Association between ovarian reserve and spontaneous miscarriage and their shared genetic architecture
Authors: Yi Yan , Fu Jing , Xie Shi , Zhang Qiong , Xu Bin , Wang Yonggang , Wang Yijing , Li Bin , Zhao Guihu , Li Jinchen , Li Yanping , Zhao Jing 
Published: September 2023

Abstract

STUDY QUESTION
Can potential mechanisms involved in the likely concurrence of diminished ovarian reserve (DOR) and miscarriage be identified using genetic data?

SUMMARY ANSWER
Concurrence between ovarian reserve and spontaneous miscarriage was observed, and may be attributed to shared genetic risk loci enriched in antigen processing and presentation and autoimmune disease pathways.

WHAT IS KNOWN ALREADY
Previous studies have shown that lower serum anti-Müllerian hormone (AMH) levels are associated with increased risk of embryo aneuploidy and spontaneous miscarriage, although findings have not been consistent across all studies. A recent meta-analysis suggested that the association between DOR and miscarriage may not be causal, but rather a result of shared underlying causes such as clinical conditions or past exposure. Motivated by this hypothesis, we conducted the present analysis to explore the concurrence between DOR and miscarriage, and to investigate potential mechanisms using genetic data.

STUDY DESIGN, SIZE, DURATION
Three data sources were used in the study: the clinical IVF data were retrospectively collected from an academically affiliated Reproductive Medicine Center (17 786 cycles included); the epidemiological data from the UK Biobank (UKB), which is a large-scale, population-based, prospective cohort study (35 316 white women included), were analyzed; and individual-level genotype data from the UKB were extracted for further analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS
There were three modules of analysis. First, clinical IVF data were used to test the association between ovarian reserve biomarkers and the subsequent early spontaneous miscarriage risk. Second, the UKB data were used to test the association of spontaneous miscarriage history and early menopause. Third, individual-level genotype data from the UKB were analyzed to identify specific pleiotropic genes which affect the development of miscarriage and menopause.

MAIN RESULTS AND THE ROLE OF CHANCE
In the analysis of clinical IVF data, the risk of early spontaneous miscarriage was 1.57 times higher in the group with AMH &lt; 1.1 ng/ml group (P &lt; 0.001), 1.62 times for antral follicular count &lt;5 (P &lt; 0.001), and 1.39 times for FSH ≥10 mIU/ml (P &lt; 0.001) in comparison with normal ovarian reserve groups. In the analysis of UKB data, participants with a history of three or more miscarriages had a one-third higher risk of experiencing early menopause (odds ratio: 1.30, 95% CI 1.13–1.49, P &lt; 0.001), compared with participants without spontaneous miscarriage history. We identified 158 shared genetic risk loci that affect both miscarriage and menopause, which enrichment analysis showed were involved in antigen processing and presentation and autoimmune disease pathways.

LIMITATIONS, REASONS FOR CAUTION
The analyses of the UKB data were restricted to participants of European ancestry, as 94.6% of the cohort were of white ethnicity. Further studies are needed in non-white populations. Additionally, maternal age at the time of spontaneous miscarriage was not available in the UKB cohort, therefore we adjusted for age at baseline assessment in the models instead. It is known that miscarriage rate in IVF is higher compared to natural conception, highlighting a need for caution when generalizing our findings from the IVF cohort to the general population.

WIDER IMPLICATIONS OF THE FINDINGS
Our findings have implications for IVF clinicians in terms of patient counseling on the prognosis of IVF treatment, as well as for genetic counseling regarding miscarriage. Our results highlight the importance of further research on the shared genetic architecture and common pathophysiological basis of DOR and miscarriage, which may lead to new therapeutic opportunities.

STUDY FUNDING/COMPETING INTEREST(S)
This work was supported by the Hunan Youth Science and Technology Innovation Talent Project (2020RC3060), the International Postdoctoral Exchange Fellowship Program (Talent-Introduction Program, YJ20220220), the fellowship of China Postdoctoral Science Foundation (2022M723564), and the Natural Science Foundation of Hunan Province, China (2023JJ41016). This work has been accepted for poster presentation at the 39th Annual Meeting of ESHRE, Copenhagen, Denmark, 25–28 June 2023 (Poster number: P-477). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER
N/A.