Background: The most widely used regimen for induction of medical abortion involves the use of oral or vaginal misoprostol. Indeed, the use of mifepristone (antiprogesterone drug) combined with prostaglandins has resulted in increased success in induction of abortion. The next logical step would be to explore the use of anti- estrogenic agents combined with misoprostol.
Aim: This trial was performed to evaluate the effect of letrozole combined with misoprostol on induction of abortion compared with usage of misoprostol alone.
Methods: The subject population was randomly divided into 2 groups: Group A: 99 women (underwent induction of abortion by letrozole 7.5 mg (Femara) once daily for 3 days, followed by misoprostol 400 mcg vaginally every 4h up to a maximum of five doses per day) Group B: 99 women (underwent induction of abortion by misoprostol 400 (Misotac) mcg vaginally every 4h up to five doses per day).
Results: The results of the study demonstrated no clinical significant difference between complete abortion rate of 78% within 24h in women diagnosed as missed abortion less than 13 weeks gestational age with the sequential regimen of letrozole and misoprostol, compared to 74% complete abortions using misoprostol alone. There was no significant difference in the induction to abortion interval (M: 8.2h & 9.4h respectively), also there was no difference concerning the side effects.
Conclusions: These results indicate that letrozole didn't show a significant improvement in the efficacy of misoprostol in induction of first trimester abortion.