Racial/ethnic differences in preterm perinatal outcomes

Racial/ethnic disparities and human milk use in necrotizing enterocolitis

BACKGROUND

The impact of human milk use on racial/ethnic disparities in necrotizing enterocolitis (NEC) incidence is unknown.

METHODS

Trends in NEC incidence and human milk use at discharge were evaluated by race/ethnicity among 47,112 very low birth weight infants born in California from 2008 to 2017. We interrogated the association between race/ethnicity and NEC using multilevel regression analysis, and evaluated the effect of human milk use at discharge on the relationship between race/ethnicity and NEC using mediation analysis.

RESULTS

Annual NEC incidence declined across all racial/ethnic groups from an aggregate average of 4.8% in 2008 to 2.6% in 2017. Human milk use at discharge increased over the time period across all racial groups, and non-Hispanic (NH) black infants received the least human milk each year. In multivariable analyses, Hispanic ethnicity (odds ratio (OR) 1.27, 95% confidence interval (CI) 1.02-1.57) and Asian or Pacific Islander race (OR 1.35, 95% CI 1.01-1.80) were each associated with higher odds of NEC, while the association of NH black race with NEC was attenuated after adding human milk use at discharge to the model. Mediation analysis revealed that human milk use at discharge accounted for 22% of the total risk of NEC in non-white vs. white infants, and 44% in black vs. white infants.

CONCLUSIONS

Although NEC incidence has declined substantially over the past decade, a sizable racial/ethnic disparity persists. Quality improvement initiatives augmenting human milk use may further reduce the incidence of NEC in vulnerable populations.

Early neurobehavior at 30 weeks postmenstrual age is related to outcome at term equivalent age

AIMS

To determine 1) the relationship between infant medical factors and early neurobehavior, and 2) the relationship between early neurobehavior at 30 weeks postmenstrual age (PMA) and neurobehavior at term equivalent age.

STUDY DESIGN

In this prospective longitudinal study, 88 very preterm infants born ≤30 weeks estimated gestational age (EGA) had neurobehavioral assessments at 30 weeks PMA using the Premie-Neuro and at term equivalent age using the NICU Network Neurobehavioral Scale (NNNS) and Hammersmith Neonatal Neurological Evaluation (HNNE).

RESULTS

Lower Premie-Neuro scores at 30 weeks PMA were related to being more immature at birth (p = 0.01; β = 3.87); the presence of patent ductus arteriosus (PDA; p < 0.01; β = -16.50) and cerebral injury (p < 0.01; β = -20.46); and prolonged exposure to oxygen therapy (p < 0.01; β = -0.01), endotracheal intubation (p < 0.01; β = -0.23), and total parenteral nutrition (p < 0.01; β = -0.35). After controlling for EGA, PDA, and number of days of endotracheal intubation, lower Premie-Neuro scores at 30 weeks PMA were independently related to lower total HNNE scores at term (p < 0.01; β = 0.12) and worse outcome on the NNNS with poorer quality of movement (p < 0.01; β = 0.02) and more stress (p < 0.01; ß = -0.004), asymmetry (p = 0.01; β = -0.04), excitability (p < 0.01; β = -0.05) and suboptimal reflexes (p < 0.01; ß = -0.06).

CONCLUSION

Medical factors were associated with early neurobehavioral performance at 30 weeks PMA. Early neurobehavior at 30 weeks PMA was a good marker of adverse neurobehavior at NICU discharge.

Influence of Patient Characteristics on Antibiotic Use Rates Among Preterm Infants

BACKGROUND

The antibiotic use rate (AUR) has emerged as a potential metric for neonatal antibiotic use, but reported center-level AURs are limited by differences in case mix. The objective of this study was to identify patient characteristics associated with AUR among a large cohort of preterm infants.

METHODS

Retrospective observational study using the Optum Neonatal Database, including infants born from January 1, 2010 through November 30, 2016 with gestational age 23-34 weeks admitted to neonatal units across the United States. Exposures were patient-level characteristics including length of stay, gestational age, sex, race/ethnicity, bacterial sepsis, necrotizing enterocolitis, and survival status. The primary outcome was AUR, defined as days with ≥ 1 systemic antibiotic administered divided by length of stay. Descriptive statistics, univariable comparative analyses, and generalized linear models were utilized.

RESULTS

Of 17 910 eligible infants, 17 836 infants (99.6%) from 1090 centers were included. Median gestation was 32.9 (interquartile range [IQR], 30.3-34) weeks. Median length of stay was 25 (IQR, 15-46) days and varied by gestation. Overall median AUR was 0.13 (IQR, 0-0.26) and decreased over time. Gestational age, sex, and race/ethnicity were independently associated with AUR (P < .01). AUR and gestational age had an unexpected inverse parabolic relationship, which persisted when only surviving infants without bacterial sepsis or necrotizing enterocolitis were analyzed.

CONCLUSIONS

Neonatal AURs are influenced by patient-level characteristics besides infection and survival status, including gestational age, sex, and race/ethnicity. Neonatal antibiotic use metrics that account for patient-level characteristics as well as morbidity case mix may allow for more accurate comparisons and better inform neonatal antibiotic stewardship efforts.

Oxidative Stress Biomarker Decreased in Preterm Neonates Treated With Kangaroo Mother Care

OBJECTIVE

Due to physiological and metabolic immaturity, prematurely born infants are at increased risk because of maternal separation in many neonatal intensive care units (NICUs). The stress induced from maternal-infant separation can lead to well-documented short-term physiologic instability and potentially lifelong neurological, sociological, or psychological sequelae. Based on previous studies of kangaroo mother care (KMC) that demonstrated improvement in physiologic parameters, we examined the impact of KMC on physiologic measures of stress (abdominal temperature, heart rate, oxygen saturation, perfusion index, near-infrared spectrometry), oxidative stress, and energy utilization/conservation in preterm infants.

METHODS

In this randomized, stratified study of premature neonates, we compared the effects on urinary concentrations of biomarkers of energy utilization and oxidative stress of 1 hr of KMC versus incubator care on Day 3 of life in intervention-group babies (n = 26) and control-group babies (n = 25), respectively. On Day 4, both groups received 1 hr of KMC. Urinary samples were collected 3 hr before and 3 hr after intervention/incubator care on both days. Energy utilization was assessed by measures of adenosine triphosphate (ATP) degradation (i.e., hypoxanthine, xanthine, and uric acid). Oxidative stress was assessed using urinary allantoin. Mixed-models analysis was used to assess differences in purine/allantoin.

RESULTS

Mean allantoin levels over Days 3 and 4 were significantly lower in the KMC group than in the control group (p = .026).

CONCLUSIONS

Results provide preliminary evidence that KMC reduces neonatal oxidative stress processes and that urinary allantoin could serve as an effective noninvasive marker for future studies.

A population-based study to identify the prevalence and correlates of the dual burden of severe maternal morbidity and preterm birth in California

BACKGROUND

Prior studies have documented associations between preterm birth and severe maternal morbidity (SMM) but the prevalence and correlates of dual burden are not adequately understood, despite significant family implications.

PURPOSE

To describe the prevalence and correlates of the dual burden of SMM and preterm birth and to understand profiles of SMM by dual burden of preterm birth.Approach: This retrospective cohort study included all California live births in 2007-2012 with gestations 20-44 weeks and linked to a birth cohort database maintained by the California Office of Statewide Health Planning and Development (n = 3,059,156). Dual burden was defined as preterm birth (<37 weeks) with severe maternal morbidity (SMM, defined by Centers for Disease Control). Predictors for dual burden were assessed using Poisson logistic regression, accounting for hospital variance.

RESULTS

Rates of preterm birth and SMM were 876 and 140 per 10,000 births, respectively. The most common indications of SMM both with and without preterm birth were blood transfusions and a combination of cardiac indications. One-quarter of women with SMM experienced preterm birth with a dual burden rate of 37 per 10,000 births. Risk of dual burden was over threefold higher with cesarean birth (primiparous primary aRR = 3.3, CI = 3.0-3.6; multiparous primary aRR = 8.1, CI = 7.2-9.1; repeat aRR = 3.9, CI = 3.5-4.3). Multiple gestation conferred a six-fold increased risk (aRR = 6.3, CI = 5.8-6.9). Women with preeclampsia superimposed on gestational hypertension (aRR = 7.3, CI = 6.8-7.9) or preexisting hypertension (aRR = 11.1, CI = 9.9-12.5) had significantly higher dual burden risk. Significant independent predictors for dual burden included smoking during pregnancy (aRR = 1.5, CI = 1.4-1.7), preexisting hypertension without preeclampsia (aRR = 3.3, CI = 3.0-3.7), preexisting diabetes (aRR = 2.6, CI = 2.3-3.0), Black race/ethnicity (aRR = 2.0, CI = 1.8-2.2), and prepregnancy body mass index <18.5 (aRR = 1.4, CI = 1.3-1.5).

CONCLUSIONS

Dual burden affects 1900 California families annually. The strongest predictors of dual burden were hypertensive disorders with preeclampsia and multiparous primary cesarean.

Risk of Adverse Pregnancy Outcomes at Advanced Maternal Age

OBJECTIVE

To study the possible associations between advanced maternal age and risk of selected adverse pregnancy outcomes.

METHODS

The study used a nationwide cohort of 369,516 singleton pregnancies in Denmark followed from 11-14 weeks of gestation to delivery or termination of pregnancy. Pregnant women aged 35 years or older were divided into two advanced maternal age groups, 35-39 years and 40 years or older, and compared with pregnant women aged 20-34 years. Adverse pregnancy outcomes were chromosomal abnormalities, congenital malformations, miscarriage, stillbirth, and birth before 34 weeks of gestation. Multivariable logistic regression analyses were performed to investigate associations between advanced maternal age and adverse pregnancy outcomes. Furthermore, a risk prediction model for a composite adverse pregnancy outcome was made with prespecified predicting factors.

RESULTS

Among the pregnant women aged 40 years or older, 10.82% experienced one or more of the selected adverse pregnancy outcomes compared with 5.46% of pregnant women aged 20-34 years (odds ratio [OR] 2.02, 99.8% CI 1.78-2.29). When pregnant women 40 years or older were compared with women aged 20-34 years, they had a higher risk of chromosomal abnormalities (3.83% vs 0.56%, OR 7.44 [CI 5.93-9.34]), miscarriage (1.68% vs 0.42%, OR 3.10 [CI 2.19-4.38]), and birth before 34 weeks of gestation (2.01% vs 1.21%, OR 1.66 [CI 1.23-2.24]), but no increased risk of congenital malformations and stillbirth. The risk prediction chart showed that advanced maternal age, use of assisted reproductive technology, nulliparous pregnancy, smoking during pregnancy, and obesity increased the absolute predictive risk of an adverse pregnancy outcome.

CONCLUSION

Women older than 40 years have a higher risk of chromosomal abnormalities, miscarriage, and birth before 34 weeks of gestation than younger women and should be monitored accordingly. No increased risk was observed for stillbirth and other congenital malformations. Several factors increase the risk of adverse pregnancy outcomes, but advanced maternal age drives a high proportion of the total risk score.

Elective caesarean section on maternal request prior to 39 gestational weeks and childhood psychopathology: a birth cohort study in China

BACKGROUND

The recommendation of non-indicated caesarean section (CS) after 39 gestational weeks has been announced based on evidence of maternal and infant physiological effects. The potential psychological risks have not been acknowledged. This study aims to investigate emotional and behavioral problems in pre-school children born with elective CS (ECS) on maternal request prior to 39 weeks.

METHODS

Pregnant women within 12 gestational weeks between November 2008 and October 2010 were invited to participate in the China-Anhui Birth Cohort Study (C-ABCS). They were asked to complete a self-administered questionnaire respectively in 1st and 3rd trimester of pregnancy to collect basic maternal characteristics. Pregnant complications and delivery modes were abstracted from medical notes. Their singleton live births were followed up at preschool age. Strengths and Difficulties Questionnaires (SDQ) were completed by parents to assess children's emotional and behavioral problems. A total of 3319 mother-child pairs were put into the final analysis. Descriptive analysis and binary logistic regression analysis were used to assess the impact of delivery modes on abnormalities in SDQ dimensions at various gestational ages.

RESULTS

The prevalence of ECS on maternal request prior to 39 weeks, at 39-40 weeks, and after 41 weeks was 16.6, 23.7 and 15.9%, respectively. Compared with those born vaginally, children born with ECS on maternal request were more likely to have total difficult problems (RR 1.519, 95% confidence interval 1.077 to 2.142). ECS on maternal request was the independent predictor of emotional problems (3.479, 1.676 to 7.222) and total difficult problems (2.172, 1.175 to 4.016) in children born prior to 39 gestational weeks.

CONCLUSION

Children delivered by ECS on maternal request have an increased risk to have emotional and behavioral problems prior to 39 gestational weeks at preschool age. The potential psychological implication prior to 39 weeks has been added to the roster of impacts of ECS on maternal request. Further research is needed to probe the potential biological mechanisms.

Sex-specific alterations in preterm brain

BACKGROUND

The literature on brain imaging in premature infants is mostly made up of studies that evaluate neonates, yet the most dynamic time of brain development happens from birth to 1 year of age. This study was designed to obtain quantitative brain measures from magnetic resonance imaging scans of infants born prematurely at 12 months of age.

METHODS

The subject group was designed to capture a wide range of gestational age (GA) from premature to full-term infants. An age-specific atlas generated quantitative brain measures. A regression model was used to predict effects of GA and sex on brain measures.

RESULTS

There was a primary effect of sex on: (1) intracranial volume, males > females; (2) proportional cerebral cortical gray matter (females > males), and (3) cerebral white matter (males > females). GA predicted cerebral volume and cerebral spinal fluid. GA also predicted cortical gray matter in a sex-specific manner with GA having a significant effect on cortical volume in the males, but not in females.

CONCLUSIONS AND RELEVANCE

Sex differences in brain structure are large early in life. GA had sex-specific effects highlighting the importance evaluating sex effects in neurodevelopmental outcomes of premature infants.

Racial and Ethnic Disparities in the Use of Mother's Milk Feeding for Very Low Birth Weight Infants in Massachusetts

OBJECTIVE

To examine the extent to which maternal race/ethnicity is associated with mother's milk use among hospitalized very low birth weight (VLBW) infants and maternal receipt of hospital breastfeeding support practices (human milk prenatal education, first milk expression <6 hours after delivery, lactation consultation <24 hours, any skin-to-skin care <1 month).

STUDY DESIGN

We studied 1318 mother-VLBW infant pairs in 9 Massachusetts level 3 neonatal intensive care units (NICUs) between January 2015 and November 2017. We estimated associations of maternal race/ethnicity with any and exclusive mother's milk on day 7, on day 28, and at discharge/transfer and hospital practices. We estimated HRs comparing the probability of continued milk use over the hospitalization by race/ethnicity and tested mediation by hospital practices, adjusting for birth weight and gestational age and including hospital and plurality as random effects.

RESULTS

Mothers were 48% non-Hispanic white, 21% non-Hispanic black, and 20% Hispanic. Initiation of mother's milk was similar across groups, but infants of Hispanic mothers (hazard ratio [HR], 2.71; 95% CI, 2.05-3.59) and non-Hispanic black mothers (HR, 1.55; 95% CI, 1.17-2.07) stopped receiving milk earlier in the hospitalization compared with infants of non-Hispanic white mothers. Hispanic mothers had lower odds of providing skin-to-skin care at <1 month (OR, 0.61; 95% CI, 0.43-0.87) compared with non-Hispanic whites.

CONCLUSIONS

Hispanic and non-Hispanic black mothers were less likely than non-Hispanic white mothers to continue providing milk for their VLBW infants throughout the NICU stay.

Outcomes of early inhaled nitric oxide use in premature African American neonates

OBJECTIVE

Meta-analysis of individual-patient clinical trial data suggests that inhaled nitric oxide (iNO) improves respiratory outcomes in premature African American neonates. We hypothesized that early iNO therapy would be associated with lower mortality and less chronic lung disease (CLD) in extremely premature African American neonates.

STUDY DESIGN

We conducted a retrospective cohort study of propensity score- and race-matched neonates 22-29 weeks gestation who were mechanically ventilated for treatment of respiratory distress and associated pulmonary hypertension (RDS + PPHN). We evaluated the association of iNO within 7 days of life with in-hospital mortality and CLD, using Cox proportional hazards regression and logistic regression, respectively.

RESULT

Among 178 matched pairs of African American patients, iNO was not associated with lower mortality (HR = 0.94, 95% CI 0.69-1.30) or less CLD (OR = 0.94, 95% CI 0.47-1.87).

CONCLUSIONS

Early, off-label iNO use is not associated with improved outcomes in premature African American neonates with RDS + PPHN.

Association of Race/Ethnicity With Very Preterm Neonatal Morbidities

IMPORTANCE

Severe morbidity in very preterm infants is associated with profound clinical implications on development and life-course health. However, studies of racial/ethnic disparities in severe neonatal morbidities are scant and suggest that these disparities are modest or null, which may be an underestimation resulting from the analytic approach used.

OBJECTIVE

To estimate racial/ethnic differences in severe morbidities among very preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study was conducted in New York City, New York, using linked birth certificate, mortality data, and hospital discharge data from January 1, 2010, through December 31, 2014. Infants born before 24 weeks' gestation, with congenital anomalies, and with missing data were excluded. Racial/ethnic disparities in very preterm birth morbidities were estimated through 2 approaches, conventional analysis and fetuses-at-risk analysis. The conventional analysis used log-binomial regression to estimate the relative risk of 4 severe neonatal morbidities for the racial/ethnic groups. For the fetuses-at-risk analysis, Cox proportional hazards regression with death as competing risk was used to estimate subhazard ratios associating race/ethnicity with each outcome. Estimates were adjusted for sociodemographic factors and maternal morbidities. Data were analyzed from September 5, 2017, to May 21, 2018.

MAIN OUTCOMES AND MEASURES

Four morbidity outcomes were defined using International Classification of Diseases, Ninth Revision, diagnosis and procedure codes: necrotizing enterocolitis, intraventricular hemorrhage, bronchopulmonary dysplasia, and retinopathy of prematurity.

RESULTS

In total, 582 297 infants were included in this study. Of these infants, 285 006 were female (48.9%) and 297 291 were male (51.0%). Using the conventional approach in the very preterm birth subcohort, black compared with white infants had an increased risk of only bronchopulmonary dysplasia (adjusted risk ratio [aRR], 1.34; 95% CI, 1.09-1.64) and a borderline increased risk of necrotizing enterocolitis (aRR, 1.39; 95% CI, 1.00-1.93). Hispanic infants had a borderline increased risk of necrotizing enterocolitis (aRR, 1.39; 95% CI, 0.98-1.96), and Asian infants had an increased risk of retinopathy of prematurity (aRR, 1.85; 95% CI, 1.15-2.97). In the fetuses-at-risk analysis, black infants had a 4.40 times higher rate of necrotizing enterocolitis (95% CI, 2.98-6.51), a 2.73 times higher rate of intraventricular hemorrhage (95% CI, 1.63-4.57), a 4.43 times higher rate of bronchopulmonary dysplasia (95% CI, 2.88-6.81), and a 2.98 times higher rate of retinopathy of prematurity (95% CI, 2.01-4.40). Hispanic infants had an approximately 2 times higher rate for all outcomes, and Asian infants had increased risk only for retinopathy of prematurity (adjusted hazard ratio, 2.43; 95% CI, 1.43-4.11).

CONCLUSIONS AND RELEVANCE

In this study, racial/ethnic disparities in neonatal morbidities among very preterm infants appear to be sizable, but may have been underestimated in previous studies, and may have implications for the future. Understanding these racial/ethnic disparities is important, as they may contribute to inequalities in health and development later in the child's life.

Effectiveness of Prenatal Vitamin D Deficiency Screening and Treatment Program: A Stratified Randomized Field Trial

CONTEXT

Despite evidence on the association between hypovitaminosis D and adverse pregnancy outcomes and the positive impact of vitamin D supplementation, no evidence exists supporting a universal screening program in pregnancy as part of routine prenatal care.

OBJECTIVE

We sought to determine the effectiveness of a prenatal screening program on optimizing 25-hydroxyvitamin D [25(OH)D] levels and preventing pregnancy complications. Also, to identify a safe regimen, we compared several regimens in a subgroup of vitamin D-deficient pregnant women.

DESIGN

Two cities of Masjed-Soleyman and Shushtar from Khuzestan province, Iran, were selected as the screening and nonscreening arms, respectively. Within the screening arm, a randomized controlled trial was conducted on 800 pregnant women.

SETTING

Health centers of Masjed-Soleyman and Shushtar cities.

PATIENTS OR PARTICIPANTS

Pregnant women aged 18 to 40 years.

INTERVENTION

Women with moderate [25(OH)D, 10 to 20 ng/mL] and severe [25(OH)D, <10 ng/mL] deficiency were randomly divided into four subgroups and received vitamin D3 (D3) until delivery.

MAIN OUTCOME MEASURE

Maternal concentration of 25(OH)D at delivery and rate of pregnancy complications.

RESULTS

After supplementation, only 2% of the women in the nonscreening site met the sufficiency level (>20 ng/mL) vs 53% of the women in the screening site. Adverse pregnancy outcomes, including preeclampsia, gestational diabetes mellitus, and preterm delivery, were decreased by 60%, 50%, and 40%, respectively, in the screening site. A D3 injection in addition to monthly 50,000 IU maintenance therapy contributed the most to achievement of sufficient levels at delivery.

CONCLUSIONS

A prenatal vitamin D screening and treatment program is an effective approach in detecting deficient women, improving 25(OH)D levels, and decreasing pregnancy adverse outcomes.

Cervical pessary to reduce preterm birth <34 weeks of gestation after an episode of preterm labor and a short cervix: a randomized controlled trial

BACKGROUND

To date, no intervention has proved effective in reducing the spontaneous preterm birth rate in singleton pregnancies following an episode of threatened preterm labor and short cervix remaining.

OBJECTIVE

This study was designed to ascertain whether cervical pessaries could be useful in preventing spontaneous preterm birth in women with singleton pregnancies and a short cervix after a threatened preterm labor episode.

STUDY DESIGN

This open randomized controlled trial was conducted in 357 pregnant women (between 24⁰-33⁶ weeks) who had not delivered 48 hours after a threatened preterm labor episode and had a short cervix remaining (≤25 mm at 24⁰-29⁶ weeks; ≤15 mm at 30⁰-33⁶ weeks). Patients were randomly assigned to cervical pessary (179) or routine management (178). The primary outcome was the spontaneous preterm birth rate <34 weeks. Spontaneous preterm birth <28 and 37 weeks and neonatal morbidity and mortality were also evaluated in an intention-to-treat analysis.

RESULTS

No significant differences between the pessary and routine management groups were observed in the spontaneous preterm birth rate <34 weeks (19/177 [10.7%] in the pessary group vs 24/175 [13.7%] in the control group; relative risk, 0.78; 95% confidence interval, 0.45-1.38). Spontaneous preterm birth <37 weeks occurred less frequently in the pessary group (26/175 [14.7%] vs 44/175 [25.1%]; relative risk, 0.58; 95% confidence interval, 0.38-0.90; P = .01). Preterm premature rupture of membranes rate was significantly lower in pessary carriers (4/177 [2.3%] vs 14/175 [8.0%]; relative risk, 0.28; 95% confidence interval, 0.09-0.84; P = .01). The pessary group less frequently required readmission for new threatened preterm labor episodes (8/177 [4.5%] vs 35/175 [20.0%]; relative risk, 0.23; 95% confidence interval, 0.11-0.47; P < .0001). No serious adverse maternal events occurred; neonatal morbidity and mortality were similar in both groups.

CONCLUSION

Pessary use did not significantly lower the spontaneous preterm birth rate <34 weeks in women with a short cervix remaining after a threatened preterm labor episode but did significantly reduce the spontaneous preterm birth rate <37 weeks, threatened preterm labor recurrence, and the preterm premature rupture of membranes rate.

Differences in Morbidity and Mortality Rates in Black, White, and Hispanic Very Preterm Infants Among New York City Hospitals

IMPORTANCE

Substantial quality improvements in neonatal care have occurred over the past decade yet racial and ethnic disparities in morbidity and mortality remain. It is uncertain whether disparate patterns of care by race and ethnicity contribute to disparities in neonatal outcomes.

OBJECTIVES

To examine differences in neonatal morbidity and mortality rates among non-Hispanic black (black), Hispanic, and non-Hispanic white (white) very preterm infants and to determine whether these differences are explained by site of delivery.

DESIGN, SETTING, AND PARTICIPANTS

Population-based retrospective cohort study of 7177 nonanomalous infants born between 24 and 31 completed gestational weeks in 39 New York City hospitals using linked 2010 to 2014 New York City discharge abstract and birth certificate data sets. Mixed-effects logistic regression with a random hospital-specific intercept was used to generate risk-adjusted neonatal morbidity and mortality rates for very preterm infants in each hospital. Hospitals were ranked using this measure, and differences in the distribution of black, Hispanic, and white very preterm births were assessed among these hospitals. The statistical analysis was performed in 2016-2017.

EXPOSURE

Race/ethnicity.

MAIN OUTCOMES AND MEASURES

Composite of mortality (neonatal or in-hospital up to 1 year) or severe neonatal morbidity (bronchopulmonary dysplasia, severe necrotizing enterocolitis, retinopathy of prematurity stage 3 or greater, or intraventricular hemorrhage grade 3 or greater).

RESULTS

Among 7177 very preterm births (VPTBs), morbidity and mortality occurred in 2011 (28%) and was higher among black (893 [32.2%]) and Hispanic (610 [28.1%]) than white (319 [22.5%]) VPTBs (2-tailed P < .001). The risk-standardized morbidity and mortality rate was twice as great for VPTB infants born in hospitals in the highest morbidity and mortality tertile (0.40; 95% CI, 0.38-0.41) as for those born in the lowest morbidity and mortality tertile (0.16; 95% CI, 0.14-0.18). Black (1204 of 2775 [43.4%]) and Hispanic (746 of 2168 [34.4%]) VPTB infants were more likely than white (325 of 1418 [22.9%]) VPTB infants to be born in hospitals in the highest morbidity and mortality tertile (2-tailed P < .001; black-white difference, 20%; 95% CI, 18%-23% and Hispanic-white difference, 11%; 95% CI, 9%-14%). The largest proportion of the explained disparities can be attributed to differences in infant health risks among black, Hispanic, and white VPTB infants. However, 40% (95% CI, 30%-50%) of the black-white disparity and 30% (95% CI, 10%-49%) of the Hispanic-white disparity was explained by birth hospital.

CONCLUSIONS AND RELEVANCE

Black and Hispanic VPTB infants are more likely to be born at hospitals with higher risk-adjusted neonatal morbidity and mortality rates, and these differences contribute to excess morbidity and mortality among black and Hispanic infants.

Intraventricular Hemorrhage in Moderate to Severe Congenital Heart Disease

OBJECTIVES

Determine the prevalence of intraventricular hemorrhage in infants with moderate to severe congenital heart disease, investigate the impact of gestational age, cardiac diagnosis, and cardiac intervention on intraventricular hemorrhage, and compare intraventricular hemorrhage rates in preterm infants with and without congenital heart disease.

DESIGN

A single-center retrospective review.

SETTING

A tertiary care children's hospital.

PATIENTS

All infants admitted to St. Louis Children's Hospital from 2007 to 2012 with moderate to severe congenital heart disease requiring cardiac intervention in the first 90 days of life and all preterm infants without congenital heart disease or congenital anomalies/known genetic diagnoses admitted during the same time period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cranial ultrasound data were reviewed for presence/severity of intraventricular hemorrhage. Head CT and brain MRI data were also reviewed in the congenital heart disease infants. Univariate analyses were undertaken to determine associations with intraventricular hemorrhage, and a final multivariate logistic regression model was performed. There were 339 infants with congenital heart disease who met inclusion criteria and 25.4% were born preterm. Intraventricular hemorrhage was identified on cranial ultrasound in 13.3% of infants, with the majority of intraventricular hemorrhage being low-grade (grade I/II). The incidence increased as gestational age decreased such that intraventricular hemorrhage was present in 8.7% of term infants, 19.2% of late preterm infants, 26.3% of moderately preterm infants, and 53.3% of very preterm infants. There was no difference in intraventricular hemorrhage rates between cardiac diagnoses. Additionally, the rate of intraventricular hemorrhage did not increase after cardiac intervention, with only three infants demonstrating new/worsening high-grade (grade III/IV) intraventricular hemorrhage after surgery. In a multivariate model, only gestational age at birth and African-American race were predictors of intraventricular hemorrhage. In the subset of infants with CT/MRI data, there was good sensitivity and specificity of cranial ultrasound for presence of intraventricular hemorrhage.

CONCLUSIONS

Infants with congenital heart disease commonly develop intraventricular hemorrhage, particularly when born preterm. However, the vast majority of intraventricular hemorrhage is low-grade and is associated with gestational age and African-American race.

Racial and Ethnic Disparities in Preterm Infant Mortality and Severe Morbidity: A Population-Based Study

BACKGROUND

Disparities exist in the rates of preterm birth and infant mortality across different racial/ethnic groups. However, only a few studies have examined the impact of race/ethnicity on the outcomes of premature infants.

OBJECTIVE

To report the rates of mortality and severe neonatal morbidity among multiple gestational age (GA) groups stratified by race/ethnicity.

METHODS

A retrospective cohort study utilizing linked birth certificate, hospital discharge, readmission, and death records up to 1 year of life. Live-born infants ≤36 weeks born in the period 2007-2012 were included. Maternal self-identified race/ethnicity, as recorded on the birth certificate, was used. ICD-9 diagnostic and procedure codes captured neonatal morbidities (intraventricular hemorrhage, retinopathy of prematurity, periventricular leukomalacia, bronchopulmonary dysplasia, and necrotizing enterocolitis). Multiple logistic regression was performed to evaluate the impact of race/ethnicity on mortality and morbidity, adjusting for GA, birth weight, sex, and multiple gestation.

RESULTS

Our cohort totaled 245,242 preterm infants; 26% were white, 46% Hispanic, 8% black, and 12% Asian. At 22-25 weeks, black infants were less likely to die than white infants (odds ratio [OR] 0.76; 95% confidence interval [CI] 0.62-0.94). However, black infants born at 32-34 weeks (OR 1.64; 95% CI 1.15-2.32) or 35-36 weeks (OR 1.57; 95% CI 1.00-2.24) were more likely to die. Hispanic infants born at 35-36 weeks were less likely to die than white infants (OR 0.66; 95% CI 0.50-0.87). Racial disparities at different GAs were also detected for severe morbidities.

CONCLUSIONS

The impact of race/ethnicity on mortality and severe morbidity varied across GA categories in preterm infants. Disparities persisted even after adjusting for important potential confounders.

Racial/Ethnic Disparities in Morbidity and Mortality for Preterm Neonates Admitted to a Tertiary Neonatal Intensive Care Unit

OBJECTIVE

The objective of this study was to assess whether in-hospital morbidity or mortality differed by race/ethnicity for preterm neonates admitted to the neonatal intensive care unit (NICU).

STUDY DESIGN

In a retrospective cohort study, preterm infants, < 37 weeks, were admitted to the NICU from 1994 to 2009. Exclusions included structural anomalies and aneuploidy. Primary outcome was in-hospital mortality (IHM). Secondary outcomes were respiratory distress syndrome (RDS), interventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), and retinopathy of prematurity (ROP). Sub-analysis of very preterm (VPT) infants, < 28 weeks, was performed. Five racial/ethnic groups (REGs) were compared: White, Black, Hispanic, Asian, and Mixed. Associations were modeled by logistic regression. White neonates (WNs) were the referent group. Unadjusted and adjusted odds ratios and 95% confidence intervals for remaining REGs were reported. p value was significant at 5% for overall tests and at Bonferroni-corrected level < 0.0125 for between-race comparisons with WNs.

RESULTS

Four thousand nine hundred fifty-five preterm neonates were identified; 153 were excluded leaving 4802 for analysis. After controlling covariates that were chosen a priori, there was no difference across REGs for IHM (all between-race comparison p values > 0.0125). There was a significant difference in RDS among Black neonates (BNs) (aOR 0.57, 95% CI 0.45-0.73; p < 0.001) and Hispanic neonates (HNs) (aOR 0.67, 95% CI 0.50-0.89; p = 0.005) compared to WNs. The risk of ROP was significantly different across REGs with HNs having a 70% increase in ROP (aOR 1.70, 95% CI 1.15-2.49; p = 0.008) and Mixed neonates (MNs) experiencing a 55% reduction (aOR 0.45, 95% CI 0.29-0.68; p < 0.001) compared to WNs. There was no difference in IVH or NEC across REGs (all p values > 0.0125). In the VPT cohort sub-analysis, BNs experienced a significant 59% reduction in IHM compared to WNs (BNs aOR 0.41, 95% CI 0.22-0.73; p = 0.003). MNs experienced a 46% reduction in ROP compared to WNs (aOR 0.54, 95% CI 0.35-0.81; p = 0.004). There was no difference in RDS, IVH, or NEC in very preterm infants across REGs (all between comparison p values > 0.0125).

CONCLUSION

In preterm neonates, in-hospital mortality does not significantly differ across racial and ethnic groups. However, in very preterm infants, in-hospital mortality for Black neonates is improved. There are morbidity differences (RDS, ROP) seen among racial/ethnic groups.

Association of Maternal Preeclampsia With Infant Risk of Premature Birth and Retinopathy of Prematurity

Importance

Studies report conflicting associations between preeclampsia and retinopathy of prematurity (ROP). This study provides explanations for the discrepancies to clarify the relationship between preeclampsia and ROP.

Objective

To evaluate the association of maternal preeclampsia and risk of ROP among infants in an unrestricted birth cohort and a restricted subcohort of preterm, very low birth weight (P-VLBW) infants.

Design, Setting, and Participants

A retrospective review of 290 992 live births within the Intermountain Healthcare System in Utah from January 1, 2001, through December 31, 2010, was performed. Generalized estimating equations for logistic regressions with covariate adjustment were applied to relate ROP to preeclampsia among the full cohort and in a subcohort of P-VLBW infants born at younger than 31 weeks' gestation and weighing less than 1500 g.

Main Outcomes and Measures

The occurrence of ROP was related to maternal preeclampsia in the full cohort and in a subcohort of P-VLBW infants.

Results

In the full cohort, 51% of the infants were male and the mean (SD) gestational age was 38.38 (1.87) weeks. In the P-VLBW cohort, 55% were male and the mean (SD) gestational age was 26.87 (2.40) weeks. In the full cohort, preeclampsia was associated with an increased risk of all ROP (adjusted odds ratio [aOR], 2.46; 95% CI, 2.17-2.79; P < .001), severe ROP (aOR, 5.21; 95% CI, 3.44-7.91; P < .001), infant death (aOR, 1.66; 95% CI, 1.16-2.38; P = .006), and giving birth to a P-VLBW infant (aOR, 7.74; 95% CI, 6.92-8.67; P < .001). In the P-VLBW subcohort, preeclampsia was inversely associated with the development of all ROP (aOR, 0.79; 95% CI, 0.68-0.92; P = .003), severe ROP (aOR, 0.62; 95% CI, 0.36-1.06; P = .08), and infant death (aOR, 0.19; 95% CI, 0.11-0.32; P < .001).

Conclusions and Relevance

Preeclampsia was associated with an increased risk of developing ROP among an unrestricted cohort but with a reduced risk of ROP among a restricted subcohort of P-VLBW infants. Although the conflicting associations in the full and P-VLBW cohorts may reflect true differences, the association of a reduced risk of ROP among the P-VLBW subcohort also may reflect biases from restricting the cohort to prematurity, because prematurity is an outcome of preeclampsia.

Human relaxins (RLNH1, RLNH2), their receptor (RXFP1) and fetoplacental growth

Relaxin, a systemic and placental hormone, has potential roles in fetoplacental growth. Human placenta expresses two RLN genes, RLNH1 and RLNH2 Maternal obesity is common and is associated with abnormal fetal growth. Our aims were to relate systemic and cord blood RLNH2, placental RLNs and their receptor (RXFP1) with fetoplacental growth in context of maternal body mass index, and associations with insulin-like growth factor 2 (IGF2) and vascular endothelial growth factor A (VEGFA) in the same placentas. Systemic, cord blood and placental samples were collected prior to term labor, divided by prepregnancy body mass index: underweight/normal (N = 25) and overweight/obese (N = 44). Blood RLNH2 was measured by ELISA; placental RLNH2, RLNH1, RXFP1, IGF2 and VEGFA were measured by quantitative immunohistochemistry and mRNAs were measured by quantitative reverse transcription PCR. Birthweight increased with systemic RLNH2 only in underweight/normal women (P = 0.036). Syncytiotrophoblast RLNH2 was increased in overweight/obese patients (P = 0.017) and was associated with placental weight in all subjects (P = 0.038). RLNH1 had no associations with birthweight or placental weight, but was associated with increased trophoblast and endothelial IGF2 and VEGFA, due to female fetal sex. Thus, while systemic RLNH2 may be involved in birthweight regulation in underweight/normal women, placental RLNH2 in all subjects may be involved in placental weight. A strong association of trophoblast IGF2 with birthweight and placental weight in overweight/obese women suggests its importance. However, an association of only RLNH1 with placental IGF2 and VEGFA was dependent upon female fetal sex. These results suggest that both systemic and placental RLNs may be associated with fetoplacental growth.