Plasma concentrations of oestrone, oestradiol, oestriol and progesterone during mechanical stretch-induced abortion at mid-trimester.

Plasma levels of unconjugated oestrone, oestradiol, oestriol and progesterone were serially studied in six uncomplicated patients in the mid-trimester of pregnancy before and during abortion induced by purely mechanical stretching of the uterus by laminaria and rubber balloon. Variability of these hormonal levels among patients was significant before the treatment. In four cases where the fetus was aborted alive, the plasma value of these hormones remained at a high level during the treatment with the exception of oestriol level in one case. In two early mid-trimester cases the fetus died during the treatment and plasma oestriol dropped significantly, while the level of the other hormones remained raised until fetal delivery. In these two cases the apparent onset of labour was noted before fetal death. It was concluded that the onset and progress of labour by mechanical stretching of the uterus is probably unrelated to the steroid hormones estimated in the present study.