1. From the Departments of Obstetrics and Gynecology (S.N.B., A.G.), Anesthesia (G.A.C.-D., V.E.O.), and Surgery (A.S.J.), Massachusetts General Hospital, and the Departments of Obstetrics and Gynecology (S.N.B., A.G.), Anesthesia (G.A.C.-D., V.E.O.), and Surgery (A.S.J.), Harvard Medical School — both in Boston.