P-620 Hormone replacement therapy with GnRH agonist pretreatment improves pregnancy outcomes in patients with previous intrauterine adhesions
Authors: Mo M , Zheng Q , Xu S , Zhang H , Geng Q , Zeng Y 
Published: June 2022

Abstract

Study question
Is there an optimal endometrial preparation protocol of frozen-thawed embryo transfer (FET) for patients with history of intrauterine adhesions (IUAs)?

Summary answer
Hormone replacement therapy with GnRH agonist pretreatment (HRT+GnRHa) is superior to conventional HRT protocol to improve pregnancy outcomes in patients with IUAs.

What is known already
FET follow hysteroscopic adhesiolysis or therapeutic treatment is being widely adopted in patients with IUAs. Proper endometrial preparation plays a key role to maximize IVF success rate and improve pregnancy results. However, it remains unclear whether there is an optimal endometrial preparation protocol for patients with history of IUAs.

Study design, size, duration
This was a retrospective cohort study of 1002 FET cycles with history IUAs in our fertility center between January 2015 to December 2020. The study was approved by the hospital's Ethics Committee.

Participants/materials, setting, methods
Eight hundred and forty-two conventional HRT cycles and 160 HRT+GnRHa cycles met the inclusion criteria were enrolled. Pregnancy outcomes were compared between the two groups. Logistic regression analysis was performed to adjust for important confounders. P &lt; 0.05 was considered statistically significant.

Main results and the role of chance
The HRT+GnRHa group was associated with higher cycle rank (1.79 vs 2.17, P =0.026) and longer infertility duration (3.04 vs 3.69, P =0.000) compared with conventional HRT group. While the latter had a higher proportion of blastocyst embryo transferred (P =0.024). There were no statistically significant differences regarding the parental age at oocyte retrieval, body mass index (BMI), number of total embryos transferred and top embryo transferred, proportion of nulliparity, indication of IVF treatment and fertilization method, and endometrial thickness. Logistic regression indicated that after controlling for potential confounders, the HRT+GnRHa group achieved higher incidence of clinical pregnancy (aOR 1.474, 95% CI: 1.002-2.170, P =0.049), ongoing pregnancy (aOR 1.823, 95% CI: 1.207-2.753, P =0.004), and live birth (aOR 1.975, 95% CI: 1.306-2.988, P =0.000) than the conventional HRT group. The miscarriage rate was comparable between the two groups (aOR 0.613, 95% CI: 0.293-1.283, P =0.194). Our results suggested that HRT+GnRHa is over conventional HRT protocol to improve pregnancy outcomes of patients with previous IUAs.

Limitations, reasons for caution
The primary limitation of this study was its retrospective nature, and it was difficult to distinguish some confounding factors. Besides, there was no grading of IUA severity as most adhesion separation surgeries were not performed in our hospital, and the detailed medical history was not available.

Wider implications of the findings
Our study offers evidence for the superiority of HRT with GnRH-a pretreatment to conventional HRT protocol in improving the pregnancy prognosis of patients with previous IUAs. Our finding deserves further confirmation in clinical practice.

Trial registration number
2018YFC1003900/2018YFC1003904, SZSM201502035