Risk factors and adverse pregnancy outcomes among births affected by velamentous umbilical cord insertion: a retrospective population-based register study

Abstract

To identify risk factors associated with velamentous cord insertion (VCI) and to evaluate the association between adverse pregnancy outcomes and VCI in singleton pregnancies. The total population of women (n=26,849) with singleton pregnancies delivered in Kuopio University Hospital during the study period between 2000 and 2011 was reviewed. Risk factors and the risk of adverse pregnancy outcomes (admission to a neonatal unit, fetal death, preterm delivery, low birth weight (LBW< 2500 g), the infant being small for its gestation age (SGA), low Apgar scores (<7) at 1 and 5 min and fetal venous pH<7.15) were evaluated separately among women with and without VCI by means of logistic regression analyses. The incidence of VCI among women with singleton pregnancies was 2.4% (n=633 of 26,849). Independent risk factors for VCI were nulliparity, obesity, fertility problems, placenta previa and maternal smoking. VCI was associated with a 1.38-, 2.01-, 3.93- and 1.39-fold increased risk of admission to a neonatal unit, preterm delivery (<37 gestation weeks), LBW and SGA, respectively compared to pregnancies involving normal cord insertion. Of the women with VCI, 15.3% underwent non-elective cesarean section compared to 8.3% (p ≤ 0.001) of women without VCI. The results suggest that the incidence of VCI increases along with an increase in fertility problems and maternal obesity. VCI is a moderate risk condition increasing the risks of prematurity and impaired fetal growth.