Racial disparity in previable birth

Impact of COVID-19 on Perinatal Outcomes and Birth Locations in a Large US Metropolitan Area

This was a population-based study to determine the impact of COVID-19 on birth outcomes in the Chicago metropolitan area, comparing pre-pandemic (April-September 2019) versus pandemic (April-September 2020) births. Multivariable regression models that adjusted for demographic and neighborhood characteristics were used to estimate the marginal effects of COVID-19 on intrauterine fetal demise (IUFD)/stillbirth, preterm birth, birth hospital designation, and maternal and infant hospital length of stay (LOS). There were no differences in IUFD/stillbirths or preterm births between eras. Commercially insured preterm and term infants were 4.8 percentage points (2.3, 7.4) and 3.4 percentage points (2.5, 4.2) more likely to be born in an academic medical center during the pandemic, while Medicaid-insured preterm and term infants were 3.6 percentage points less likely (-6.5, -0.7) and 1.8 percentage points less likely (-2.8, -0.9) to be born in an academic medical center compared to the pre-pandemic era. Infant LOS decreased from 2.4 to 2.2 days (-0.35, -0.20), maternal LOS for indicated PTBs decreased from 5.6 to 5.0 days (-0.94, -0.19), and term births decreased from 2.5 to 2.3 days (-0.21, -0.17). The pandemic had a significant effect on the location of births that may have exacerbated health inequities that continue into childhood.

Neonatal Intensive Care Unit Latent Profiles of Maternal Distress: Associations With 5-Year Maternal and Child Mental Health Outcomes

OBJECTIVE

To examine profiles of distress of mothers of preterm infants in the neonatal intensive care unit (NICU) and relate profiles to maternal and child outcomes at child age 5 years.

METHOD

A racially and economically diverse sample of mothers (n = 94; 39% African American, 52% White) of preterm infants (≤30 weeks of gestation) completed validated questionnaires assessing depression, anxiety (state and trait), NICU stress, and life stress at NICU discharge of their infant. Mothers reported on their own and their children's symptomatology at child age 5. A latent profile analysis was conducted to categorize maternal symptomatology.

RESULTS

Latent profile analysis yielded 4 distinct maternal profiles: low symptomatology, high NICU stress, high depression and anxiety, and high state anxiety. Social determinants of health factors including age, education, neighborhood deprivation, and infant clinical risk distinguished the profiles. Mothers in the high depression and anxiety profile reported more anxiety and life stress at follow-up and reported their children experienced more anxious/depressed symptoms.

CONCLUSION

Existing literature has gaps related to examining multiple dimensions of NICU distress and understanding how patterns of mood/affective symptoms, life stressors, and related social determinants of health factors vary across mothers. In this study, one specific profile of maternal NICU distress demonstrated enduring risks for poorer maternal and child mental health outcomes. This new knowledge underscores sources of disparate health outcomes for mothers of preterm infants and the infants themselves. Universal screening is needed to identify at-risk dyads for poor health outcomes in need of individualized interventions that address both maternal and child well-being.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science. We actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our author group. While citing references scientifically relevant for this work, we also actively worked to promote sex and gender balance in our reference list. While citing references scientifically relevant for this work, we also actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our reference list.

Racial disparities in the development of comorbid conditions after preterm birth: A narrative review

Despite recognition and attempts to reduce racial disparities in perinatal outcomes, Black infants are still disproportionately represented among those who are born preterm. Postnatal investigations of racial disparities in comorbidities and outcomes after preterm birth are increasing, although their results and interpretations are conflicting. In the present review, we 1.) identify important methodological limitations of that literature 2.) summarize the conflicting literature investigating racial disparities, specifically Black-white differences, in postnatal comorbidities and outcomes after preterm birth 3.) describe mechanisms by which racism operates to contextualize our understanding to inform future work to actively reduce disparities in preterm birth and subsequently, its complications.

Nitric oxide-related gene and microRNA expression in peripheral blood in pregnancy vary by self-reported race

Adverse pregnancy outcomes disproportionately affect non-Hispanic (NH) Black patients in the United States. Structural racism has been associated with increased psychosocial distress and inflammation and may trigger oxidative stress. Thus, the nitric oxide (NO) pathway (involved in the regulation of inflammation and oxidative stress) may partly explain the underlying disparities in obstetric outcomes.Cohort study of 154 pregnant patients with high-risk obstetric histories; n = 212 mRNAs and n = 108 microRNAs (miRNAs) in the NO pathway were evaluated in circulating white blood cells. NO pathway mRNA and miRNA transcript counts were compared by self-reported race; NH Black patients were compared with women of other races/ethnicities. Finally, miRNA-mRNA expression levels were correlated.Twenty-two genes (q < 0.10) were differentially expressed in self-identified NH Black individuals. Superoxide dismutase 1 (SOD1), interleukin-8 (IL-8), dynein light chain LC8-type 1 (DYNLL1), glutathione peroxidase 4 (GPX4), and glutathione peroxidase 1 (GPX1) were the five most differentially expressed genes among NH Black patients compared to other patients. There were 63 significantly correlated miRNA-mRNA pairs (q < 0.10) demonstrating potential miRNA regulation of associated target mRNA expression. Ten miRNAs that were identified as members of significant miRNA-mRNA pairs were also differentially expressed among NH Black patients (q < 0.10).These findings support an association between NO pathway and inflammation and infection-related mRNA and miRNA expression in blood drawn during pregnancy and patient race/ethnicity. These findings may reflect key differences in the biology of inflammatory gene dysregulation that occurs in response to the stress of systemic racism and that underlies disparities in pregnancy outcomes.

What Role Does Hispanic/Latina Ethnicity Play in the Relationship Between Maternal Mental Health and Preterm Birth?

OBJECTIVE

To investigate the association of prepregnancy and prenatal depression and/or anxiety on preterm birth (PTB), while also exploring Hispanic/Latina ethnicity as a potential effect modifier.

METHODS

Study population included respondents of UT-PRAMS (2016-2019). Associations between prepregnancy and prenatal depression and/or anxiety and PTB were evaluated using Poisson regression models accounting for stratified survey sampling.

RESULTS

Women with prepregnancy and prenatal depression and anxiety, compared to those without, had a 67 percent (95% CI: 19%, 134%) higher probability of experiencing PTB, after controlling for relevant sociodemographic, lifestyle, and reproductive history factors. Impact of depression on PTB was slightly higher than impact of anxiety. Hispanic/Latina ethnicity was found to protect against PTB for those with prepregnancy and prenatal depression alone (aPR: 0.53, 95% CI: 0.24, 1.21) or both depression and anxiety (aPR: 0.51, 95% CI: 0.18, 1.40) compared to being non-Hispanic/Latina (aPR: 1.79, 95% CI: 1.25, 2.55 for depression alone; aPR: 1.62, 95% CI: 1.18, 2.21 for depression and anxiety).

CONCLUSIONS

Overall, Utah women reporting prepregnancy and prenatal depression and anxiety were more likely to have a PTB. Being of Hispanic/Latina ethnicity was found to mitigate the risk of PTB among women with depression and anxiety.

IMPLICATIONS

Prepregnancy and prenatal mental health screenings and treatment are key to lessening the impacts of depression and anxiety on both mother and infant. Hispanic/Latina ethnicity may be protective against PTB among women experiencing mental distress. Whether this is through increased social support or through a different mechanism should be explored in future research.

Controversies in treatment practices of the mother-infant dyad at the limit of viability

In the setting of threatened extreme preterm birth, balancing maternal and fetal risks and benefits in order to choose the best available treatment options is of utmost importance. Inconsistency in treatment practices for infants born between 22 and 24 weeks of gestatotional age may account for inter-hospital variation in survival rates with and without impairment. Most importantly, non-biased and accurate information must be presented to the family as soon as extremely preterm birth is suspected, including counseling on morbidities and mortality associated with delivery at the limits of viability. This review will focus on different therapeutic medical and surgical practices available for threatened extremely preterm birth to improve fetal and maternal outcomes while highlighting the importance of patient-centered approaches.

Prevalence and Predictors of Medical Complexity in a National Sample of VLBW Infants

BACKGROUND AND OBJECTIVES

Very low birth weight (VLBW) infants are at high risk for morbidities beyond the neonatal period and ongoing use of health care. Specific morbidities have been studied; however, a comprehensive landscape of medical complexity in VLBW infants has not been fully described. We sought to (1) describe the prevalence of complex chronic conditions (CCCs) and (2) determine the association of demographic, hospital, and clinical factors with CCCs and CCCs or death.

METHODS

This retrospective cross-sectional analysis of discharge data from the Kids' Inpatient Database (2009-2012) included infants with a birth weight <1500 g and complete demographics. Outcomes included having CCCs or having either CCCs or dying. Analyses were weighted; univariate and multiple logistic regression models were used to estimate unadjusted and adjusted odds ratios. A dominance analysis with Cox-Snell R ² determined the relative contribution of demographic, hospital, and clinical factors to the outcomes.

RESULTS

Among our weighted cohort of >78 000 VLBW infants, >50% had CCCs or died. After adjustments, the prevalence of CCCs or CCCs or death differed by sex, race and ethnicity, hospital location, US region, receipt of surgery, transfer status, and birth weight. Clinical factors accounted for the highest proportion of the model's ability to predict CCCs and CCCs or death at 93.3% and 96.3%, respectively, whereas demographic factors were 11.5% and 2.3% and hospital factors were 5.2% and 1.4%, respectively.

CONCLUSIONS

In this nationally representative analysis, medical complexity is high among VLBW infants. Varying contributions of demographic, hospital, and clinical factors in predicting medical complexity offer opportunities to investigate future interventions to improve care delivery and patient outcomes.

Racial inequality in perinatal outcomes in two Brazilian birth cohorts

This study aimed to estimate and compare racial inequality in low birth weight (LBW), preterm birth (PTB), and intrauterine growth restriction (IUGR) in two Brazilian birth cohorts. This was a cross-sectional study nested within two birth cohorts in Ribeirão Preto (RP) and São Luís (SL), whose mothers were interviewed from January to December 2010. In all, 7430 (RP) and 4995 (SL) mothers were interviewed. The maternal skin color was the exposure variable. Associations were adjusted for socioeconomic and biological covariates: maternal education, per capita family income, family economic classification, household head occupation, maternal age, parity, marital status, prenatal care, type of delivery, maternal pre-pregnancy BMI, hypertension, hypertension during pregnancy, and smoking during pregnancy collected from questionnaires applied at birth. Statistical analysis was done with the chi-squared test and logistic regression. In RP, newborns from mothers with black skin color had a higher risk of LBW and IUGR, even after adjusting for socioeconomic and biological variables (P<0.001). In SL, skin color was not a risk factor for LBW (P=0.859), PTB (P=0.220), and IUGR (P=0.062), before or after adjustment for socioeconomic and biological variables. The detection of racial inequality in these perinatal outcomes only in the RP cohort after adjustment for socioeconomic and biological factors may be reflecting the existence of racial discrimination in the RP society. In contrast, the greater miscegenation present in São Luís may be reflecting less racial discrimination of black and brown women in this city.

Regional Contribution of Previable Infant Deaths to Infant Mortality Rates in the United States

OBJECTIVE

Lack of standardization of infant mortality rate (IMR) calculation between regions in the United States makes comparisons potentially biased. This study aimed to quantify differences in the contribution of early previable live births (<20 weeks) to U.S. regional IMR.

STUDY DESIGN

Population-based cohort study of all U.S. live births and infant deaths recorded between 2007 and 2014 using Centers for Disease Control and Prevention's (CDC's) WONDER database linked birth/infant death records (births from 17-47 weeks). Proportion of infant deaths attributable to births <20 vs. 20 to 47 weeks, and difference (ΔIMR) between reported and modified (births ≥20 weeks) IMRs were compared across four U.S. census regions (North, South, Midwest, and West).

RESULTS

Percentages of infant deaths attributable to birth <20 weeks were 6.3, 6.3, 5.3, and 4.1% of total deaths for Northeast, Midwest, South, and West, respectively, p < 0.001. Contribution of < 20-week deaths to each region's IMR was 0.34, 0.42, 0.37, and 0.2 per 1,000 live births. Modified IMR yielded less regional variation with IMRs of 5.1, 6.2, 6.6, and 4.9 per 1,000 live births.

CONCLUSION

Live births at <20 weeks contribute significantly to IMR as all result in infant death. Standardization of gestational age cut-off results in more consistent IMRs among U.S. regions and would result in U.S. IMR rates exceeding the healthy people 2020 goal of 6.0 per 1,000 live births.

Multiomics Characterization of Preterm Birth in Low- and Middle-Income Countries

IMPORTANCE

Worldwide, preterm birth (PTB) is the single largest cause of deaths in the perinatal and neonatal period and is associated with increased morbidity in young children. The cause of PTB is multifactorial, and the development of generalizable biological models may enable early detection and guide therapeutic studies.

OBJECTIVE

To investigate the ability of transcriptomics and proteomics profiling of plasma and metabolomics analysis of urine to identify early biological measurements associated with PTB.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic/prognostic study analyzed plasma and urine samples collected from May 2014 to June 2017 from pregnant women in 5 biorepository cohorts in low- and middle-income countries (LMICs; ie, Matlab, Bangladesh; Lusaka, Zambia; Sylhet, Bangladesh; Karachi, Pakistan; and Pemba, Tanzania). These cohorts were established to study maternal and fetal outcomes and were supported by the Alliance for Maternal and Newborn Health Improvement and the Global Alliance to Prevent Prematurity and Stillbirth biorepositories. Data were analyzed from December 2018 to July 2019.

EXPOSURES

Blood and urine specimens that were collected early during pregnancy (median sampling time of 13.6 weeks of gestation, according to ultrasonography) were processed, stored, and shipped to the laboratories under uniform protocols. Plasma samples were assayed for targeted measurement of proteins and untargeted cell-free ribonucleic acid profiling; urine samples were assayed for metabolites.

MAIN OUTCOMES AND MEASURES

The PTB phenotype was defined as the delivery of a live infant before completing 37 weeks of gestation.

RESULTS

Of the 81 pregnant women included in this study, 39 had PTBs (48.1%) and 42 had term pregnancies (51.9%) (mean [SD] age of 24.8 [5.3] years). Univariate analysis demonstrated functional biological differences across the 5 cohorts. A cohort-adjusted machine learning algorithm was applied to each biological data set, and then a higher-level machine learning modeling combined the results into a final integrative model. The integrated model was more accurate, with an area under the receiver operating characteristic curve (AUROC) of 0.83 (95% CI, 0.72-0.91) compared with the models derived for each independent biological modality (transcriptomics AUROC, 0.73 [95% CI, 0.61-0.83]; metabolomics AUROC, 0.59 [95% CI, 0.47-0.72]; and proteomics AUROC, 0.75 [95% CI, 0.64-0.85]). Primary features associated with PTB included an inflammatory module as well as a metabolomic module measured in urine associated with the glutamine and glutamate metabolism and valine, leucine, and isoleucine biosynthesis pathways.

CONCLUSIONS AND RELEVANCE

This study found that, in LMICs and high PTB settings, major biological adaptations during term pregnancy follow a generalizable model and the predictive accuracy for PTB was augmented by combining various omics data sets, suggesting that PTB is a condition that manifests within multiple biological systems. These data sets, with machine learning partnerships, may be a key step in developing valuable predictive tests and intervention candidates for preventing PTB.

Factors Associated With Maternal and Neonatal Interventions at the Threshold of Viability

OBJECTIVE

To quantify the influence of maternal sociodemographic, medical, and pregnancy characteristics on decisions to offer or receive antepartum and neonatal interventions with deliveries occurring at 22-23 weeks of gestation.

METHODS

This is a case-control study of U.S. live births at 22 0/7-23 6/7 weeks of gestation using National Center for Health Statistics vital statistics birth records from 2012 to 2016. We analyzed three outcomes in the treatment of periviable delivery: 1) maternal interventions (cesarean delivery, maternal hospital transfer or antenatal corticosteroid administration), 2) neonatal interventions (neonatal intensive care unit admission, surfactant administration, antibiotic administration, or assisted ventilation), and 3) combined interventions (at least one maternal and at least one neonatal intervention). Logistic regression estimated the influence of characteristics on interventions received.

RESULTS

Of 19,844,580 U.S. live births from 2012 to 2016, 24,379 (0.12%) occurred at 22-23 weeks of gestation. Of these, 37.5% received maternal interventions, 51.7% received neonatal interventions, and 28.0% received combined interventions. Rates of births receiving at least one intervention were 38.9% and 78.3% for 22 and 23 weeks of gestation, respectively. Preeclampsia was the factor most positively associated with interventions. Other factors positively associated with interventions were increasing maternal age, Medicaid, low educational attainment, multiparity, twin gestation, and infertility treatment. Some factors had opposite influences on maternal compared with neonatal interventions. The presence of birth defects was positively associated with maternal interventions but negatively associated with neonatal interventions, whereas being of black race was negatively associated with maternal interventions but positively associated with neonatal interventions.

CONCLUSION

Maternal and neonatal interventions occur frequently at the threshold of viability, especially at 23 weeks of gestation where the occurrence of interventions exceeds 50%. This study identifies sociodemographic and medical factors associated with using interventions with periviable deliveries. These data elucidate observed practice patterns in the management of periviable births and may assist providers in the counseling of women at risk of periviable birth.

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.

Regional and practitioner variations in reporting infant mortality

Objective: Assess regional differences in categorization of preterm delivery outcomes and impact on variation in reported infant mortality rates.Study design: A 27-item questionnaire was distributed to 1072 practitioners associated with U.S. birth hospitals. Five clinical scenarios were created to identify how participants classify delivery outcomes. Statistical analysis included Chi-square analysis and multinomial logistic regression.Results: 234 questionnaires were completed (response rate 22%). While >90% respondents classified a 14-week pregnancy loss with no sign of life as a miscarriage, only 22% would provide a fetal death certificate. Likewise, 37% would provide a certificate of live birth for a loss at 16 weeks with signs of life. There was notable regional variation in classifying these as live births (Northeast: 41%, Midwest: 44%, South: 13%, and West: 18%, p = .003).Conclusion: Regional practice variation in recording both live births and stillbirths was noted. Greater standardization in reporting practices may be warranted to improve the accuracy of reported birth outcomes in the U.S.

Metabolites and metabolic pathways associated with glucocorticoid resistance in pregnant African-American women

Glucocorticoid resistance (GR) is associated with exposure to chronic stress and an increased risk of metabolic and inflammatory disorders in both animal and human populations. Studies on ethnic disparities highlight the African-American (AA) population as having a high propensity to both GR and chronic stress exposure. Glucocorticoids and inflammation play a very important role in pregnancy outcome and fetal development. To date, however, the metabolites and metabolic pathways associated with GR during pregnancy have not been identified, obscuring the mechanisms by which adverse health consequences arise, and thus impeding targeted therapeutic intervention. The objective of this study was to perform untargeted high-resolution metabolomics (HRM) profiling on 273 pregnant AA women, to identify metabolites and metabolic pathways associated with GR during the first trimester of pregnancy and to evaluate their cross-sectional association with birth outcomes and psychosocial variables related to chronic stress exposure. For this study, GR was determined by the concentration of dexamethasone required for 50% inhibition (Dex IC50) of the cytokine tumor-necrosis factor alpha (TNF-alpha) release in vitro in response to a standard dose of lipopolysaccharide. The results for Metabolome-Wide Association Studies (MWAS) and pathway enrichment analysis for serum metabolic associations with Dex IC50, showed energy (nicotinamide and TCA cycle), amino acid, and glycosphingolipid metabolism as top altered pathways. Bioinformatic analysis showed that GR, as indicated by elevated Dex IC50 in the pregnant women, was associated with increased inflammatory metabolites, oxidative stress related metabolites, increased demand for functional amino acids to support growth and development, and disruption in energy-related metabolites. If confirmed in future studies, targeting these physiologically significant metabolites and metabolic pathways may lead to future assessment and intervention strategies to prevent inflammatory and metabolic complications observed in pregnant populations.

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GR is associated with chronic stress and is a risk factor for adverse health outcomes, especially among African Americans.

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Metabolites and metabolic pathways associated with GR relate to energy production, amino acid metabolism, and inflammation.

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Findings provide a foundation for future studies investigating risk factors in this health disparity population.

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.

Variation in relationships between maternal age at first birth and pregnancy outcomes by maternal race: a population-based cohort study in the United States

OBJECTIVE

To estimate absolute risks of obstetric outcomes in the USA according to maternal age at first birth from age 15 to 45 separately by maternal race.

DESIGN AND SETTING

Population-based cohort study.

SETTING

Vital statistics Birth Cohort-Linked Birth- Infant Death Data Files and Fetal Death Data Files in the USA.

PARTICIPANTS

16 514 849 births to nulliparous women from 2004 to 2013.

OUTCOME MEASURES

We estimated absolute risks of obstetric outcomes (multiple gestations, caesarean delivery, early and late preterm birth, small for gestational age birth, stillbirth, neonatal mortality, postneonatal infant mortality) at each year of maternal age from 15 to 45 years using logistic regression in the overall population and stratified by maternal race. We modelled maternal age flexibly to allow curvilinear shapes and plotted risk curves for each outcome.

RESULTS

In the overall population, multiple gestations, caesarean delivery and stillbirth risks were lowest at young maternal ages with linear or quadratic increases with age. Curves for preterm birth, small for gestational age, neonatal mortality and postneonatal mortality were u or j shaped, with nadirs between 20 and 29 years, and elevated risks at both younger and older maternal ages. In race-stratified analyses, the shapes of the curves were generally similar across races. Risks increased for all women for all outcomes after age 30. However, increased risks at young maternal ages were most pronounced for white and Asian/Pacific Islander women, for whom young childbearing was least common. Conversely, risks at older ages were more pronounced for Black and American Indian/Alaska Native women, for whom delayed childbearing was least common.

CONCLUSION

Our findings confirm risks associated with first births to women younger than 20 and older than 30 years, provide easily interpretable risk curves and illuminate variability in these relationships across categories of maternal race in the USA.

Maternal exposure to benzene and toluene and preterm birth. A longitudinal study

BACKGROUND

Exposure to air pollutants has several effects on human health, including during pregnancy.

OBJECTIVE

To identify whether exposure to benzene and toluene among pregnant women contributes to preterm delivery.

DESIGN AND SETTING

Longitudinal study using data on newborns from mothers living in São José dos Campos (SP) in 2016, who had been exposed to benzene and toluene.

METHODS

A logistic regression model with three hierarchical levels was constructed using maternal variables relating to newborns, and using benzene and toluene concentrations in quartiles. Occurrences of cesarean births, twins or malformations were excluded. Maternal exposure windows of 5, 10, 15, 30, 60 and 90 days prior to delivery were considered.

RESULTS

Out of the 9,562 live births, 3,671 newborns were included and 343 newborns were born at less than 37 weeks of gestation (9.3%). The average birth weight was 3,167.2 g. Exposure to benzene and toluene was significantly associated (P = 0.04) with preterm delivery in the five-day window. There was no association in any of the other exposure windows.

CONCLUSIONS

It was possible to identify that maternal exposure to benzene and toluene has an acute effect on preterm delivery.

Ways of knowing in precision health

Precision health can provide an avenue to bridge and integrate ways of knowing for research and practice. Nurse scientists have a long-standing interest in using multiple sources of information to address research questions of significance to the profession and discipline of nursing, which can lead to much needed contributions to precision health care. In this paper, nursing scientists discuss emerging research methods including omics, electronic sensors, and geospatial data, and mixed methods that further develop nursing science and contribute to precision health initiatives. The authors provide exemplars of the types of knowledge and ways of knowing that, using these and other advanced data and analytic strategies, may advance precision health within the context of nursing science.

Genomic and molecular characterization of preterm birth

Preterm birth (PTB) complications are the leading cause of long-term morbidity and mortality in children. By using whole blood samples, we integrated whole-genome sequencing (WGS), RNA sequencing (RNA-seq), and DNA methylation data for 270 PTB and 521 control families. We analyzed this combined dataset to identify genomic variants associated with PTB and secondary analyses to identify variants associated with very early PTB (VEPTB) as well as other subcategories of disease that may contribute to PTB. We identified differentially expressed genes (DEGs) and methylated genomic loci and performed expression and methylation quantitative trait loci analyses to link genomic variants to these expression and methylation changes. We performed enrichment tests to identify overlaps between new and known PTB candidate gene systems. We identified 160 significant genomic variants associated with PTB-related phenotypes. The most significant variants, DEGs, and differentially methylated loci were associated with VEPTB. Integration of all data types identified a set of 72 candidate biomarker genes for VEPTB, encompassing genes and those previously associated with PTB. Notably, PTB-associated genes RAB31 and RBPJ were identified by all three data types (WGS, RNA-seq, and methylation). Pathways associated with VEPTB include EGFR and prolactin signaling pathways, inflammation- and immunity-related pathways, chemokine signaling, IFN-γ signaling, and Notch1 signaling. Progress in identifying molecular components of a complex disease is aided by integrated analyses of multiple molecular data types and clinical data. With these data, and by stratifying PTB by subphenotype, we have identified associations between VEPTB and the underlying biology.

Disparities and the American Health Care System

The United States' health care system is often compared with those of other industrialized countries, and consistently ranks poorly in terms of health care delivery, efficiency, and quality. However, there are several considerations unique to the United States that are often distorted in these analyses, and when considered in the context of the convoluted ethnic and social disparities that persist in the United States, the successes of the American health care system become more apparent.

Effectiveness of an infant mortality prevention home-visiting program on high-risk births in Ohio

OBJECTIVES

The Ohio Infant Mortality Reduction Initiative (OIMRI) is a home-visiting program that aims to reduce infant mortality among infants of high-risk black women. This study examined birth outcomes among OIMRI participants and compared program participants to matched non-OIMRI women.

DESIGN

Program data were linked to birth records, death records, and Medicaid claims data. Propensity score matching was used to match program participants with like women in Ohio.

SAMPLE

The sample consisted of 2,837 black mothers from 14 counties in Ohio.

MEASUREMENTS

Infant mortality, causes of death, and birth weight were examined.

RESULTS

There were 25 deaths among 2,837 OIMRI participants from 2010 to 2015, for an infant mortality rate of 8.8 deaths per 1,000 live births (95% CI 5.4-12.2). Among those women who participated in OIMRI, three fewer deaths per 1,000 births within the first year of life were estimated compared to those not in OIMRI; however, this was not statistically significant.

CONCLUSIONS

The number of infant deaths among women enrolled in the OIMRI program was not significantly different from those who did not participate in OIMRI. Programs like OIMRI cannot singlehandedly address the infant mortality disparity but may help prevent some infant mortality risks.

Reproductive suppression, birth defects, and periviable birth

We argue that reproductive suppression has clinical implications beyond its contribution to the burden of spontaneous abortion. We theorize that the incidence of births before the 28th week of gestation, which contribute disproportionately to infant morbidity and mortality, varies over time in part due to reproductive suppression in the form of selection in utero. We further theorize that the prevalence of structural birth defects among survivors to birth from conception cohorts gauges selection in utero. We based these theories on literature positing that natural selection conserved mechanisms that spontaneously abort "risky" pregnancies including those otherwise likely to yield infants with structural birth defects or small-for-gestational age males. We test our theory using high-quality birth defect surveillance data. We identify 479,885 male infants exposed to strong selection defined as membership in conception cohorts ranked in the lowest quartile of odds of a birth defect among live-born females. We estimate the risk of periviable birth among these infants as a function of selective pressure as well as of mother's race/ethnicity and age. We find that male infants from exposed conception cohorts exhibited 10% lower odds of periviable birth than males from other conception cohorts. Our findings support the argument that selection in utero has implications beyond its contribution to the burden of spontaneous abortion.

Quality Improvement in Perinatal Medicine and Translation of Preterm Birth Research Findings into Clinical Care

Billions of dollars are spent yearly in perinatal medicine on studies designed to improve outcomes for mothers and their neonates. However, implementing research findings is challenging and imperfect. Strategies for implementation must be multifaceted and comprehensive. These implementation challenges extend to, and are often greater in, translational and basic science research. The purpose of this review is to discuss current challenges in the provision of quality perinatal and neonatal medical care, particularly those related to preterm birth, and provide examples of prematurity-related perinatal quality collaborative initiatives. Finally, the authors review considerations in implementing both clinical and translational/basic science prematurity research.

Understanding periviable birth: A microeconomic alternative to the dysregulation narrative

Periviable infants (i.e., those born in the 20th through 26th weeks of gestation) suffer much morbidity and approximately half die in the first year of life. Attempts to explain and predict these births disproportionately invoke a "dysregulation" narrative. Research inspired by this narrative has not led to efficacious interventions. The clinical community has, therefore, urged novel approaches to the problem. We aim to provoke debate by offering the theory, inferred from microeconomics, that risk tolerant women carry, without cognitive involvement, high risk fetuses farther into pregnancy than do other women. These extended high-risk pregnancies historically ended in stillbirth but modern obstetric practices now convert a fraction to periviable births. We argue that this theory deserves testing because it suggests inexpensive and noninvasive screening for pregnancies that might benefit from the costly and invasive interventions clinical research will likely devise.

Genetics, hormonal influences, and preterm birth

Prematurity is a devastating disease with high neonatal morbidity and mortality based on gestational age at birth. Genetic and hormonal signals impact directly on the maternal predisposition to preterm birth or sudden onset of myometrial contractility. Candidate gene or genome-wide approaches are beginning to identify potential variants for women at risk for premature delivery or increased responsiveness to hormonal signals including progesterone. However, a majority of these studies have not yielded definitive results to allow for at this stage for development of personalized therapy.

Pregnant trauma victims experience nearly 2-fold higher mortality compared to their nonpregnant counterparts

BACKGROUND

Trauma is the leading nonobstetric cause of death in women of reproductive age, and pregnant women in particular may be at increased risk of violent trauma. Management of trauma in pregnancy is complicated by altered maternal physiology, provider expertise, potential disparate imaging, and distorted anatomy. Little is known about the impact of trauma on maternal mortality.

OBJECTIVE

We sought to: (1) characterize nonviolent and violent trauma among pregnant women; (2) determine whether pregnancy is associated with increased mortality following traumatic injury; and (3) identify risk factors for trauma-related death in pregnant women.

STUDY DESIGN

We studied 1148 trauma events among pregnant girls and women and 43,608 trauma events among nonpregnant girls and women of reproductive age (14-49 years) who presented to any accredited trauma center in Pennsylvania for treatment of trauma-related injuries from 2005 through 2015, as captured in the Pennsylvania Trauma Outcome Study. Traumas were categorized as violent (eg, homicide or assault) or nonviolent (eg, motor vehicle accident or accidental fall). We used modified Poisson regression to estimate relative rate of trauma-related death, adjusting for demographic characteristics and severity of trauma.

RESULTS

Compared to nonpregnant women, pregnant women and girls had a lower injury severity score (8.9 vs 10.9, P < .001) and were significantly more likely to experience violent trauma (15.9% vs 9.8%, P < .001). Pregnant trauma victims had a 1.6-fold higher rate of mortality compared to their nonpregnant counterparts (P < .001), and were both more likely to be dead on arrival and to die during their hospital course (adjusted relative risk, 2.33, P < .001, and adjusted relative risk, 1.79, P = .004, respectively). Pregnancy was associated with increased mortality in both victims of nonviolent and violent trauma (adjusted relative risk, 1.69, P = .002, and adjusted relative risk, 1.60, P = .007, respectively). Pregnant trauma victims were less likely to undergo surgery (adjusted relative risk, 0.70, P = .001) and more likely to be transferred to another facility (adjusted relative risk, 1.72, P < .001). Even after adjusting for demographics and injury severity score, violent trauma was associated with 3.14-fold higher mortality in pregnant women and girls compared to nonviolent trauma (adjusted relative risk, 3.14, P = .003).

CONCLUSION

Pregnant women and girls are nearly twice as likely to die after trauma and twice as likely to experience violent trauma. Universal screening for violence and trauma during pregnancy may provide an opportunity to identify women at risk for death during pregnancy.

County-level Variation in Infant Mortality Reporting at Early Previable Gestational Ages

BACKGROUND

Infant mortality rate (IMR), or number of infant deaths per 1000 livebirths, varies widely across the US While fetal deaths are not included in this measure, reported infant deaths do include those delivered at previable gestations, or ≤20 weeks gestation. Variation in reporting of these events may have a significant impact on IMR estimates.

METHODS

This retrospective analysis used US National Center for Health Statistics 2007-2013 data from 2391 US counties. Counties were categorised by US region, demographic characteristics, and state-level fetal death reporting requirements. County percentage of fetal deaths among all 17-20 week fetal and infant deaths was evaluated using multivariable linear regression. County-level characteristics were then included in multivariable linear regression to determine the associated change in county IMR.

RESULTS

County percentage of deaths at 17-20 weeks reported as fetal ranged from 0% to 100% (mean 63.7%). Every 1 point increase in this percentage was associated with a 0.02 point decrease in county IMR (95% confidence interval (CI) 0.02, 0.03). When county IMRs were recalculated holding the percentage of fetal vs. infant deaths at 17-20 weeks constant at 63.7%, results suggest that the predicted gap in county IMR between Northeast and Midwest regions would narrow by 0.45 points.

CONCLUSIONS

Variable reporting of previable fetal and infant deaths may compromise the validity of county IMR comparisons. Improved consistency and accuracy of fetal and infant death reporting is warranted.

The association between maternal race and adverse outcomes in twin pregnancies with similar healthcare access

OBJECTIVE

To compare twin pregnancy outcomes between white and nonwhite women with similar access to health care.

METHODS

Retrospective cohort study of all twin pregnancies delivered by a single maternal-fetal medicine practice from 2005-2016. All patients had private health insurance and equal access to physician care. Outcomes were compared between white and nonwhite women using logistic regression to adjust for differences at baseline.

RESULTS

Of the 858 women included, 730 (85.1%) were white and 128 (14.9%) were nonwhite. Univariate analysis demonstrated that nonwhite women had higher rates of preterm birth <32 weeks (12.5 versus 6.7%, p = .022), cesarean delivery (78.1% versus 61.4% of all women, p < .001 and 43.5% versus 16.1% of women who attempted labor, p < .001), preeclampsia (22.4% versus 14.5%, p = .029) and gestational diabetes (23.2% versus 7.3%, p < .001). On adjusted analysis, nonwhite race remained significantly associated with cesarean delivery in women who attempted labor (aOR 2.27, 95% CI: 1.09, 4.71) and gestational diabetes (aOR 2.61, 95% CI: 1.53, 4.45).

CONCLUSIONS

Nonwhite women with twin pregnancies have an increased risk of adverse outcomes that cannot be explained by access to care. Although improving access to care is an important goal for health care systems, our data suggest that this alone will not eliminate all disparities in health care outcomes between women of different races.

Survival of Infants Born at Periviable Gestational Ages

Periviable births are those occurring from 20 0/7 through 25 6/7 weeks of gestation. Among and within developed nations, significant variation exists in the approach to obstetric and neonatal care for periviable birth. Understanding gestational age-specific survival, including factors that may influence survival estimates and how these estimates have changed over time, may guide approaches to the care of periviable births and inform conversations with families and caregivers. This review provides a historical perspective on survival following periviable birth, summarizes recent and new data on gestational age-specific survival rates, and addresses factors that have a significant impact on survival.

Differences in morning-evening type and sleep duration between Black and White adults: Results from a propensity-matched UK Biobank sample

Biological evidence suggests that ethno-racial differences in morning-evening type are possible, whereby Blacks may be more likely to be morning type compared to Whites. However, population-level evidence of ethno-racial difference in morning-evening type is limited. In an earlier study, we reported that morning type was more prevalent in Blacks compared to Whites in the United Kingdom (UK) Biobank cohort (N = 439 933). This study aimed to determine if these ethno-racial differences persisted after accounting for an even broader range of social, environmental and individual characteristics and employing an analytic approach that simulates randomization in observational data, propensity score modeling. Data from UK Biobank participants whose self-identified race/ethnicity was Black/Black British or White; who did not report daytime napping, shift work or night shift work; who provided full mental health information; and who were identified using propensity score matching were used (N = 2044). Each sample was strongly matched across all social, environmental and individual characteristics as indicated by absolute standardized mean differences <0.09 for all variables. The prevalence of reporting nocturnal short, adequate and long sleep as well as morning, intermediate and evening type among Blacks (n = 1022) was compared with a matched sample of Whites (n = 1022) using multinomial logistic regression models. Blacks had a 62% greater odds of being morning type [odds ratio (OR) = 1.620, 95% confidence interval (CI): 1.336-1.964, p < .0001] and a more than threefold greater odds of reporting nocturnal short sleep (OR = 3.453, 95% CI: 2.846-4.190, p < .0001) than Whites. These data indicate that the greater prevalence of morning type and short nocturnal sleep in Blacks compared to Whites is not fully explained by a wide range of social and environmental factors. If sleep is an upstream determinant of health, these data suggest that ethno-racially targeted public health sleep intervention strategies are needed.

Racial/ethnic differences in preterm perinatal outcomes

BACKGROUND

Racial disparities in preterm birth and infant death have been well documented. Less is known about racial disparities in neonatal morbidities among infants who are born at <37 weeks of gestation.

OBJECTIVE

The purpose of this study was to determine whether the risk for morbidity and death among infants who are born preterm differs by maternal race.

STUDY DESIGN

A retrospective cohort design included medical records from preterm deliveries of 19,325 black, Hispanic, and white women in the Consortium on Safe Labor. Sequentially adjusted Poisson models with generalized estimating equations estimated racial differences in the risk for neonatal morbidities and death, controlling for maternal demographics, health behaviors, and medical history. Sex differences between and within race were examined.

RESULTS

Black preterm infants had an elevated risk for perinatal death, but there was no difference in risk for neonatal death across racial groups. Relative to white infants, black infants were significantly more likely to experience sepsis (9.1% vs 13.6%), peri- or intraventricular hemorrhage (2.6% vs 3.3%), intracranial hemorrhage (0.6% vs 1.8%), and retinopathy of prematurity (1.0% vs 2.6%). Hispanic and white preterm neonates had similar risk profiles. In general, female infants had lower risk relative to male infants, with white female infants having the lowest prevalence of a composite indicator of perinatal death or any morbidity across all races (30.9%). Differences in maternal demographics, health behaviors, and medical history did little to influence these associations, which were robust to sensitivity analyses of pregnancy complications as potential underlying mechanisms.

CONCLUSION

Preterm infants were at similar risk for neonatal death, regardless of race; however, there were notable racial disparities and sex differences in rare, but serious, adverse neonatal morbidities.

Nonresponse to 17-alpha hydroxyprogesterone caproate for recurrent spontaneous preterm birth prevention: clinical prediction and generation of a risk scoring system

BACKGROUND

Spontaneous preterm birth remains a leading cause of neonatal morbidity and mortality among nonanomalous neonates in the United States. Spontaneous preterm birth tends to recur at similar gestational ages. Intramuscular 17-alpha hydroxyprogesterone caproate reduces the risk of recurrent spontaneous preterm birth. Unfortunately, one-third of high-risk women will have a recurrent spontaneous preterm birth despite 17-alpha hydroxyprogesterone caproate therapy; the reasons for this variability in response are unknown.

OBJECTIVE

We hypothesized that clinical factors among women treated with 17-alpha hydroxyprogesterone caproate who suffer recurrent spontaneous preterm birth at a similar gestational age differ from women who deliver later, and that these associations could be used to generate a clinical scoring system to predict 17-alpha hydroxyprogesterone caproate response.

STUDY DESIGN

Secondary analysis of a prospective, multicenter, randomized controlled trial enrolling women with ≥1 previous singleton spontaneous preterm birth <37 weeks' gestation. Participants received daily omega-3 supplementation or placebo for the prevention of recurrent preterm birth; all were provided 17-alpha hydroxyprogesterone caproate. Women were classified as a 17-alpha hydroxyprogesterone caproate responder or nonresponder by calculating the difference in delivery gestational age between the 17-alpha hydroxyprogesterone caproate-treated pregnancy and her earliest previous spontaneous preterm birth. Responders were women with pregnancy extending ≥3 weeks later compared with the delivery gestational age of their earliest previous preterm birth; nonresponders delivered earlier or within 3 weeks of the gestational age of their earliest previous preterm birth. A risk score for nonresponse to 17-alpha hydroxyprogesterone caproate was generated from regression models via the use of clinical predictors and was validated in an independent population. Data were analyzed with multivariable logistic regression.

RESULTS

A total of 754 women met inclusion criteria; 159 (21%) were nonresponders. Responders delivered later on average (37.7±2.5 weeks) than nonresponders (31.5±5.3 weeks), P<.001. Among responders, 27% had a recurrent spontaneous preterm birth (vs 100% of nonresponders). Demographic characteristics were similar between responders and nonresponders. In a multivariable logistic regression model, independent risk factors for nonresponse to 17-alpha hydroxyprogesterone caproate were each additional week of gestation of the earliest previous preterm birth (odds ratio, 1.23; 95% confidence interval, 1.17-1.30, P<.001), placental abruption or significant vaginal bleeding (odds ratio, 5.60; 95% confidence interval, 2.46-12.71, P<.001), gonorrhea and/or chlamydia in the current pregnancy (odds ratio, 3.59; 95% confidence interval, 1.36-9.48, P=.010), carriage of a male fetus (odds ratio, 1.51; 95% confidence interval, 1.02-2.24, P=.040), and a penultimate preterm birth (odds ratio, 2.10; 95% confidence interval, 1.03-4.25, P=.041). These clinical factors were used to generate a risk score for nonresponse to 17-alpha hydroxyprogesterone caproate as follows: black +1, male fetus +1, penultimate preterm birth +2, gonorrhea/chlamydia +4, placental abruption +5, earliest previous preterm birth was 32-36 weeks +5. A total risk score >6 was 78% sensitive and 60% specific for predicting nonresponse to 17-alpha hydroxyprogesterone caproate (area under the curve=0.69). This scoring system was validated in an independent population of 287 women; in the validation set, a total risk score >6 performed similarly with a 65% sensitivity, 67% specificity and area under the curve of 0.66.

CONCLUSIONS

Several clinical characteristics define women at risk for recurrent preterm birth at a similar gestational age despite 17-alpha hydroxyprogesterone caproate therapy and can be used to generate a clinical risk predictor score. These data should be refined and confirmed in other cohorts, and women at high risk for nonresponse should be targets for novel therapeutic intervention studies.