Obstetric and Perinatal Outcomes of Singleton Pregnancies After in-vitro Fertilization in Siriraj Hospital, A Matched Case-Control Study

Objective: To compare obstetric and perinatal outcomes between singletons born after IVF and natural conception. Methods: A total of 141 singleton pregnancies conceived by IVF were included. Another 141 singleton pregnancies conceived naturally were randomly selected as comparison group, matched by age. Data were retrospectively extracted from medical records, including baseline characteristics and delivery data. Various characteristics, including pregnancy and neonatal outcomes were compared between groups. Results: Women in IVF group were more likely to be nulliparous and had previous miscarriage (88.7% vs. 76.6%, 0=0.003; and 26.2% vs. 14.8%, p=0.018, respectively). Underlying diseases and complications during pregnancy were comparable between the 2 groups. Mean gestational age was lower in IVF group (37.9 ± 2.0 vs. 38.4 ± 1.6, p=0.008), but without clinical significance. Primary cesarean section was significantly more common among women in IVF group (74.4% vs. 54.6%, p<0.001) and the majority were elective cases (61.9% vs. 23.4%, p<0.001). There were no significant differences in terms of rates of preterm labor, birth weight, low birth weight, small for gestational age, neonatal intensive care unit admissions, and perinatal mortality. Conclusion: Singleton pregnancies after IVF were not associated with higher risks of adverse obstetric and perinatal outcomes, compared with naturally conceived group, but IVF pregnancies are associated with a high rate of cesarean sections.