Efficacy of GnRH agonist trigger in women having history of follicular-endometrial asynchrony with clomiphene/IUI cycles in unexplained infertility.

Purpose: An alternative option to human chorionic gonadotropin (hCG) is GnRH agonist (GnRH-a) for ovulation trigger in intrauterine insemination (IUI) cycles. This study aims to compare the efficacy of GnRH-a with hCG in women with history of follicular-endometrial asynchrony after clomiphene in IUI cycles.

Methods: This prospective observational study recruited 631 women with unexplained infertility and follicular-endometrial asynchrony (follicle ≥ 18 mm, endometrial thickness (ET) < 7 mm) in previous two failed clomiphene/IUI cycles.

Congenital malformations among babies born following letrozole or clomiphene for infertility treatment.

Context: Clomiphene citrate (CC) is the first line drug for ovulation induction but because of its peripheral antiestrogenic effect, letrozole was introduced as the 2nd line drug. It lacks the peripheral antiestrogenic effect and is associated with similar or even higher pregnancy rates. Since letrozole is a drug for breast cancer, its use for the purpose of ovulation induction became controversial in the light of studies indicating an increased incidence of congenital malformations.