Preterm Birth and Gestational Length in Four Race-Nativity Groups, Including Somali Americans

Group antenatal care compared with standard antenatal care for Somali-Swedish women: a historically controlled evaluation of the Hooyo Project

OBJECTIVES

Comparing language-supported group antenatal care (gANC) and standard antenatal care (sANC) for Somali-born women in Sweden, measuring overall ratings of care and emotional well-being, and testing the feasibility of the outcome measures.

DESIGN

A quasi-experimental trial with one intervention and one historical control group, nested in an intervention development and feasibility study.

SETTING

Midwifery-led antenatal care clinic in a mid-sized Swedish town.

PARTICIPANTS

Pregnant Somali-born women (<25 gestational weeks); 64 women in gANC and 81 in sANC.

INTERVENTION

Language-supported gANC (2017-2019). Participants were offered seven 60-minute group sessions with other Somali-born women led by one to two midwives, in addition to 15-30 min individual appointments with their designated midwife.

OUTCOMES

Primary outcomes were women's overall ratings of antenatal care and emotional well-being (Edinburgh Postnatal Depression Scale (EPDS)) in gestational week ≥35 and 2 months post partum. Secondary outcomes were specific care experiences, information received, social support, knowledge of pregnancy danger signs and obstetric outcomes.

RESULTS

Recruitment and retention of participants were challenging. Of eligible women, 39.3% (n=106) declined to participate. No relevant differences regarding overall ratings of antenatal care between the groups were detected (late pregnancy OR 1.42, 95% CI 0.50 to 4.16 and 6-8 weeks post partum OR 2.71, 95% CI 0.88 to 9.41). The reduction in mean EPDS score was greater in the intervention group when adjusting for differences at baseline (mean difference -1.89; 95% CI -3.73 to -0.07). Women in gANC were happier with received pregnancy and birth information, for example, caesarean section where 94.9% (n=37) believed the information was sufficient compared with 17.5% (n=7) in standard care (p<0.001) in late pregnancy.

CONCLUSIONS

This evaluation suggests potential for language-supported gANC to improve knowledge acquisition among pregnant Somali-born women with residence in Sweden ˂10 years. An adequately powered randomised trial is needed to evaluate the effectiveness of the intervention.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03879200).

Nativity and perinatal outcome disparities in the United States: Beyond the immigrant paradox

In the United States (US), epidemiologists have long documented paradoxically lower rates of adverse perinatal health outcomes among immigrant birthing people than what might be expected in light of socioeconomic and language barriers to healthcare, especially as compared to their US-born racial and ethnic counterparts. However, researchers have also documented significant variability in this immigrant birth paradox when examining within and across racial and ethnic subgroups. This review paper summarizes fifty years of research regarding differences in low, preterm birth, and infant mortality in the US, according to the nativity status of the birthing person. While there is ample evidence of the importance of nativity in delineating a pregnant person's risk of adverse infant outcomes, this review also highlights the relative paucity of research exploring the intersection of acculturation, ethnic enclaves, and structural segregation. We also provide recommendations for advancing the study of perinatal outcomes among immigrants.

Black Nativity and Health Disparities: A Research Paradigm for Understanding the Social Determinants of Health

After more than a century of research and debate, the scientific community has yet to reach agreement on the principal causes of racialized disparities in population health. This debate currently centers on the degree to which "race residuals" are a result of unobserved differences in the social context or unobserved differences in population characteristics. The comparative study of native and foreign-born Black populations represents a quasi-experimental design where race is "held constant". Such studies present a unique opportunity to improve our understanding of the social determinants of population health disparities. Since native and foreign-born Black populations occupy different sociocultural locations, and since populations with greater African ancestry have greater genetic diversity, comparative studies of these populations will advance our understanding of the complex relationship between sociocultural context, population characteristics and health outcomes. Therefore, we offer a conceptual framing for the comparative study of native and foreign-born Blacks along with a review of 208 studies that compare the mental and physical health of these populations. Although there is some complexity, especially with respect to mental health, the overall pattern is that foreign-born Blacks have better health outcomes than native-born Blacks. After reviewing these studies, we conclude with suggestions for future studies in this promising area of social and medical research.

Maternal nativity and risk of adverse perinatal outcomes among Black women residing in California, 2011-2017

OBJECTIVE

Examine the risk of adverse perinatal outcomes among the United States (US)-born and foreign-born Black women in California.

STUDY DESIGN

The study comprised all singleton live births to Black women in California between 2011 and 2017. We defined maternal nativity as US-born or foreign-born. Using Poisson regression, we computed risk ratios (RR) and 95% confidence intervals (CI) for three adverse perinatal outcomes: preterm birth, small for gestational age deliveries, and infant mortality.

RESULTS

Rates of adverse perinatal outcomes were significantly higher among US-born Black women. In adjusted models, US-born Black women experienced an increased risk of preterm birth (RR 1.51, 95% CI 1.39, 1.65) and small for gestational age deliveries (RR 1.52, 95% CI 1.41, 1.64), compared to foreign-born Black women.

CONCLUSIONS

Future studies should consider experiences of racism across the life course when exploring heterogeneity in the risk of adverse perinatal outcomes by nativity among Black women in the US.

The Association of Preterm Birth With Maternal Nativity and Length of Residence Among Non-Hispanic Black Women

Background

Preterm birth (PTB) is associated with future cardiovascular disease (CVD) risk and disproportionally affects non-Hispanic Black (NHB) women. Limited data exist on the influence of length of US residence on nativity-related disparities in PTB. We examined PTB by maternal nativity (US born vs foreign born) and length of US residence among NHB women.

Methods

We analyzed data from 2699 NHB women (1607 US born; 1092 foreign born) in the Boston Birth Cohort, originally designed as a case-control study. Using multivariable logistic regression, we investigated the association of PTB with maternal nativity and length of US residence.

Results

In the total sample, 29.1% of women delivered preterm (31.4% and 25.6% among US born and foreign born, respectively). Compared with foreign born, US-born women were younger (25.8 vs 29.5 years), had higher prevalence of obesity (27.6% vs 19.6%), smoking (20.5% vs 4.9%), alcohol use (13.2% vs 7.4%), and moderate to severe stress (73.5% vs 59.4%) (all P < 0.001). Compared with US-born women, foreign-born women had lower odds of PTB after adjusting for sociodemographic characteristics, alcohol use, stress, parity, smoking, body mass index, chronic hypertension, and diabetes (adjusted odds ratio [aOR], 0.79; 95% confidence interval [CI], 0.65-0.97). Foreign-born NHB women with < 10 years of US residence had 43% lower odds of PTB compared with US-born (aOR, 0.57; 95% CI, 0.43-0.75), whereas those with ≥ 10 years of US residence did not differ significantly from US-born women in their odds of PTB (aOR, 0.76; 95% CI, 0.54-1.07).

Conclusions

The prevalence of CVD risk factors and proportion of women delivering preterm were lower in foreign-born than US-born NHB women. The "foreign-born advantage" was not observed with ≥ 10 years of US residence. Our study highlights the need to intensify public health efforts in exploring and addressing nativity-related disparities in PTB.

Population based cohort study of fetal deaths, and neonatal and perinatal mortality at term within a Somali diaspora

Background

Somali women deliver at greater gestational age with limited information on the associated perinatal mortality. Our objective is to compare perinatal mortality among Somali women with the population rates.

Methods

This is a retrospective cohort study from all births that occurred in Minnesota between 2011 and 2017. Information was obtained from certificates of birth, and neonatal and fetal death. Data was abstracted from 470,550 non-anomalous births ≥37 and ≤ 42 weeks of gestation. The study population included U.S. born White, U.S. born Black, women born in Somalia or self-identified as Somali, and women who identified as Hispanic regardless of place of birth (377,426). We excluded births < 37 weeks and > 42 weeks, > 1 fetus, age < 18 or > 45 years, or women of other ethnicities. The exposure was documented ethnicity or place of birth, and the outcomes were live birth, fetal death, neonatal death prior to 28 days, and perinatal mortality rates. These were calculated using binomial proportions with 95% confidence intervals and compared using odds ratios adjusted (aOR) for diabetes, hypertension and maternal body mass index.

Results

The aOR [95%CI] for stillbirth rate in the Somali cohort was greater than for U.S. born White (2.05 [1.49–2.83]) and Hispanic women (1.90 [1.30–2.79]), but similar to U.S. born Black women (0.88 [0.57–1.34]). Neonatal death rates were greater than for U.S. born White (1.84 [1.36–2.48], U.S. born Black women (1.47 [1.04–2.06]) and Hispanic women (1.47 [1.05–2.06]). This did not change after analysis was restricted to those with spontaneous onset of labor. When analyzed by week, at 42 weeks Somali aOR for neonatal death was the same as for U.S. born White women, but compared against U.S. born Black and Hispanic women, was significantly lower.

Conclusions

The later mean gestational age at delivery among women of Somali ethnicity is associated with greater overall risk for stillbirth and neonatal death rates at term, except compared against U.S. born Black women with whom stillbirth rates were not different. At 42 weeks, Somali neonatal mortality decreased and was comparable to that of the U.S. born White population and was lower than that of the other minorities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04163-z.

Beginning to Optimize Peripartum Care for Somalia-Born Women by Evaluating Labor, Postpartum and Neonatal Outcomes in the Somali Population Delivering at a Tertiary Care Center in Vermont

Vermont has a large population of Somali immigrants and previous research has shown outcome disparities in this population. Labor curves, pregnancy and delivery outcomes information is required and critical to optimize current labor management in an institution that provides obstetrical care for this population. Data were collected for both Somalia-born and non Somalia-born parturients in pre-pregnancy, pregnancy, delivery, neonatal and cervical change categories and were compared to non Somalia-born parturients to observe differences in demographic factors and outcomes as well as labor progress. Overall labor length trended differently between the two groups, the rate of preterm birth in the vaginal delivery group in the Somali population was much lower than the unmatched control group and overall more lacerations were noted. Findings are consistent with prior studies related to reduced preterm birth rate in Somalia-born women. Observation regarding refusal of care demonstrates need for targeted research related to concerns of Somali immigrants.

Social and ethnic disparities in stillbirth and infant death in Denmark, 2005-2016

Ethnic disparity in stillbirth and infant death has been demonstrated in Europe. As the relation between migration and health change over time, this population based register study investigated the recent figures and explored if potential differences could be explained by the well-known educational and income inequalities in stillbirth and infant death using a novel approach. Stillbirth and infant mortality varied considerably according to country of origin, with only immigrants from China, Norway, and Poland having an overall lower risk than Danish women. Women of Pakistani, Turkish, and Somali origin had a particularly high risk of both outcomes. Women from recent high conflict areas displayed a pattern with increased stillbirth risk. An observed excess risks across generations was found, which is disturbing and rule out factors related to language barriers or newness. Differences in educational level and household income explained only part of the observed inequalities. Strengthening of the maternity care system to better understand and meet the needs of immigrant women seems needed to mitigate the disparities.

Developing a theoretical evolutionary framework to solve the mystery of parturition initiation

Eutherian mammals have characteristic lengths of gestation that are key for reproductive success, but relatively little is known about the processes that determine the timing of parturition, the process of birth, and how they are coordinated with fetal developmental programs. This issue remains one of biology's great unsolved mysteries and has significant clinical relevance because preterm birth is the leading cause of infant and under 5 year old child mortality worldwide. Here, we consider the evolutionary influences and potential signaling mechanisms that maintain or end pregnancy in eutherian mammals and use this knowledge to formulate general theoretical evolutionary models. These models can be tested through evolutionary species comparisons, studies of experimental manipulation of gestation period and birth timing, and human clinical studies. Understanding how gestation time and parturition are determined will shed light on this fundamental biological process and improve human health through the development of therapies to prevent preterm birth.

Black Pregnant Women "Get the Most Judgment": A Qualitative Study of the Experiences of Black Women at the Intersection of Race, Gender, and Pregnancy

BACKGROUND

Pronounced racial disparities in maternal and infant health outcomes persist in the United States. Using an ecosocial and intersectionality framework and biopsychosocial model of health, we aimed to understand Black pregnant women's experiences of gendered racism during pregnancy.

METHODS

We conducted semistructured interviews with 24 Black pregnant women in New Haven, Connecticut. We asked women about their experience of being pregnant, experiences of gendered racism, and concerns related to pregnancy and parenting Black children. Transcripts were coded by three trained analysts using grounded theory techniques.

RESULTS

Women experienced gendered racism during pregnancy-racialized pregnancy stigma-in the form of stereotypes stigmatizing Black motherhood that devalued Black pregnancies. Women reported encountering assumptions that they had low incomes, were single, and had multiple children, regardless of socioeconomic status, marital status, or parity. Women encountered racialized pregnancy stigma in everyday, health care, social services, and housing-related contexts, making it difficult to complete tasks without scrutiny. For many, racialized pregnancy stigma was a source of stress. To counteract these stereotypes, women used a variety of coping responses, including positive self-definition.

CONCLUSIONS

Racialized pregnancy stigma may contribute to poorer maternal and infant outcomes by way of reduced access to quality health care; impediments to services, resources, and social support; and poorer psychological health. Interventions to address racialized pregnancy stigma and its adverse consequences include anti-bias training for health care and social service providers; screening for racialized pregnancy stigma and providing evidence-based coping strategies; creating pregnancy support groups; and developing a broader societal discourse that values Black women and their pregnancies.

Health Advantages and Disparities in Preterm Birth Among Immigrants Despite Disparate Sociodemographic, Behavioral, and Maternal Risk Factors in San Diego, California

INTRODUCTION

Reproductive health advantages have been reported among selected immigrants, but few studies have included new immigrants and refugees, nor simultaneously adjusted for socioeconomic, behavioral, and medical disparities.

METHODS

We examined the risk of preterm birth (PTB, < 37 weeks' gestation) among singleton live births in San Diego County from 2007 to 2012. Multivariable regression was used to compare PTB (1) by nativity within racial/ethnic groups and (2) among immigrants compared to United States (US) born Whites, while adjusting for sociodemographic, behavioral, reproductive and medical variables.

RESULTS

Among 230,878 singleton live births, overall PTB prevalence was highest among parturient women who were US-born Blacks (10.9%), Philippine (10.8%) and US-born Filipinas (10.7%), and US-born Asians (8.6%) despite differences in socioeconomic and maternal risk factors, and lowest among Somali (5.5%) migrants. Blacks born in Somalia or outside of the US, had significantly lower overall PTB prevalence compared to US-born Blacks (5.5% vs 7.6% vs 10.9%). Compared to US-born Whites, spontaneous PTB risk was significantly lower among Somali migrants (4.8% vs 3.7%, adjusted relative risk, aRR 0.7 [95% Confidence Intervals 0.5-0.9]), but higher among Philippine migrants (4.8% vs 7.7%, aRR 1.4 [1.3-1.6]). The strongest risk factor for overall PTB among nulliparous US-born Blacks was preexisting diabetes (aRR 3.81 [2.05-7.08]), and preexisting hypertension among Filipinas (aRR: 3.27 [2.36-4.54] and US-born Asians (aRR: 3.64 [1.61-8.24]).

CONCLUSION

Black migrants had lower PTB prevalence compared to US-born Blacks, but this immigrant advantage was not observed in other racial/ethnic groups. Compared to US-born Whites, Somali migrants had significantly lower risk of spontaneous PTB while Filipinas had elevated risk.

The color of health: how racism, segregation, and inequality affect the health and well-being of preterm infants and their families

Racism, segregation, and inequality contribute to health outcomes and drive health disparities across the life course, including for newborn infants and their families. In this review, we address their effects on the health and well-being of newborn infants and their families with a focus on preterm birth. We discuss three causal pathways: increased risk; lower-quality care; and socioeconomic disadvantages that persist into infancy, childhood, and beyond. For each pathway, we propose specific interventions and research priorities that may remedy the adverse effects of racism, segregation, and inequality. Infants and their families will not realize the full benefit of advances in perinatal and neonatal care until we, collectively, accept our responsibility for addressing the range of determinants that shape long-term outcomes.

Disproportionate Preterm Delivery Among Black Women: a State-Level Analysis

Preterm delivery occurs at extraordinarily higher rates among Black women than among women of any other race or ethnicity. For those children who survive, many face a lifetime of health and developmental challenges as well as difficulties in school and life. Previous studies have provided substantive evidence that the preterm delivery disparity experienced by Black women is associated with ongoing distress caused by racism. Our study examines rates of preterm delivery for Black women in the USA to determine the level of risk associated with living in specific states. Using a logistic regression model, we examined the impact of the delivery state, controlling for known clinical, economic, and demographic risk factors. We found that 32 of the 35 states included in our analysis were associated with a statistically significantly increased risk of preterm delivery among Black women, as compared to the state with the lowest preterm delivery rate for Black women. These findings allowed us to organize states into a continuum of preterm delivery risk. Because of the harmful effects of preterm delivery and its disproportionate impact among Black women and infants, we recommend that a measure of preterm delivery be included in any state plan to assess, intervene in, and monitor racial disparities.

Relationship between vitamin D status and the vaginal microbiome during pregnancy

OBJECTIVE

Evidence supports an inverse association between vitamin D and bacterial vaginosis (BV) during pregnancy. Furthermore, both the vaginal microbiome and vitamin D status correlate with pregnancy outcome. Women of African ancestry are more likely to experience BV, to be vitamin D deficient, and to have certain pregnancy complications. We investigated the association between vitamin D status and the vaginal microbiome.

STUDY DESIGN

Subjects were assigned to a treatment (4400 IU) or a control group (400 IU vitamin D daily), sampled three times during pregnancy, and vaginal 16S rRNA gene taxonomic profiles and plasma 25-hydroxyvitamin D [25(OH)D] concentrations were examined.

RESULT

Gestational age and ethnicity were significantly associated with the microbiome. Megasphaera correlated negatively (p = 0.0187) with 25(OH)D among women of African ancestry. Among controls, women of European ancestry exhibited a positive correlation between plasma 25(OH)D and L. crispatus abundance.

CONCLUSION

Certain vaginal bacteria are associated with plasma 25(OH)D concentration.