Environmental risks and pregnancy

There are more than 84,000 chemicals used in homes and businesses in this country, with little information on the effects of most of them during pregnancy. However, a small number of chemicals are known to be harmful to an unborn baby. Most of these are found in the workplace, but certain environmental pollutants found in air and water, as well as chemicals used at home, also may pose a risk during pregnancy. A pregnant woman can inhale these chemicals, ingest them in food or drink, or, in some cases, absorb them through the skin. For most hazardous substances, a pregnant woman would have to be exposed to a large amount for a long time in order for them to harm her baby.

Most workplaces have preventive measures to help reduce exposures to chemicals. However, because little is known about the effects of most chemicals on reproduction, a woman should discuss any chemical exposures in her workplace with her health care provider, preferably before pregnancy. She and her provider can determine whether additional on-the-job protections or alternative duty assignment is advisable. This is especially important for women who work in industries such as agriculture, manufacturing, dry cleaning, printing, pharmaceutical manufacturing and health care. Pregnant women also can take steps to help protect themselves and their babies from pollutants and potentially risky chemicals used at home.

What are the risks of lead exposure during pregnancy?
Lead is a metal that was found for many years in gasoline, paint and other products used in homes and businesses. Although lead is still present in the environment, the amounts have decreased greatly since the 1970s when the U.S. Environmental Protection Agency (EPA) banned its use in these products.

Lead poses health risks for everyone, but young children and unborn babies are at greatest risk. Exposure to high levels of lead during pregnancy contributes to miscarriage, preterm delivery, low birthweight and developmental delays in the infant. Lead is harmful even after birth. Children exposed to high levels of lead may develop behavioral and learning problems, slowed growth and hearing loss.
Women who live in older homes may be exposed to lead in deteriorating lead-based paint. Many homes built before 1978 were painted with lead-based paint. As long as paint is not crumbling or peeling, it poses little risk. However, crumbling paint can produce lead dust when the surface is disturbed, especially when it is sanded or scraped.

Children with pica, a pattern of eating non-food substances, such as paint, clay, dirt and plaster, are at especially high risk of high blood lead levels if they dig peeling paint off walls and eat it, or chew on accessible areas, such as windowsills. If lead-based paint needs to be removed from a home, pregnant women and children should stay out of the home until the project has been completed. Only experts should remove leaded paint, using proper precautions. For information on licensed lead-abatement contractors, visit the EPA Web site.

A pregnant woman also can be exposed to significant amounts of lead in her drinking water if her home has lead pipes, lead solder on copper pipes, or brass faucets. A pregnant woman can contact her local health department or water supplier to find out how to get pipes tested for lead.

The EPA recommends running water for 15 to 30 seconds before using it for drinking or cooking to help reduce lead levels. Water from the cold water pipe, which contains less lead than hot water, should be used for cooking and drinking during pregnancy, and for preparing baby formula. Many home filters do not remove lead, so a pregnant woman should look for a filter that is certified by NSF International to remove lead.

Other possible sources of lead in the home include:
• Lead crystal glassware and some ceramic dishes. Pregnant women and children should avoid frequent use of these items. Commercial ceramics are generally safer than those made by craftspeople.
• Some arts and crafts materials (for example, oil paints, ceramic glazes, stained glass materials). A woman should use lead-free alternatives (such as acrylic or watercolor paints) during pregnancy and breastfeeding.
• Certain folk remedies for upset stomach, including those containing greta and azarcon.
• Vinyl mini-blinds imported from other countries.
• Lead solder in cans of food imported from other countries.
• Old painted toys.
• Cosmetics containing surma or kohl.

All people residing in the home who are exposed to lead on the job (for example, painters, plumbers and those working in smelters, auto repair shops, battery manufacturing plants or certain types of construction) should change their clothing (including shoes) and shower at work to avoid bringing lead into the home. They should wash contaminated clothing at work, if possible, or wash it at home separately from the rest of the family's clothing. The Occupational Safety and Health Administration (OSHA) requires that companies provide changing facilities for lead workers. For more information, visit the OSHA Web site.

Does mercury exposure pose a risk in pregnancy?
Mercury is a metal that is present in the environment. Elemental (pure) mercury and methyl mercury are two forms of mercury that may pose risks in pregnancy.

Elemental mercury is used in thermometers, dental fillings and some batteries. One recent study found a slightly increased risk of miscarriage in women working with amalgam in dental offices. Amalgam is a silver-colored material used to fill cavities in teeth, containing elemental mercury, silver and other metals. Some countries (Sweden and Canada) recommend that dentists avoid using dental amalgam in pregnant women as a precaution, although there is no evidence that it will harm their babies. Pregnant women who are concerned about the use of amalgam should discuss the use of alternative filling materials with their dentists. Women who work in industries that use mercury to manufacture products (including electrical, chemical and mining industries) should discuss their workplace exposures with their health care providers and take all recommended precautions.

Mercury enters the environment from natural sources (such as volcanic activity) and man-made sources (such as coal-burning or other industrial pollution). Mercury in the air eventually is deposited in water where it is converted by bacteria to a more dangerous form (methyl mercury), which accumulates in the tissues of fish. Eating fish is the main source of methyl mercury exposure in humans.
Trace amounts of mercury are present in many types of fish, but mercury is most concentrated in large fish that eat other fish. For this reason, the U.S. Food and Drug Administration (FDA) and the EPA advise pregnant women to avoid eating swordfish, shark, king mackerel and tilefish, and to limit consumption of albacore (white) tuna to 6 ounces or less a week. These fish may contain enough mercury to harm an unborn baby's developing nervous system, sometimes leading to learning disabilities. For additional guidance on eating fish during pregnancy, read Food-borne Risks in Pregnancy.

What other metals pose a risk in pregnancy?
Arsenic is another metal suspected of posing pregnancy risks. It enters the environment through natural sources (forest fires and weathering of rock) and man-made sources (mining and electronics manufacturing). Although arsenic is a well-known poison, the small amounts normally found in the environment are unlikely to harm a fetus.

However, certain women may be exposed to higher levels of arsenic that may pose an increased risk of pregnancy complications, including miscarriage and birth defects.
Women who may be exposed to higher levels of arsenic include those who:
• Work at or live near metal smelters
• Live in agricultural areas where arsenic fertilizers (now banned) were used on crops
• Live near hazardous waste sites or incinerators
• Drink well water containing high levels of arsenic

This can occur in the locations described above, or in certain parts of the country with naturally high levels of arsenic in rock (including parts of New England, the Southwest, the Northwest and Alaska).

Women who live in areas that may have high arsenic levels can help protect themselves from arsenic exposure by limiting their contact with soil. Women who use well water should have their water tested for arsenic to determine whether it is safe to drink or drink bottled water. For more information, visit the EPA Web site. Community water suppliers already test it for arsenic.

Until 2003, arsenic was included as part of a preservative in pressure-treated lumber that was used to build decks and outdoor play sets. The EPA recommends applying a penetrating stain or sealant to these structures at least once a year to reduce exposure to arsenic. Anyone who works with arsenic (for example, in semiconductor manufacturing, metal smelting, or applying herbicides) should avoid bringing the metal home on clothing and shoes.

Can pesticides harm an unborn baby?
There is little proof that exposure to pest-control products at levels commonly used at home pose a risk to the fetus. However, all insecticides are to some extent poisonous. Some studies suggest that high levels of exposure to pesticides may contribute to miscarriage, preterm delivery and birth defects. Therefore, pregnant women should avoid pesticides whenever possible.

A pregnant woman can reduce her exposure to pesticides by controlling pest problems with less toxic products. For example, she can place sticky traps in areas inaccessible to children. If she must have her home or property treated with pesticides, a pregnant woman should:
• Have someone else apply the chemicals and leave the area for the amount of time indicated on the package instructions.
• Remove food, dishes and utensils from the area before the pesticide is applied. Afterwards, have someone open the windows and wash off all surfaces on which food is prepared.
• Close all windows and turn off air conditioning when pesticides are used outdoors, so fumes aren't drawn into the house.
• Wear rubber gloves when gardening to prevent skin contact with pesticides.

Pregnant women may be concerned about the safety of insect repellants during pregnancy. The insect repellant DEET (diethyltoluamide) is among the most effective at keeping insects, such as mosquitoes and ticks, from biting. Preventing insect bites is important during pregnancy because mosquito- and tick-borne infections, such as West Nile virus and Lyme disease, may be harmful in pregnancy. Because the safety of DEET during pregnancy has not been fully assessed, a pregnant woman should apply insect repellents with DEET mainly to her clothing, and only in small amounts to exposed skin, when necessary . She can minimize her need for DEET by staying indoors during dawn and dusk, when mosquitoes are most likely to bite, and by wearing long pants and long sleeves.

What are organic solvents?
Solvents are chemicals that dissolve other substances. Organic solvents include alcohols, degreasers, paint thinners and varnish removers. Lacquers, silk-screening inks and paints also contain these chemicals. A 1999 Canadian study found that women who were exposed to solvents on the job during their first trimester of pregnancy were 13 times more likely than unexposed women to have a baby with a major birth defect, like spina bifida (open spine), clubfoot, heart defects and deafness. The women in the study included factory workers, laboratory technicians, artists, graphic designers and printing industry workers.

Other studies have found that women workers in semiconductor plants exposed to high levels of solvents called glycol ethers were almost 3 times more likely to miscarry than unexposed women. Glycol ethers also are used in jobs that involve photography, dyes and silk-screen printing.

Pregnant women who work with solvents, including women who do arts and crafts at home, should minimize their exposure by making sure their workplace is well ventilated and by wearing appropriate protective clothing, including gloves and a face mask. They should never eat or drink in their work area. To learn more about the chemicals she works with, a woman can ask her employer for the Material Safety Data Sheets for the products she uses or contact the National Institute for Occupational Safety and Health.

Is drinking chlorinated tap water safe during pregnancy?
In recent years, media reports have raised concerns about possible pregnancy risks from by-products of chlorinated drinking water. Chlorine is added to drinking water to kill disease-causing microbes. However, when chlorine combines with other materials in water, it forms chemical by-products, including trihalomethanes (THMs). The level of THMs and other chlorification by-products in water supplies varies, although the EPA regulates the maximum level permitted in water supplies.

A 1998 California study suggested that women who consumed more than five glasses a day of cold tap water containing high levels of trihalomethanes had an increased risk of miscarriage. However, a more recent North Carolina study found little or no increased risk from these chemicals. Scientists continue to study the safety of these chemicals during pregnancy. Until we know more, pregnant women who are concerned about chlorination by-products may choose to drink bottled water. Drinking water also can become contaminated with pesticides, lead, arsenic and other metals. Women who suspect their water supply may be affected can have their water tested or drink bottled water.

Can air pollution harm the fetus?
Most women who live in areas with higher-than-average levels of air pollution have healthy babies. However, studies from the United States and other countries suggest that babies of pregnant women exposed to high levels of certain air pollutants (such as polycyclic aromatic hydrocarbons and small particle pollution, both of which result from vehicle exhaust and industrial sources) may be slightly more likely than babies of pregnant women living in less polluted areas to be small for their gestational age.

Air quality in many areas of the country has improved since the first Clean Air Act was passed in 1970. However, some pregnant women, including those living in large cities, are still exposed to unhealthful levels of pollution. Individuals can help limit their exposure to pollution by limiting outdoor activities, especially exercise, on days when air quality is expected to be poor.

Do household cleaning products pose a risk in pregnancy?
Although some household cleansers contain solvents, there are many safe alternatives. Pregnant women should read labels carefully and avoid products (such as some oven cleaners) with labels stating that they are toxic.

Products that contain ammonia or chlorine are unlikely to harm an unborn baby, although their odors may trigger nausea in a pregnant woman. A pregnant woman should open windows and doors and wear rubber gloves when using these products. She should never mix ammonia and chlorine products because the combination produces fumes that are dangerous for anyone.

A pregnant woman who is worried about household cleansers or bothered by their odors can substitute safe, natural products. For example, baking soda can be used as a powdered cleanser to scrub greasy areas, pots and pans, sinks, tubs and ovens. A solution of vinegar and water can effectively clean many surfaces, such as countertops.

Incidence of Birth Defects in the United States

Heart and circulation 1 in 115
Muscles and skeleton 1 in 130
Genital and urinary tract 1 in 135
Nervous system and eye 1 in 235
Club foot 1 in 400
Chromosomal syndromes 1 in 600
Down syndrome 1 in 800
Respiratory tract 1 in 900
Cleft lip/palate 1 in 930
Fragile X 1 in 1,500
Congenital syphilis 1 in 2,000
Spina bifida 1 in 2,000
Congenital HIV infection 1 in 2,700
Metabolic disorders 1 in 3,500
Anencephaly 1 in 8,000
PKU (Phenylketonuria) 1 in 12,000

Topamax May Raise Risk of Birth Defects

Small Study Shows Increase in Birth Defects When Epilepsy/Migraine Drug Is Used During Pregnancy By Salynn Boyles
WebMD Health News
Reviewed by Brunilda Nazario, MD

July 21, 2008 -- The epilepsy and migraine prevention drug Topamax has been linked to an increased risk of birth defects in babies born to epilepsy patients who took it during pregnancy, a small study shows.

In a study published in the latest issue of the journal Neurology, taking Topamax (topiramate) during pregnancy was associated with a birth defect risk within the range of risk seen in other anti-epileptic drugs, researchers reported.

But the incidence of birth defects seen when Topamax was taken with other anti-epileptic drugs was higher than expected.

The study was small, but it is among the first to link Topamax to birth defects in humans, confirming what has been seen in previous animal studies.

"More research needs to be done to confirm these results, especially since it was a small study," researcher John Craig, MRCP, of the Royal Group of Hospitals in Belfast, Northern Ireland said in a news release.

He added that although the study included only epilepsy patients, the results may be of particular relevance for migraine patients "since [Topamax] is also used for preventing migraines, which is an even more common condition that also occurs frequently in women of childbearing age."

Read full story on Topamax and birth defects.

Ritalin may cause birth defects

For women who are pregnant, Ritalin® (methylphenidate hydrochloride) may not be safe to take. This is based on animal studies that looked at the effects of the drug during pregnancy.

Ritalin and Pregnancy Category C
The U.S. Food and Drug Administration (FDA) uses a category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category C is given to medicines that have not been studied in pregnant humans but that appear to cause harm to the fetus in animal studies. Also, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.

Ritalin was given a pregnancy Category C rating because it was shown to cause birth defects in rats and rabbits. Also, giving Ritalin to pregnant rats caused low birth weight in the baby rats.

It is important to note that animals do not always respond to medicines the same way that humans do. Therefore, a pregnancy Category C medicine may be given to a pregnant woman if the healthcare provider believes that the benefits to the mother outweigh any possible risks to the unborn child.

Recommendations for Ritalin and Pregnant Women
If you are taking Ritalan and pregnancy occurs, or if you are thinking about becoming pregnant while taking the drug, let your healthcare provider know. He or she will consider the benefits and risks of Ritalin during pregnancy before making a recommendation for your particular situation.

New Study Shows Early Ritalin May Cause Long-term Effects On The Brain

ScienceDaily (Dec. 29, 2004) — San Juan, Puerto Rico, December 12, 2004 – A new study conducted in rats by the National Institutes of Health (NIH) and McLean Hospital/Harvard Medical School suggests that the misdiagnosis of attention-deficit hyperactivity disorder (ADHD) combined with prescription drug use in children may lead to a higher risk of developing depressive symptoms in adulthood.

Read complete story on long term effects of ritalin.

Morning Sickness, Legal Miscarriage

Editorial from The New York Times: July 30, 1984

Merrell Dow, the maker of the morning sickness drug Bendectin, has agreed to pay $120 million to settle claims that the drug causes birth defects. For that money - more than was paid even in the case of thalidomide - you'd think Bendectin had been proved some kind of a hazard. But it hasn't.

The company has so far won both the cases that have come to trial, and the Food and Drug Administration believes Bendectin is safe. From more than 20 epidemiological studies the agency concludes there's no evidence that the drug increases the natural rate of birth defects.

So why did the company choose to settle? Juries' hearts go out to deformed children and their parents. In one Bendectin case the jury decided the child's injuries were not caused by the drug but awarded $20,000 for medical expenses anyway. The company won on retrial. In the other case a jury awarded $750,000 and was reversed by the judge, whose decision is now under appeal.

These two wins by Merrell Dow did not discourage new claims, as the company had hoped. In fact, each trial stimulated a flood of new claims. Since even wins were only adding to the costs of defense, the company says, it decided to settle. It, or its insurers, may also have anticipated some costly losses; animal tests indicate a possible link with some kinds of birth defect, although these are not confirmed by epidemiology.

So there's now no drug on the market that's recommended for morning sickness. That may be all to the good: No drug should be lightly taken in pregnancy, and morning sickness can be treated through control of diet. But something is badly wrong with the route to the Bendectin settlement. If the drug is unsafe or ineffective, the Food and Drug Administration should have been the first to act against it. If Bendectin indeed increases the rate of birth defects, courts should so determine and the company should pay. That's not what's happened. The courts have so far determined the opposite but the company has paid anyway. Judgment of the issue has been usurped by the parties' considerations of legal cost and risk. Like the Vietnam veterans in the $180 million Agent Orange settlement, the Bendectin claimants will now receive administratively determined payments from the trust fund created by the defendant. With Agent Orange, too, there's been no proof, only quite flimsy suspicions that the herbicide has caused more than a skin disease. In both cases the central issue of causation has been left unresolved. The court administrators of these grand payouts will have little rational basis for excluding any veteran exposed to a drop of Agent Orange or anyone with a birth defect whose mother took Bendectin. Satisfying the F.D.A.'s safety requirements should not absolve a company of liability for unexpected damage caused by its drug. But Federal safety review, if properly conducted, ought to count for something. Courts are a necessary forum for second-guessing the F.D.A. and resolving scientific uncertainties. But in the case of Bendectin, they did neither. With Bendectin and Agent Orange, the law has made a devastation and called it a settlement.

Medication fact sheets for pregnant and lactating women

To educate the public, the Organization of Teratology Information Specialists has compiled Fact Sheets on various exposures of concern. Fact Sheets answer frequently asked questions about exposures during pregnancy and lactation. Currently available Fact Sheets are listed at the Organization of Teratology Information Specialists website (listed below and in the Links and Resources) by category of exposure. All medications are listed by generic name. The generic name can be found on your prescription or medication packaging listed as the Active Ingredient, or in parentheses after the medication’s brand name.

Organization of Teratology Information Specialists: Fact Sheets