Effect of perinatal asphyxia on level of thyroid hormones in term neonates

Abstract

Background: To evaluate how perinatal asphyxia alters the thyroid function in term newborn by comparing cord blood and 18-24 hours venous blood in between newborns with and without asphyxia. Methods: A prospective case-control study was carried out at Tertiary care pediatric center in central India. 60 Full term newborn with perinatal asphyxia requiring bag and mask ventilation for ≥1 minute or APGAR at 1 and 5 minute ≤7 or required intubation for resuscitation as cases and control -60 normal term newborn with APGAR ≥7 at 1 and 5 minute were selected. Cord blood and 18 to 24 hour after birth venous blood were collected in both groups and compared for level of thyroid hormones (T3, T4, TSH) via radioimmunoassay. Results: There was no significant difference observed in cord blood thyroid hormones (P>0.05). But a significant lower level of thyroid hormones observed in asphyxiated group as compared to control group in venous sample 18-24 hours after birth [mean± standard deviation; T3 case=68.87 ± 21.08, T3 control=79.93 ± 20.52, P=0.004; T4 case 6.48 ± 2.41, T4 control=8.89 ± 1.46, P<0.001; TSH case=4.33 ± 4.36; TSH control=8.45 ± 1.70, P<0.001]. Conclusions: Perinatal asphyxia depresses the TSH level which further leads to decrease in T3 and T4 suggestive of central hypothyroidism.