SERUM PROGESTERONE CONCENTRATIONS ON THE DAY AFTER HUMAN CHORIONIC-GONADOTROPIN ADMINISTRATION AND PROGESTERONE OOCYTE RATIOS PREDICT IN-VITRO FERTILIZATION-EMBRYO TRANSFER OUTCOME

Purpose: In gonadotropin-releasing hormone analogue-pretreated in vitr o fertilization-embryo transfer cycles, pregnancy rates are inversely related to serum progesterone levels on the day of administration of h uman chorionic gonadotropin. The relationship of the progesterone conc entration on other days in the periovulatory period to pregnancy rates in such cycles is little studied. We therefore retrospectively analyz ed the relationship between progesterone concentrations on the day aft er human chorionic gonadotropin and pregnancy in 114 cycles, 28 and 23 of which produced clinical and ongoing/delivered pregnancies, respect ively. To assess the effect of the extent of follicular luteinization on success, we also studied the relationship between the progesterone concentration per oocyte retrieved and pregnancy for the day of and da y after human chorionic gonadotropin. Results: Progesterone concentrat ions on the day after human chorionic gonadotropin were inversely asso ciated with clinical pregnancy by multiple logistic regression analysi s (P < 0.05). Progesterone/oocyte ratios were inversely associated wit h clinical pregnancy (P < 0.05) and ongoing/delivered pregnancy (P < 0 .02) for both the day of and the day after human chorionic gonadotropi n. Conclusion: The study results extend the window of time during whic h elevated progesterone concentration is associated with poor outcome to at least 2 days. This finding is consistent with hypothetical mecha nisms attributing the link between progesterone concentration and outc ome to either endometrial or follicle/oocyte events. The association o f lack of follicular luteinization (low progesterone per oocyte ratios ) and favorable outcome suggests a predominant effect of progesterone on follicle/oocyte quality. Further studies are needed to clarify the mechanisms underlying the association between progesterone and in vitr o fertilization-embryo transfer outcome.