The cholesterol-lowering drugs (known as statins) Lipitor, Zocor, Pravachol, Crestor , Lescol, Mevacor, and Baycol may be linked to severe central nervous system defects and malformed limbs, according to researchers from the U.S. National Institutes of Health (NIH). One to three percent of the prescriptions for these medications are for women in their childbearing years.
These findings, published in a research letter in the April 8, 2004 issue of the New England Journal of Medicine (NEJM), showed that 20 of 52 babies exposed to statins in the womb were born with malformations.
"We can't tell whether the defects were caused by the use of statin medications, but other birth defect studies suggest that these are the kinds of problems that occur if the embryo does not get enough cholesterol in early pregnancy to develop normally," said one of the study's authors, Dr. Maximilian Muenke, a senior investigator and chief of the medical genetics branch at the National Human Genome Research Institute in Bethesda, Md.
The real problem, according to Dr. Nancy Green, medical director for the March of Dimes, is that about half of all pregnancies are unplanned, so exposure to drugs can happen inadvertently before a woman even knows she's pregnant.
"Statins are very good for general health. But there's a lot we don't know about their safety in pregnancy because there is no national system for monitoring the safety of drugs during pregnancy," Green noted.
Of the 20 babies born with malformations mentioned in NEJM, five had severe central nervous system defects and five had malformed limbs. One baby had both, according to Muenke. There were also two cases of a very rare birth defect called holoprosencephaly, which occurs when the brain fails to divide properly. "These are such very rare birth defects that one would not expect to find the number we found in a population this small," Muenke said. He added that it's hard to know if there are more birth defects found in women who take statins, because the FDA reporting system is voluntary and many women don't report early-pregnancy statin exposure.
