Analgesic exposure during pregnancy may affect aspects of fetal gonadal development that are targeted by endocrine disruptors.
We investigated whether therapeutically relevant doses of acetaminophen and ibuprofen affect germ cell (GC) development in human fetal testes/ovaries using
and xenograft approaches.
First-trimester human fetal testes/ovaries were cultured and exposed to acetaminophen or ibuprofen (7 d). Second-trimester human fetal testes were xenografted into mice and exposed to acetaminophen (1 or 7 d), or ibuprofen (7 d). To determine mechanism of action, a human GC tumor–derived cell line (NTera2) exhibiting fetal GC characteristics was used in addition to
and
rat models.
Gonocyte (TFAP2C
) number was reduced relative to controls in first-trimester human fetal testes exposed in vitro to acetaminophen (-28%) or ibuprofen (-22%) and also in ovaries exposed to acetaminophen (-43%) or ibuprofen (-49%). Acetaminophen exposure reduced gonocyte number by 17% and 30% in xenografted second-trimester human fetal testes after treatment of host mice for 1 or 7 d, respectively. NTera2 cell number was reduced following exposure to either analgesic or prostaglandin E
(PGE
) receptor antagonists, whereas PGE
agonists prevented acetaminophen-induced reduction in NTera2 cell number. Expression of GC pluripotency genes, and genes that regulate DNA/histone methylation, also differed from controls following analgesic and PGE
receptor antagonist exposures. Gene expression changes were observed in rat fetal testis/ovary cultures and after in vivo acetaminophen exposure of pregnant rats. For example, expression of the epigenetic regulator
, was increased following exposure to acetaminophen in human NTera2 cells, rat fetal testis/ovary cultures, and in fetal testes and ovaries after in vivo exposure of pregnant rats, indicating translatability across experimental models and species.
Our results demonstrate evidence of PGE
-mediated effects of acetaminophen and ibuprofen on GC/NTera2 cells, which raises concerns about analgesic use during human pregnancy that warrant further investigation. https://doi.org/10.1289/EHP2307....

Effects of Exposure to Acetaminophen and Ibuprofen on Fetal Germ Cell Development in Both Sexes in Rodent and Human Using Multiple Experimental Systems

10.1289/EHP2307