A new analysis of published studies found an approximate 80% increased risk of spontaneous preterm birth (both before 37 and 34 weeks) when women become pregnant via in vitro fertilization (IVF) than through spontaneous conception. The Ultrasound in Obstetrics and Gynecology analysis included 15 studies with approximately 62,000 patients and about 3800 preterm births events.
"Placental development may play a key role in the pathogenesis of spontaneous preterm birth in IVF pregnancies. We recommend ultrasound cervical screening in this high risk group in order to apply timely preventive strategies," said lead author Dr. Paolo Cavoretto, of the IRCCS San Raffaele Hospital, in Milan, Italy. "Future research reporting pregnancy outcomes should always emphasize etiological differentiation of preterm birth."