[Short-term outcomes and their related risk factors of extremely preterm and extremely low birth weight infants in Guangdong province].

Objective: To study the short-term outcomes and their related risk factors of extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI) in Guangdong province. Methods: The neonatal and corresponding maternal medical records of 2 392 cases of EPI and ELBWI discharged from 26 tertiary hospitals in Guangdong province during 2013-2017 were collected. Chi -square test or linear-by-linear association chi -square was used to analyze the following data on an annual basis: (1) the proportion of EPI and ELBWI in all discharged infants and preterm infants; (2) the difference in survival rate of EPI and ELBWI in different regions and types of hospital; and (3) the difference in incidence of complications. A binary Logistic regression model was established to analyze the death-related risk factors. Results: From 2013 to 2017, the enrolled infants each year were 331, 418, 458, 574 and 611, respectively. Totally, there were 1 352 (56.5%) male infants. The gestational age was (27.7±1.9) weeks, and the birth weight was (919±158) g. The proportion of EPI and ELBWI in all discharged infants increased from 2013 to 2017 (χ(2)=68.636, P< 0.01), and so did the proportion in all discharged preterm infants (χ(2)=73.463, P< 0.01). The overall survival rate was 60.4% (1 445/2 392), which increased from 2013 to 2017 (χ(2)=11.424, P< 0.01). Besides, the survival rate was higher in the Pearl River Delta region than that in the non-Pearl River Delta region (61.7% (1 325/2 146) vs. 48.8% (120/246), χ(2)=15.505, P< 0.01), and also higher in women and children specialist hospitals than that in general hospitals (66.5% (702/1 056) vs . 55.6% (743/1 336), χ(2)=29.104, P< 0.01). The overall incidence of complications was 89.0% (2 130/2 392) for neonatal respiratory distress syndrome (NRDS), 72.2% (1 041/1 442) for bronchopulmonary dysplasia (BPD), 40.5% (625/1 544) for retinopathy of prematurity (ROP), 12.3% (237/1 922) for necrotizing enterocolitis (NEC), 31.0% (578/1 865) for periventricular-intraventricular hemorrhage (PV-IVH), 34.1% (656/1 922) for nosocomial infection, 26.9% (625/2 327) for patent ductus arteriosus (PDA), and 4.4% (82/1 865) for periventricular leukomalacia (PVL). From 2013 to 2017, the incidence of PVL decreased (χ(2)=6.093, P= 0.014), but the incidence of BPD and PDA increased (χ(2)=24.476 and 11.741, respectively, both P< 0.01). Multivariate Logistic regression analysis showed that Apgar score ≤7 at 5-minute ( OR= 1.830, 95 %CI 1.373-2.437, P< 0.01), NRDS ( OR= 1.407, 95 %CI 1.222-1.621, P< 0.01), invasive assisted ventilation ( OR= 1.825, 95 %CI 1.241-2.683, P< 0.01), maternal cervical insufficiency ( OR= 2.044, 95 %CI 1.002-4.169, P= 0.049), and medical care withdrawal ( OR= 25.532, 95 %CI 18.867-34.553, P< 0.01) increased the risk of early neonatal death, while the increase in gestational age ( OR= 0.869, 95 %CI 0.802-0.941, P< 0.01), discharged from Guangzhou and Shenzhen ( OR= 0.606, 95 %CI 0.451-0.813, P< 0.01), antenatal use of steroids ( OR= 0.624, 95 %CI 0.471-0.828, P< 0.01), premature rupture of membranes ( OR= 0.667, 95 %CI 0.466-0.955, P= 0.027), and pulmonary surfactant treatment ( OR= 0.532, 95 %CI 0.419-0.676, P< 0.01) could decrease the risk. For the mortality in the late or post-neonatal period, placenta previa ( OR= 2.355, 95 %CI 1.006-5.516, P= 0.048), cervical insufficiency ( OR= 3.306, 95 %CI 1.259-8.679, P= 0.015), PV-IVH ( OR= 1.486, 95 %CI 1.135-1.946, P< 0.01), invasive assisted ventilation ( OR= 2.143, 95 %CI 1.208-3.801, P< 0.01), and medical care withdrawal ( OR= 286.532, 95 %CI 87.840-934.661, P< 0.01) increased the risk, while the increase of birthweight ( OR= 0.997, 95 %CI 0.996-0.999, P< 0.01) decreased the risk. Conclusions: The survival rate of EPI and ELBWI increases annually, but the incidence of complications is still high. Invasive assisted ventilation, medical care withdrawal and maternal cervical insufficiency are associated with mortality in both early and late neonatal or post-neonatal period.