Interaction between triglyceride-glucose index and body mass index on pregnancy loss in Chinese women with polycystic ovary syndrome: a secondary analysis of a randomized clinical trial.

If you have polycystic ovary syndrome (PCOS) and are trying to get pregnant, a new study suggests that two common health measurements — your body weight (BMI) and a marker of how your body handles fat and sugar (called the triglyceride-glucose index, or TyG) — may work together to affect your chances of pregnancy loss.

Researchers analyzed data from a large clinical trial called the PCOS Acupuncture and Clomiphene Trial, which followed 855 women with PCOS across 27 hospitals in China. They looked at how BMI and the TyG index — individually and together — influenced insulin resistance, metabolic syndrome, and pregnancy outcomes like ovulation, conception, and pregnancy loss.

The findings were striking. Women who had both a high BMI (28.0 kg/m² or above) and a high TyG score faced dramatically higher risks: they were over 11 times more likely to have insulin resistance and had significantly lower odds of ovulating, conceiving, and achieving a clinical pregnancy compared to women with healthy BMI and low TyG levels. Importantly, BMI and TyG appeared to interact with each other — meaning their combined effect on pregnancy loss was greater than either factor alone.

What does this mean for you? If you have PCOS, managing both your weight and your metabolic health — not just one or the other — may be especially important for improving your fertility and reducing the risk of pregnancy loss. Lifestyle changes that address inflammation, blood sugar regulation, and weight are key parts of a comprehensive approach.

Acupuncture, which was part of the original trial this analysis drew from, is one tool that some women with PCOS use as part of a broader fertility support plan. To explore whether acupuncture may be right for your situation, consider consulting a licensed acupuncturist with experience in reproductive health.

This secondary analysis of the PCOS Acupuncture and Clomiphene Trial (NCT01573858; n=855 women with PCOS across 27 Chinese hospitals) investigated interaction and joint effects of BMI and triglyceride-glucose (TyG) index on insulin resistance (IR), metabolic syndrome (MetS), and pregnancy outcomes using generalized linear models, multinomial logistic regression, and restricted cubic spline analysis. A statistically significant BMI × TyG interaction was identified for pregnancy loss (P<0.05). Joint analysis revealed that women with BMI ≥28.0 kg/m² and TyG T3 faced markedly elevated adjusted odds of IR (OR: 11.55; 95% CI: 3.47–38.45) and MetS (OR: 46.21; 95% CI: 3.92–545.01), with significantly reduced odds of ovulation, conception, and clinical pregnancy versus BMI <24.0/TyG T1. The combined TyG+BMI model yielded an AUC of 0.604 for pregnancy loss prediction (sensitivity 68%, specificity 50%). Clinically, screening PCOS patients for both adiposity and lipid-glucose dysregulation together — rather than independently — may better stratify pregnancy loss risk and guide integrative treatment planning.