Lee SY, et al. - Researchers conducted this retrospective cohort study to evaluate potential connections between maternal thyrotropin (TSH) levels in pregnancy and obstetric and perinatal results. Participants in the study were 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. The sample consisted of 8,413 pregnant women (mean age 29.1 years) and their fetuses and infants (mean GA at birth 38.5 weeks, mean birth weight 3.2 kg). Findings suggested an association of maternal serum TSH concentration > 4mIU/L in pregnancy with nearly 2-fold raised risks of prematurity and respiratory distress syndrome in offspring. In addition, elevated TSH was linked to statistically non-significant raises in the risk of fetal loss, preeclampsia/eclampsia, and low birth weight.