Association of Neurodevelopmental Outcomes and Neonatal Morbidities of Extremely Premature Infants With Differential Exposure to Antenatal Steroids

Background: Very preterm (VPT) delivery after severe preeclampsia (PE) has been associated with adverse perinatal outcome. It is unclear whether fetal exposure to PE per se modifies the prevalence of neonatal morbidities associated with VPT birth. Objectives: To evaluate neonatal morbidity in VPT infants exposed to maternal PE compared to morbidity in nonexposed VPT infants. Methods: This retrospective study consisted of all inborn infants delivered before 30 gestational weeks admitted to a tertiary-level neonatal intensive care unit between 1998 and 2014: 195 infants exposed to maternal PE were compared to 957 infants without maternal PE (background group). Prevalence rates of neonatal morbidity, cerebral palsy (CP), and mortality at 2 years of age were obtained from patient records. Results: The PE group had a lower median (IQR) birth weight (795 [262] g) and a higher median gestational age (GA) (27 [3] weeks) at birth than the background group (890 [385] g and 26 [3] weeks, respectively; both p < 0.001). Exposure to maternal PE was associated with lower rates of severe intraventricular hemorrhage (IVH) (2 vs. 11%), retinopathy of prematurity requiring treatment (2 vs. 7%), mortality (9 vs. 15%), and CP (4 vs. 8%). Exposure to PE remained associated with a reduced prevalence of severe IVH (OR 0.17, 95% CI 0.05–0.57) after adjustment for GA, multiple birth, Apgar score, delivery mode, sex, and antenatal steroid treatment. Conclusion: Fetal exposure to PE is associated with a decreased rate of severe IVH following VPT birth. Studies on underlying mechanisms may provide a basis for prevention of IVH in the VPT infant.

Bronchopulmonary dysplasia (BPD) is one of the few diseases in neonatal medicine that has continued to evolve since its first description about 50 years ago. Over these years, advancements in neonatal medicine such as antenatal steroids and exogenous surfactant therapy have significantly reduced neonatal mortality and lowered the limits of viability for preterm infants. Although the incidence of BPD continues to be high, especially in extremely low birth weight infants, the clinical picture has evolved into a milder disease with low mortality or significant morbidities. This new BPD is the result of complex interactions between altered alveolar and vascular development, injury by ante- and postnatal pathogenic factors, and reparative processes in the lung. There has been significant progress in our understanding of risk factors for BPD, but challenges persist in its definition, and in finding effective preventive strategies. There are promising developments with newer preventive interventions such as mesenchymal stem cells, exosomes, immunomodulators, and growth factors, but they are still in preclinical stage. The future challenges include finding ways to define BPD based on the severity of lung pathology, which can better predict long-term outcomes, development of early predictors of lung disease, and finding innovative and evidence-based preventive and management strategies.

Objective We aimed to compare the rates of “surfactant treated respiratory disease” and other neonatal morbidities among moderately preterm (MPT) infants exposed to no, partial, or a complete course of antenatal corticosteroids (ANS). Study Design This observational cohort study evaluated MPT infants (290/7–336/7 weeks’ gestational age), born between January 2012 and November 2013 and enrolled in the “MPT Registry” of the National Institute of Child Health and Human Development Neonatal Research Network. Results Data were available for 5,886 infants, including 676 with no exposure, 1225 with partial, and 3,985 with a complete course of ANS. Among no, partial, and complete ANS groups, respectively, there were significant differences in rates of delivery room resuscitation (4.1, 1.4, and 1.2%), surfactant-treated respiratory disease (26.5, 26.3, and 20%), and severe intracranial hemorrhage (3, 2, and 0.8%). Complete ANS course was associated with lower surfactant-treated respiratory disease, compared with partial ANS (odds ratio [OR] 0.62; 95% confidence interval [CI] 0.52–0.74), and no ANS groups (OR 0.52; 95% CI 0.41–0.66) on adjusted analysis. Conclusion In MPT infants, ANS exposure is associated with lower delivery room resuscitation, surfactant-treated respiratory disease, and severe intracranial hemorrhage; with the lowest frequency of morbidities associated with a complete course.