Tool to predict adverse outcomes in low birthweight babies developed
MedWire News: Researchers in Israel have developed a tool to estimate the occurrence of adverse outcomes in very low birthweight (VLBW) infants.
"The provision of appropriate and up-to-date estimates of poor neonatal outcomes for specific groups of infants may be useful in counseling families on treatment options for these infants," say Amir Kugelman (Bnai Zion Medical Center, Haifa) and colleagues.
Writing in the Archives of Pediatrics and Adolescent Medicine, they explain that the use of gestational age alone to make decisions regarding intensive care for VLBW infants is error-prone and that more factors affecting these infants' prognosis need to be identified.
Kugelman and team therefore developed a tool to estimate adverse neonatal outcomes for 2544 VLBW (≤1500 g) infants born at 24-26 weeks' gestation that incorporated factors at birth significantly associated with poor outcomes into a linear regression model.
Stepwise logistic regression analyses showed that gender-specific birthweight z-score (odds ratios [ORs] 1.67-2.22 for each unit decrease) and lack of prenatal steroids (ORs 2.00-2.56) were significantly associated with poor outcomes at 24, 25, and 26 weeks' gestation. Male gender was also found to be a significant predictor for poor outcomes at 25 and 23 weeks' gestation.
Poor outcomes were defined as the composite of mortality or severe neurologic or pulmonary morbidity at discharge from the hospital.
At 24, 25, and 26 weeks' gestation, significantly lower rates of observed poor outcomes were present in female versus male infants with increasing birthweight percentile group (<25th, 25-27th, >75th percentiles as determined from the charts of Kramer et al) and with prenatal steroid therapy.
Based on these analyses, the authors developed a model for estimating the rates of poor neonatal outcomes that included four predictors.
According to linear regression analysis, estimated poor outcomes were calculated as the sum of the percentages determined for each of these predictors: gestational age (26, 25, and 24 weeks; 0, 17, and 34%, respectively), gender-specific birthweight percentile group (>75th, 25-75th, <25th percentiles; 0, 13, 26%, respectively), lack of prenatal steroid therapy (16%), and male gender (7%).
Estimated poor outcome rates for the 36 subgroups of infants ranged from 25% to 100% and correlated well with observed rates, at an intraclass correlation coefficient of 0.93.
"Our population-based study shows that the combined poor outcomes of death or severe morbidity at discharge of infants born at 24 to 26 weeks' gestation were significantly influenced by three parameters available at birth in addition to [gestational age]," write the authors.
Kugelman et al conclude that although their study used data from Israel, the principles of its model may help to create estimation tools for other populations using their own morbidity and mortality data.
By Piriya Mahendra