Fifty women with previous diagnosis of inadequate luteal phase and
threatened abortion underwent a prospective, randomized, double-blind study in one medical center carried out with a parallel trial. The primary objective was to establish the effects of vaginal
progesterone (
Crinone 8%) in reducing both
pain and uterine contractions (UCs). The gel with or without (placebo) vaginal
progesterone was administered once a day since the diagnosis of
threatened abortion and for 5 days. The efficacy on
pain symptom amelioration was evaluated by a 5-score intensity gradation, while the UCs were evaluated by ultrasound. The secondary objective of the study was to evaluate the outcome of the pregnancies. The use of
progesterone was effective both on
pain relief and on the frequency of the UCs that decreased after 5 days of vaginal
progesterone administration (P < 0.005). The evaluation of the ongoing pregnancy and
spontaneous abortion in both study groups after 60 days showed that 4 patients of group A and 8 patients of group B miscarried (P < 0.05). In conclusion, patients with
threatened abortion benefit from vaginal
progesterone by a reduction of UCs and
pain. The use of vaginal
progesterone improved the outcome of pregnancies complicated by
threatened abortion and previous diagnosis of inadequate luteal phase.