New research offers hope for better pregnancy outcomes in patients with adenomyosis undergoing assisted reproductive treatments

Adenomyosis is associated with lower live birth rates in those undergoing assisted reproductive technology protocols. While pre-treatment with gonadotropin-releasing hormone analogue (GnRHa) before embryo transfer appears to improve outcomes, results have been inconsistent. Now, researchers from China have tackled this uncertainty through a retrospective cohort study and a meta-analysis of existing literature, revealing that GnRHa pre-treatment is associated with significantly higher live birth rates.

Adenomyosis, a condition that affects more than one in five women worldwide, results in the inner lining of the uterus growing into the surrounding muscular wall. Beyond the pain and discomfort, adenomyosis also creates serious challenges for women trying to conceive. Assisted reproductive technologies (ART), such as in vitro fertilization (IVF) and embryo transfer (ET), are known to have lower chances of leading to a successful pregnancy and live birth in women with adenomyosis. Thus, improving these outcomes has become an important goal in reproductive medicine.

One promising approach is the use of gonadotropin-releasing hormone analogue (GnRHa) before ET to temporarily suppress estrogen production. The idea is that lowering certain hormone levels may improve the uterine environment and increase the likelihood of implantation and pregnancy. Unfortunately, the evidence for this approach has been inconsistent; some studies suggest it helps, others found it made no difference, and guidelines from different medical bodies contradict each other. Part of the confusion stems from studies not distinguishing between fresh embryo transfers (ETs) and frozen embryo transfers (FETs), two procedures that differ in important biological characteristics.

To shed light on this issue, a research team led by Professors Tao Wu and Qing Xue from Peking University, China, conducted a study that analyzed GnRHa pre-treatment for the two types of ETs separately, combining their own patient data with a systematic review of existing literature. Their paper was made available online on December 17, 2024, and published in Volume 132, Issue S2 of BJOG: An International Journal of Obstetrics & Gynaecology on April 15, 2025.

First, they conducted a retrospective cohort study, analyzing outcomes from 413 treatment cycles across 369 women with adenomyosis treated at Peking University First Hospital between 2015 and 2023. They compared live birth rates, clinical pregnancy rates, and miscarriage rates between women who had received GnRHa pre-treatment and those who had not, and used statistical modeling to account for confounding factors like age, body mass index, uterine size, and embryo quality. Second, they carried out a meta-analysis, pooling their findings with those from six other studies on this topic.

The results were remarkably consistent and clear across both parts of the study. “After adjusting for confounders in our cohort study, the odds of achieving a live birth after ET or FET were 2.65 times and 2.43 times higher, respectively, for women with GnRHa pre-treatment than for those without,” remarks Prof. Wu. The meta-analysis confirmed this pattern, with women receiving GnRHa pre-treatment showing significantly higher live birth rates after both ET and FET cycles. Notably, miscarriage rates did not differ significantly between the two groups.

Overall, the findings support GnRHa pre-treatment as a worthwhile option for women with adenomyosis undergoing either type of ET and the authors suggest it should be actively considered in clinical practice. However, the researchers acknowledged that all studies included in the meta-analysis were conducted in China, which could affect how broadly the conclusions apply. “More worldwide studies on this topic and randomized controlled trials are warranted to strengthen this newfound evidence,” concludes Prof. Xue.

Overall, this study sets the foundation for further research from diverse international populations, paving the way for universally applicable clinical guidelines for the treatment of adenomyosis in women undergoing assisted reproduction.