Impact of Hypothyroidism in Pregnancy on Feto-Maternal Outcomes: A Prospective Observational Study

Introduction Hypothyroidism represents an endocrine disorder marked by the insufficient production of hormones by the thyroid gland, with significant effects on bodily functions. Its occurrence during pregnancy is of particular concern due to its profound effects on both maternal and fetal health outcomes. Aim To study the impact of hypothyroidism in pregnancy and its correlation with feto-maternal outcomes. Methodology The present study is a two-year prospective observational study carried out at a tertiary care hospital from July 2022 to June 2024. A total of 350 antenatal women with singleton pregnancies and without any pre-existing medical disorder were screened. Serum thyroid stimulating hormone (TSH) was evaluated with a cut-off value of 4.0 mIU/L. If serum TSH was abnormal, free thyroxine (FT4) and free triiodothyronine (FT3) levels were assessed. The participants were categorized into three groups designated as euthyroid, overt hypothyroidism, and subclinical hypothyroidism. TSH was periodically re-evaluated at 16 weeks, 20 weeks, and 32 weeks. All patients were monitored up to the point of delivery, allowing for comparison of outcomes across the three groups. Results The prevalence of hypothyroidism in the present study was 11.14% (n=39). Eight percent (n=28) of the cases had subclinical hypothyroidism whereas 3.14% (n=11) of cases had overt hypothyroidism. Hypothyroidism was more common in the 26-30 years age group. There was a higher incidence of hypothyroidism in multigravida patients. Lower segment caesarean section (LSCS) was the most common mode of delivery in the women with hypothyroidism. Maternal outcomes included preeclampsia, eclampsia, anemia, gestational hypertension, gestational diabetes mellitus (GDM), spontaneous miscarriage, preterm labor, oligohydramnios, etc. The fetal outcomes included intrauterine growth restriction (IUGR), low birth weight (LBW) and fetal distress. Conclusion Early diagnosis and adequate treatment of maternal hypothyroidism leads to successful pregnancy outcomes. Therefore, universal thyroid screening in pregnancy is recommended in order to prevent maternal and fetal complications.