PIP: The authors have assayed plasma prolactin, estradiol, and progesterone in 30 women undergoing voluntary termination of pregnancy by vacuum aspiration under general anesthesia, in order to study in more detail, the correlations between PRL and sexual steroid hormones during the 1st trimester of pregnancy. Results obtained in the various plasma samples taken at intervals until 5 hours following vacuum curettage show a marked increase in PRL in the control group, from 80 to 3000 ng/ml, with a progressive decrease at the 5th hour. A much slighter increase was found in patients treated with Metergoline, compared to that of the former group, with an increase from 90 to 180 ng/ml, while in those patients treated with Sulpiride, the maximum increase ranges between 160-340 ng/ml. The plasma level of E2 decreased significantly and progressively after the sample taken at 30 minutes, with a similar pattern in the 3 groups. The plasma progesterone concentrations showed a similar patern in the groups treated with Metergoline and Sulpiride, with a progessive decrease in comparison with basal levels. On the contrary, the increase was found in the control groups, in comparison with basal values, in samples taken at 30 minutes, with a slow, progressive decrease in subsequent samples. It can be concluded from these results that the stress caused by vacuum curettage under anesthesia causes a stronger stimulation of PRL than the inhibition of this hormone caused by the fall of E2 and P concentrations; the inhibitory effect of Metergoline on PRL did not completely annul the effect of anesthesia and vacuum curettage on PRL production. While E2 shows a progressive decrease compared to basal values, with a similar behavior in all 3 groups, P, which decreases in the 2 groups that have undergone pharmacological treatment, shows a peak increase in the sample taken at 30 minutes. THe significance of this observation is not yet clear, and will be the subject of further study. (author's modified)