Lee SY, et al. - Researchers conducted this retrospective cohort study to evaluate potential connections between maternal thyrotropin (thyroid-stimulating hormone [TSH]) levels in pregnancy and obstetric and perinatal outcomes. Women (aged ≥18 years) with a singleton gestation and no known thyroid disease seen for prenatal care at Boston Medical Center from January 1, 2003 through May 22, 2014, and their fetuses and infants have been involved. The sample consisted of 8,413 pregnant women (mean age 29.1 years, 15% white, 60% black, 13% Hispanic) and their fetuses and infants (mean gestational age at birth 38.5 weeks, 52% male, mean birth weight 3.2 kg). The authors discovered that maternal serum TSH concentration > 4 mIU/L in pregnancy was related to nearly 2-fold increased risks of prematurity and respiratory distress syndrome in offspring. In addition, elevated TSH was linked to statistically non-significant increases in the risk of fetal loss, preeclampsia/eclampsia, and low birth weight.