Association of Maternal Thyroid-stimulating Hormone Levels with Psychological Well-being, Sexual Function, and Quality of Life During Pregnancy.

We primarily investigated whether depressive and anxiety symptoms, sexual function, and quality of life differed between pregnant women grouped using a predefined maternal thyroid-stimulating hormone (TSH) cutoff of 2.5 mIU/L, with complementary continuous analyses used to characterize the TSH-outcome relationships. In this prospective single-center observational cohort (November 2025-January 2026), 208 pregnant women attending antenatal care completed the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Arizona Sexual Experiences Scale (ASEX), and the 13-item Quality of Life Short Form (YKK-13) before physician evaluation and blood sampling. After predefined exclusions (including autoimmune thyroid disease and thyroid-related medication use) and endocrinology consultation for TSH ≥ 2.5 mIU/L, 192 participants were included (TSH < 2.5 mIU/L, n = 102; TSH ≥ 2.5 mIU/L, n = 90) with complete questionnaire data. Baseline age, gestational age, gravida, parity, and body mass index were similar between groups. Median BDI and BAI scores were higher in the TSH ≥ 2.5 mIU/L group than in the TSH < 2.5 mIU/L group (BDI: 13.0 vs 10.0; p = 0.002; BAI: 11.0 vs 8.0; p = 0.009). YKK-13 and ASEX scores showed no statistically significant between-group differences (p = 0.068 for YKK-13 and p = 0.400 for ASEX). In exploratory pairwise analyses, the first detectable difference in BDI was observed for TSH < 2.5 versus 2.5- < 4.5 mIU/L (p = 0.007), while comparisons between 2.5- < 4.5 and ≥ 4.5 mIU/L were not significant for BDI, BAI, YKK-13, or ASEX (all p > 0.05). In complementary analyses treating TSH as a continuous variable, higher maternal TSH was weakly but monotonically associated with higher depression and anxiety scores and lower quality of life, with no evidence of a nonlinear or threshold-like relationship. Maternal TSH ≥ 2.5 mIU/L was associated with higher depressive and anxiety symptom scores in unadjusted comparisons, whereas sexual function and quality-of-life scores were broadly comparable across TSH strata. Given the absence of FT4 and thyroid autoantibody measurements, the use of a fixed pragmatic TSH cutoff, the lack of trimester-specific reference intervals, and the absence of multivariable adjustment, these findings should be interpreted as exploratory and hypothesis-generating rather than as evidence of an independent or causal association.