DOES THE PROGESTERONE TO MATURE OOCYTE INDEX HAVE A PREDICTIVE VALUE FOR THE PREGNANCY OUTCOMES IN FRESH INTRACYTOPLASMIC SPERM INJECTION (ICSI) CYCLES?

The significance of premature luteinization (PL) and its implications on assisted reproductive technology outcomes is a matter of continued debate. Many definitions based on heterogeneous cut-off values were proposed to predict the impact of PL on ICSI cycle outcomes such as isolated progesterone (P) level, progesterone/estradiol ratio, and recently progesterone to oocyte ratio. To compare the predictive value of progesterone to mature oocyte index (PMOI), and isolated P level on the day of ovulation triggering for pregnancy outcomes in fresh GnRH antagonist ICSI cycles. This is a retrospective cohort study including infertile women who underwent their first or second fresh day-3 embryo transfer after GnRH antagonist ICSI cycles between January 2017 and April 2019 in a single university-affiliated IVF center. PMOI was calculated by dividing serum P (ng/ml) by the number of mature oocytes retrieved. A receiver operating curve (ROC) analysis was performed to detect the predictability of P and PMOI for pregnancy outcomes. Multivariate regression analysis models were used to examine the impact of PL parameters on the likelihood of pregnancy. We did a subset analysis for patients based on the percentiles of P and PMOI levels (≥75th and < 75th percentiles). A total of 402 ICSI cycles matched our eligibility criteria during this period. The area under the curve (AUC) was higher for PMOI (0.68) than the isolated P level (0.59). In the unadjusted univariate analysis, both P and PMOI showed a significant effect on the ongoing pregnancy rate (p=0.031, p <0.001 for P and PMOI, respectively). PMOI demonstrated a significant predictive potential for lower ongoing pregnancy rate (aOR: 0.034, 95% CI 0.001-0.885, p< 0.04) when adjusted to cycle covariates (age, body mass index, antral follicle count, anti-Müllerian Hormone, gonadotrophins dose, stimulation days, peak estradiol, and embryos transferred). On the contrary, the negative impact of P level on pregnancy rate was no longer evident (aOR: 0.542, 95% CI 0.284-1.036, p=0.064). Patients with high P (≥75th percentile; 1.29ng/ml) and low PMOI (< 75th percentile; 0.143) had higher number of mature oocytes (16.6±4.8 vs. 7.4±4.8, P< 0.001), implantation (20.8 vs. 8.5%, p< 0.001) and ongoing pregnancy rates (42.9 vs. 17.1 %, p< 0.001) when compared to high P and high PMOI. Moreover, no significant difference in implantation and pregnancy rates was found between patients with high PMOI and high P and those with high PMOI but normal P (8.5 vs. 10.3%, p< 0.7 and 17.1 vs. 17.9%, p< 0.9, respectively). PMOI has a better prognostic value than P alone in the prediction of pregnancy outcomes in ICSI cycles. The negative impact of high PMOI on cycle outcomes seems not to be affected by HP.