In vitro fertilization and preterm delivery, low birth weight, and admission to the neonatal intensive care unit: a prospective follow-up study

ObjectiveTo compare the risk of preterm delivery, low birth weight, and admission of the newborn to a neonatal intensive care unit (NICU) in women pregnant after fertility treatment and subfertile women with the risk in fertile women.DesignProspective follow-up study.SettingAarhus University Hospital, Skejby, Denmark, 1989–2006.Patient(s)A total of 20,080 liveborn singletons.Intervention(s)None.Main Outcome Measure(s)Preterm delivery, low birth weight, and admission of the newborn to a NICU.Result(s)After adjustment we found a statistically significantly increased risk of preterm delivery and very preterm delivery in women who conceived after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) compared with fertile women. Compared with fertile women, the risk of preterm delivery and very preterm delivery was not statistically significantly different in women pregnant after non-IVF assisted reproductive treatment (non-IVF ART) or subfertile women. We found no association between IVF/ICSI and the risk of low birth weight at term or admittance to the NICU.Conclusion(s)The increased risk of preterm delivery after IVF/ICSI may be due to the fertility treatment or unknown characteristics in the couples who undergo IVF/ICSI.