Opioids Linked to High Risk of Birth Defects

March 4, 2011

Findings from a new study have important implications for women who are pregnant or planning a pregnancy and are taking opioid pain killers.

Infants born to women who take opioid pain killers such as codeine, oxycodone or hydrocodone just before or in early pregnancy are at increased but modest risk of birth defects, according to findings published in the American Journal of Obstetrics and Gynecology.

The study, which was conducted by CDC researchers, found that 2-3% of mothers interviewed were treated with prescription analgesics just before or during early pregnancy (the study did not examine illicit use of these medications).

The most commonly used opioid medications reported by women were codeine and hydrocodone. Treatment with opioid analgesics was linked to several types of congenital heart defects as well as spina bifida, hydrocephaly, congenital glaucoma and gastroschisis; these findings are consistent with previous studies.

This study found that women who took prescription opioid medications just before or during early pregnancy had about two times the risk for having a baby with hypoplastic left heart syndrome as women who were not treated with these opioid medications.

"Women who are pregnant, or thinking about becoming pregnant, should know there are risks associated with using prescription painkillers," said CDC Director Thomas R. Frieden, MD, MPH.

Congenital heart defects are the most common type of birth defect, affecting nearly 40,000 births in the United States each year. Many infants with congenital heart defects die in the first year of life, and infants who survive often require numerous surgeries, lengthy hospitalizations, and a lifetime of treatment for related disabilities.

While some medications are known to be harmful when taken during pregnancy, the safety of most medications taken by pregnant women has not been determined. The effects depend on many factors, such as:

  • How much medication was taken
  • When during the pregnancy the medication was taken
  • Other health conditions a woman might have
  • Other medications a woman takes

"It's important to acknowledge that although there is an increased risk for some types of major birth defects from an exposure to opioid analgesics, that absolute risk for any individual woman is relatively modest," said the study's lead author, Cheryl S. Broussard, PhD, from the CDC's National Center on Birth Defects and Developmental Disabilities. "However, with very serious and life threatening birth defects like hypoplastic left heart syndrome, the prevention of even a small number of cases is very important.

She advices patients who are pregnant or planning a pregnancy to speak with their physician if they are taking or considering taking any medication. “This includes prescription and over-the-counter medications, as well as dietary or herbal products," she said.

The findings from the study were based on the CDC-sponsored National Birth Defects Prevention Study, an ongoing population-based study that is the largest ever conducted on the causes of birth defects in the United States.

Source: CDC