[Risk factors for extrauterine growth retardation in very low birth weight infants: a multicenter study]

Objective: To investigate the incidence and risk factors of extrauterine growth retardation (EUGR) in very low birth weight infants (VLBWI). Methods: This prospective, multicenter observational cohort study was conducted based on Shandong Neonatal Network (SNN). The clinical data of the VLBWI (n=1 051), who were admitted to 27 neonatal intensive care units from January 1, 2018 to December 31, 2018, were collected and analyzed. According to the weight at discharge or 36 weeks of postmenstrual age, all the enrolled VLBWI were assigned into EUGR group and non-EUGR group. Univariate and multivariate logistic regression analyses were used to detect the risk factors for EUGR in preterm small for gestational age (SGA) and non-SGA infants. Results: A total of 1 051 VLBWI were enrolled, with 51.7% (543/1 051) male. The incidence of EUGR in the whole group was 60.7% (638/1 051), and were 78.3% (90/115) and 46.9% (53/113) in extremely low birth weight infant (ELBWI) and extremely preterm infants (EPI), respectively. The incidence of EUGR in SGA and non-SGA infants were 87.6% (190/217) and 53.7% (448/834), respectively. Logistic regression analysis showed that, withholding feeds (OR=1.531, 1.237, 95%CI: 1.180-1.987, 1.132-1.353, both P<0.01) and time to achieve full enteral feeding (OR=1.090, 1.023, 95%CI: 1.017-1.167, 1.002-1.045, P=0.014, 0.034) were independent risk factors of EUGR in both SGA and non-SGA infants. For SGA infants, cesarean delivery was an independent risk factor for EUGR (OR=8.147, 95%CI: 2.127-31.212, P=0.002); while for non-SGA infants, hypertensive disorders during pregnancy (OR=2.572, 95%CI: 1.496-4.421, P=0.001) and the duration of invasive ventilation (OR=1.050, 95%CI: 1.009 - 1.092, P=0.016) were independent risk factors of EUGR. Besides, moderate and severe bronchopulmonary dysplasia (OR=2.241, 95%CI: 1.173-4.281, P=0.015), necrotizing enterocolitis (OR=5.633, 95%CI: 1.333-23.796, P=0.019) and retinopathy of prematurity (OR=2.219, 95%CI: 1.268-3.885, P=0.005) were associated with EUGR. Conclusions: The incidence of weight-defined EUGR is high in VLBWI, especially in preterm SGA infants. Avoiding delaying feeds after birth and achieving full enteral feeding early may reduce the incidence of EUGR.