Prolactin and human placental lactogen changes in maternal serum and amniotic fluid in midtrimester induced abortions

Abstract

Prolactin (hPRL) and human placental lactogen (hPL) concentrations in maternal serum and amniotic fluid were serially determined in 19 patients undergoing midtrimester elective abortion. Two subgroups were studied: Group 1 (10 patients) received 40 mg. of intra-amniotic prostaglandin F2α (PGF2α); in Group 2 (nine patients), 200 ml. of 20 per cent sodium chloride was instilled in the amniotic cavity. Maternal serum samples were serially obtained for 24 hours after induction of abortion by either abortifacient. Serial anmiotic fluid samples were obtained in Group 1 for the first seven hours after induction of abortion. The time from induction of abortion to fetal death (IDT) as well as the induction-abortion time (IAT) were recorded in all cases. Maternal serum hPL values declined significantly within one and one half hour from the induction of abortion. At six hours, a decline of more than 50 per cent of the original hPL value occurred in both groups. Prolactin in maternal serum did not show significant changes until six hours after induction. In Group 1, a significant drop of 40.5 per cent occurred at this time. In Group 2, a similiar declining trend was apparent, but this did not reach statistical significance until 12 hours after induction. In the amniotic fluid, no significant change in the hPRL values was noticed throughout the observation time. Amniotic fluid hPL did show a rising trend, ranging to between 41.1 and 79.4 per cent above the base-line value. However, this change was not statistically significant. The decrease in maternal serum hPRL following the more rapid fall in hPL in both study groups indicates a close dependency of hPRL levels on the intact functions of the fetoplacental unit. Changes in the amniotic content of these lactogenic hormones appear to be independent of the respective changes of these hormones in maternal serum.