FRIDAY, July 2, 2010 (HealthDay News) -- There are few things more chilling to expectant parents than the possibility that their child might come into the world with a birth defect that threatens the child's health or life.
But there's a lot that a woman can do before and during pregnancy to reduce the child's risk for developing a birth defect, doctors say. Most of these precautions are common-sense measures that apply to anyone who wants to lead a healthy life.
"Women of reproductive age should be cognizant of the fact they need to be healthy," said Dr. Michael Katz, senior vice president for research and global programs at the March of Dimes, a pediatrics professor emeritus at Columbia University and a consultant to New York-Presbyterian Hospital in New York City. "They should be living a healthy lifestyle anyway. It's not an extra chore. It's a good lifestyle."
About one in every 33 children born in the United States has some sort of birth defect, according to the U.S. Centers for Disease Control and Prevention. Most birth defects develop during the first three months of pregnancy and involve some structural, functional or biochemical abnormality that results in the child's disability or death.
Heart defects are the most common, making up a fourth to a third of all birth defects, according to the CDC. About 1 of every 100 to 200 babies is born with a heart defect.
Heart defects are more common because the fetal development of the heart is complicated, with many opportunities for things to go wrong. "The heart is a very complex organism, and it comes together from many different forces developing in the embryo," Katz said.
Most often, newborns with heart defects have what's called an atrial septal defect or a ventricular septal defect. They are born with a hole in their heart.
"The heart has four chambers -- two on top called atrial, two on bottom called ventricle. They are separated by a muscular wall called the septum," said Dr. Adolfo Correa, medical supervisor for the CDC's National Center on Birth Defects and Developmental Disabilities. "In some of the babies that are born with congenital heart defects, that wall hasn't been closed completely. There is a hole between the right side and the left side.
"That prevents some of the blood from becoming oxygenated at the lungs and then circulated to organs to provide oxygen. The blood that goes into the tissues is not as well-oxygenated as it might be. Sometimes those defects are very mild, and sometimes they can be very large and severe and interfere in the development of the child."
Other common birth defects noted by the CDC include:
- Neural tube defects, such as spina bifida and anencephaly, which affect about 1 of 1,000 pregnancies.
- Cleft lip or cleft palate, which affects about 1 in 700 to 1,000 babies.
But there's at least one encouraging thing that women should know about heart defects, neural tube defects and orofacial defects, according to the March of Dimes: Medical researchers believe that environmental exposure plays a role in whether a child develops these birth defects.
That means there are steps women can take to protect their children.
Obesity and diabetes are two important risk factors for heart defects, Correa said. Controlling weight and blood sugar levels are key to protecting the health of unborn child.
"Women of childbearing age should see their physicians about ways to achieve a healthy weight to make sure their pregnancy is a healthy one," he said. "When diabetes is well-controlled, the risk of birth defects can be reduced to the average risk in the population. Women with diabetes really need to see their physicians and make sure their diabetes is under good control."
Women also can reduce risk for birth defects through their diet. For example, experts say they should be taking in at least 400 micrograms of folic acid every day. Folic acid has been shown to prevent neural tube defects.
The problem with lifestyle risk factors, though, is that the behaviors really should be in place before a woman becomes pregnant, Katz and Correa said. Because birth defects develop so early in pregnancy, to truly protect her child, a woman should be fit, have any diabetes under control and be taking folic acid before conception.
Take, for example, the need to have good folic acid levels. "Neural tube abnormalities occur at the very beginning of the pregnancy, even before the woman is likely to know she's pregnant," Katz said.
Other preventive measures, however, can be undertaken after a woman knows she is pregnant. One important step is to review all prescription and non-prescription medications with an obstetrician, to make sure nothing is being taken that could damage the fetus.
"Whenever she is pregnant and a drug is prescribed to her, she should ask, 'Is this drug safe to take during pregnancy?' If the answer is, 'I don't know,' that needs to be researched further," Katz said.
Expectant mothers also need to be cautious when it comes to exposure to infectious diseases. When traveling during pregnancy, for instance, it's important to be inoculated against prevalent diseases or take steps to avoid exposure.
Katz cited the example of a woman receiving anti-malarial treatment before visiting a part of the world where malaria runs rampant, or receiving a rubella immunization before traveling. But there are infectious diseases that have swept the United States that women should take protective measures against, as well.
"Swine flu is a very important disease to avoid in pregnant women because it can cause the death of the fetus," he said.
The U.S. National Institute of Child Health and Human Development has more on birth defects.
For more on spina bifida and pregnancy, read about one couple's story.