To study the association of birth weight of a full-term neonate with the maternal thyroid stimulating hormone levels

Background

Low birth weight (LBW) affects 17–18% of Indian neonates. Thyroid dysfunction complicates 10–16% ofpregnancies in India, yet data on maternal thyroid stimulating hormone (TSH) and birth weight from Central India arelimited. The objective is to determine the association between maternal first-trimester TSH levels and birth weight of fulltermneonates, and to identify other maternal factors influencing birth weight. Materials and Methods: This cross-sectionalstudy enrolled 210 mother–neonate pairs at a tertiary hospital in Bhopal over 12 months. First-trimester TSH was classifiedas euthyroid (0.1–3.5 mIU/L), subclinical hypothyroidism (SCH; 3.5–10.0), or overt hypothyroidism (>10.0). Spearman’scorrelation, ANOVA, Fisher’s exact test, and odds ratios with 95% CIs were computed. Significance was set at p < 0.05.Results: Thyroid dysfunction was present in 16.2% of mothers (SCH 12.9%, overt 3.3%). Mean birth weight differedsignificantly: euthyroid 2996 ± 401 g, SCH 2658 ± 449 g, overt 2485 ± 387 g (F = 9.62; p = 0.001). TSH correlatednegatively with birth weight (ρ = –0.348; p < 0.001). Overt hypothyroidism conferred an 11.70-fold LBW risk (95% CI2.42–56.50; p = 0.002); the SCH association showed a trend but was not significant (OR 2.51; 95% CI 0.90–7.03; p = 0.08).Hemoglobin was the strongest positive correlate (r = 0.325; p < 0.001).