Gonadotropin Releasing Hormone Agonists Combined with Hormone Replacement Therapy Significantly Improves Reproductive Outcomes for Patients with Thin Endometrium and Intramural Fibroids in Frozen Embryo Transfer Cycles.

BACKGROUND

Both intramural myomas and thin endometrium exert a detrimental influence on the outcomes of assisted reproductive technology (ART). The downregulation of gonadotropin releasing hormone agonists (GnRH-a) is regarded as an effective approach to reducing the size of intramural fibroids and enhancing endometrial receptivity. Consequently, we conducted this study to assess whether the GnRH-a combined with hormone replacement therapy (GnRH-a-HRT) can improve reproductive outcomes in frozen embryo transfer cycles for patients with a thin endometrium (≤7 mm) and intramural fibroids.

METHODS

This retrospective cohort study encompassed 360 patients who underwent frozen embryo transfer following in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles. Patients were stratified into three groups based on the endometrial preparation protocol: the natural cycle (NC) group (n=96), the hormone replacement therapy (HRT) group (n=180), and the GnRH-a-HRT group (n=84). The live birth rate (LBR) was designated as the primary outcome, while clinical pregnancy rate (CPR), miscarriage rate, and ectopic pregnancy rate were classified as secondary outcomes.

RESULTS

The LBR and CPR in the GnRH-a-HRT group were significantly higher than those in both the HRT group and the NC group (both P < 0.0001). A logistic regression model indicated that the LBR was significantly higher in the GnRH-a-HRT group compared to both the HRT group (odds ratio, 0.269; 95% confidence interval, 0.114-0.637; P = 0.003) and the NC group (odds ratio, 0.524; 95% confidence interval, 0.457-0.956; P = 0.023). Subgroup analyses based on the number and dimension of fibroids demonstrate the positive efficacy of the GnRH-a-HRT regimen.

CONCLUSION

Compared to NC and HRT protocol, improved reproductive outcomes were observed in the GnRH-a-HRT group. These findings provide valuable insights for exploration of the underlying mechanisms by which the GnRH-a-HRT protocol enhances reproductive outcomes in patients of thin endometrium with intramural fibroids.