Twin gestation and neurodevelopmental outcome in extremely low birth weight infants.

OBJECTIVE: The purpose of this work was to compare the risk-adjusted incidence of death or neurodevelopmental impairment at 18 to 22 months' corrected age between twin and singleton extremely low birth weight infants. We hypothesized that twin gestation is independently associated with increased risk of death or adverse neurodevelopmental outcomes at 18 to 22 months' corrected age in these infants. METHODS: We conducted a retrospective study of inborn extremely low birth weight infants admitted to Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network units between 1997 and 2005, who either died or had follow-up data available at 18 to 22 months' corrected age. Neurodevelopmental impairment, the primary outcome variable, was defined as the presence of any 1 of the following: moderate or severe cerebral palsy, severe bilateral hearing loss, bilateral blindness, Bayley Mental Developmental Index or Psychomotor Developmental Index of <70. Death was included with neurodevelopmental impairment as a composite outcome. Results were compared for both twins, twin A, twin B, same-gender twins, unlike-gender twins, and singleton infants. Logistic regression analysis was performed to control for demographic and clinical factors that were different among the groups. RESULTS: The cohort of infants who either died or were assessed for neurodevelopmental impairment consisted of 7630 singleton infants and 1376 twins. Logistic regression adjusting for clinical and sociodemographic risk factors showed an increased risk of death or neurodevelopmental impairment for twins as a group when compared with the singletons. On analyzing twin A and B separately as well, risk of death or neurodevelopmental impairment was increased in both twin A and twin B. CONCLUSIONS: Twin gestation in extremely low birth weight infants is associated with an independent increased risk of death or neurodevelopmental impairment at 18 to 22 months' corrected age compared with singleton-gestation infants. Both first- and second-born twins are at increased risk.

Maternal age, multiple birth, and extremely low birth weight infants.

OBJECTIVES: To compare the rates of adverse neurodevelopmental outcome or death at 18 to 22 months among extremely low birth weight (ELBW) infants born to mothers >or=4 0 years to the corresponding rates among infants of younger mothers. STUDY DESIGN: Prospective evaluation of ELBW infants to quantify the relative risks of maternal age and multiple birth for death or adverse neurodevelopmental outcome. RESULTS: The sample consisted of 14 671 live ELBW births divided into maternal age groups: <20, 20 to 29, 30 to 39, and >or= 40 years. Of infants born to mothers >or= 40 years, 20% were multiples. Mothers >or= 40 years had high rates of obstetric interventions and medical morbidities compared with mothers <40 years. ELBW live births of mothers >or= 40 years were 22% more likely to survive and had a 13% decreased risk of neurodevelopmental impairment or death compared with mothers <20. Multiple birth, however, was associated with a 10% greater risk of neurodevelopmental impairment or death. CONCLUSION: Although mothers >or= 40 years had high pregnancy-related morbidities, we found no overall increased risk of the composite outcome of death or NDI. Multiple birth, however, was a predictor of all adverse outcomes examined, regardless of maternal age.

Aggressive vs. conservative phototherapy for infants with extremely low birth weight.

BACKGROUND: It is unclear whether aggressive phototherapy to prevent neurotoxic effects of bilirubin benefits or harms infants with extremely low birth weight (1000 g or less). METHODS: We randomly assigned 1974 infants with extremely low birth weight at 12 to 36 hours of age to undergo either aggressive or conservative phototherapy. The primary outcome was a composite of death or neurodevelopmental impairment determined for 91% of the infants by investigators who were unaware of the treatment assignments. RESULTS: Aggressive phototherapy, as compared with conservative phototherapy, significantly reduced the mean peak serum bilirubin level (7.0 vs. 9.8 mg per deciliter [120 vs. 168 micromol per liter], P<0.01) but not the rate of the primary outcome (52% vs. 55%; relative risk, 0.94; 95% confidence interval [CI], 0.87 to 1.02; P=0.15). Aggressive phototherapy did reduce rates of neurodevelopmental impairment (26%, vs. 30% for conservative phototherapy; relative risk, 0.86; 95% CI, 0.74 to 0.99). Rates of death in the aggressive-phototherapy and conservative-phototherapy groups were 24% and 23%, respectively (relative risk, 1.05; 95% CI, 0.90 to 1.22). In preplanned subgroup analyses, the rates of death were 13% with aggressive phototherapy and 14% with conservative phototherapy for infants with a birth weight of 751 to 1000 g and 39% and 34%, respectively (relative risk, 1.13; 95% CI, 0.96 to 1.34), for infants with a birth weight of 501 to 750 g. CONCLUSIONS: Aggressive phototherapy did not significantly reduce the rate of death or neurodevelopmental impairment. The rate of neurodevelopmental impairment alone was significantly reduced with aggressive phototherapy. This reduction may be offset by an increase in mortality among infants weighing 501 to 750 g at birth. (ClinicalTrials.gov number, NCT00114543.)

Does labor influence neonatal and neurodevelopmental outcomes of extremely-low-birth-weight infants who are born by cesarean delivery?

OBJECTIVE: The purpose of this study was to examine the influence of labor on extremely-low-birth-weight infants who were born by cesarean delivery with reference to neonatal and neurodevelopmental outcomes. We hypothesized that infants who are born by cesarean delivery without labor will have better outcomes than those infants who are born by cesarean delivery with labor. STUDY DESIGN: This was a retrospective cohort study of extremely-low-birth-weight infants (birth weight, 401-1000 g) who were born by cesarean delivery and cared for in the National Institute for Child Health and Human Development Neonatal Network, during calendar years 1995 to 1997. A total of 1606 extremely-low-birth-weight infants were born by cesarean delivery and survived to discharge. Of these, 1273 infants (80.8%) were examined in the network follow-up clinics at 18 to 22 months of corrected age and had a complete data set (667 infants were born without labor, 606 infants were born with labor). Outcome variables that were examined include intraventricular hemorrhage grade 3 to 4, periventricular leukomalacia, and neurodevelopmental impairment. RESULTS: Mothers in the cesarean delivery without labor group were older (P<.001), more likely to be married (P<.05), less likely to be supported by Medicaid (P<.01), more likely to have preeclampsia/hypertension (P<.001), more likely to receive prenatal steroids (P<.005), and less likely to have received antibiotics (P<.001). Infants who were born by cesarean delivery without labor had higher gestational age (P<.001), lower birth weight (P<.01), and were less likely to be outborn (P<.001). By univariate analysis, infants who were born by cesarean delivery with labor had a higher incidence of grade 3 to 4 intraventricular hemorrhage (23.3% vs 12.1%, P<.001), periventricular leukomalacia (8.5% vs 4.7%, P<.02), and neurodevelopmental impairment (41.7% vs 34.6%, P<.02). Logistic regression analysis that controlled for all maternal and neonatal demographic and clinical variables that were statistically associated with labor or no labor revealed that the significant differences in grade 3 to 4 intraventricular hemorrhage, periventricular leukomalacia, and neurodevelopmental impairment were no longer evident. CONCLUSION: In extremely-low-birth-weight infants who were born by cesarean delivery and after control for other risk factors, labor does not appear to play a significant role in adverse neonatal outcomes and neurodevelopmental impairment at 18 to 22 months of corrected age.