Frozen-thawed embryo transfer: does the addition of low-dose choriogonadotropin alfa to progesterone in the luteal phase of artificial cycles improve the endometrium and increase the chances of pregnancy?

Objective: Primary: To evaluate the effect of low doses of recombinant hCG (choriogonadotropin alfa) in the luteal phase of frozen-thawed embryo transfers (FET) of artificial cycles on the chances of pregnancy in patients aged ≤38years. Secondary: To assess the chances of pregnancy in the FET groups of artificial cycles using micronized vaginal progesterone (VP) versus injectable intramuscular progesterone (IMP) and the chances of pregnancy in type-1 embryo transfers (two top embryos).

Methods: This retrospective cohort study included 122 cycles of FET and compared two groups of patients aged 38 years or younger, one given hCG in the luteal phase and one not administered hCG.

Results: The clinical pregnancy rates (CPR) in the control and hCG groups were 45% and 45.16%, respectively (p=0.9999). The live birth rates (LBR) were 33.33% and 32.25%, respectively, (p=0.99909). The CPR in the VP group (83 patients) was 46.89% versus 41.02% in the IMP group, (p=0.5459). The LBR was 33.73% in the VP group and 30.76% in the IMP group (39 patients), (p=0.7559).

Conclusions: The CPR and LBR of patients undergoing FET in groups prescribed and not prescribed low doses of recombinant hCG were similar. No significant difference was found between patients given VP or IMP.