Racial and ethnic disparities in United States: stillbirth rates: trends, risk factors, and research needs

The association of short-term increases in ambient PM2.5 and temperature exposures with stillbirth: racial/ethnic disparities among Medicaid recipients

Racial/ethnic disparities in the association between short-term (eg, days, weeks), ambient fine particulate matter (PM2.5) and temperature exposures and stillbirth in the United States have been understudied. A time-stratified, case-crossover design using a distributed lag nonlinear model (0- to 6-day lag) was used to estimate stillbirth odds due to short-term increases in average daily PM2.5 and temperature exposures among 118 632 Medicaid recipients from 2000 to 2014. Disparities by maternal race/ethnicity (Black, White, Hispanic, Asian, American Indian) and zip code-level socioeconomic status (SES) were assessed. In the temperature-adjusted model, a 10 μg m-3 increase in PM2.5 concentration was marginally associated with increased stillbirth odds at lag 1 (0.68%; 95% CI, -0.04% to 1.40%) and lag 2 (0.52%; 95% CI, -0.03 to 1.06) but not lag 0-6 (2.80%; 95% CI, -0.81 to 6.45). An association between daily PM2.5 concentrations and stillbirth odds was found among Black individuals at the cumulative lag (0-6 days: 9.26% 95% CI, 3.12%-15.77%) but not among other races or ethnicities. A stronger association between PM2.5 concentrations and stillbirth odds existed among Black individuals living in zip codes with the lowest median household income (lag 0-6: 14.13%; 95% CI, 4.64%-25.79%). Short-term temperature increases were not associated with stillbirth risk among any race/ethnicity. Black Medicaid enrollees, and especially those living in lower SES areas, may be more vulnerable to stillbirth due to short-term increases in PM2.5 exposure. This article is part of a Special Collection on Environmental Epidemiology.

Association between maternal religious service attendance and pregnancy loss in the United States: a secondary analysis of the Future Families & Child Wellbeing Study

Background

Accumulating evidence suggests that spirituality and religiosity may be associated with improved health outcomes. However, few studies have examined maternal religiosity as a protective factor for perinatal outcomes. We explored the association between maternal religious attendance and pregnancy loss.

Methods

Data were drawn from the Future Families & Child Wellbeing Study's first and second waves and medical records (n=1874). Religious attendance was a self-reported response to the question "About how often do you attend religious services?" Pregnancy loss was measured from responses to the second wave survey question, "Since focal child's birth, have you had any miscarriages/abortions/stillbirths?" Logistic regression estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between maternal religious attendance frequency and pregnancy loss, overall and by race. Models were adjusted for sampling weights, religious preference, socioeconomic and behavioral factors.

Results

8% (n=164) of mothers reported having a pregnancy loss. Of those with a pregnancy loss, 28% (n=46) attended services hardly ever and 20% (n=20) attended services once a week or more. Women who attended services more frequently had 58% increased odds of not experiencing a pregnancy loss (OR:1.58;95%CI:1.01,2.48) after adjusting for potential confounding. A post hoc analysis found no difference in pregnancy loss type or subsequent reproductive history based on attendance level.

Conclusions

Results suggest that higher maternal religious attendance frequency may be a protective factor for pregnancy loss. Further research is needed to understand the association between maternal religious attendance and mechanisms for pregnancy loss.

Social Determinants of Health and Risk of Stillbirth in the United States

OBJECTIVE

Our aim was to evaluate the impact of social determinants of health (SDoH) risk factors on stillbirth among pregnancy-related hospitalizations in the United States.

STUDY DESIGN

We conducted a cross-sectional analysis of delivery-related hospital discharges using annualized data (2016-2017) from the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample. The International Classification of Diseases, 10th Revision ICD-10-CM codes were used to select women with singleton stillbirth. Z-codes were utilized to identify SDoH risk factors and their subtypes. The association between SDoH risk factors and stillbirth was assessed using survey logistic regression models.

RESULTS

We analyzed 8,148,646 hospitalizations, out of which 91,140 were related to stillbirth hospitalizations, yielding a stillbirth incidence of 1.1%. An increased incidence was observed for non-Hispanic (NH) Blacks (1.7%) when compared with NH Whites (1.0%). The incidence of stillbirth was greater in hospitalizations associated with SDoH risk factors compared with those without risk factors [2.0% vs. 1.1% (p <0.001)]. Among patients with SDoH risk factors, the rate of stillbirth was highest in those designated as NH other (3.0%). Mothers that presented with SDoH risk factors had a 60% greater risk of stillbirth compared with those without (odds ratio [OR] = 1.61 [95% confidence interval (CI) = 1.33-1.95], p < 0.001). The SDoH issues that showed the most significant risk for stillbirth were: occupational risk (OR = 7.05 [95% CI: 3.54-9.58], p < 0.001), upbringing (OR = 1.87 [95% CI: 1.23-2.82], p < 0.001), and primary support group and family (OR = 5.45 [95% 3.84-7.76], p < 0.001).

CONCLUSION

We found pregnancies bearing SDoH risk factors to be associated with a 60% elevated risk for stillbirth. Future studies should target a variety of risk reduction strategies aimed at modifiable SDoH risk factors that can be widely implemented at both the population health level as well as in the direct clinical setting.

KEY POINTS

· Health disparities exist in stillbirth rates, especially among NH Black women.. · Social determinants of health risk factors increase the risk of stillbirth.. · There is a need for further study on the impact of specific SDoH risk factors on stillbirth risk..

Levels, Trends, and Risk Factors for Stillbirths in the United States: 2000-2017

OBJECTIVE

This study documents 2000 to 2017 trends in stillbirth rates and changes in associations between known maternal and fetal risk factors and stillbirths for 2000 to 2002 versus 2015 to 2017 in the United States.

STUDY DESIGN

We conducted a retrospective, population-based analysis of stillbirths and live-births using national vital statistics data. We calculated annual stillbirth rates overall and by gestational age; and examined stillbirth rates by maternal age, race-ethnicity, and state for 2000 to 2002 versus 2015 to 2017. We used Chi-squared tests to examine associations between maternal and fetal risk factors separately for early (20-27 weeks) and late (28+ weeks) stillbirths compared with live-births for 2000 to 2002 versus 2015 to 2017.

RESULTS

Stillbirth rates declined by 7.5% (p < 0.001) during 2000 to 2006 but remained flat at approximately 6 stillbirths per 1,000 births thereafter. Throughout 2000 to 2017, there were significant improvements in stillbirth rates at 39+ weeks nationally (p < 0.001), but rates varied greatly between and within states. Sociodemographic (advanced maternal age, Black race, low education, unmarried status, and rural residence), obstetric, and other medical factors (>3 births, use of infertility treatment, maternal obesity, diabetes, chronic hypertension, eclampsia, no prenatal care, and tobacco use) were significantly more prevalent in women with late than early stillbirths or live births. Notably, late and total stillbirth rates were approximately 30% higher for women >35 years than for women <35 years and twice as high for non-Hispanic Black than non-Hispanic White women; American Indian/Alaska Native women represented the only racial-ethnic group with significantly higher late stillbirth rates in 2015 to 2017 than in 2000 to 2002. Pregnancy and fetal factors (multiple pregnancy, male fetus, and breech presentation) were more prevalent in women with early than late stillbirths or live births.

CONCLUSION

U.S. stillbirth rates have plateaued since 2006. There are persistent differential risk profiles for early versus late stillbirths which can inform stillbirth prevention strategies (e.g., close observation of women with risk factors for stillbirth) and new research into the causes of stillbirths by gestational age.

KEY POINTS

· U.S. stillbirth rates have plateaued since 2006.. · Stillbirth rates vary between and within U.S. states and by maternal and fetal factors.. · Early versus late stillbirths have different risk profiles which can guide stillbirth prevention strategies..

Population-Level Study on Fetal Deaths and Preterm Births during SARS-CoV-2 Pandemic in the State of Michigan

OBJECTIVE

The aim of the study is to explore the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on preterm birth at different gestational ages and fetal death in the state of Michigan.

STUDY DESIGN

Data on live births and fetal deaths in the state of Michigan from March to November in the years 2017 through 2020 were obtained from Michigan Department of Health and Human Services (MDHHS). Preterm birth rate, fetal death rate (per 1,000 live births) overall and stratified by race and maternal comorbidities during the period of pandemic (March-November 2020) were compared with the same period (March-November) in the prepandemic years (2017-2019).

RESULTS

Of 328,879 live births and 1,470 fetal deaths during the study period, 77,983 live births and 242 fetal deaths were reported in 2020. Compared with prepandemic years, fetal death rate per 1,000 live births was significantly lower in 2020 (3.1 vs. 4.7 [2017], 5.2 [2018], 4.4 [2019], p-value <0.001). The adjusted risk for fetal death in 2020 was decreased (odds ratio [OR] = 0.64 [95% confidence interval (CI): 0.56-0.74], p <0.0001), compared with prepandemic years. Fetal death was significantly associated with African-American race, pregnancy hypertension and prepregnancy diabetes. No significant difference in the proportion of preterm births (<37 weeks' gestation) was noted between pandemic and prepandemic years (9.9 vs. 10.0%, p = 0.50). There was no significant difference in the risk of preterm birth across gestational age strata (<28, 28-316/7, 32-366/7, 37-416/7, and >42 weeks) between pandemic and prepandemic years on multinomial analysis. Significant associations with preterm birth across all years included African American race, lower level of maternal education, pregnancy-induced hypertension, chronic hypertension, prepregnancy diabetes, congenital anomalies, previous preterm birth, and prolonged rupture of membranes >12 hours.

CONCLUSION

Fetal death rate was significantly lower whereas preterm births remained unchanged during pandemic in comparison with prepandemic years in the state of Michigan.

KEY POINTS

· A decrease in fetal death rate was noted during SARS CoV-2 pandemic in the State of Michigan.. · Overall state-wide rates of preterm birth did not change in 2020, compared to previous years.. · Significant risk factors associated with preterm birth and fetal deaths did not differ between prepandemic and pandemic years..

Racial and ethnic inequities in stillbirth in the US: Looking upstream to close the gap: Seminars in Perinatology

Though stillbirth rates in the United States improved over the previous decades, inequities in stillbirth by race and ethnicity have persisted nearly unchanged since data collection began. Black and Indigenous pregnant people face a two-fold greater risk of experiencing the devastating consequences of stillbirth compared to their White counterparts. Because race is a social rather than biological construct, inequities in stillbirth rates are a downstream consequence of structural, institutional, and interpersonal racism which shape a landscape of differential access to opportunities for health. These downstream consequences can include differences in the prevalence of chronic health conditions as well as structural differences in the quality of health care or healthy neighborhood conditions, each of which likely plays a role in racial and ethnic inequities in stillbirth. Research and intervention approaches that utilize an equity lens may identify ways to close gaps in stillbirth incidence or in responding to the health and socioemotional consequences of stillbirth. A community-engaged approach that incorporates experiential wisdom will be necessary to create a full picture of the causes and consequences of inequity in stillbirth outcomes. Investigators working in tandem with community partners, utilizing a combination of qualitative, quantitative, and implementation science approaches, may more fully elucidate the underpinnings of racial and ethnic inequities in stillbirth outcomes.

Risk factors for late (28+ weeks' gestation) stillbirth in the United States, 2014-2015

BACKGROUND

In the United States (US) late stillbirth (at 28 weeks or more of gestation) occurs in 3/1000 births.

AIM

We examined risk factors for late stillbirth with the specific goal of identifying modifiable factors that contribute substantially to stillbirth burden.

SETTING

All singleton births in the US for 2014-2015.

METHODS

We used a retrospective population-based design to assess the effects of multiple factors on the risk of late stillbirth in the US. Data were drawn from the US Centers for Disease Control and Prevention live birth and fetal death data files.

RESULTS

There were 6,732,157 live and 18,334 stillbirths available for analysis (late stillbirth rate = 2.72/1000 births). The importance of sociodemographic determinants was shown by higher risks for Black and Native Hawaiian and Other Pacific Islander mothers compared with White mothers, mothers with low educational attainment, and older mothers. Among modifiable risk factors, delayed/absent prenatal care, diabetes, hypertension, and maternal smoking were associated with increased risk, though they accounted for only 3-6% of stillbirths each. Two factors accounted for the largest proportion of late stillbirths: high maternal body mass index (BMI; 15%) and infants who were small for gestational age (38%). Participation in the supplemental nutrition for women, infants and children program was associated with a 28% reduction in overall stillbirth burden.

CONCLUSIONS

This study provides population-based evidence for stillbirth risk in the US. A high proportion of late stillbirths was associated with high maternal BMI and small for gestational age, whereas participation in supplemental nutrition programs was associated with a large reduction in stillbirth burden. Addressing obesity and fetal growth restriction, as well as broadening participation in nutritional supplementation programs could reduce late stillbirths.

Pregnancy loss in major fetal congenital heart disease: incidence, risk factors and timing

OBJECTIVE

Fetuses with congenital heart disease (CHD) are at increased risk of pregnancy loss compared with the general population. We aimed to assess the incidence, timing and risk factors of pregnancy loss in cases with major fetal CHD, overall and according to cardiac diagnosis.

METHODS

This was a retrospective, population-level cohort study of fetuses and infants diagnosed with major CHD between 1997 and 2018 identified by the Utah Birth Defect Network (UBDN), excluding cases with termination of pregnancy and minor cardiovascular diagnoses (e.g. isolated aortic/pulmonary pathology and isolated septal defects). The incidence and timing of pregnancy loss were recorded, overall and according to CHD diagnosis, with further stratification based on presence of isolated CHD vs additional fetal diagnosis (genetic diagnosis and/or extracardiac malformation). Adjusted risk of pregnancy loss was calculated and risk factors were assessed using multivariable models for the overall cohort and prenatal diagnosis subgroup.

RESULTS

Of 9351 UBDN cases with a cardiovascular code, 3251 cases with major CHD were identified, resulting in a study cohort of 3120 following exclusion of cases with pregnancy termination (n = 131). There were 2956 (94.7%) live births and 164 (5.3%) cases of pregnancy loss, which occurred at a median gestational age of 27.3 weeks. Of study cases, 1848 (59.2%) had isolated CHD and 1272 (40.8%) had an additional fetal diagnosis, including 736 (57.9%) with a genetic diagnosis and 536 (42.1%) with an extracardiac malformation. The observed incidence of pregnancy loss was highest in the presence of mitral stenosis (< 13.5%), hypoplastic left heart syndrome (HLHS) (10.7%), double-outlet right ventricle with normally related great vessels or not otherwise specified (10.5%) and Ebstein's anomaly (9.9%). The adjusted risk of pregnancy loss was 5.3% (95% CI, 3.7-7.6%) in the overall CHD population and 1.4% (95% CI, 0.9-2.3%) in cases with isolated CHD (adjusted risk ratio, 9.0 (95% CI, 6.0-13.0) and 2.0 (95% CI, 1.0-6.0), respectively, based on the general population risk of 0.6%). On multivariable analysis, variables associated with pregnancy loss in the overall CHD population included female fetal sex (adjusted odds ratio (aOR), 1.6 (95% CI, 1.1-2.3)), Hispanic ethnicity (aOR, 1.6 (95% CI, 1.0-2.5)), hydrops (aOR, 6.7 (95% CI, 4.3-10.5)) and additional fetal diagnosis (aOR, 6.3 (95% CI, 4.1-10)). On multivariable analysis of the prenatal diagnosis subgroup, years of maternal education (aOR, 1.2 (95% CI, 1.0-1.4)), presence of an additional fetal diagnosis (aOR, 2.7 (95% CI, 1.4-5.6)), atrioventricular valve regurgitation ≥ moderate (aOR, 3.6 (95% CI, 1.3-8.8)) and ventricular dysfunction (aOR, 3.8 (95% CI, 1.2-11.1)) were associated with pregnancy loss. Diagnostic groups associated with pregnancy loss were HLHS and variants (aOR, 3.0 (95% CI, 1.7-5.3)), other single ventricles (aOR, 2.4 (95% CI, 1.1-4.9)) and other (aOR, 0.1 (95% CI, 0-0.97)). Time-to-pregnancy-loss analysis demonstrated a steeper survival curve for cases with an additional fetal diagnosis, indicating a higher rate of pregnancy loss compared to cases with isolated CHD (P < 0.0001).

CONCLUSIONS

The risk of pregnancy loss is higher in cases with major fetal CHD compared with the general population and varies according to CHD type and presence of additional fetal diagnoses. Improved understanding of the incidence, risk factors and timing of pregnancy loss in CHD cases should inform patient counseling, antenatal surveillance and delivery planning. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

The impact of COVID-19 vaccinations on stillbirth rates among pregnant women in the Metro-Detroit area

Infection by COVID-19 increases maternal morbidity and mortality prompting both the American College of Obstetrics and Gynecology and the Society of Maternal Fetal Medicine to strongly recommend vaccination during pregnancy. Limited data exist assessing the risk of intrauterine fetal death (IUFD) associated with COVID vaccination during pregnancy. This was a retrospective chart review at a large multisite hospital system in Metro Detroit which reviewed data from 13,368 pregnancies. We compared IUFD rates between vaccinated and unvaccinated patients. The rate of stillbirths among unvaccinated women (0.75%) was not statistically different from those who were vaccinated (0.60%). Individuals with government insurance were less likely to be vaccinated and more likely to have IUFD in comparison to patients with private insurance. The rate of stillbirths among Black women was significantly higher than among White women at a rate of 1.1% compared to 0.53% (p=0.008) with no difference in stillbirth rates among vaccinated vs unvaccinated racial distribution. Lastly, it is worth noting that the overall vaccination rate at our healthcare system in pregnancy was very poor (0.26%). In conclusion, this is a large population of highly diverse patients which indicates that COVID-19 vaccination does not lead to IUFD. We plan to use this data to help drive an educational vaccination campaign to try to increase our COVID-19 vaccination rate in our pregnant patients. Systemic racism and social determinants of health have played a large factor in COVID-19 outcomes, and our data highlights that this is the case for IUFD in Black women. Improvements must be made to identify barriers for these women to allow for better pregnancy outcomes. We acknowledge that individuals with government insurance may also have other barriers to healthcare or face healthcare inequity which leaves room for improvement on getting these individuals vaccinated and getting the resources they need to have better pregnancy outcomes.

Stillbirth After Adolescent and Young Adult Cancer: A Population-Based Study

BACKGROUND

Gonadotoxic effects of cancer treatment may increase risk of adverse birth outcomes in adolescent and young adult (AYA, aged 15-39 years) women diagnosed with cancer. We estimated risk of stillbirth (fetal death of gestational age ≥20 weeks or weighing ≥350 grams) in a population-based sample of AYA women.

METHODS

AYA women diagnosed with cancer between January 1, 1995, and December 31, 2015, were identified using the Texas Cancer Registry and linked to live birth and fetal death certificates through December 31, 2016. Among AYA women, cumulative incidence of stillbirth was estimated by gestational age, and Poisson regression models identified factors associated with stillbirth. Standardized fetal mortality ratios (SMR) compared the observed fetal mortality rate in AYA women with the expected fetal mortality rate in the general population.

RESULTS

A total of 11 628 live births and 68 stillbirths occurred to 8402 AYA women after diagnosis. Cumulative incidence of stillbirth in AYA women was 0.70% (95% confidence interval [CI] = 0.51% to 0.96%) at 40 weeks of gestation. Risk of stillbirth was higher among Hispanic (risk ratio [RR] = 2.64, 95% CI = 1.29 to 5.41) and non-Hispanic Black (RR = 4.13, 95% CI = 1.68 to 10.16) women compared with non-Hispanic White women; there was no association with receipt of chemotherapy or time since diagnosis. Age- and race and ethnicity-adjusted fetal mortality rate in AYA women was similar to the general population (SMR = 0.99, 95% CI = 0.77 to 1.26).

CONCLUSIONS

AYA women may be counseled that overall risk of stillbirth is low, and for most, cancer does not appear to confer additional risk.

Prediction of stillbirth low resource setting in Northern Uganda

BACKGROUND

Women of Afro-Caribbean and Asian origin are more at risk of stillbirths. However, there are limited tools built for risk-prediction models for stillbirth within sub-Saharan Africa. Therefore, we examined the predictors for stillbirth in low resource setting in Northern Uganda.

METHODS

Prospective cohort study at St. Mary's hospital Lacor in Northern Uganda. Using Yamane's 1967 formula for calculating sample size for cohort studies using finite population size, the required sample size was 379 mothers. We doubled the number (to > 758) to cater for loss to follow up, miscarriages, and clients opting out of the study during the follow-up period. Recruited 1,285 pregnant mothers at 16-24 weeks, excluded those with lethal congenital anomalies diagnosed on ultrasound. Their history, physical findings, blood tests and uterine artery Doppler indices were taken, and the mothers were encouraged to continue with routine prenatal care until the time for delivery. While in the delivery ward, they were followed up in labour until delivery by the research team. The primary outcome was stillbirth 24 + weeks with no signs of life. Built models in RStudio. Since the data was imbalanced with low stillbirth rate, used ROSE package to over-sample stillbirths and under-sample live-births to balance the data. We cross-validated the models with the ROSE-derived data using K (10)-fold cross-validation and obtained the area under curve (AUC) with accuracy, sensitivity and specificity.

RESULTS

The incidence of stillbirth was 2.5%. Predictors of stillbirth were history of abortion (aOR = 3.07, 95% CI 1.11-8.05, p = 0.0243), bilateral end-diastolic notch (aOR = 3.51, 95% CI 1.13-9.92, p = 0.0209), personal history of preeclampsia (aOR = 5.18, 95% CI 0.60-30.66, p = 0.0916), and haemoglobin 9.5 - 12.1 g/dL (aOR = 0.33, 95% CI 0.11-0.93, p = 0.0375). The models' AUC was 75.0% with 68.1% accuracy, 69.1% sensitivity and 67.1% specificity.

CONCLUSION

Risk factors for stillbirth include history of abortion and bilateral end-diastolic notch, while haemoglobin of 9.5-12.1 g/dL is protective.

Evolving stillbirth rates among Black and White women in the United States, 1980-2020: A population-based study

Background

Given slowing secular declines and persistent racial disparities, stillbirth remains a major health burden in the US. We investigate changes in stillbirth rates overall and for Black and White women, and determine how maternal age, delivery year (period), and birth year (cohort) have shaped trends.

Methods

We designed a sequential time-series analysis utilising the 1980 to 2020 US vital records data of live births and stillbirths at ≥24 weeks gestation. Stillbirth rates overall and among Black and White women were examined. We undertook an age-period-cohort analysis to evaluate temporal changes in stillbirth trends.

Findings

Of 157,192,032 live births and 710,832 stillbirths between 1980 and 2020, stillbirth rates per 1000 births declined from 10.6 (95% confidence interval [CI] 10.5, 10.7) in 1980 to 5.8 (95% CI 5.7, 5.8) in 2020. Stillbirth rates declined from 9.2 to 5.0 per 1000 births among White women (rate ratio [RR] 0.54, 95% CI 0.53, 0.55), and from 17.4 to 10.1 per 1000 births among Black women (RR 0.57, 95% CI 0.55, 0.59). Black women experienced persistent two-fold higher rates compared to White women (2.01, 95% CI 1.97, 2.05 in 2020). Stillbirth rates declined until 2005, increased from 2005 to the mid-2010s and plateaued thereafter. Strong cohort effects contributed to declining rates in earlier cohorts (1930-1955) and increasing rates among women born after 1980.

Interpretation

Age, period, and birth cohorts greatly influenced US stillbirth rates over the last forty years. The decline in stillbirth rate was evident between 1980 and 2005, however subsequent declines have been minimal, reflecting no further gains for cohorts of women born in 1955-1980 and stagnation of period effects starting in 2005. A significant racial disparity persisted with a two-fold excess in stillbirth rates for Black compared to White women, underscoring the need for targeted health and social policies to address disparities.

Funding

None.

Socioeconomic inequality and stillbirth rate disparities among native and foreign mothers: evidence from Greece

We study, for the first time, stillbirth differentials among native and migrant populations in Greece using national vital registration microdata for the period of 2010–2014. We employ conventional demographic measures and propose a standardization procedure to delineate the effect of selected distributions of livebirths on the observed stillbirth rates. The stillbirth rate among immigrant mothers is 40% higher than among natives, an excess which persists throughout gestational intervals and age groups. Our findings also show a clear gradient of stillbirth rates by maternal education, favoring more educated women, and this finding applies to both native and immigrant mothers. Our standardization methodology shows that the distribution of births by maternal educational level and age play a role; this finding implies that elevated immigrant stillbirth rates may be attributed to a certain extent to the specific characteristics of this group, since immigrant women have, on average, a younger age structure and lower educational attainment.

Epidemiology of stillbirths based on different gestational thresholds at a tertiary hospital

INTRODUCTION

The stillbirth rate (SBR) is an important public health indicator. We studied the distribution of maternal and fetal characteristics and time trends of the SBR at KK Women's and Children's Hospital (KKH), Singapore, from 2004 to 2016 based on various definitions of stillbirth.

METHODS

Data was obtained from the Data Warehouse and Stillbirth Reporting System of KKH from 2004 to 2016. SBRs were calculated based on three definitions (fetal deaths at ≥ 20 weeks, 24 weeks or 28 weeks of gestation per 1,000 total births) and were described with maternal and fetal characteristics, and by year.

RESULTS

From 2004 to 2016, the SBR declined by 44.7%, 25.5% and 18.9% based on Definitions I, II and III, respectively. The SBR at KKH in 2016 was 5.2 (Definition I), 4.1 (Definition II) and 3.0 (Definition III) per 1,000 total births. The SBR was significantly higher in women aged ≥ 35 years, nulliparas and female fetuses. The number of live births at 24-27+6 weeks of gestation was more than four times higher than that of stillbirths (822 vs. 176). There were 104 (12.7%) neonatal deaths during this gestation period, giving a high survival rate of 87.3%.

CONCLUSION

The SBR in KKH is relatively lower than that in other developed countries. There is a need to consider revising our hospital and national definitions of the stillbirth lower boundary from 28 weeks to 24 weeks of gestation. This would allow us to make better comparisons with other developed countries, in line with improvements in healthcare.

Racial and Ethnic Disparities in Medical Complexity and In-Hospital Death Among US-Born VLBW Infants

BACKGROUND AND OBJECTIVE

To assess the racial and ethnic disparity in the prevalence of complex chronic conditions (CCC) and/or in-hospital death among US-born very low birth weight (VLBW, <1500 g) infants.

METHODS

This retrospective, cross-sectional analysis of discharge data from the Kids' Inpatient Database, included VLBW infants born in US hospitals in 2009 and 2012 (n = 554825, weighted n = 573693) exlcuding those with missing demographics. The main outcome was CCC or death. Multiple logistic regression modeling estimated the association of various characteristics with CCC or death, considering race and ethnicity.

RESULTS

There was heterogeneity in the association of insurance status and hospital region and experiencing CCC or death when compared across races and ethnicities. Infants of all races and ethnicities had higher odds of CCC or death if they had an operative procedure, were outborn, or had a birth weight of <500 g or 500 g to 999 g compared with 1000 g to 1499 g. Non-Hispanic Black infants <500 g, however, had the highest odds of CCC or death compared with those 1000 g to 1499 g (adjusted odds ratio 67.2, 95% confidence interval, 48.6-93.0), 2.3 times higher than the odds for non-Hispanic White infants (AOR 2.32, 95% confidence interval, 1.57-3.42).

CONCLUSIONS

Insurance and region were associated with increased prevalence of CCC or death in certain racial and ethnic groups. Additionally, non-Hispanic Black infants <500 g had >2.3 times the odds of CCC or death compared with non-Hispanic White infants, relative to infants 1000 g to 1499 g. Additional investigation is needed to understand the drivers of these disparities.

Family resiliency and family functioning in Non-Hispanic Black and Non-Hispanic White families of preterm infants

PURPOSE

The purpose of this study was to examine the relationship between resiliency factors and family functioning in families of preterm infants (< 37 weeks gestation) from two different racial groups hospitalized in a neonatal intensive care unit (NICU).

DESIGN AND METHODS

A cross-sectional design was used at five Level III/IV NICUs in a Midwestern city/suburbs. Seventy-nine family units (24 Non-Hispanic Black and 55 Non-Hispanic White) completed four instruments that assessed families' use of specific resiliency factors and a measure of family functioning. Demographic data were also collected.

RESULTS

Using linear mixed modeling, the significant predictors of family functioning for both Non-Hispanic Black and Non-Hispanic White, even after adjusting for education, income and race, were the protective factors "hardiness" (coefficient = -0.021) and "resources" (coefficient = -0.0052). The fixed effects in the model accounted for 48% (Marginal R² = 0.48) of the variance on family functioning and the fixed and random effects accounted for 59% (Conditional R^2, 0.59) of the variance on family functioning. Sixteen percent of the total sample rated their family as dysfunctional.

CONCLUSIONS

Findings from this study suggest that assessment of protective factors related to hardiness and resources individualize nursing interventions to support the resiliency of both Non-Hispanic Black and Non-Hispanic White families, regardless of differences in income and education. Further research studying resiliency in families of preterm infants is needed to understand the impact on long-term family functioning.

PRACTICE IMPLICATIONS

Understandingindividual family strengths,through the identification of resiliency (protective and recovery) factors could predict at-risk families before discharge. In collaboration with other health care professionals, nurses can assess individual family needs and strengths, within the context of their socioeconomic environment, and the racial and cultural influences that are important to the family.

Hispanic Ethnicity, Nativity and the Risk of Stillbirth

The objective of this study was to examine stillbirth risk by nativity and Hispanic ethnicity. We analyzed births and fetal deaths among women of Hispanic origin within gestational ages of 20-42 weeks from the 2014-2019 Birth and Fetal Death. Foreign-born Hispanic mothers were 8% less likely (HR 0.92, 95% CI 0.90-0.95) to experience stillbirth than their counterparts. Stratified by ethnicity, foreign-born Mexican and Central/South American women had a lower risk of stillbirth (HR 0.85, 95% CI 0.81-0.88 and HR 0.68, 95% CI 0.63-0.75, respectively) while foreign-born Puerto Rican women were more likely to experience stillbirth (HR 1.37, 95% CI 1.24-1.51) than their native-born counterparts. While overall foreign-born Hispanic mothers were less likely to experience stillbirth than native-born Hispanic mothers, this differed depending on ethnicity. Counseling regarding risk of stillbirth among Hispanic women should take into consideration nativity and country of origin as influential factors.

Ethnic variation in causes of stillbirth in high income countries: A systematic review and meta-analysis

OBJECTIVE

Inequities in stillbirth rate according to ethnicity persist in high income nations. The objective of the present study is to investigate whether causes of stillbirth differ by ethnicity in high-income nations.

METHODS

The following databases were searched since their inception to 1 February 2021: Medline, Embase, Scopus, CINAHL, Cochrane Library, and Global Health. Cohort, cross-sectional, and retrospective studies were included. Causes of stillbirth were aligned to the International Classification of Disease 10 for Perinatal Mortality (ICD10-PM) and pooled estimates were derived by meta-analysis.

RESULTS

Fifteen reports from three countries (72 555 stillbirths) were included. Seven ethnic groups - "Caucasian" (n = 11 studies), "African" (n = 11 studies), "Hispanic" (n = 7 studies), "Indigenous Australian" (n = 4 studies), "Asian" (n = 2 studies), "South Asian" (n = 2 studies), and "American Indian" (n = 1 study) - were identified. There was an overall paucity of recent, high-quality data for many ethnicities. For those with the greatest amount of data - Caucasian, African, and Hispanic - no major differences in the causes of stillbirth were identified.

CONCLUSION

There is a paucity of high-quality information on causes of stillbirth for many ethnicities. Improving investigation and standardizing classification of stillbirths is needed to assess whether causes of stillbirth differ across more diverse ethnic groups.

Racial Disparities in Stillbirth Risk Factors among non-Hispanic Black Women and non-Hispanic White Women in the United States

INTRODUCTION

Historically, stillbirth risk factors are more prevalent among non-Hispanic Black women than non-Hispanic White women, including age < 20, lower formal educational attainment, prepregnancy obesity, smoking, hypertension, diabetes, short interpregnancy interval, small for gestational age newborn, late prenatal care, and previous cesarean birth. We examined whether these disparities have changed since 2011 and identified a group of risk factors that differed between Black women and White women when accounting for correlations among variables.

METHODS

In a random sample of 315 stillbirths from the National Center for Health Statistics' 2016 fetal death data, Black women and White women were compared for each risk factor using t-tests or chi-square tests. Variables with p ≤ .20 were analyzed using multivariate analysis of variance.

RESULTS

In this sample, Black women experiencing stillbirth were less likely to have a Bachelor's degree (12.94% vs. 28.49%, p = .04), and more likely to be obese (44.5% vs. 29.1%, p = .01) than White women. Multivariate analysis accounting for correlations among variables showed a group of risk factors that differed between Black women and White women: age < 20, lower education, prepregnancy obesity, hypertension (chronic and pregnancy-associated), nulliparity before stillbirth, and earlier gestation.

CLINICAL IMPLICATIONS

Less formal education, obesity, age <20, hypertension, chronic and pregnancy-associated, nulliparity, and earlier gestation are important to consider in multilevel stillbirth prevention interventions to decrease racial disparity in stillbirth. Respectfully listening to women and taking their concerns seriously is one way nurses and other health care providers can promote equity in health outcomes for childbearing women.

An Analysis of the Trend of Fetal Mortality Rates among Working and Jobless Households in Japan, 1995-2019

This study aimed to identify differences in the trends of artificial and spontaneous fetal mortality rates between working and jobless households depending on ages, periods, and birth cohorts in Japan. Vital Statistics data from 1995 to 2019 and age groups in 5–year increments from 15 to 19 years through 45 to 49 years were used. Bayesian age–period–cohort analysis was used to evaluate changes in each of the outcomes. As a result, the difference in maternal age–standardized rate of both the artificial and spontaneous fetal mortality rates between the two types of households decreased in the periods analyzed. However, there was a statistically significant difference in the mortality rate between jobless and working households, regardless of maternal ages, periods, and cohorts for the artificial fetal mortality rate. A statistically significant difference was also observed for the spontaneous fetal mortality rates in some maternal ages, periods, and cohorts. In addition, the trend of birth cohort effects was particularly different between the two types of households for both the artificial and spontaneous fetal mortality rates.

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.

Ethnic disparities in stillbirth risk in Yunnan, China: a prospective cohort study, 2010-2018

Background

Racial and ethnic disparities in stillbirth risk had been documented in most western countries, but it remains unknown in China. This study was to determine whether exist ethnic disparities in stillbirth risk in mainland China.

Methods

Pregnancy outcomes and ethnicity data were obtained from the National Free Preconception Health Examination Project (NEPHEP), a nationwide prospective population-based cohort study conducted in Yunnan China from 2010-2018. The Han majority and other four main minorities including Yi, Dai, Miao, Hani were investigated in the analysis. The stillbirth hazards were estimated by life-table analysis. The excess stillbirth risk (ESR) was computed for Chinese minorities using multivariable logistic regression.

Results

Compared with other four minorities, women in Han majority were more likely to more educated, less multiparous, and less occupied in agriculture. The pattern of stillbirth hazard of Dai women across different gestation intervals were found to be different from other ethnic groups, especially in 20-23 weeks with 3.2 times higher than Han women. The ESR of the Dai, Hani, Miao, and Yi were 45.05, 18.70, -4.17 and 12.28%, respectively. Adjusted for maternal age, education, birth order and other general risk factors, the ethnic disparity still persisted between Dai women and Han women. Adjusted for preterm birth further (gestation age <37 weeks) can reduce 16.91% ESR of Dai women and made the disparity insignificant. Maternal diseases and congenital anomalies explained little for ethnic disparities.

Conclusions

We identified the ethnic disparity in stillbirth risk between Dai women and Han women. General risk factors including sociodemographic factors and maternal diseases explained little. Considerable ethnic disparities can be attributed to preterm birth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-10102-y.

Racial and Ethnic Disparities in Fetal Deaths - United States, 2015-2017

The spontaneous death or loss of a fetus during pregnancy is termed a fetal death. In the United States, national data on fetal deaths are available for losses at ≥20 weeks' gestation.* Deaths occurring during this period of pregnancy are commonly known as stillbirths. In 2017, approximately 23,000 fetal deaths were reported in the United States (1). Racial/ethnic disparities exist in the fetal mortality rate; however, much of the known disparity in fetal deaths is unexplained (2). CDC analyzed 2015-2017 U.S. fetal death report data and found that non-Hispanic Black (Black) women had more than twice the fetal mortality rate compared with non-Hispanic White (White) women and Hispanic women. Fetal mortality rates also varied by maternal state of residence. Cause of death analyses were conducted for jurisdictions where >50% of reports had a cause of death specified. Still, even in these jurisdictions, approximately 31% of fetal deaths had no cause of death reported on a fetal death report. There were differences by race and Hispanic origin in causes of death, with Black women having three times the rate of fetal deaths because of maternal complications compared with White women. The disparities suggest opportunities for prevention to reduce the U.S. fetal mortality rate. Improved documentation of cause of death on fetal death reports might help identify preventable causes and guide prevention efforts.

Maternal cardiovascular function and risk of intrapartum fetal compromise in women undergoing induction of labor: pilot study

OBJECTIVE

Identification of the fetus at risk of intrapartum compromise has many benefits. Impaired maternal cardiovascular function is associated with placental hypoperfusion predisposing to intrapartum fetal distress. The aim of this study was to assess the predictive accuracy of maternal hemodynamics for the risk of operative delivery due to presumed fetal compromise in women undergoing induction of labor (IOL).

METHODS

In this prospective cohort study, patients were recruited between November 2018 and January 2019. Women undergoing IOL were invited to participate in the study. A non-invasive ultrasonic cardiac output monitor (USCOM-1A®) was used for cardiovascular assessment. The study outcome was operative delivery due to presumed fetal compromise, which included Cesarean or instrumental delivery for abnormal fetal heart monitoring. Regression analysis was used to test the association between cardiovascular markers, as well as the maternal characteristics, and the risk of operative delivery due to presumed fetal compromise. Receiver-operating-characteristics-curve analysis was used to assess the predictive accuracy of the cardiovascular markers for the risk of operative delivery for presumed fetal compromise.

RESULTS

A total of 99 women were recruited, however four women were later excluded from the analysis due to semi-elective Cesarean section (n = 2) and failed IOL (n = 2). The rate of operative delivery due to presumed fetal compromise was 28.4% (27/95). Women who delivered without suspected fetal compromise (controls) were more likely to be parous, compared to those who had operative delivery due to fetal compromise (52.9% vs 18.5%; P = 0.002). Women who underwent operative delivery due to presumed fetal compromise had a significantly lower cardiac index (median, 2.50 vs 2.60 L/min/m² ; P = 0.039) and a higher systemic vascular resistance (SVR) (median, 1480 vs 1325 dynes × s/cm⁵ , P = 0.044) compared to controls. The baseline model (being parous only) showed poor predictive accuracy, with an area under the curve of 0.67 (95% CI, 0.58-0.77). The addition of stroke volume index (SVI) < 36 mL/m² , SVR > 7.2 logs or SVR index (SVRI) > 7.7 logs improved significantly the predictive accuracy of the baseline model (P = 0.012, P = 0.026 and P = 0.012, respectively).

CONCLUSION

In this pilot study, we demonstrated that prelabor maternal cardiovascular assessment in women undergoing IOL could be useful for assessing the risk of intrapartum fetal compromise necessitating operative delivery. The addition of SVI, SVR or SVRI improved significantly the predictive accuracy of the baseline antenatal model. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Findings in Stillbirths Associated with Placental Disease

OBJECTIVE

Placental disease is a leading cause of stillbirth. Our purpose was to characterize stillbirths associated with placental disease.

STUDY DESIGN

The Stillbirth Collaborative Research Network conducted a prospective, case-control study of stillbirths and live births from 2006 to 2008. This analysis includes 512 stillbirths with cause of death assignment and a comparison group of live births. We compared exposures between women with stillbirth due to placental disease and those due to other causes as well as between women with term (≥ 37 weeks) stillbirth due to placental disease and term live births.

RESULTS

A total of 121 (23.6%) out of 512 stillbirths had a probable or possible cause of death due to placental disease by Initial Causes of Fetal Death. Characteristics were similar between stillbirths due to placental disease and other stillbirths. When comparing term live births to stillbirths due to placental disease, women with non-Hispanic black race, Hispanic ethnicity, lack of insurance, or who were born outside of the United States had higher odds of stillbirth due to placental disease. Nulliparity and antenatal bleeding also increased risk of stillbirth due to placental disease.

CONCLUSION

Multiple discrete exposures were associated with stillbirth caused by placental disease. The relationship between these factors and utility of surveillance warrants further study.

The weathering hypothesis and stillbirth: racial disparities across the life span

Objective: Given that studies have consistently demonstrated increased risk of stillbirth with increasing maternal age as well as race-ethnic disparities in stillbirth, the primary research question is how stillbirth risks within and between race-ethnic groups change with age.Design: Using fetal death (stillbirth) and live birth data from the National Center for Health Statistics 2007-2014. We calculated crude stillbirth rates (per 1,000 deliveries). Using multivariable logistic regression, we calculated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for stillbirth across age groups to examine disparities in stillbirth among non-Hispanic blacks (blacks) and non-Hispanic whites (whites).Results: Rates and risks of stillbirth increased as maternal age increased; however, the magnitude of risk varies by race-ethnicity. Compared to women less than 20, black women age 40+ had a risk of almost 3.5 times (aOR = 3.47, 95% CI = 3.24-3.70) whereas among white women age 40+, the risk was more than 2.5 times (aOR = 2.68, 95% CI = 2.55-2.82). The risk of stillbirth among blacks compared to whites increased, peaking at ages 30-34 (aOR = 2.64, 95% CI = 2.56-2.73). At age 35 and beyond, the disparity in risks declined.Conclusion: As age increased, the risk of stillbirth increased for both blacks and whites. Because the disparity in risk between blacks and whites did not continue to increase with age, stillbirth does not seem to reflect the weathering hypothesis as other perinatal outcomes do.

Obstetric Care Consensus #10: Management of Stillbirth: (Replaces Practice Bulletin Number 102, March 2009)

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained, even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Management of Stillbirth: Obstetric Care Consensus No, 10

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

An iterative design process to develop a randomized feasibility study and inform recruitment of minority women after stillbirth

BACKGROUND

Yearly, approximately 25,000 US women experience stillbirth and African American women have a 2.2 fold increased risk of stillbirth compared with white women. After stillbirth, women are subject to a sevenfold increased risk of post-traumatic stress compared with women after a live-birth. This paper presents findings from phase one of a National Institutes of Health funded, two-phase feasibility study to examine an online yoga intervention to reduce symptoms of post-traumatic stress in mothers after stillbirth. An iterative design was used to (1) inform the development of the online yoga intervention and (2) inform recruitment strategies to enroll minority women into phase two.

METHODS

Ten mothers (N = 5 stillbirth moms with no yoga experience, N = 5 nonstillbirth moms with yoga experience) participated in a series of online yoga videos (N = 30) and were assessed for self-compassion (SC) and emotional regulation (ER) before and after each video. An independent group of five minority women who had experienced stillbirth were interviewed about cultural barriers to recruitment and perceptions/opinions of yoga. A mean was calculated for SC and ER scores for each video at pre- and post-time points. The percent change of the mean difference between pre-post SC and ER scores were used to select videos for phase two. Videos with a negative change score or that had a 0% change on SC or ER were not used. A combination of deductive and inductive coding was used to organize the interview data, generate categories, and develop themes.

RESULTS

Five of the 30 tested yoga videos were not used. An additional 12 videos were developed, filmed, and used in the prescription for phase two. Topics from interview findings included perceived benefits/barriers of and interest in yoga, preferred yoga environment, suggested recruitment methods, content of recruitment material, and recommended incentives.

CONCLUSIONS

Online yoga may be beneficial for improving emotional regulation and self-compassion, but further testing is needed. Additionally, minority women express interest in online yoga but suggest that researchers apply culturally specific strategies regarding methods, content of material, and incentives to recruit minority women into a study.

Time-Varying Exposure to Ozone and Risk of Stillbirth in a Nonattainment Urban Region

In a racially and ethnically diverse urban area (Harris County, Texas) with historic nonattainment O3 levels, we obtained birth and fetal death records from 2008-2013 and estimated maternal residential O3 concentrations from conception until delivery using inverse-distance interpolation from the local air monitoring network. We examined multipollutant models (with fine particulate matter and nitrogen dioxide) and effect measure modification by race/ethnicity and length of gestation. We found a 9% (95% confidence interval (CI): 1, 18) increased stillbirth risk associated with a 3.6-parts-per-billion increase in O3 exposure. The risk was higher among women with pregnancies of <37 gestational weeks (hazard ratio (HR) = 1.13, 95% CI: 1.04, 1.23) compared with women with pregnancies of longer gestation (HR = 1.05, 95% CI: 0.87, 1.27) and among Hispanic women (HR = 1.14, 95% CI: 1.02, 1.27). We also conducted a case-crossover analysis and detected no associations with short-term exposure. To our knowledge, this study is the first to use time-to-event analyses to examine stillbirth risk associated with time-varying prenatal ozone (O3) exposure over pregnancy. Our findings indicate that maternal O3 exposure over pregnancy is associated with stillbirth risk and that Hispanic women and women with shorter pregnancies might be at particular risk.

Risks of stillbirth and neonatal death with advancing gestation at term: A systematic review and meta-analysis of cohort studies of 15 million pregnancies

BACKGROUND

Despite advances in healthcare, stillbirth rates remain relatively unchanged. We conducted a systematic review to quantify the risks of stillbirth and neonatal death at term (from 37 weeks gestation) according to gestational age.

METHODS AND FINDINGS

We searched the major electronic databases Medline, Embase, and Google Scholar (January 1990-October 2018) without language restrictions. We included cohort studies on term pregnancies that provided estimates of stillbirths or neonatal deaths by gestation week. We estimated the additional weekly risk of stillbirth in term pregnancies that continued versus delivered at various gestational ages. We compared week-specific neonatal mortality rates by gestational age at delivery. We used mixed-effects logistic regression models with random intercepts, and computed risk ratios (RRs), odds ratios (ORs), and 95% confidence intervals (CIs). Thirteen studies (15 million pregnancies, 17,830 stillbirths) were included. All studies were from high-income countries. Four studies provided the risks of stillbirth in mothers of White and Black race, 2 in mothers of White and Asian race, 5 in mothers of White race only, and 2 in mothers of Black race only. The prospective risk of stillbirth increased with gestational age from 0.11 per 1,000 pregnancies at 37 weeks (95% CI 0.07 to 0.15) to 3.18 per 1,000 at 42 weeks (95% CI 1.84 to 4.35). Neonatal mortality increased when pregnancies continued beyond 41 weeks; the risk increased significantly for deliveries at 42 versus 41 weeks gestation (RR 1.87, 95% CI 1.07 to 2.86, p = 0.012). One additional stillbirth occurred for every 1,449 (95% CI 1,237 to 1,747) pregnancies that advanced from 40 to 41 weeks. Limitations include variations in the definition of low-risk pregnancy, the wide time span of the studies, the use of registry-based data, and potential confounders affecting the outcome.

CONCLUSIONS

Our findings suggest there is a significant additional risk of stillbirth, with no corresponding reduction in neonatal mortality, when term pregnancies continue to 41 weeks compared to delivery at 40 weeks.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015013785.

Cigarette Smoking Status and Substance Use in Pregnancy

Objectives Substance use during pregnancy is a significant public health issue. Prenatal substance use increased in the past decade while prenatal cigarette smoking has remained stable. Co-use of tobacco and other drugs is a concern because of potential additive risks. This study aims to describe the prevalence rates of substance use among pregnant women and examine the association between smoking status (nonsmoker, recent quitter and current smoker) and other drug use. Methods In this cross-sectional study, pregnant women (n = 500) were recruited from two obstetric practices to complete three substance use screeners and have their urine tested for 12 different drug classes, including cannabis, opioids and cocaine. Participants were divided into three groups based on survey responses: nonsmokers, recent quitters (smoked in the month prior to pregnancy but not past month) and current smokers (past-month). Results Approximately 29% of participants reported smoking in the month before pregnancy. During pregnancy, 17, 12 and 71% were current smokers, recent quitters and nonsmokers respectively. Overall prevalence of illicit or prescription drug use in pregnancy was 27%. Cannabis was the most common drug used in pregnancy with prevalence of 22%, followed by opioids (4%), cocaine (1%), tricyclic antidepressants (TCAs) (1%), amphetamines (1%), and benzodiazepines (1%). On multivariable logistic regression, smoking in pregnancy was associated with a positive urine drug screen; with adjusted odds ratio (aOR) 4.7 (95% CI 2.6-8.3) for current smokers and 1.6 (95% CI 0.8-3.3) for recent quitters. Factors negatively associated with positive drug screen were second and third trimester pregnancies, 0.5 (0.3-0.9) and 0.3 (0.2-0.6) respectively; and employment, 0.5 (0.3-0.8). Conclusions for Practice Co-use of tobacco and illicit drugs, particularly cannabis, is relatively high during pregnancy. Additional research is needed to understand the health implications of co-use versus use of tobacco only. Given the strong association between smoking and other drug use, clinicians should routinely assess for illicit drug use in women who smoke during pregnancy.

Developing evidence-based recommendations for optimal interpregnancy intervals in high-income countries: protocol for an international cohort study

INTRODUCTION

Short interpregnancy interval (IPI) has been linked to adverse pregnancy outcomes. WHO recommends waiting at least 2 years after a live birth and 6 months after miscarriage or induced termination before conception of another pregnancy. The evidence underpinning these recommendations largely relies on data from low/middle-income countries. Furthermore, recent epidemiological investigations have suggested that these studies may overestimate the effects of IPI due to residual confounding. Future investigations of IPI effects in high-income countries drawing from large, population-based data sources are needed to inform IPI recommendations. We aim to assess the impact of IPIs on maternal and child health outcomes in high-income countries.

METHODS AND ANALYSIS

This international longitudinal retrospective cohort study will include more than 18 million pregnancies, making it the largest study to investigate IPI in high-income countries. Population-based data from Australia, Finland, Norway and USA will be used. Birth records in each country will be used to identify consecutive pregnancies. Exact dates of birth and clinical best estimates of gestational length will be used to estimate IPI. Administrative birth and health data sources with >99% coverage in each country will be used to identify maternal sociodemographics, pregnancy complications, details of labour and delivery, birth and child health information. We will use matched and unmatched regression models to investigate the impact of IPI on maternal and infant outcomes, and conduct meta-analysis to pool results across countries.

ETHICS AND DISSEMINATION

Ethics boards at participating sites approved this research (approval was not required in Finland). Findings will be published in peer-reviewed journals and presented at international conferences, and will inform recommendations for optimal IPI in high-income countries. Findings will provide important information for women and families planning future pregnancies and for clinicians providing prenatal care and giving guidance on family planning.

Association of participation in a supplemental nutrition program with stillbirth by race, ethnicity, and maternal characteristics

BACKGROUND

Participation in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) has been associated with lower risk of stillbirth. We hypothesized that such an association would differ by race/ethnicity because of factors associated with WIC participation that confound the association.

METHODS

We conducted a secondary analysis of the Stillbirth Collaborative Research Network's population-based case-control study of stillbirths and live-born controls, enrolled at delivery between March 2006 and September 2008. Weighting accounted for study design and differential consent. Five nested models using multivariable logistic regression examined whether the WIC participation/stillbirth associations were attenuated after sequential adjustment for sociodemographic, health, healthcare, socioeconomic, and behavioral factors. Models also included an interaction term for race/ethnicity x WIC.

RESULTS

In the final model, WIC participation was associated with lower adjusted odds (aOR) of stillbirth among non-Hispanic Black women (aOR: 0.34; 95% CI 0.16, 0.72) but not among non-Hispanic White (aOR: 1.69; 95% CI: 0.89, 3.20) or Hispanic women (aOR: 0.91; 95% CI 0.52, 1.52).

CONCLUSIONS

Contrary to our hypotheses, control for potential confounding factors did not explain disparate findings by race/ethnicity. Rather, WIC may be most beneficial to women with the greatest risk factors for stillbirth. WIC-eligible, higher-risk women who do not participate may be missing the potential health associated benefits afforded by WIC.

Racial residential segregation and racial disparities in stillbirth in the United States

We examined whether current and/or persistent racial residential segregation is associated with black-white stillbirth disparities among 49,969 black and 71,785 white births from the Consortium on Safe Labor (2002-2008). Black-white segregation was measured using the dissimilarity index and the isolation index, categorized into population-based tertiles. Using hierarchical logistic models, we found low and decreasing levels of segregation were associated with decreased odds of stillbirth, with blacks benefitting more than whites. Decreasing segregation may prevent approximately 900 stillbirths annually among U.S. blacks. Reducing structural racism, segregation in particular, could help reduce black-white stillbirth disparities.

Establishment of Legal Paternity for Children of Unmarried American Women : Trade-Offs in Male Commitment to Paternal Investment

The establishment of a legal father for children of unmarried parents reflects both high paternity confidence and male willingness to commit to paternal investment. Whether an unmarried man voluntarily acknowledges paternity after a child is born has important consequences for both the mother and child. This paper brings to bear a life history perspective on paternity establishment, noting that men face trade-offs between mating and parental effort and that women will adjust their investment in children based on expected male investment. I predict that paternity establishment will be more likely when the mother has high socioeconomic status, when maternal health is good, and when the child is male, low parity, or a singleton (versus multiple) birth. I further predict that establishment of paternity will be associated with increased maternal investment in offspring, resulting in healthier babies with higher birthweights who are more likely to be breastfed. These predictions are tested using data on 5.4 million births in the United States from 2009 through 2013. Overall the results are consistent with the hypothesis that the trade-offs men face between reproductive and parental investment influence whether men voluntarily acknowledge paternity when a child is born.

Prediction of stillbirth from maternal demographic and pregnancy characteristics

OBJECTIVES

To develop a model for prediction of stillbirth based on maternal characteristics and components of medical history and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and to unexplained causes.

METHODS

This was a prospective screening study of 113 415 singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation and at 19 + 0 to 24 + 6 weeks. The study population included 113 019 live births and 396 (0.35%) antepartum stillbirths; 230 (58%) were secondary to impaired placentation and 166 (42%) were due to other or unexplained causes. Multivariable logistic regression analysis was used to determine the factors from maternal characteristics and medical history which provided a significant contribution to the prediction of stillbirth.

RESULTS

The risk for stillbirth increased with maternal weight (odds ratio (OR), 1.01 per kg above 69 kg), was higher in women of Afro-Caribbean racial origin (OR, 2.01), those with assisted conception (OR, 1.79), cigarette smokers (OR, 1.71), and in those with a history of chronic hypertension (OR, 2.62), systemic lupus erythematosus/antiphospholipid syndrome (OR, 3.61) or diabetes mellitus (OR, 2.55) and was increased in women with a history of previous stillbirth (OR, 4.81). Screening with the model predicted 26% of unexplained stillbirths and 31% of those due to impaired placentation, at a false-positive rate of 10%; within the impaired-placentation group the detection rate of stillbirth < 32 weeks' gestation was higher than that of stillbirth ≥ 37 weeks (38% vs 28%).

CONCLUSIONS

A model based on maternal characteristics and medical history recorded in early pregnancy can potentially predict one-third of subsequent stillbirths. The extent to which such stillbirths could be prevented remains to be determined. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Exploring the Experience of Life Stress Among Black Women with a History of Fetal or Infant Death: a Phenomenological Study

INTRODUCTION

Disparate birth outcomes among Black women continue to be a major public health problem. Whereas prior research has investigated the influence of stress on Black women's birth outcomes, few studies have explored how stress is experienced among Black women across the life course. The objectives of this study were to describe the experience of stress across the life course among Black women who reported a history of fetal or infant death and to identify stressful life events (SLE) that may not be represented in the widely used SLE inventory.

METHODS

Using phenomenological, qualitative research design, in-depth interviews were conducted with six Black women in Kansas who experienced a fetal or infant death.

RESULTS

Analyses revealed that participants experienced multiple, co-occurring stressors over the course of their lives and experienced a proliferation of stress emerging in early life and persisting into adulthood. Among the types of stressors cited by participants, history of sexual assault (trauma-related stressor) was a key stressful life event that is not currently reflected in the SLE inventory.

CONCLUSION

Our findings highlight the importance of using a life-course perspective to gain a contextual understanding of the experiences of stress among Black women, particularly those with a history of adverse birth outcomes. Further research investigating Black women's experiences of stress and the mechanisms by which stress impacts their health could inform efforts to reduce disparities in birth outcomes. An additional focus on the experience and impact of trauma-related stress on Black women's birth outcomes may also be warranted.

Specific antenatal interventions for Black, Asian and Minority Ethnic (BAME) pregnant women at high risk of poor birth outcomes in the United Kingdom: a scoping review

BACKGROUND

Disparity exists in maternal and infant birth outcomes of Black and Minority Ethnic (BAME) women giving birth in the United Kingdom (UK) compared to the majority. There is therefore a need to reconsider existing maternity service provision to ensure culturally competent services. The purpose of this scoping review was to ascertain what specific maternity interventions have been implemented in the UK for BAME women (2004-2014) so that increased awareness of the need and scope of specific maternity interventions for BAME women can be identified.

METHODS

A scoping review was conducted in order to determine the evidence base. It was determined that no prior systematic reviews had been conducted and it was apparent that literature in this field was sparse. Scoping review is an ideal method when literature is likely to be heterogeneous and the research field relatively unexplored. A keyword strategy was used implementing population (P), intervention (I), comparison (C) and outcomes (O).

RESULTS

An initial 2188 papers were identified. Following screening and review, only 5 heterogeneous papers remained suitable and were included. The included interventions employed sample sizes of N = 160-1441, examined a range of different outcome measures and were delivered across different parts of the UK with high numbers of BAME residents.

CONCLUSIONS

There is a lack of rigorous research interventions and practice interventions which are currently documented, of specific maternity interventions which are aimed to address culturally competent maternity services and the sharing of best practice addressing the increased risks of BAME women delivering in the UK.

Care of the Childbearing Family With Intrauterine Fetal Demise

Intrauterine fetal demise (IUFD), or stillbirth, is the death of a fetus greater than 20 weeks gestation. Several factors contribute to risk for IUFD, although in many cases the exact etiology is unknown. Nurses are a vital part of the interdisciplinary health care team caring for families with IUFD, who require timely and sensitive care to enable an uncomplicated birth and grieving process.

The Role of Infection and Inflammation in Stillbirths: Parallels with SIDS?

It has been suggested that stillbirths are part of the spectrum of infant deaths that includes sudden infant death syndrome (SIDS). This paper examines the hypothesis that risk factors associated with stillbirths might contribute to dysregulation of inflammatory responses to infections that could trigger the physiological responses leading to fetal loss. These include genetic factors (ethnic group, sex), environmental (infection, cigarette smoke, obesity), and developmental (testosterone levels) factors. Interactions between the genetic, environmental, and developmental risk factors are also considered, e.g., the excess of male stillborn infants in relation to the effects of testosterone levels during development on pro-inflammatory responses. In contrast to SIDS, inflammatory responses of both mother and fetus need to be considered. Approaches for examining the hypothesis are proposed.

Temporal trends in maternal medical conditions and stillbirth

OBJECTIVE

The objective of this study was to estimate the prevalence and temporal trends of medical conditions among women with stillbirth and to determine the effect of medical comorbidities on the trend of stillbirth.

STUDY DESIGN

The Nationwide Inpatient Sample (NIS) for the years 2008-2010 was first queried for all delivery-related discharges. A multivariable logistic regression model was constructed with adjusted odds ratios (ORs) and 95% confidence intervals (CIs) calculated for medical conditions among women with stillbirth. The NIS was then queried for the years 2000-2010, and the effect of maternal medical conditions on the stillbirth rate was estimated.

RESULTS

From 2008 to 2010, there were 51,080 deliveries to women with stillbirth, giving a rate of 4.08 per 1000 live births. Women with stillbirth were more likely to be African American (OR, 2.12; 95% CI, 2.07-2.17), with an age less than 25 years (OR, 1.19; 95% CI, 1.16-1.22) or older than 35 years (OR, 1.40; 95% CI, 1.37-1.44) compared with women without stillbirth. Medical conditions such as cardiac, rheumatological, and renal disorders; hypertension; diabetes; thrombophilia; and drug, alcohol and tobacco use, were independent predictors of fetal demise in multivariable logistic regression modeling. From 2000 to 2010, despite an increase in the total number of births to women with comorbidities, there was a significant decrease in the stillbirth rate, which was more pronounced among women with comorbidities compared with women without comorbidities (P=.021).

CONCLUSION

From 2000 to 2010, there was a significantly greater decrease in the stillbirth rate among women with maternal medical conditions than there was among women without comorbidities. These findings occurred despite an overall increase in the number of pregnancies to women with medical comorbidities over the time period. Because the NIS does not include information on gestational age, birthweight, or whether subjects had antepartum testing, we are not able to determine the effect of these variables on the observed outcomes.

Stillbirth rates among Haitians in Canada

BACKGROUND

Data on cultural groups at risk of stillbirth in high-income countries are scarce. We sought to determine disparities in stillbirth by gestational age for Haitian vs. non-Haitian Canadians.

METHODS

We used data on 10,287 stillbirths and 2,482,364 livebirths from 1981-2010 in the province of Quebec, Canada. Stillbirth rates for Haitians were compared with non-Haitians using fetuses at risk denominators, and Cox proportional hazards regression models with gestational age as the time scale.

RESULTS

Stillbirth rates were much higher for Haitians than non-Haitians during the study period (7.2 vs. 3.9 per 1000 total births). Disparities between Haitians and non-Haitians were largest at 32-36 weeks of gestation [hazard ratio 2.22, 95% confidence interval 1.61, 3.07].

CONCLUSIONS

Stillbirth rates in Haitian Canadians giving birth in Quebec are exceptionally high. Disparities were greatest during the late preterm period.

A population-based case-control study of stillbirth: the relationship of significant life events to the racial disparity for African Americans

Stillbirths (fetal deaths occurring at ≥20 weeks' gestation) are approximately equal in number to infant deaths in the United States and are twice as likely among non-Hispanic black births as among non-Hispanic white births. The causes of racial disparity in stillbirth remain poorly understood. A population-based case-control study conducted by the Stillbirth Collaborative Research Network in 5 US catchment areas from March 2006 to September 2008 identified characteristics associated with racial/ethnic disparity and interpersonal and environmental stressors, including a list of 13 significant life events (SLEs). The adjusted odds ratio for stillbirth among women reporting all 4 SLE factors (financial, emotional, traumatic, and partner-related) was 2.22 (95% confidence interval: 1.43, 3.46). This association was robust after additional control for the correlated variables of family income, marital status, and health insurance type. There was no interaction between race/ethnicity and other variables. Effective ameliorative interventions could have a substantial public health impact, since there is at least a 50% increased risk of stillbirth for the approximately 21% of all women and 32% of non-Hispanic black women who experience 3 or more SLE factors during the year prior to delivery.

Maternal racial origin and adverse pregnancy outcome: a cohort study

OBJECTIVE

To examine the association between maternal racial origin and a wide range of adverse pregnancy outcomes after adjustment for confounding factors in obstetric history and maternal characteristics.

METHODS

This was a retrospective study in women with singleton pregnancies attending their first routine hospital visit at 11 + 0 to 13 + 6 weeks of gestation. Data on maternal characteristics, and medical and obstetric history were collected and pregnancy outcomes ascertained. Regression analysis was performed to examine the association between racial origin and adverse pregnancy outcomes including pre-eclampsia (PE), gestational hypertension (GH), gestational diabetes mellitus (GDM), preterm delivery (PTD), small-for-gestational age (SGA), large-for-gestational age (LGA), miscarriage, stillbirth and elective and emergency Cesarean section (CS).

RESULTS

The study population included 76 158 singleton pregnancies with a live fetus at 11 + 0 to 13 + 6 weeks. In addition to maternal characteristics and obstetric history, Afro-Caribbean racial origin was associated with increased risk for miscarriage, stillbirth, PE, GH, spontaneous PTD, GDM, SGA and CS. In women of South Asian racial origin there was increased risk for PE, GDM, SGA and CS, and East Asian race contributed to the prediction of GDM and SGA.

CONCLUSION

Maternal racial origin should be combined with other maternal characteristics and obstetric history when calculating an individualized adjusted risk for adverse pregnancy outcome.