What is estriol?

Estriol is a form of estrogen that is predominantly produced during pregnancy. It is one of the three main types of estrogen, along with estradiol and estrone. Estriol is synthesized mainly by the placenta from precursors provided by the fetal adrenal glands and liver, playing a critical role in maintaining pregnancy and supporting fetal development.

In the context of pregnancy, estriol levels are often monitored as they can provide insights into the health of the fetus and the placenta. Increased levels of estriol are generally associated with a healthy pregnancy, while lower levels may indicate potential complications.

The other hormonal options listed do not accurately describe estriol's role or type. Testosterone and progesterone are crucial hormones during pregnancy, but they are not classified as estrogens. Cortisol, while important for various body functions, also does not belong to the estrogen category. Thus, understanding estriol's specific identity as a form of estrogen emphasizes its significance in reproductive health during pregnancy.