A multi-center research on risk factors of hyperbilirubinemia in late preterm infants

Objective To investigate the risk factors of hyperbilirubinemia in late preterm infants. Methods The clinical data of 815 late preterm infants (449 males and 366 females) from 25 hospitals in Beijing were collected from October 2015 to April 2016, including 340 cases(41.7%) with hyperbilirubinemia (hyperbilirubinemia group), and 475 cases without hyperbilirubinemia (control group). The clinical data of two groups were compared, and the maternal factors influencing hyperbilirubinemia in late preterm infants were analyzed with logistic regression. Results There were no significant differences in gender ratio (M∶F 1.39 vs. 1.12, t=1.811, P=0.172) and birth weight[ (2 502.6±439.6)g vs. (2 470.2±402.9)g, χ2=2.330, P=0.127) ]between two groups. The incidence rates of hyperbilirubinemia in infants of 34 wks, 35 wks and 36 wks of gestational age were 22.9% (87/174), 35% (119/300) and 42.1% (143/341) respectively (χ2=1.218, P=0.544) . The multivariate logistic regression analysis indicated that the maternal age (OR=1.044, 95% CI:1.010-1.080, P=0.011) was independent risk factor and multiple births (OR=1.365, 95% CI: 0.989-1.883, P=0.048) , premature rupture of membranes (OR=2.350, 95% CI: 1.440-3.833, P=0.001) , cesarean section (OR=1.540, 95% CI: 0.588-4.031, P=0.014) were risk factors for hyperbilirubinemia in late preterm infants. Conclusions The incidence of hyperbilirubinemia in late preterm infants is relatively high. Maternal age, multiple births, premature rupture of membranes and cesarean section are risk maternal factors related to hyperbilirubinemia in late preterm infants. Key words: Hyperbilirubinemia; Maternal risk factor; Late preterm infants