Blastocyst versus cleavage stage transfer in in vitro fertilization: differences in neonatal outcome?
OBJECTIVE: To compare neonatal outcome of blastocyst and cleavage stage embryo transfers after IVF. DESIGN: Register study. PATIENT(S): Treatments reported from all Swedish IVF clinics. INTERVENTION(S): None. SETTING: Births recorded in the Swedish Medical Birth Register after IVF performed, 2002-2006. MAIN OUTCOME MEASURE(S): Some neonatal characteristics were compared in 1,311 infants born after