Risk of preterm birth appears to vary by season

Women who become pregnant in spring are more vulnerable to preterm birth than those who conceive in other seasons, according to researchers at the University of Pittsburgh. Results of a large study of such seasonal variation in preterm birth, or birth prior to 37 weeks gestation, are being presented at the 27th annual meeting of the Society of Maternal-Fetal Medicine, being held today through Saturday at the Hilton San Francisco and Towers in California.