<p><strong>OBJECTIVE: </strong>Furosemide renal clearance is slow after very preterm (VP) birth and increases with postnatal maturation. We compared furosemide dose frequency and total daily dose between postmenstrual age (PMA) groups in VP infants.</p>

<p><strong>STUDY DESIGN: </strong>Observational cohort study of VP infants exposed to a repeated-dose course of furosemide in Pediatrix neonatal intensive care units (NICU) from 1997 to 2016.</p>

<p><strong>RESULTS: </strong>We identified 6565 furosemide courses among 4638 infants. There were no statistically significant differences between PMA groups on the odds of receiving more frequent furosemide dosing. Furosemide courses initiated at &lt;28 weeks PMA were associated with a higher total daily dose than those initiated at a later PMA.</p>

<p><strong>CONCLUSIONS: </strong>Furosemide dosing practices in the NICU are similar across PMA groups, despite maturational changes in drug disposition. Research is needed to identify and test rational dosing strategies across the PMA spectrum for this commonly used but unproven pharmacotherapy.</p>

<p><strong>OBJECTIVE: </strong>Examine the effect of off-label surfactant on mortality and morbidity in more mature and larger premature infants diagnosed with respiratory distress syndrome (RDS).</p>

<p><strong>STUDY DESIGN: </strong>Cohort study of premature infants born at 30-36 weeks, birth weight &gt; 2 kg, and a diagnosis of RDS. We compared the odds of mortality and morbidity between infants who were exposed vs unexposed to surfactant. We used a treatment effects model to balance covariates between groups.</p>

<p><strong>RESULTS: </strong>Of 54,964 included infants, 25,278 (46%) were exposed to surfactant. The frequency of mortality and morbidities were higher in the exposed group in unadjusted analyses. Following adjustment with a doubly robust treatment effects model, we found no significant treatment effect of surfactant on mortality or morbidity.</p>

<p><strong>CONCLUSION: </strong>Surfactant exposure is not associated with reduced or increased mortality or morbidity in more mature premature infants with RDS.</p>

<p><strong>IMPORTANCE: </strong>Postnatally acquired cytomegalovirus (CMV) is typically benign in term infants but in very low-birth-weight (VLBW) infants can cause pneumonitis and sepsislike illness. Whether postnatal CMV infection results in long-term pulmonary sequelae in these infants is unknown.</p>

<p><strong>OBJECTIVE: </strong>To investigate the association between postnatal CMV infection and bronchopulmonary dysplasia (BPD) and mortality in a large multicenter cohort of VLBW infants.</p>

<p><strong>DESIGN, SETTING, AND PARTICIPANTS: </strong>Conducted between October 2014 and June 2015, this propensity-matched retrospective cohort study involved 101,111 hospitalized VLBW (&lt;1500 g) infants at 348 neonatal intensive care units in the United States from 1997 to 2012. We matched infants with postnatal CMV infection 1:1 to comparison infants using propensity scores, and we used Poisson regression to examine the effect of postnatal CMV on the combined risk for death or BPD at 36 weeks' postmenstrual age. To describe features of postnatal CMV infection, we extracted clinical and laboratory data from 7 days before until 7 days after infants met criteria for postnatal CMV.</p>

<p><strong>EXPOSURES: </strong>Postnatal CMV infection was defined as a diagnosis of CMV or detection of CMV from blood, urine, cerebrospinal fluid, or respiratory secretions on or after day of life 21. Infants with a CMV diagnosis or virologic detection of CMV prior to day of life 21 were not considered to have postnatal infection.</p>

<p><strong>MAIN OUTCOMES AND MEASURES: </strong>The primary outcome was death or BPD at 36 weeks' postmenstrual age.</p>

<p><strong>RESULTS: </strong>Of 101,111 infants, 328 (0.3%) had postnatal CMV infection. We matched a comparison infant to 303 CMV-infected infants (92%) for a final cohort of 606 infants. The median gestational age and birth weight of this cohort were 25 weeks and 730 g, respectively. Postnatal CMV infection was associated with an increased risk for death or BPD at 36 weeks' postmenstrual age (risk ratio, 1.21; 95% CI, 1.10-1.32) and BPD (risk ratio, 1.33; 95% CI, 1.19-1.50). Changes in cardiorespiratory status associated with postnatal CMV infection included a new requirement for vasopressor medications (9%; n = 29), intubation for mechanical ventilation (15%; n = 49), a new oxygen requirement (28%; n = 91), and death (1.2%; n = 4).</p>

<p><strong>CONCLUSIONS AND RELEVANCE: </strong>In VLBW infants, postnatal CMV infection was associated with increased risk for BPD. Further studies are needed to determine the role of preventive measures against CMV in this population.</p>