Survival rates and complications among 243 cases of extremely low birth weight infants

Abstract

Objective To review the trends of survival rates and complications in extremely low birth weight (ELBW) infants and to improve the prognosis of ELBW infants. Method From January 1999 to December 2015, ELBW infants in our hospital were retrospectively studied. Their survival rates and complications were compared among groups with different birth weight, and the risk factors for survival were identified using multivariate unconditional logistic regression analysis. Result A total of 243 ELBW infant were collected. The median gestational age of ELBW infant was 27.3 weeks (23~34 weeks), and their median birth weight was 890 g (490~995 g). Excluding 40 cases refused treatment, the cure and survival rates of the remaining 203 ELBW infants were 43.8% (89/203) and 65.0% (132/203), respectively. The survival rate in ELBW infant with birth weight<600 g was 0/3, increased to 70.8% (68/96) when birth weight was 900 ~999 g, with an ascending trend with increased birth weight (χ2 trend=12.673, P<0.001). The most common complications of 243 cases were neonatal respiration distress syndrome [87.7% (213/243)], sepsis [45.3% (110/243)], intraventricular hemorrhage [37.4% (91/243)], bronchopulmonary dysplasia [36.6% (89/243)] and pheumonia [36.6% (89/243)]. The incidence of complications (including intracerebral hemorrhage and hydrocephalus), decreased with increased birth weight. Multivariate unconditional logistic regression analysis found that birth weight below 800 g (<700 g: OR=22.333, 95%CI 1.493~334.148, P=0.024; 700~799 g: OR=3.573, 95%CI 1.075~11.874, P=0.038), stage Ⅲ necrotizing enterocolitis (OR=8.803, 95%CI 1.308~59.244, P=0.025), stage Ⅲ and Ⅳ of intraventricular hemorrhage (OR=8.902, 95%CI 1.127~70.338, P=0.038) and mechanical ventilation (OR=3.597, 95%CI 1.043~12.410, P=0.043) were risk factors affecting the ELBW infant′s survival. Conclusion As birth weight increases, the survival rate also increases, and the rate of complications decreases. Birth weight, stage Ⅲ necrotizing enterocolitis, stage Ⅲ and Ⅳ intraventricular hemorrhage and mechanical ventilation are risk factors for the ELBW infant′s survival. Key words: Infant, extremely low birth weight; Survival rate; Mortality; Complication; Risk factors