Maternal fT4 blood level during pregnancy in euthyroid pregnant women correlates positively with neonate's Apgar score.

OBJECTIVES: The study investigated, whether the FT4 and TSH blood levels in euthyroid pregnant women correlate with neonatal Apgar score. MATERIAL AND METHODS: The study group included 102 euthyroid pregnant women and their newborns. All women underwent clinical assessment (including pregnancy and perinatal interview and physical examination) and laboratory tests involving TSH and FT4 blood concentrations measurements three times, in each trimester. The neonate's overall condition was assessed with the Apgar scale. RESULTS: A significant positive correlation was described between FT4 concentrations in the study group in the first and second trimester and the newborns' condition assessed on the Apgar scale at 1 minute (Spearman's Rs rank correlation, R = 0.2418; p = 0.014 for the first trimester, and R = 0.2015; p = 0.043 for the second trimester); FT4 concentrations in the first trimester and Apgar score at 3 minutes (Spearman's Rs rank correlation, R = 0.2066; p = 0.038) and between FT4 in the second trimester and the results of Apgar score in the 5th minute (Spearman's Rs rank correlation, R = 0.2231; p = 0.024). Otherwise, maternal TSH concentrations did not significantly correlate with neonatal Apgar score. Analysis of the correlation between the tested thyroid hormones and the birth weight of newborns, as well as delivery date, did not show any significant correlations CONCLUSION: Our study disclosed the impact of maternal FT4 concentration on neonatal outcome expressed by Apgar score. The results presented reveal potential clinically relevant benefits derived from profound thyroid screening during pregnancy.