Background: At present, progesterone administration is widely used. There is no agreement on whether estradiol (E2) addition should be supplement to progesterone (P) as luteal phase support (LPS). The present meta-analysis was conducted to clarify whether E2 supplementation as LPS has beneficial effect on the clinical outcome after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

Methods: MEDLINE, Google Scholar and the Cochrane Library were searched from the incipiency until May 2019. The primary outcome was clinical pregnancy rate (CPR), ongoing pregnancy rate (ongoing PR), embryo implantation rate (IR), spontaneous abortion rate (AR). Thirteen, seven, four, and ten studies were included while evaluating the effect of E2 supplementation on CPR, ongoing PR, IR, and AR, respectively.

Results: The results showed that E2+P group had significant higher CPR (OR=1.39, P=0.0001) and ongoing PR (OR=1.36, P=0.01) than that of P-only group. No significant differences were found between IR (P=0.47) and AR (P=0.43) between E2+P and P- only groups. Subgroup analysis of the GnRH-a/ant showed that GnRH-a protocol group had a significant higher CPR (OR=1.37, P=0.02) and ongoing PR (OR=1.76, P=0.002) with E2+P, whereas GnRH-ant protocol group had no difference in CPR (P=0.6), ongoing PR (P=0.44), IR (P=0.18), and AR (P=0.87) among E2+P and P- only groups.

Conclusions: The results suggest that E2 supplementation as LPS has beneficial effect on the clinical outcomes only during cycles with GnRH-a protocol.

Luteal phase support; Estradiol; IVF; ICSI; Ovarian stimulation