NEW YORK (Reuters Health) - Treating high-risk pregnant women with a progesterone hormone during the second and third trimester to prevent preterm birth seems to be safe for the fetus, according to a report in Obstetrics & Gynecology. High levels of progesterone are produced by the placenta, which helps maintain the pregnancy. A drop in the levels of this hormone is thought to be one of the steps that stimulate the onset of labor.
