OBJECTIVE: The objective of this study was to create and validate new intrauterine weight, length, and head circumference growth curves using a contemporary, large, racially diverse US sample and compare with the Lubchenco curves.METHODS: Data on 391 681 infants (Pediatrix Medical Group) aged 22 to 42 weeks at birth from 248 hospitals within 33 US states (1998–2006) for birth weight, length, head circumference, estimated gestational age, gender, and race were used. Separate subsamples were used to create and validate curves. Smoothed percentile curves (3rd to 97th) were created by the Lambda Mu Sigma (LMS) method. The validation sample was used to confirm representativeness of the curves. The new curves were compared with the Lubchenco curves.RESULTS: Final sample included 257 855 singleton infants (57.2% male) who survived to discharge. Gender-specific weight-, length-, and head circumference-for-age curves were created (n = 130 111) and successfully validated (n = 127 744). Small-for-gestational age and large-for-gestational age classifications using the Lubchenco curves differed significantly from the new curves for each gestational age (all P < .0001). The Lubchenco curves underestimated the percentage of infants who were small-for-gestational-age except for younger girls (≤36 weeks), for whom it was more likely to be overestimated; underestimated percentage of infants (≤36 weeks) who were large-for-gestational-age; and overestimated percentage of infants (>36 weeks) who were large-for-gestational-age.CONCLUSIONS: The Lubchenco curves may not represent the current US population. The new intrauterine growth curves created and validated in this study, based on a contemporary, large, racially diverse US sample, provide clinicians with an updated tool for growth assessment in US NICUs. Research into the ability of the new definitions of small-for-gestational-age and large-for-gestational-age to identify high-risk infants in terms of short-term and long-term health outcomes is needed.

Inhaled nitric oxide improves gas exchange in neonates, but the efficacy of low-dose inhaled nitric oxide in reducing the need for extracorporeal membrane oxygenation has not been established.

Background. Poor growth is a common problem in premature neonates and may be associated with neurodevelopmental delay. Objective. To evaluate the incidence of extrauterine growth restriction (growth values ≤10th percentile of intrauterine growth expectation based on estimated postmenstrual age in premature (23–34 weeks’ estimated gestational age) neonates at the time they are discharged from the hospital. Design/Methods. Using a database formed from a computer-assisted tool that generates clinical progress notes and discharge summaries on neonatal intensive care unit admissions, we reviewed data on neonates discharged from 124 neonatal intensive care units between January 1, 1997, and December 31, 2000. We evaluated neonates who were born between 23 and 34 weeks’ estimated gestational age without congenital anomalies and who were cared for at and discharged from the same hospital. For each patient, we compared the discharge growth values to the expected values based on our intrauterine growth data and postmenstrual age on the day of discharge. We defined extrauterine growth restriction as having a measured growth value (weight, length or head circumference) that was ≤10th percentile of the predicted value. In each specific birth weight and estimated gestational age group, we counted the number of neonates ≤10th percentile for each growth parameter and calculated the percentage of patients who had values ≤10th percentile at discharge. Using logistic regression, we evaluated the factors associated with extrauterine growth restriction for weight, length, and head circumference. Results. Our sample included 24 371 premature neonates. Data on discharge weight, length, and head circumference was available on 23 970, 17 203, and 20 885 neonates, respectively. The incidence of extrauterine growth restriction was common (28%, 34%, and 16% for weight, length, and head circumference, respectively). For each growth parameter, the incidence of extrauterine growth restriction increased with decreasing estimated gestational age and birth weight. Factors independently associated with extrauterine growth restriction were male gender, need for assisted ventilation on day 1 of life, a history of necrotizing enterocolitis, need for respiratory support at 28 days of age, and exposure to steroids during the hospital course. Conclusions. Extrauterine growth restriction remains a serious problem in premature neonates especially for neonates who are small, immature, and critically ill.

The incidence of the neonatal abstinence syndrome, a drug-withdrawal syndrome that most commonly occurs after in utero exposure to opioids, is known to have increased during the past decade. However, recent trends in the incidence of the syndrome and changes in demographic characteristics and hospital treatment of these infants have not been well characterized.