A study published on October 14, 2010 in the Oxford journal, Human Reproduction, shows a link between mothers who took painkillers such as acetaminophen, aspirin and ibuprofen during pregnancy, and an increase in future reproductive problems in their male children. Reuters news in London also published a November 9, 2010 article on this study and stated that women who took a combination of more than one of these drugs during pregnancy had an increased risk of giving birth to sons with undescended testicles.
The study showed that the condition of undescended testicles, known as cryptorchidism, is linked to later creating poor semen quality and a greater risk of testicular cancer in the male's adult life. The article noted that this could explain the sharp increase over the past few decades in male reproductive disorders.
Lead researcher Henrik Leffers of Rigshospitalet, the national hospital of Denmark, commented, "Women may want to try to reduce their analgesic use during pregnancy. However, as biologists this is not something we can advise women about. So we recommend that pregnant women seek advice from their physician." According to Leffers' team, which consisted of researchers from Finland, Denmark and France, more than half of pregnant women in Western countries report taking mild analgesics.
The study was conducted by questioning 834 women in Denmark and 1,463 in Finland about their use of the painkillers during pregnancy. Their male babies were then examined to see if there were any possible reproductive issues related to undescended testicles. Additional study work was done on rats which showed long term effects of the usage of these drugs leading to insufficient supplies of the male hormone testosterone during a critical period of gestation when the male organs are forming.
In the human part of the study, the results showed that women who took more than one of these painkillers simultaneously had a seven-fold increased risk of giving birth to sons with this form of reproductive problem as compared with women who took nothing.
Neal Patel of the Royal Pharmaceutical Society commented in the Reuters article, "This study adds to the body of evidence about the effect of medicines on fetal development. However, due to study limitations, further research is needed to draw firm conclusions about the effect of painkillers on male fertility."
In summing up the impact that these findings could have on the human population, lead researchers Leffers commented to Reuters, "Although we should be cautious, the use of mild analgesics constitutes by far the largest exposure to endocrine disruptors among pregnant women, and use of these compounds is at present the best suggestion for an exposure that can affect a large proportion of the human population."