Effects of pre- and postnatal maternal stress on infant temperament and autonomic nervous system reactivity and regulation in a diverse, low-income population.

We examined the prospective associations of objective and subjective measures of stress during pregnancy with infant stress reactivity and regulation, an early-life predictor of psychopathology. In a racially and ethnically diverse low-income sample of 151 mother-infant dyads, maternal reports of stressful life events (SLE) and perceived stress (PS) were collected serially over gestation and the early postpartum period. Infant reactivity and regulation at 6 months of age was assessed via maternal report of temperament (negativity, surgency, and regulation) and infant parasympathetic nervous system physiology (respiratory sinus arrhythmia [RSA]) during the Still Face Paradigm. Regression models predicting infant temperament showed higher maternal prenatal PS predicted lower surgency and self-regulation but not negativity. Regression models predicting infant physiology showed higher numbers of SLE during gestation predicted greater RSA reactivity and weaker recovery. Tests of interactions revealed SLE predicted RSA reactivity only at moderate to high levels of PS. Thus, findings suggest objective and subjective measures of maternal prenatal stress uniquely predict infant behavior and physiology, adjusting for key pre- and postnatal covariates, and advance the limited evidence for such prenatal programming within high-risk populations. Assessing multiple levels of maternal stress and offspring stress reactivity and regulation provides a richer picture of intergenerational transmission of adversity.

Patient-to-nurse ratios and outcomes of moderately preterm infants.

OBJECTIVE: Moderately preterm infants (30-34(6/7) weeks' gestational age) represent the largest population of NICU residents. Whether their clinical outcomes are associated with differences in NICU nurse-staffing arrangements has not been assessed. The objective of this study was to test the influence of patient-to-nurse ratios (PNRs) on outcomes of care provided to moderately preterm infants. PATIENTS AND METHODS: Using data from a prospective, multicenter, observational cohort study of 850 moderately preterm infants from 10 NICUs in California and Massachusetts, we tested for associations between PNR and several important clinical outcomes by using multivariate random-effects models. To correct for the influence of NICU size, we dichotomized the sample into those with an average daily census of <20 or > or =20 infants. RESULTS: Overall, we found few clinically significant associations between PNR and clinical outcomes of care. Mean PNRs were higher in large compared with small NICUs (2.7 vs 2.1; P < .001). In bivariate analyses, an increase in PNR was associated with a slightly higher daily weight gain (5 g/day), greater gestational age at discharge, any intraventricular hemorrhage, and severe retinopathy of prematurity. After controlling for case mix, NICU size, and site of care, an additional patient per nurse was associated with a decrease in daily weight gain by 24%. Other variables were no longer independently associated with PNR. CONCLUSIONS: In this population of moderately preterm infants, the PNR was associated with a decrease in daily weight gain, but was not associated with other measures of quality. In contrast with findings in the adult intensive care literature, measured clinical outcomes were similar across the range of nurse-staffing arrangements among participating NICUs. We conclude that the PNR is not useful for profiling hospitals' quality of care delivery to moderately preterm infants.

Neonatal intensive care unit census influences discharge of moderately preterm infants.

OBJECTIVE: The timely discharge of moderately premature infants has important economic implications. The decision to discharge should occur independent of unit census. We evaluated the impact of unit census on the decision to discharge moderately preterm infants. DESIGN/METHODS: In a prospective multicenter cohort study, we enrolled 850 infants born between 30 and 34 weeks' gestation at 10 NICUs in Massachusetts and California. We divided the daily census from each hospital into quintiles and tested whether discharges were evenly distributed among them. Using logistic regression, we analyzed predictors of discharge within census quintiles associated with a greater- or less-than-expected likelihood of discharge. We then explored parental satisfaction and postdischarge resource consumption in relation to discharge during census periods that were associated with high proportions of discharge. RESULTS: There was a significant correlation between unit census and likelihood of discharge. When unit census was in the lowest quintile, patients were 20% less likely to be discharged when compared with all of the other quintiles of unit census. In the lowest quintile of unit census, patient/nurse ratio was the only variable associated with discharge. When census was in the highest quintile, patients were 32% more likely to be discharged when compared with all of the other quintiles of unit census. For patients in this quintile, a higher patient/nurse ratio increased the likelihood of discharge. Conversely, infants with prolonged lengths of stay, an increasing Score for Neonatal Acute Physiology II, and minor congenital anomalies were less likely to be discharged. Infants discharged at high unit census did not differ from their peers in terms of parental satisfaction, emergency department visits, home nurse visits, or rehospitalization rates. CONCLUSIONS: Discharges are closely correlated with unit census. Providers incorporate demand and case mix into their discharge decisions.