By Ulysses Torassa
As a physician, Tamar,* of Denver, Colorado, knew to stay away from drugs, alcohol, and cigarettes during pregnancy. But upon learning she was pregnant for the first time, the normally laid-back doctor suddenly felt anxious about her everyday surroundings. Spooked by headlines linking birth defects to everything from smoggy air to microwave ovens, she felt guilty drinking tap water and avoided household chores out of fear that cleaning products would harm her fetus.
"On the one hand you feel so blessed," she said. "But at the same time, you look around and you worry -- is it safe?" Protective instincts naturally kick in when you're pregnant, and every mother-to-be wants to ensure her baby is as healthy as possible. But where is the line between prudent caution and paranoia? How far should you go to avoid risks of problems and complications, in light of media reports that raise questions about hazards in our everyday environment?
Experts in teratology (the study of abnormalities in physiological development) say protecting your unborn baby needn’t mean turning your life upside down. In fact, they say, getting too stressed-out about tiny, theoretical risks isn't healthy.
"In general, there is a tendency for women to be very alarmed," says Gideon Koren, M.D., director of Motherisk, a teratology information service based at the Hospital for Sick Children in Toronto. "The media and other sources often highlight bad things and ignore studies that are reassuring. It leads a lot of women to have high levels of anxiety and avoid small pleasures."
Consider these statistics: 3 to 4 percent of babies will be born with a birth defect, usually the result of a genetic abnormality. Just 4 to 5 percent of these cases have a known "environmental" (non-genetic) cause, and of those, half are due to the effects of uncontrolled preexisting diabetes on the developing fetus, according to Lynn Martinez, program director of the Genetics and Birth Defects Program at the Utah State Department of Health. Most of the rest involve risks such as infections, poor nutrition, cigarettes, alcohol, and prescription or recreational drugs.
"If a mother is not actually poisoned by an outside toxin, the evidence for increased risk for any kind of problem just isn't there," said Martinez. "Even though only 5 percent of birth defects have any kind of known environmental cause, we get 10,000 calls a year here. And that's what they're calling about."
At the same time, activists point out that we don't know enough about the effects of many chemicals and pollutants on pregnancy. And since a fetus is growing at an astonishing pace during its nine months in the womb, it's not unreasonable to worry that a small amount of toxin could disrupt the exquisitely orchestrated process.
Activists like Daniel Swartz former executive director of the Children's Environmental Health Network in Washington, D.C., suggest pregnant women err on the side of caution and try to reduce their exposure to cleaning solvents, air pollution, and unfiltered tap water.
But even Swartz says that the potential hazards in our normal environment pale in comparison to well-known risks like mercury, cigarettes, alcohol, drugs, and lack of prenatal care. "In the grand scheme of things, taking your prenatal vitamins is likely to be more important," he said. To reassure moms-to-be, BabyTalk canvassed experts to separate reality from rumor. Here's what we found:
Pesticides on Food
What you've heard: Pesticides can cause birth defects.
What the truth is: For years, scientists have known that exposure to the pesticide DDT was linked to an increased risk of miscarriage and premature births. But DDT and its cousins, including chlordane and dieldrin, were banned in the United States decades ago (although residues persist in some waterways). Studies of women exposed to high levels of pesticides through their job or by applying bug sprays in the home have come up with conflicting results, some finding a small association and others not finding any at all.
Another study of births to women potentially exposed to aerial spraying of malathion (a common agricultural pesticide) found no difference in the risk for birth defects or low birth weight. The U.S. Environmental Protection Agency (EPA) says risk from malathion ingested through food is "low and not of concern."
What you can do: As long as you're not working in agriculture or exposed daily to pesticides on the job, you have little to worry about. Commercially and organically grown produce are safe. Experts stress that it's crucial for pregnant women to make sure to eat a balanced diet, including plenty of fruits and vegetables. Rinsing produce well with water makes sense, whether you're pregnant or not, to remove dirt and pesticide residue. Organically grown produce is also an option, but is more expensive. Pesticide concentrations do vary by product, so you may want to splurge on organics for fruits and vegetables that don't have a outer peel -- such as strawberries, bell peppers, spinach, cherries, celery, apples, apricots, and green beans -- to reduce your exposure.
What you've heard: Women who drink lots of tap water have an increased chance of miscarriage and birth defects.
What the truth is: In recent years, scientists have become interested in a class of chemicals called disinfection byproducts that arise when chlorine used to treat water combines with organic material, such as algae. The best-known of these are trihalomethanes (THMs); the EPA lowered the amount of THMs allowed in public water systems. Three other byproducts, haloacetic acid, chlorite, and bromate, are also now limited.
Animal studies suggest that high exposures to these chemicals may have effects on development. Some studies have also found a correlation between high exposures and miscarriages or birth defects in humans, although the EPA says no clear link can be made. However, the agency also said that because the compounds are so pervasive, they deserve to be taken seriously and studied further. More research is under way, but teratology experts say if there are any ill effects, they are likely to be very minimal.
What is known is that methyl mercury in waterways can collect over time in large fish. As a result, the Food and Drug Administration (FDA) issued an advisory that pregnant women should avoid eating certain types of large fish (shark, swordfish, king mackerel, and tilefish) and limit their fish intake to no more than 12 ounces a week because methyl mercury can harm the developing brain and nervous system.
What you can do: For goodness' sake, stay hydrated. If you're thinking that bottled water is the answer, think again. Swartz of the Children's Environmental Health Network said there's no evidence it's any purer or safer than tap water. You can also check with your local water utility to get the latest results of water-quality testing. If you're still worried, you can install a water filter on your tap. In addition to adhering to the FDA fish advisory, some experts also recommend that pregnant women avoid tuna steaks, and limit their intake of canned tuna to no more than 6 ounces per week.
What you've heard: Living in a smoggy city increases the chance of birth defects.
What the truth is: A study of babies born in the Los Angeles area suggested that mothers exposed to auto exhaust and industrial emissions during the second month of pregnancy have a greater risk of giving birth to a baby with a specific type of heart problem, called a ventricular septal defect. Exposure to ozone, another ingredient in smog, during the second month was linked to other types of heart and blood vessel deformities (conotruncal heart defects, pulmonary artery/valve defects, and aortic artery/valve defects).
Most experts say the study wasn't strong enough to prove a link to air pollution. For one thing, they took a mother's residence at delivery and assumed that's where she lived during her second month. The study also didn't control for smoking -- a known risk for birth defects -- or the air quality where she worked during the day.
Experts like Donald Mattison, M.D., of the National Institute of Child Health and Human Development in Bethesda, Maryland, say they are more concerned about the effects of indoor air on pregnancy. Secondhand smoke is known to affect the fetus, and mold, which grows on dark, damp surfaces, can release spores harmful to a newborn's developing lungs.
What you can do: Chances of harm are small, but if you live in a particularly smoggy area like Los Angeles, Denver, or Houston, you may want to stay indoors on smog alert days. But don't avoid doing what you need to do. If you're worried about air quality, it's more important to keep a clean house and stay away from smokers than to move away from a smoggy city. Mold thrives when the humidity is over 40 percent, so try to keep moisture levels down by running the air conditioner or using a dehumidifier if necessary. You'll also want to check for any leaky windows and be sure to regularly clean household surfaces with diluted bleach, an antifungal spray, or an ammonia-based cleaner.
Electrical and Magnetic Fields
What you've heard: Using a microwave while pregnant can trigger a miscarriage.
What the truth is: A 2002 study in the journal Epidemiology claimed to have found a link between magnetic fields from common household appliances -- such as microwave ovens, fluorescent lamps, and hair dryers -- and a risk of early miscarriage. But the experts we spoke to dismissed these results as weak.
"Typically, women do not put these machines on their belly," said Dr. Koren, of the Motherisk program. "If you calculate how much radiation there is when you use these things normally, it is below what these studies suggest is a problem." Dr. Koren points out that years ago, pregnant women were advised to wear lead aprons when sitting in front of video display terminals because of similar concerns, and these fears turned out to be unfounded.
Dr. Mattison agreed, saying studies of electromagnetic fields have been fraught with problems, including how to measure exposures and how to account for the pervasiveness of electrical appliances in our lives. "It's probably unlikely that they play a role, given what we know about the level of energy that these appliances put out," he said.
What you can do: You don't need to do much. It's wise to make sure the oven door closes firmly and isn't bent or warped. If you're really cautious, you may want to avoid leaning against one while it's operating.
Cleaning Products, Etc.
What you've heard: Don't paint or use cleaning products -- the fumes can damage the fetus.
What the truth is: Studies have shown that women who "huff" -- sniff glue and paint to get high -- are more likely to have children with birth defects. And women who work in certain industries that expose them to organic solvents do have a greater chance of giving birth to a child with a major malformation. Scientists have even linked being around these substances on the job to subsequent color blindness in offspring.
But using solvents around the house for short periods of time (simple cleaning or repairs) doesn't trigger the high concentrations that were found in the workplace air. And there are no studies linking household solvent use to miscarriage or birth defects.
What you can do: If you work in auto manufacturing, a dry cleaning or chemical plant, as a lab technician, or in certain textiles jobs, be sure to investigate the chemicals involved. Be particularly wary of organic solvents, including benzene, toluene (often found in spray paints, glues, and lacquers), and zylene.
Pass on heavy-duty tasks like stripping or refinishing furniture. Even though most household paints are made with latex, public health officials generally recommend that pregnant women stay away from painting walls, and some suggest cutting back on painting as a hobby. And pregnant or not, don't ever remove old paint that you believe was applied before 1978 as it probably contains lead, which is known to harm neurological development.
If you want to be cautious, you can reduce your exposure to solvents by having someone else pump gas and pick up the dry cleaning. (For the latter, that person would ideally also remove the plastic and let the clothes air out a bit.) Solvents and related compounds are also present in some hair dyes, nail polishes, and nail removers. Teratology experts aren't as concerned about those exposures, although it may be wise to give up acrylic nails until after the baby is born, as working with these products in nail salons has been associated with a slight risk of miscarriage.
So what's the bottom line? For the most part, you can rest easy. As long as you're not working around strong chemicals, most of what you'll come across in your daily life is fairly harmless. If taking extra precautions makes you feel better, then go ahead. But don't feel guilty if you drink water out of the tap or eat commercially-grown veggies. Being worried and stressed while pregnant is at least as bad as any environmental risk -- or worse -- for you and your baby.
Ulysses Torassa is a freelance writer.
* Name changed for privacy.