ACE Inhibitors & Pregnancy: Implications for Breastfeeding?

Just two days ago, a friend of mine was wondering if she will be able to breastfeed since she takes heart medication.

I pointed her toward the Motherisk site for further research and told her that it might be possible. And then, this news about a class of blood pressure medications, hit the news for causing birth defects if taken in the first trimester of pregnancy.

I took this quote from the Internation Herald Tribune, but I’ve seen the study reported around Europe and North America.

• ACE inhibitors, may cause birth defects if taken during the first three months of pregnancy, doctors are reporting. Pregnant women and those who are planning to become pregnant should avoid the drugs, the researchers and officials at the Food and Drug Administration warn.
• ACE inhibitors have long been known to cause birth defects if taken later in pregnancy, but until now they were considered safe if taken in the first trimester.
• The new information comes from a study of the medical records of 29,507 infants, published Thursday in The New England Journal of Medicine by researchers from Vanderbilt University and Boston University. The study cited 209 infants who had been exposed to the drugs in the first trimester, 18 of whom had birth defects; in half, the heart was affected.
• The rate of defects among infants exposed to the drugs was 2.7 times that of infants who were not. Infants whose mothers had taken other blood pressure medicines had no increased risk.

Now, I am not a health care professional, but instinctviely it seems to me that if a medication is harmful inside the womb, it’s probably not safe in breast milk. That said, my instincts aren’t well enough educated on this topic.

All drugs are metabolized in breast milk, but not to the same levels and most don’t reach “therapeutic levels” in milk (i.e. a dose that causes an effect). That doesn’t mean any and every medication should be stopped so that women can breastfeed or that women who take meds have to bottlefeed. A discussion with the lactation consultant, midwife or doctor at the hospital is necessary. They should know (or find out) the research on the drug you take and arrange for your milk to be tested. If your caregiver is not especially breastfeeding-friendly, you might have to insist on the test.

I take thyroid hormone every day and while I know traces of it show up in my milk, it is a trace, not a dose that can harm the baby. Still, I think mothers do have to be vigilant about watching their babies. In the same way you’d notice if they have gas pain after you eat broccoli for dinner, you should notice if they behave differently after you take your meds.