Can Taking Aspirin During Pregnancy Make Your Son Infertile?

The Scoop

For moms-to-be expecting boys, a study suggests that taking common over-the-counter pain medications during pregnancy may dramatically increase their sons' risk for developing undescended testicles (cryptorchidism), a condition known to contribute to poor semen quality later in life.

Published November 8, 2010, in the journal Human Reproduction, researchers in Denmark asked over 2,000 women to recall how frequently they used ibuprofen, paracetamol, or aspirin, or a combination of the drugs, during pregnancy. According to their findings, taking pain medication for any length of time doubled the risk for a boy baby to be born with undesceded testicles. As the UK's Telegraph reports on the study, women who used more than one painkiller simultaneously, such as paracetamol and ibuprofen, had a sevenfold increased risk of giving birth to sons with some form of cryptorchidism compared to women who took nothing. Women who took a painkiller for more than two weeks were almost two and a half times as likely to have a boy with the condition and taking the drugs during the second trimester appeared to be the most sensitive time.

What's the connection? Experiments on rats have shown that certain compounds in the medications act as "endocrine disruptors," meaning they change certain hormone levels in the body. In this case, researchers believe the pain meds reduce the availability of testosterone to developing baby boys.

According to Dr. Henrik Leffers, senior scientist at Rigshospitalet in Copenhagen and study lead author, "If exposure to endocrine disruptors is the mechanism behind the increasing reproductive problems among young men in the Western World, this research suggests that particular attention should be paid to the use of mild analgesics [pain medication] during pregnancy, as this could be a major reason for the problems."

Your Pregnancy

What's safe when it comes to pain relief from minor aches and pains? Trying natural, medication-free methods first may be a good idea. If you have a headache, massage your face and neck to relieve any muscular tension or rest in a darkened room with a washcloth over your eyes. For sore muscles, take a relaxing shower or bath—or use your pain as an excuse for a little prenatal massage!

If your pain or injury does seem like it will require pain medication to ease, consult your doctor or midwife first, even when it comes to OTC pain killers.

"Women may want to try to reduce their analgesic [pain medication] use during pregnancy. However ... we recommend that pregnant women seek advice from their physician before using mild analgesics and in general follow the advice to use as little medicine during pregnancy as possible," advises Dr. Leffers.