A comparison of letrozole to gonadotropins for ovulation induction in subjects with advanced maternal age: a retrospective pilot study.

This retrospective study was performed to compare the success of ovulation induction using letrozole versus gonadotropins in women at least 38 years of age, with normal ovarian reserve. Pregnancy and clinical pregnancy rates (PR) were statistically higher with gonadotropin than with letrozole stimulation.

A comparison of letrozole to gonadotropins for ovulation induction, in subjects who failed to conceive with clomiphene citrate.

Objective: To compare pregnancy rates (PR) for letrozole and gonadotropins in individuals who failed to conceive with clomiphene citrate (CC).

Design: Retrospective cohort study.

Setting: University reproductive center.

Successful pregnancies after transplantation of frozen-thawed mouse ovaries into chimeric mice that received lethal-dose radiation.

Objective: To study whether fecundity was recovered in mice into which umbilical cord blood cells (UCBCs) were transfused after lethal-dose radiation, followed by transplantation of frozen-thawed ovaries.

Design: Prospective basic research study.

Setting: Academic research laboratory.