Strengthen Luteal Phase Support for the Patients With Low Serum Progesterone on the Day of Embryo Transfer in Artificial Endometrial Preparation Cycles: a Large-sample Retrospective Trial
Abstract Background: The low serum progesterone (P) on the day of frozen embryo transfer (FET) is associated with diminished pregnancy rates in artificial endometrium preparation cycles using vaginal micronized P, but it is no consensus whether the strengthened luteal phase support (LPS) for the patients with low P on the FET day in artificial cycles is beneficial. A single centric, large-sample retrospective trial was aimed to investigate the contribution of strengthened LPS to the pregnancy outcomes for the groups of low P levels on the FET day in artificial endometrium preparation cycles.Methods: Women who had undergone first artificial cycle for endometrium preparation after freeze-all in our clinic during 2016 and 2018 were classified into two groups depending on the serum P levels on the FET day, routine LPS was administered for group B (P ≥10.0ng/ml on the FET day, n=1261) and strengthened LPS (routine LPS+ im P 40mg daily) for group A (P <10.0 ng/ml on the FET day, n=1295), the primary endpoint was the live birth rate and secondary endpoints were clinical pregnancy, miscarriage and neonatal outcomes.Results: The results showed the clinical pregnancy rate in group A was lower than group B (48.4% vs 53.2%, aRR 0.81, 95% CI 0.68, 0.96), the miscarriage rate was similar between the two groups (16.0% vs 14.7%, aRR 1.09, 95%CI 0.77, 1.54). The live birth rate was slightly lower than group B (39.5% vs 43.3%, aRR 0.84, 95%CI 0.70, 1.0). The birthweights and other neonatal outcomes were found no difference between the two groups (P>0.05).Conclusions: The strengthened LPS for the section of patients of low P levels on the FET day might help to have a reasonable pregnancy outcome, although the live birth rate was slightly lower than the groups with normal serum P levels on the FET day and usage of routine LPS. Trial registration: no available.