Serum progesterone concentration on day of embryo transfer in donor oocyte cycles

To evaluate the association between serum progesterone (P) levels on the day of embryo transfer (ET) and pregnancy rates in fresh donor IVF/ICSI cycles.

Fresh donor cycles with day 3 ET from 10/2007 to 8/2012 were included (n = 229). Most cycles (93 %) were programmed with a gonadotropin releasing hormone (GnRH) agonist; oral, vaginal or transdermal estradiol was used for endometrial priming, and intramuscular P was used for luteal support (50-100 mg/day). Recipient P levels were measured at ET, and P dose was increased by 50-100 % if <20 ng/mL per clinic practice. The main outcome measure was rate of live birth (> = 24 weeks gestational age). Generalized estimating equations were used to account for multiple cycles from the same recipient, adjusted a priori for recipient and donor age.

Mean recipient serum P at ET was 25.5 ± 10.1 ng/mL. Recipients with P < 20 ng/mL at ET, despite P dose increases after ET, were less likely to achieve clinical pregnancy (RR = 0.75, 95 % CI = 0.60-0.94, p = 0.01) and live birth (RR = 0.77, 95 % CI = 0.60-0.98, p = 0.04), as compared to those with P ≥ 20 ng/mL. P dose increases were more often required in overweight and obese recipients.

Serum P levels on the day of ET in fresh donor IVF/ICSI cycles were positively correlated with clinical pregnancy and live birth rates. An increase in P dose after ET was insufficient to rescue pregnancy rates. Overweight and obese recipients may require higher initial doses of P supplementation. Future research is needed to define optimal serum P at ET and the interventions to achieve this target.