Baseline premenstrual symptom severity is associated with pregnancy during Korean medicine infertility treatment: a cohort study

Infertility imposes a substantial burden, and simple, non-invasive baseline indicators may help characterize the probability of pregnancy during treatment. Premenstrual symptoms arise during the luteal phase and depend on ovulation, but their association with fertility has not been examined directly. This study examined whether baseline premenstrual symptom severity was associated with pregnancy during Korean medicine infertility treatment. This cohort analysis included 185 women undergoing a four-month Korean medicine infertility programme. Baseline premenstrual symptom severity was assessed across psychological, physical, and other MMP domains. Domain-specific logistic models reported both age-adjusted estimates and estimates adjusted for age, BMI, infertility duration, primary infertility, menstrual-cycle irregularity, PCOS, and prior IUI/IVF. Model performance was internally validated using 1,000 bootstrap resamples and repeated 10-fold cross-validation. Higher baseline premenstrual symptom severity was associated with pregnancy. Pregnancy rates increased from 12.7% in the lowest psychological symptom quartile to 35.0% in the highest (unadjusted p for trend = 0.010). In fully adjusted models, the odds ratios per SD were 1.66 (95% CI 1.17–2.36, p = 0.005) for psychological symptoms, 1.51 (1.06–2.16, p = 0.023) for physical symptoms, and 1.43 (1.00–2.04, p = 0.049) for other symptoms. Bootstrap optimism-corrected AUC was 0.66 (95% CI 0.59–0.74). These findings challenge the assumption that premenstrual symptoms impair fertility. We hypothesize that symptom severity may index ovulatory and luteal-phase activity, but ovulation, progesterone, and related hormones were not measured, so this interpretation remains unconfirmed. The results offer reassurance for symptomatic patients and point to the need for mechanistic studies that incorporate hormonal profiling.