fish-eating moms also appeared to have better motor and communication skills as well as social skills. 

The key component of fish is omega-3 fatty acids, which Bernstein says are critical to fetal neural development. 

And although fish contains high levels of omega-3 fatty acids, there are other good sources, including flaxseed, nuts (particularly walnuts), soybeans, and eggs. There are also many foods fortified with omega-3s, including breads, juices, margarines, and oils, as well as omega-3 supplements . However, be aware that many of the sources of this omega-3 are from fish oil. 

Other foods you should try to avoid during pregnancy, says Bernstein, include those with a link to listeria, a bacterium that may increase the risk of miscarriage , premature birth, stillbirth, or fetal illness. 

According to the FDA, foods more likely to contain listeria include: 


  • Unpasteurized milk and soft cheeses such as feta, Brie, Camembert, Roquefort, queso blanco, and Panela, unless the label says "made with pasteurized milk"

  • Refrigerated meat spreads or pates

  • Refrigerated smoked seafood (unless it is cooked in a casserole or other dish)

  • Hot dogs and deli meats, unless they are heated until steaming


Experts also warn against eating undercooked eggs, raw eggs, or eggnog made with uncooked eggs, which can be contaminated with salmonella. "Problems can ensue due to vomiting and dehydration that can occur if you contract salmonella during pregnancy," says Bernstein.

Pregnancy Weight Gain Myths

One huge pregnancy myth involves how much additional food is really necessary to encourage the development of a healthy baby. While the old saying "eating for two" still applies, Bernstein reminds us we're not feeding two adults.

"The latest information tells us that the average woman needs only about 300 extra calories a day if they are of normal weight when they conceive," he says.

But the real news that's been gradually emerging in studies is that food intake, and particularly weight gain during pregnancy, is now viewed on a much more personalized basis.

"If you're very overweight when you get pregnant, then it's possible you should not add any additional calories to your diet, and it might even be OK if you lose a little bit of weight during pregnancy, particularly if this occurs because you have cut out all the junk food and switched to a healthier diet," says Bernstein.

One study published in the journal Obstetrics and Gynecology in 2007 showed that overweight women who gained less than the recommended 15 pounds during pregnancy actually had better pregnancy outcomes, with a lower risk of preeclampsia, cesarean delivery, and abnormal-sized babies -- large or small.

At the same time, if you are underweight at conception , then you may have to add more than 300 calories a day and increase weight gain, just to get you up to speed to what your baby needs to grow strong and healthy, says Bernstein.

Pregnancy and Alcohol Myths

Some of our favorite beverages -- coffee, tea, and alcohol -- have all come under scrutiny when it comes to consuming them during pregnancy. Of the three, says Davis, alcohol remains the most serious concern.

"It still falls under the heading of 'association' and not direct link, but since there is no data to show a clear cutoff point where alcohol consumption will not harm an unborn baby, the general recommendation is that no level is considered safe," says Davis.

And while a news story airing on Good Morning America Weekend in February 2008 questioned whether or not moderate drinking was really OK during pregnancy, the American College of Obstetricians and Gynecologists stands firm on its "no alcohol" policy during pregnancy. In a prepared statement it continued to "strongly urge women not to ignore the public health warnings associated with consuming alcohol while pregnant."

The March of Dimes has echoed that sentiment and continues to urge women not to use any alcohol during pregnancy or if they suspect they are pregnant.

At the same time, should you panic if, two weeks after a night of heavy drinking, you discover you are pregnant? Davis says absolutely not.

"There is a very good chance that it isn't going to harm your baby," says Davis.

The most convincing link between alcohol intake during pregnancy and the development of fetal alcohol syndrome (a collection of symptoms that can lead to severe learning and social disabilities) relates to binge drinking during pregnancy -- high alcohol intake on more than one occasion.

Pregnancy and Caffeine Myths

Although the relative safety of caffeine consumption during pregnancy has rmained a point of debate in many medical circles, recently a small but significant new study reinforced the idea that reducing caffeine intake during pregnancy below even conservative recommended intakes may have merit.

In research published in the American Journal of Obstetrics and Gynecology in February 2008, epidemiologists from the Kaiser Permanente Division of Research in California found that women who consumed 200 milligrams or more of caffeine a day -- equal to about 12 ounces of coffee or about 30 ounces of tea -- may double their risk of miscarriage.

According to the American College of Obstetricians and Gynecologists, "moderate caffeine consumption doesn't appear to cause miscarriage or preterm birth." Moderate caffeine consists of less than 200 milligrams of caffeine a day (about 12 ounces of coffee). The March of Dimes also recommends no more than 200 milligrams caffeine per day for women who are pregnant. 

Davis believes personal risk factors should be taken into consideration. "If you are at increased risk for miscarriage, if you have a history of pregnancy loss, if you are exposed to other factors that might increase the risk of miscarriage, then it's probably a good idea to avoid caffeine, or at least restrict intake under what the latest research suggests," she says.

At the same time, if you are young and healthy and your pregnancy is not at any great risk, you can probably safely consume a little more than that. And certainly, she says, going overboard once or twice during your pregnancy is not likely to cause you any great harm.

Pregnancy and Lifestyle Myths

While diet is certainly a major concern during pregnancy, many women worry about environmental risks as well. From computers and microwave ovens to hair dye and nail polish, myth and fact are often intertwined. 

To help set the record straight on these factors, Davis and Bernstein, along with obstetrician Pamela Berens, MD, from the University of Texas Health Sciences Center at Houston, and experts from the March of Dimes offer these words of advice. 



  • Microwave Ovens. "No good science shows microwaves harm the fetus," says Berens. 


  • Computers. "The radiation is miniscule, particularly now with the use of LCD screens and no exposure to the cathode ray tube monitors of the past," says Bernstein. That said, he cautions against long hours on keyboards during pregnancy. "It can increase your risk of carpal tunnel syndrome , a painful wrist-related injury."


  • Air Travel. The concern is exposure to radiation that may occur via X-rays at some security checkpoints, and due to flying at high altitudes. But Bernstein says the amount of exposure is small. Additionally, there is no evidence that the change in air pressure found in plane cabins can cause a miscarriage or premature labor . However, if your flight is longer than one hour, be certain to get up and walk around several times during your flight. Pregnancy increases the risk of blood clots in the legs, and so does sitting for a long period of time.


  • Cats. The major threat is a parasite known as toxoplasma, which you can contract from exposure to feline fecal matter. The way to avoid it, says Berens, is simply to avoid changing your cat's litter box during pregnancy. She adds that most people who have cats have already been exposed, so they likely have the antibodies against it. To be sure, however, you can ask your doctor for a blood test. Since toxoplasma can also be found in soil, raw/undercooked meat, and unwashed produce, you can prevent infection by cooking food thoroughly, washing produce thoroughly, and wearing gloves when gardening.


  • Hair Dye. It's an old myth that's hard to kill, mostly because doctors themselves frequently err on the side of caution by recommending women don't dye or color heir hair during pregnancy, particularly during the first trimester , when critical development changes are occurring in the baby. And while there fails to be any definitive research showing direct links between hair coloring and fetal health (ditto for hair straightening chemicals or permanent waves), an animal study published in 2006 in the journal Biotechnology & Biotechnology Equipment showed an increased risk of cataracts, affecting vision, in the offspring of female rats who had dye components injected under the skin during pregnancy.


  • Nail Polish. The chemicals of concern here fall under the heading of "phthalates" and can be found not only in some nail polishes, but also hairsprays, deodorants, and other personal care items, as well as many room deodorizers. Though there is no conclusive evidence they cause problems, many studies have shown evidence that phthalates are endocrine disrupters -- chemicals that may have an impact on gender hormones. In one small study conducted at the University of Rochester in 2005, researchers found the greater the exposure of mothers to phthalates during pregnancy (determined by urine samples), the greater the risk of genital-related abnormalities in their sons.


  • Skin Care. The primary concerns in this category continue to be the acne medication Accutane, an oral retinoid prescription drug. Because studies show it has been linked to birth defects, an FDA regulation known as "iPledge" requires women of childbearing age to commit to using contraceptives before receiving a prescription.


  • Smoking. It is not only bad for your health, it is bad for your baby as well. According to the March of Dimes, smoking doubles the chances of having a low-birth-weight baby, as well as increasing the risk of premature birth. Premature and low-birth-weight babies face an increased risk of serious health problems during the newborn period, as well as chronic lifelong disabilities including cerebral palsy, mental retardation, and learning disabilities.

By Colette Bouchez
Reviewed by Louise Chang
©2005-2010 WebMD, LLC. All rights reserved

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