WEDNESDAY, Nov. 17 (HealthDay News) -- Use of over-the-counter pain medication during pregnancy -- particularly in the second trimester -- may increase the risk of congenital cryptorchidism, a finding which may explain recent marked increases in the incidence of this condition, according to research published online Nov. 8 in Human Reproduction.
David Møbjerg Kristensen, of the University of Copenhagen in Denmark, and colleagues conducted a prospective birth cohort study of 2,297 Danish and Finnish pregnant women to investigate the potential endocrine-disrupting properties of mild analgesics ingested during pregnancy, using congenital cryptorchidism in their male offspring as a measured outcome. The researchers also undertook a rat study of the effect of mild analgesics on anogenital distance (AGD) after intrauterine exposure.
The researchers found no significant association in the Finnish cohort (studied by questionnaire only), postulated to be because many women did not consider these analgesics to be "medications." In the Danish cohort (all completed a questionnaire and some a follow-up telephone interview), there was a dose-dependent association of mild analgesic intake with congenital cryptorchidism, especially in the second trimester; ibuprofen and aspirin approximately quadrupled the risk of cryptorchidism. Simultaneous use of more than one painkiller during the second trimester increased the risk 16-fold. In the rats, intrauterine exposure to mild analgesics was associated with a decrease in AGD.
"Collectively, the results [point] to a scenario where the use of mild analgesic medicine has a possible effect on fetal development with implications for later reproductive health," the authors write. "Therefore, more investigations are urgently needed and we will for our part continue to follow the boys in our cohorts, who currently are entering puberty."
The Novo Nordisk Foundation provided some funding for the study.