December 7th, 2021

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Pregnancy Outcomes for Frozen-Thawed Day 5 Blastocyst Transferred After Different Duration of Progesterone Supplementation in Hormone Replacement Therapy Cycle
Authors:  Yanhong Mao, M.M., Zhidan Hong, M.M., Chun Zhou, M.D., Bo Zhang, M.M., Ming Zhang, M.D., and Ling Ma, M.D.
  OBJECTIVE: To study the differences in clinical out-comes between frozen-thawed blastocyst transfer (FET) on the 6th day and 7th day of progesterone supplementation in hormone replacement treatment (HRT) cycle.

STUDY DESIGN: A retrospective cohort study was designed. 446 patients who received HRT protocol to prepare the endometrium for FET of day 5 blastocysts were enrolled. In group A (n=266), day 5 blastocysts were transferred on the 7th day of progesterone supplementation, and in group B (n=180), day 5 blastocysts were transferred on the 6th day of progesterone supplementation.

RESULTS: There was no significant difference in implantation rate (48.00% vs. 46.71%, p>0.05) and clinical pregnancy rate (62.78% and 58.33%, p>0.05) between the 2 groups. However, significant difference was observed in miscarriage rate, specifically, 9.60% in group A and 25.71% in group B (p<0.001). The live birth rate (LBR) in group A was significantly higher than in group B (56.77% vs. 43.33%, p=0.005). By multivariable logistic regression adjusted for confounding factors, it was found that the LBR significantly correlated with the duration of progesterone supplementation before FET (aOR= 1.694, 95% CI 1.128–2.544, p=0.011).

CONCLUSION: The miscarriage rate decreased and live birth rate increased for FET of day 5 blastocysts undertaken on the 7th day of progesterone supplementation as compared with that on the 6th day.
Keywords:  endometrium; infertility, IVF-ICSI outcome, frozen embryo transfer; live birth rate; miscarriage rate; progesterone supplementation; receptivity; replacement hormone therapy cycle; window of implantation
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