Transfer of cryopreserved-thawed embryos: the natural cycle versus controlled preparation of the endometrium with gonadotropin-releasing hormone agonist and exogenous estradiol and progesterone (GEEP).

Modeled on our successful experience with oocyte donation, we present a novel, viable approach to cryopreserved-thawed embryo transfers (ETs) in women with recalcitrant ovarian dysfunction: gonadotropin-releasing hormone agonist and exogenous estradiol and progesterone (GEEP). After attainment of ovarian suppression, seven such women received physiological steroidal replacement regimens with cryopreserved-thawed ETs prospectively synchronized with the 4th day of progesterone administration and two conceived. These GEEP cycles and cryopreserved-thawed ETs were prospectively compared with cryopreserved-thawed ETs performed on the 4th day of exposure to progesterone in 20 spontaneous cycles and in 5 oocyte donation-steroidal replacement cycles. Pregnancies occurred after three cryopreserved-thawed ETs in each of these groups. We conclude that GEEP constitutes a successful preparation for cryopreserved-thawed ETs, at the least, in women with ovulatory dysfunction.