Acute changes in serum prolactin concentration have no effect on the secretion of progesterone, estradiol, or chorionic gonadotropin during early pregnancy.

ABSTRACT

The relationship between the circulating levels of PRL and progesterone, estadiol, and hCG was studied during the first half of pregnancy. The subjects were 1) nine hyperprolactinemic women who conceived during bromocriptine treatment and whose treatment was discontinued at the 7th to 11th weeks of gestation; 2) five women given chlorpromazine during the 11th to 12th weeks of pregnancy; and 3) four pregnant women give bromocriptine during the 11th to 12th weeks of pregnancy. In group 1, discontinuation of bromocriptine resulted in elevated serum PRL concentrations, but this was not associated with any significant changes in the circulating levels of estradiol, progesterone, and hCG. In group 2, chlorpromazine increased the serum PRL concentration but had no effect on serum estradiol, progesterone, or hCG concentrations. In group 3, bromocriptine decreased the serum PRL level, but this was not associated with any alteration in steroid hormone or hCG levels. Our results show that during early pregnancy acute moderate changes in the serum PRL concentration do not affect placental hormone secretion.