Changes in the serum levels of human chorionic gonadotropin and the pulsatility index of uterine arteries during conservative management of retained adherent placenta.

OBJECTIVE: Our purpose was to assess the natural course of retained adherent placenta at term.

METHODS: Five cases of retained adherent placenta, clinically diagnosed as placenta accreta, were managed conservatively without methotrexate. To assess the biochemical and circulatory changes in the placentas, the serum levels of human chorionic gonadotropin (hCG) and the pulsatility index (PI) of the uterine arteries were examined.

RESULTS: Serum hCG levels decreased spontaneously; the half-life of serum hCG was calculated to be 5.2 +/- 0.26 days (mean +/- SEM). The PI of the uterine arteries remained at the level of pregnant women at term, but became elevated within a few days after the removal of the placentas. All the placentas were successfully removed transvaginally within 6 weeks postpartum.

CONCLUSIONS: The changes in serum hCG observed in this study indicated the spontaneous degeneration of the placenta. Such changes might be similar to those reported to occur during treatment with methotrexate. In contrast, the PI of the uterine arteries did not reflect degeneration of the placenta.