Adverse obstetric and perinatal outcomes of singleton pregnancies may be related to maternal factors associated with infertility rather than the type of assisted reproductive technology procedure used

Objective To compare obstetric and perinatal outcomes of singleton pregnancies conceived with different types of assisted reproductive technology (ART) procedures with those of naturally conceived pregnancies. Design Retrospective cohort study. Setting The perinatal database of the Japanese Society of Obstetrics and Gynecology. Patient(s) A total of 242,715 women with singleton pregnancies were examined as a base cohort. Three study groups were created according to the type of ART procedure used, namely ovulation stimulation medications (n = 4,111), IUI (n = 2,351), and IVF-ET (n = 4,570). Controls adjusted for multiple maternal characteristics were selected randomly for each study group. Intervention(s) None. Main Outcome Measure(s) Obstetric and perinatal outcomes. Result(s) Patients who conceived through the ART procedures were associated with an increased incidence of placenta previa, preterm delivery, and low birth weight infant and a decreased incidence of spontaneous cephalic delivery, regardless of the type of ART procedure. Conclusion(s) Among singleton pregnancies, patients conceived with ART procedures were at increased risk for several adverse obstetric and perinatal outcomes, regardless of the type of ART procedure used. These results suggest that maternal factors associated with infertility may contribute to the adverse outcomes rather than the ART procedures themselves.