The study group will include pregnant women > 18 years of age with insulin-requiring diabetes who will receive corticosteroid therapy to accelerate fetal lung maturation between 24 and 34 weeks of pregnancy. Only those women not in active labor and with singleton gestations will be included. A control group will be comprised of pregnant women with singleton gestations without insulin-requiring diabetes who will receive corticosteroid therapy also to accelerate fetal lung maturation.