Prolactin changes in maternal plasma following termination by vacuum curettage and the effect of bromocriptine treatment on these changes.

To study the prolactin secretion and its dependence on the sex steroid concentrations during pregnancy, we measured the circulating prolactin, oestradiol-17 beta, progesterone and testosterone levels following vacuum curettage for termination of early pregnancy in 10 normal women and in 10 other women whose prolactin levels had been lowered with bromocriptine treatment. In normal women, anaesthesia and vacuum curettage led to consistent and significant (p < 0.01) rises in prolactin levels between 0.5 to 5 hours after abortion. This increase was not seen in women treated with bromocriptine whose prolactin level of 8.6 +/- 1.4 ng/ml (mean +/- SE) before abortion was lower than that of 29.6 +/- 6.4 ng/ml found in normal women. The oestradiol and progesterone concentrations decreased rapidly but similarly in both groups of patients following the evacuation of the uterus, whereas the testosterone level did not change significantly. These results indicate: (i) vacuum curettage stimulates prolactin secretion, (ii) the prolactin-stimulating effect of stress appears to be stronger than the prolactin-suppressing effect of postabortal oestradiol and/or progesterone declines, and (iii) bromocriptine blocks the stress-induced prolactin rise.