High AMH Levels Tied to Increased Risk of Miscarriage in Overweight Women: Study Finds

Both anti-Müllerian hormone and body mass index influence pregnancy outcomes in women with PCOS undergoing in vitro fertilization (IVF). PCOS, a common endocrine disorder in reproductive-aged women, is characterized by hormonal imbalances, irregular ovulation, and metabolic complications. Elevated serum AMH levels in these women reflect a higher count of small antral follicles, making it a key marker of ovarian reserve. However, its impact on pregnancy outcomes, particularly with BMI, remains an area of ongoing research.

Against the above background, Qian Wang, Department of Pediatric Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China, and colleagues aimed to investigate how varying combinations of AMH and BMI influence pregnancy outcomes in women with PCOS undergoing IVF.

For this purpose, the researchers conducted a post hoc secondary analysis of a multicenter randomized trial. They evaluated 625 women from a single center who had measured AMH levels before undergoing IVF treatment. Based on their BMI and AMH levels, the participants were categorized into six groups: Group A (normal weight with low AMH), Group B (normal weight with intermediate AMH), Group C (normal weight with high AMH), Group D (overweight/obesity with low AMH), Group E (overweight/obesity with intermediate AMH), and Group F (overweight/obesity with high AMH).

The study led to the following findings:

• After adjustment using multivariable logistic regression, women in the overweight/obesity group with high AMH levels had a higher risk of clinical pregnancy miscarriage (aOR: 3.30) compared to those with normal weight and intermediate AMH levels.
• Women with normal weight and high AMH levels (aOR: 3.74) had an increased risk of ovarian hyperstimulation syndrome (OHSS) compared to those with normal weight and intermediate AMH levels.
• Overweight/obese women with high AMH levels also showed a higher risk of OHSS (aOR: 3.61) compared to those with normal weight and intermediate AMH levels.

In conclusion, the researchers found that in women with PCOS, high serum AMH levels were associated with an increased risk of clinical pregnancy miscarriage in those who were overweight or obese but not in women with normal weight. Additionally, women with elevated AMH levels faced a higher risk of ovarian hyperstimulation syndrome, and this risk remained elevated even when coupled with a higher BMI.

The study also indicated that women with normal weight and low AMH levels were more likely to deliver prematurely in twin pregnancies than those with normal weight and intermediate AMH levels. The researchers emphasize the need for further studies to validate these findings and investigate the underlying mechanisms.

Reference:

Niu, Y., Han, X., Xiao, H., Miao, R., Ouyang, G., Wang, Q., & Wei, D. (2025). Effect of different combinations of serum AMH levels and BMI on pregnancy outcomes in women with polycystic ovary syndrome. AJOG Global Reports, 100461. https://doi.org/10.1016/j.xagr.2025.100461