The Black-White Disparity in Preterm Birth: Race or Racism?

Policy Points

• Racism is an upstream determinant of health that influences health through many midstream and downstream factors. This Perspective traces multiple plausible causal pathways from racism to preterm birth.
• Although the article focuses on the Black-White disparity in preterm birth, a key population health indicator, it has implications for many other health outcomes.
• It is erroneous to assume by default that underlying biological differences explain racial disparities in health. Appropriate science-based policies are needed to address racial disparities in health; this will require addressing racism.

     

Pregnancy Intendedness,Maternal Psychosocial Factors and Preterm Birth

Objectives: This study examined associations between reported pregnancy intendedness and several maternal psychosocial factors in relation to preterm birth (<37 weeks' completed gestation). Methods: Women were recruited into a prospective cohort study between the 24th and 29th weeks of pregnancy in central North Carolina from 1996 to 2000. Prior to delivery, participants responded to questions about pregnancy intendedness, life events impacts, depressive symptoms, and coping style. Results: Women who reported not intending their pregnancy had increased odds of reporting low, medium and high levels of perceived stress during pregnancy (OR = 1.4 [95% CI: 1.1, 1.9], OR = 2.2 [95% CI: 1.7, 2.8], and OR = 3.4 [95% CI: 2.6, 4.5], respectively, relative to very low), medium and high levels of depressive symptoms (OR = 2.2 [95% CI: 1.8, 2.9] and OR = 3.1 [95% CI: 2.4, 3.9], respectively), and medium and high levels of several coping styles. Reporting not intending the pregnancy was not associated with increased risk of preterm birth (Risk Ratio [RR] = 1.0, 95% CI: 0.8, 1.1), but reporting the highest quartile of perceived stress (RR = 1.6, 95% CI: 1.1, 2.3) and the highest tertile of distancing coping style (compared with lowest quartile) was associated with preterm birth (RR = 1.4, 95% CI: 1.1, 1.9). Interactions between pregnancy intendedness and the psychosocial variables perceived stress, depression or coping style did not modify the psychosocial variable's associations with preterm birth. Conclusions: Pregnancy intendedness remains an important concept in the reproductive health literature integrally tied to indicators of maternal mental health, but not necessarily to pregnancy outcomes.     

Medical and Psychosocial Risk Profiles for Low Birthweight and Preterm Birth

ObjectivesLow birthweight and preterm birth are risk factors for infant mortality and persistent problems. This study uses representative data to assess whether distinct latent profiles of co-occurring medical and psychosocial factors have implications for preterm birth and low birthweight.MethodsData are from the Pregnancy Risk Assessment Monitoring System, a cross-sectional survey constituting representative data on pregnancies from 2012 to 2013. Latent class analysis derived classes of pregnant women potentially at risk for low birthweight and/or preterm birth.ResultsLatent class analysis identified five homogenous profiles of interrelated psychosocial and medical factors. Risk was greatest for the profile marked by high rates of medical factors, followed by a high risk for a profile marked by a combination of very low income and psychosocial factors. Two profiles involving low income and very low income also indicated greater risk for adverse birth outcomes related to socioeconomic status.ConclusionsMore attention should be paid to screening for and addressing psychosocial risk in concert with prenatal care. Women who show high-risk profiles can be monitored and supported by an interdisciplinary care team, when warranted.     

大气污染对低出生体重和早产影响的Meta分析

目的 研究各主要大气污染物对低出生体重(LSW)和早产的影响.方法 通过计算机检索收集国内外1999-2009年公开发表的有关大气污染对不良妊娠结局影响的相关文献14篇,按照制定的纳入排除标准对文献进行筛选,利用Stata9.0的Meta模块对人选文献进行异质性检验和相应的效应值合并.采用Meta分析获得的合并OR值作为最终的合并效应值.结果 建立各主要污染物与低出生体重和早产的暴露.反应关系,其中PM10浓度每升高50μg/m3,所对应的低出生体重及早产发生的合并OR值分别为1.07(95%CI:1.024～1.119,P＜0.01)、1.217(95%CI:1.045～1.415,P＜0.05);SO2浓度每升高43λg/m3(15 ppb),所对应的低出生体重或早产发生的合并OR值分别为1.137(95%CI:1.047～1.235,P＜0.05)、1.163(95%CI:1.082～1.250,P＜0.01);NO2每升高21μg/m3(10 ppb),所对应的低出生体重发生的合并OR值为1.03(95%CI:1.008～1.054,P＜0.01);CO每升高1.25 mg/m3(1 ppm),所对应的低出生体重发生的合并OR值为1.066(95%C1:1.016～1.117,P＜0.01);NO2以及CO对早产影响的合并效应值无统计学意义(P＞0.05).结论 本研究综合定量分析的结果 表明,大气污染能够增加低出生体重和早产发生的危险,妊娠期妇女有必要采取有效的措施减少大气污染的暴露.     

Racial/Ethnic Inequities in Low Birth Weight and Preterm Birth: The Role of Multiple Forms of Stress

Introduction Racial/ethnic inequities in low birth weight (LBW) and preterm birth (PTB) persist in the United States. Research has identified numerous risk factors for adverse birth outcomes; however, they do not fully explain the occurrence of, or inequalities in PTB/LBW. Stress has been proposed as one explanation for differences in LBW and PTB by race/ethnicity. Methods Using the Pregnancy Risk Assessment Monitoring System (PRAMS) data from 2012 to 2013 for 21 states and one city (n?=?15,915) we used Poisson regression to estimate the association between acute, financial and relationship stressors and LBW and PTB, and to examine the contribution of these stressors individually and simultaneously to racial/ethnic differences in LBW and PTB. Results Adjusting for age and race/ethnicity, acute (p?<?0.001), financial (p?<?0.001) and relationship (p?<?0.05) stressors were associated with increased risk of LBW, but only acute (p?<?0.05) and financial (p?<?0.01) stress increased risk of PTB. Across all models, non-Hispanic blacks had higher risk of LBW and PTB relative to non-Hispanic whites (IRR 1.87, 95% CI 1.55, 2.27 and IRR 1.46, 95% CI 1.18, 1.79). Accounting for the effects of stressors attenuated the risk of LBW and PTB by 17 and 22% respectively, but did not fully explain the increased likelihood of LBW and PTB among non-Hispanic blacks. Discussion Results of this study demonstrate that stress may increase the risk of LBW and PTB. While stressors may contribute to racial/ethnic differences in LBW and PTB, they do not fully explain them. Mitigating stress during pregnancy may help promote healthier birth outcomes and reduce racial/ethnic inequities in LBW and PTB.     

The Association Between Major Birth Defects and Preterm Birth

Objective To evaluate the association between preterm birth and major birth defects by maternal and infant characteristics and specific types of birth defects. Study Design We pooled data for 1995–2000 from 13 states with population-based birth defects surveillance systems, representing about 30% of all U.S. births. Analyses were limited to singleton, live births from 24–44 weeks gestational age. Results Overall, birth defects were more than twice as common among preterm births (24–36 weeks) compared with term births (37–41 weeks gestation) (prevalence ratio [PR] = 2.65, 95% confidence interval [CI] 2.62–2.68), and approximately 8% of preterm births had a birth defect. Birth defects were over five times more likely among very preterm births (24–31 weeks gestation) compared with term births (PR = 5.25, 95% CI 5.15–5.35), with about 16% of very preterm births having a birth defect. Defects most strongly associated with very preterm birth included central nervous system defects (PR = 16.23, 95% CI 15.49–17.00) and cardiovascular defects (PR = 9.29, 95% CI 9.03–9.56). Conclusions Birth defects contribute to the occurrence of preterm birth. Research to identify shared causal pathways and risk factors could suggest appropriate interventions to reduce both preterm birth and birth defects.     

Stress and Preterm Birth: Neuroendocrine,Immune/Inflammatory,and Vascular Mechanisms

A growing literature suggests that maternal psychological and social stress is a significant and independent risk factor for a range of adverse reproductive outcomes including preterm birth. Several issues remain to be addressed about stress and vulnerability to stress during pregnancy. Of these, perhaps one of the most important questions relates to biologic plausibility. Parturition, the process that results in birth, is a biological phenomenon. Very little empirical research to date, however, has examined the role of biological processes, if any, as mediators of the relationship between stress and preterm birth. In this paper we discuss the maternal, placental, and fetal neuroendocrine, immune/inflammatory, and vascular processes that may bridge the experience of social adversity before and during pregnancy and the biological outcome of preterm birth.     

Maternal Chlamydia trachomatis Infections and Preterm Birth: The Impact of Early Detection and Eradication During Pregnancy

The risks for preterm birth are heterogeneous and there remains much to elucidate regarding etiology of this adverse perinatal outcome. Antenatal infection with Chlamydia trachomatis, a highly prevalent sexually-transmitted infection, may convey a higher risk of preterm birth. Early detection and eradication of this sexually-transmitted infection without recurrent/persistent infection during pregnancy may serve as an intervention that reduces the risk of preterm birth. The objective of this study was to characterize the association between early antenatal detection and eradication of maternal C. trachomatis infection and the likelihood of preterm birth among pregnant women in an urban county. A retrospective cohort study was conducted in Hamilton County, Ohio (2006–2011) to evaluate the risk of preterm birth among women with maternal C. trachomatis infections detected and eradicated at or before 20 weeks gestation—the intervention group. Infected women whose infections were detected after 20 weeks gestation or persistent during the pregnancy represented the reference group. The study population contained 3,354 pregnant women with documented C. trachomatis infections. The relative risk for moderate to late spontaneous preterm birth (32–36 weeks gestation) was 0.54 (95 % CI 0.37–0.80) for women in the intervention group who were 19 years of age and younger. Pregnant adolescents benefited the most from early detection and eradication of antenatal C. trachomatis infections through a reduction in the risk of PTB at 32–36 weeks gestation. This finding suggests the importance of early antenatal detection and effective treatment of C. trachomatis.     

Choriodecidual Infection and Preterm Birth

Of all U.S. births, 11% occur preterm. These infants are responsible for the majority of perinatal mortality and morbidity. Infants at highest risk are those born weighing < 1000 g and those born at < 28 weeks gestation. Recent evidence suggests that the majority of these preterm births are caused by bacterial infections of the chorioamnion, with the organisms originating in the vagina. The mechanisms leading to preterm labor and rupture of membranes involve an inflammatory response involving increased production of cytokines, prostaglandins, and metalloproteases. Results of treatment trials to eradicate the infection and reduce preterm birth have been mixed.     

Post-Injury Medical and Psychosocial Care in Children: Impact of Traumatic Stress Symptoms

This study examined after-hospital medical and psychosocial care parents sought for their child following an injury and how this was affected by parent and child traumatic stress symptoms. Whereas the majority of parents (> 70%) reported seeking after-hospital pediatric medical services, less than one-third sought psychosocial assistance. More severe child or parent acute traumatic stress within the first month post injury was associated with a greater number of subsequent outpatient medical visits. Level of child or parent acute stress was also related to the type of psychosocial help sought. Results support trauma-informed care and symptom screening in children and parents post injury.     

空气污染对早产和低出生体重影响的流行病学研究现况

空气污染对不良妊娠结局的影响研究日益被国内外的专家所关注,空气污染物与早产和低出生体重的研究有待进一步开展。该文就近年来有关空气污染物(可吸入颗粒物、细颗粒物、CO、NO2、SO2等)对早产和低出生体重影响的流行病学研究进行了综述,为控制空气污染和减少不良妊娠结局的发生以及进一步探索其可能的机制提供有益的参考。     

Low Birth Weight and Preterm Birth Among Arab-American Women in Ohio

Maternal and Child Health Journal - There is limited evidence about prevalence and odds of adverse birth outcomes among Arab American women in the United States. We estimated the prevalence of low...     

Intention to Become Pregnant and Low Birth Weight and Preterm Birth: A Systematic Review

Increased stress, psychosocial problems, economic disadvantages, and lack of prenatal care are proposed to explain discrepancies in the outcome of unintended pregnancies. Studies of maternal intention and pregnancy outcomes have yielded varied results. Objective is to review studies of the risk of low birth weight (LBW)/preterm births (PTB) associated with unintended pregnancies ending in a live birth. We reviewed studies reporting on maternal intentions and outcomes from Medline, Embase, CINAHL, and bibliographies of identified articles. An unintended pregnancy was further classified as mistimed (not intended at that time) or unwanted (not desired at any time). Studies reporting an association between pregnancy intention and any of the outcomes were included. Study quality was assessed for biases in selection, exposure assessment, confounder adjustment, analyses, outcomes assessment, and attrition. Unadjusted and adjusted data from included studies were extracted by two reviewers. There were significantly increased odds of LBW among unintended pregnancies [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.25, 1.48] ending in a live birth. Within the unintended category, mistimed (OR 1.31, 95% CI 1.13, 1.52) and unwanted (OR 1.51, 95% CI 1.29, 1.78) pregnancies were associated with LBW. There were statistically significantly increased odds of PTB among unintended (OR 1.31, 95% CI 1.09, 1.58), and unwanted (OR 1.50, 95% CI 1.41, 1.61) but not for mistimed (OR 1.36, 95% CI 0.96, 1.93) pregnancies. Unintended, unwanted, and mistimed pregnancies ending in a live birth are associated with a significantly increased risk of LBW and PTB.     

胎盘微生态与早产的研究进展

保持孕妇体内微生态系统的动态平衡对保护母婴健康至关重要。胎盘是胎儿与母体之间进行物质交换的重要器官,长期以来均被认为是无菌的。然而,最新的多重组织学和高通量测序研究结果显示,即使在没有感染的情况下,胎盘和胎膜可能也不是无菌的,相反胎盘有着不同于其他器官系统的、丰富的微生物群。据有关报道显示,胎盘上的微生物会直接影响胎儿的健康,可能会导致胎儿早产甚至流产。世界卫生组织估计,每年约有1 500万名婴儿早产,早产是导致婴幼儿患病和死亡的主要原因,严重威胁孕妇和胎儿健康。文章就胎盘微生态与早产的研究进展进行综述,旨在为临床早期胎盘微生态的监测和早产的预防提供参考依据。     

超声对宫颈检测在早产中的应用价值

目的:探讨超声检测宫颈长度及形态对妊娠分娩结局的影响,为预测早产发生提供重要参考依据。方法:经腹、会阴、阴道超声检测100例早产的孕妇的宫颈管长度及宫颈形态,比较不同长度和形态的早产率。结果:100例早产中70例宫颈长度检测,宫颈长度<25mm早产率约70%,宫颈长度在25~29mm早产率约21%,宫颈长度≥30mm早产率约9%。100例早产中30例宫颈形态检测,"T"形宫颈早产率约10%,"Y"形宫颈早产率约13%,"V"形宫颈早产率约30%,"U"形宫颈早产率约47%。结论:超声对宫颈长度及形态检测在早产中的应用价值很高。     

Second Births to Teenage Mothers: Risk Factors For Low Birth Weight and Preterm Birth

CONTEXT: Teenagers are more likely than older women to have a low-birth-weight infant or a preterm birth, and the risks may be particularly high when they have a second birth. Identifying predictors of these outcomes in second teenage births is essential for developing preventive strategies.
METHODS: Birth certificate data for 1993–2002 were linked to identify second births to Milwaukee teenagers. Predictors of having a low-birth-weight second infant or a preterm second birth were identified using logistic regression.
RESULTS: The same proportion of first and second infants were low-birth-weight (12%), but second births were more likely than first births to be preterm (15% vs. 12%). In analyses that adjusted for demographic, pregnancy and behavioral characteristics, the odds that a second infant was low-birth-weight or preterm were elevated if the mother smoked during pregnancy (odds ratios, 2.2 and 1.9, respectively), had inadequate prenatal weight gain (1.8 and 1.4), had an interpregnancy interval of less than 18 months (1.6–2.9 and 1.4–2.3) or was black (2.7 and 1.7). Women who had received an adequate level of prenatal care had reduced odds of both outcomes (0.6 and 0.4). Women younger than 16 also had increased odds of having a low-birth-weight second infant. Further adjustment for socioeconomic characteristics yielded largely the same results. In addition, women who were unmarried or did not identify a father were at increased risk of both outcomes (1.5 for each), and poor women were at risk of having a low-birth-weight infant (1.3).
CONCLUSIONS: Predictors of poor birth outcomes include modifiable behaviors. Prenatal interventions addressing these behaviors could help improve outcomes.     

Acknowledging the Impact of Race and Ethnicity on Better Birth Outcomes: Celebrating the Work of Emile Papiernik

Maternal and Child Health Journal -     

Total Adverse Childhood Experiences and Preterm Birth: A Systematic Review

Maternal and Child Health Journal - Total adverse childhood experiences (ACEs) are gaining prominence as a risk factor for preterm birth (PTB). The emerging literature examining this relationship...