Year: 2026 | Month: January-March | Volume: 11 | Issue: 1 | Pages: 147-154
DOI: https://doi.org/10.52403/ijshr.20260117
Prevalence and Clinical Impact of Thyroid Dysfunction in Pregnant Women with Gestational Diabetes Mellitus: A Case-Control Study in a Tertiary Care Setting
Bhagyashree1, Pratima2
1Tutor/Senior Resident, 2Associate Professor
Department of Obstetrics & Gynaecology, Sri Krishna Medical College and Hospital,Muzaffarpur, Bihar, India
Corresponding Author: Pratima
ABSTRACT
Background: Gestational diabetes mellitus (GDM) and thyroid disorders are two common endocrine conditions in pregnancy; each associated with adverse maternal and neonatal outcomes. Emerging evidence suggests a bidirectional relationship between glucose intolerance and thyroid dysfunction, warranting focused evaluation in high‑risk obstetric populations.
Methods: A hospital‑based case–control study was conducted on 120 pregnant women (60 GDM cases, 60 controls) between 24–28 weeks of gestation. Standard oral glucose tolerance testing was used to diagnose GDM. Thyroid function was assessed via serum TSH, free T4, and free T3, with classification into overt and subclinical hypo‑ or hyperthyroidism. Associations with maternal age, BMI, parity, and obstetric/neonatal outcomes were analyzed using chi‑square and logistic regression.
Results: Women with GDM had significantly higher mean TSH (5.83 vs. 3.44 mIU/L, p<0.0001) and lower T4 (8.80 vs. 11.73 μg/dl, p<0.0001) and T3 (135.67 vs. 167.48 ng/dl, p<0.0001) compared to controls. Thyroid dysfunction was more prevalent in cases (55%) than controls (38.3%), with subclinical hypothyroidism being the most frequent abnormality (31.7% vs. 23.3%). Descriptive trends indicated higher rates of thyroid dysfunction in women >30 years, increased elective cesarean deliveries among hypothyroid cases, and poorer neonatal outcomes (low birth weight, low APGAR scores) among infants of hyperthyroid mothers, though these did not reach statistical significance.
Conclusion: Pregnant women with GDM exhibit a significantly higher burden of thyroid dysfunction, particularly hypothyroidism. While associations with maternal age, delivery mode, and neonatal outcomes were not statistically significant, observed trends highlight potential compounded risks.
Keywords: Gestational diabetes mellitus (GDM), Thyroid dysfunction, Hypothyroidism, Hyperthyroidism, Pregnancy outcomes