Effects of estradiol supplementation during the luteal phase of in vitro fertilization cycles: a meta-analysis.

OBJECTIVE

To clarify whether adding E(2) to standard luteal P supplementation is beneficial both in GnRH agonist and antagonist IVF cycles.

DESIGN

Meta-analysis of nine randomized controlled trials.

SETTING

University hospital center for reproductive medicine and IVF.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Clinical pregnancy rate (PR) per patient, clinical PR per embryo transfer (ET), implantation rate, ongoing PR per patient, clinical abortion rate, and ectopic PR.

RESULT(S): There were no statistically significant differences between E(2)+P versus P-only group regarding overall IVF outcomes. From seven studies including GnRH agonist cycles, no statistical significant differences were found between the two groups in clinical PR per patient (relative risk [RR] 1.32, 95% confidence interval [CI] 0.79-2.19), clinical PR per ET (RR 1.83, 95% CI 0.96-3.49), implantation rate (RR 1.20, 95% CI 0.34-4.21), ongoing PR per patient (RR 1.34, 95% CI 0.37-4.82), clinical abortion rate (RR 1.05, 95% CI 0.48-2.28), and ectopic PR (RR 0.53, 95% CI 0.07-4.10). Clinical PR per patient (RR 0.94, 95% CI 0.62-1.42) and ongoing PR per patient (RR 1.09, 95% CI 0.79-1.50) from three studies including GnRH antagonist cycles only were all similar between the two groups.

CONCLUSION(S): The combined data presented in this meta-analysis suggest that the addition of E(2) to P for luteal phase support does not improve IVF outcomes in GnRH agonist and antagonist cycles. However, the authors feel that there is an obvious need for further large-scale studies regarding GnRH antagonist cycles.