The effect of progesterone on fetal and placental development in normal and protein-energy-restricted rats.

Maternal protein-energy restriction (25% of the ad libitum intake) during the first 10 days of pregnancy resulted in severely altered fetal growth rates. Fetal development was assessed by body weight, brain weight, brain DNA, and brain protein content on fetal days 16, 18, 20 and at term. The individual placentas were also examined (weight, DNA and protein content) on each of these fetal days. Progesterone was administered commencing with day 3 of pregnancy until the day Caesarian section was done, in an attempt to rehabilitate placental development. This treatment did not improve placental development on fetal days 16 or 18. However, fetal development was significantly improved on day 16 and day 20, as compared to the dietary-restricted group without progesterone.