Neonatal and fetal effects of antithyroid peroxidase positivity in hypothyroidism in pregnancy - A hospital-based prospective analytical study

Abstract

Objectives: The objectives of this study were to evaluate the fetal and neonatal outcomes for pregnant women with autoimmune hypothyroidism and to compare them to hypothyroid and euthyroid women. Methods: A total of 309 women were included in the study. 159 hypothyroid women were categorized as “Cases” and 150 euthyroid women were “Controls.” Serum thyroid-stimulating hormone (TSH) was done for all women, and in hypothyroid women, antithyroid peroxidase (TPO) was also done for the mothers. Cases were subdivided on the basis of anti-TPO positivity. Fetal and neonatal complications were noted in all three groups along with basic parameters such as baby weight and Apgar scores. Meconium aspiration, neonatal intensive care unit (NICU) admission, jaundice, intrauterine growth retardation, intrauterine death (IUD), low or very low birth weight, congenital anomalies, hypothyroidism in the newborn, and neonatal death were the parameters noted. Testing of the babies was done with serum TSH on day of life 3 and serum bilirubin whenever clinically jaundice was suspected. The study period was 2 years. Results: Hypothyroidism is significantly associated with an increased risk of IUD (p=0.038), NICU admissions in babies (p=0.004), neonatal jaundice (p=0.027), low or very low birth weight babies (p=0.0003), congenital anomalies in the babies (p=0.026), and neonatal deaths (p=0.007). Anti-TPO positivity is significantly associated with increased risk of IUD (p=0.044) and hypothyroidism in the newborn of hypothyroid mothers (p=0.045). Conclusions: Anti-TPO positivity and hypothyroidism are both significantly associated with certain fetal complications such as IUD, neonatal jaundice, increased NICU admissions, and hypothyroidism in the newborn. Mothers with hypothyroidism who are TPO positive have a higher risk of neonatal mortality and morbidity, although small. Hence, screening should be done in all hypothyroid women in pregnancy and their babies. Universal screening with serum TSH is recommended in pregnancy and in the newborn on day 3 of life.