Paracetamol, aspirin, and indomethacin induce endocrine disturbances in the human fetal testis capable of interfering with testicular descent.

CONTEXT: Masculinization depends on the fetal testis. Exposure of the human fetus during pregnancy to paracetamol and/or to other mild analgesics is associated with an increased risk of cryptorchidism.

OBJECTIVE

We aimed to determine whether mild analgesics disrupted the morphology and endocrine function of the human testis.

DESIGN

We used an in vitro system based on the culture of human fetal testes exposed or not to paracetamol, its metabolite N-(4-hydroxyphenyl)-arachidonoylethanolamide (AM404), aspirin, indomethacin, and ketoconazole at 10(-4) to 10(-7) M.

SETTING

The study was conducted at the University of Rennes I.

PATIENTS/

PARTICIPANTS

Human fetal testes were from pregnant women after induced abortion, between 7 and 12 weeks of gestation (GW).

MAIN OUTCOME MEASURES: Testosterone (RIA), anti-Müllerian hormone (ELISA), insulin-like factor 3 (RIA), and prostaglandin (PG) D2 and PGE2 (ELISA) were assayed in the medium. Testicular cells were counted using histology and image analysis. The possible nuclear receptor-mediated activities of the analgesics were investigated using reporter cell lines expressing estrogen, androgen, and peroxisome proliferator-activated γ receptors.

RESULTS

Indomethacin and aspirin stimulated testosterone production, particularly by the younger testes (8-9 GW vs 10-12 GW). Paracetamol, AM404, and ketoconazole decreased insulin-like factor 3 levels. Aspirin stimulated whereas ketoconazole inhibited AMH production. PGE2 levels were inhibited by paracetamol and aspirin in the 7 to 12 GW testes and by indomethacin but only in 7 to 9.86 GW testes. The inhibitory trends seen for PGD2 were not statistically significant.

CONCLUSIONS

Analgesics at concentrations relevant to human exposure cause endocrine disturbances in the fetal testis. We suggest that the fetal human testis displays slight critical age windows for sensitivity to direct exposure to aspirin, indomethacin, and paracetamol. The analgesic-induced inhibition of INSL3 may be the mechanism by which analgesics increase the risk of cryptorchidism. Greater caution is required concerning consumption of analgesics during pregnancy.