Abstract
Objective: The aim of this study is to investigate risk factors associated with spontaneous early preterm delivery.
Methods: The study included 1865 singleton pregnancies with 31 spontaneous deliveries between 23 and 35 weeks' gestation compared to 1834 deliveries at the term analysed between 2008 and 2009. Both groups were 100% Caucasian.
Results: Spontaneous early delivery occurred in 31(1.2%) of the 2528 pregnancies. In the preterm delivery group, compared with unaffected pregnancies, there was an increased incidence of maternal anaemia (OR 2.8, 95%CI: 1.8–4.5; p < 0.001). Previous preterm delivery between 23 and 34 weeks’ gestation (OR 10.7, 95%CI: 5.2–21.7; p < 0.001) as well as vaginal bleeding beyond the first trimester (OR 3.8, 95%CI: 1.2–12.1; p = 0.039), assisted conception (4.1, 95%CI: 2.0–8.4; p = 0.001) and fetal loss before 16 weeks’ gestation (OR 4.2, 95%CI: 2.5–7.1; p < 0.001) are strongly associated with spontaneous preterm delivery.
Conclusions: Previous preterm delivery as well as fetal loss before 16 weeks’ gestation, assisted conception, vaginal bleeding beyond the first trimester and maternal anaemia are strongly associated with an increased risk for spontaneous early preterm delivery.