Estriol is primarily produced by which organ?

Estriol is primarily produced by the placenta during pregnancy. It is an estrogen that plays a vital role in maintaining pregnancy and supporting fetal development. The placenta synthesizes estriol by converting precursor steroids, largely from the mother's hormones and the fetal adrenal glands. This production peaks during the third trimester, making estriol a significant indicator of fetal well-being and gestational health.

While the ovaries can produce estrogen, including estriol, this typically occurs outside of pregnancy and at much lower levels compared to the placenta. Additionally, the testes are responsible for producing male hormones and do not significantly contribute to estriol levels. The adrenal glands also produce various hormones, but they primarily generate androgens and corticosteroids rather than estrogens like estriol. Therefore, the placenta is the key organ associated with estriol production, highlighting its crucial role in pregnancy-related hormonal regulation.