This study compares two different methods to prepare the uterine lining of recipients for implantation in cycles using donor eggs. The study method requires less time than the standard method.

It is hypothesized that both methods would be suitable for use in egg donor cycles.

Currently a combination of medications is used to prepare the uterine lining of recipients for implantation in egg donor cycles. The protocol used most commonly is as follows: Initially the individual's own pituitary-ovarian system is suppressed using a GnRH agonist so there are not conflicting signals sent to the uterus. This is followed by hormonal medication identical to what is secreted by the ovaries to prepare the uterine lining for subsequent embryo transfer in donor egg cycles.This preparation typically takes a minimum of four weeks.

This study will compare a different medication, a GnRh antagonist (which is commonly used in IVF) to suppress an individual's system during the preparation of the uterine lining. This protocol would generally take only two weeks to prepare the uterine lining.

Inclusion Criteria:

• recipients awaiting egg donation
• some ovarian function
• normal endometrial cavity

Exclusion Criteria:

• submucosal myoma
• myoma(s) greater than 4 centimeters
• endometrial polyp
• DES exposure
• documented recalcitrant thin endometrium ( <7 mm)
• untreated vulvovaginitis
• active pelvic infection
• endometrial cancer or suspected/known hormonally sensitive cancers
• breast cancer
• thromboembolic disease
• cerebrovascular or coronary heart disease
• diabetes mellitus
• hepatic tumors or active liver disease
• severe hypertension
• headaches with neurologic disease
• cholestatic disease
• heavy smoking over age 35