Preterm birth in the United States: the impact of stressful life events prior to conception and maternal age

Computational Approaches for Connecting Maternal Stress to Preterm Birth

Multiple studies have hinted at a complex connection between maternal stress and preterm birth (PTB). This article describes the potential of computational methods to provide new insights into this relationship. For this, we outline existing approaches for stress assessments and various data modalities available for profiling stress responses, and review studies that sought either to establish a connection between stress and PTB or to predict PTB based on stress-related factors. Finally, we summarize the challenges of computational methods, highlighting potential future research directions within this field.

Effect of active-duty military service on neonatal birth outcomes: a systematic review

INTRODUCTION

Increasing numbers of women serve in the armed forces in countries worldwide. Stress experienced during pregnancy is associated with adverse birth outcomes including preterm delivery (PTD) and low birth weight (LBW). Several characteristics of military employment and lifestyle can increase stress acting on active-duty servicewomen (ADSW) and hence may increase the risk of adverse neonatal outcomes. This paper reviews the prevalence of PTD, preterm labour (PTL), LBW and stillbirth in babies born to ADSW in the armed forces.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Medline, EMBASE, Web of Science, Global Health and CINAHL Plus databases were searched from inception to July 2021 (November 2023, EMBASE) using subject heading and keyword searches for English language journal articles on babies born to ADSW in any military branch and any country. The Joanna Briggs Institute prevalence critical appraisal tool assessed risk of bias in included papers. Studies were paired with a comparator non-active-duty population to generate a prevalence ratio as the effect measure. A narrative synthesis was conducted.

RESULTS

21 observational studies fulfilled the eligibility criteria. They were all conducted in the US military, involved a total of 650 628 participants, and were published between 1979 and 2023. Their results indicate increased LBW in ADSW compared with non-service women. There was insufficient evidence to conclude or rule out whether ADSW have increased rates of PTD or PTL.

CONCLUSIONS

ADSW may be at increased risk of having an LBW baby. However, caution is needed if seeking to generalise the findings beyond the US context. This review highlights a growing need for female-specific research in other armed forces and, specifically, into reproductive health. Such research is necessary to inform military maternity pathways and policies in ways that safeguard mothers and their babies while enhancing military readiness.

Association of Antenatal Housing Instability with Perinatal Care Utilization and Outcomes

Background: Social determinants of health are important contributors to maternal and child health outcomes. Limited existing research examines the relationship between housing instability during pregnancy and perinatal care utilization. Our objective was to evaluate whether antenatal housing instability is associated with differences in perinatal care utilization and outcomes. Materials and Methods: Participants who were surveyed during their postpartum hospitalization were considered to have experienced housing instability if they answered affirmatively to at least one of six screening items. The primary outcome was adequacy of prenatal care measured by the Adequacy of Prenatal Care Utilization index. Maternal, neonatal, and postpartum outcomes, including utilization and breastfeeding, were also collected as secondary outcomes. Multivariable logistic regression models were adjusted for sociodemographic and clinical covariates. Results: In this cohort (N = 490), 11.2% (N = 55) experienced housing instability during pregnancy. Participants with unstable housing were more likely to have inadequate prenatal care (17.3% vs. 3.9%; odds ratio [OR] 5.11, 95% confidence interval [CI] 2.15-12.14, p < 0.001), but findings were not significant after adjustment (aOR 1.72, 95% CI 0.55-5.41, p = 0.35). Similarly, postpartum visit attendance was lower for individuals with unstable housing (79.6% vs. 91.2%), but there was no difference in the odds of the postpartum visit attendance after adjustment (OR 0.69, 95% CI 0.29-1.66, p = 0.14). Conclusions: There were no statistically significant association with the maternal, neonatal, and other postpartum secondary outcomes. Housing instability appears to be a risk marker that is related to other social determinants of health. Given the range of housing instability experiences, future research must account for specific types and degrees of housing instability and their potential perinatal consequences.

Parental Preconception Adversity and Offspring Health in African Americans: A Systematic Review of Intergenerational Studies

Background: This systematic review explores the empirical literature addressing the association between parental preconception adversity and offspring physical health in African-American families. Method: We conducted a literature search in PubMed, Web of Science, PsycINFO, CINAHL, and Scopus through June 2021. Articles were included if they: reported data about at least two generations of African-American participants from the same family; measured parental preconception adversity at the individual level; measured at least one offspring physical health outcome; and examined associations between parental adversity and child health. Results: We identified 701 unique articles; thirty-eight articles representing 30 independent studies met inclusion criteria. Twenty-five studies (83%) reported that parental preconception adversity was associated with child health; six studies (20%) reported that parental preconception adversity was not associated with at least one offspring outcome; several studies reported both. Only six studies (20%) reported an association specific to African Americans. Conclusion: Empirical evidence linking parental preconception adversity with offspring physical health in African Americans is limited and mixed. In the current literature, very few studies report evidence addressing intergenerational associations between parental preconception adversity and offspring physical health in the African-American population, specifically, and even fewer investigate forms of parental preconception adversity that have been shown to disproportionately affect African Americans (e.g., racism). To better understand root causes of racial health disparities, more rigorous systematic research is needed to address how intergenerational transmission of historical and ongoing race-based trauma may impact offspring health among African Americans.

Racial and Ethnic Disparities in the Perinatal Health of Infants Conceived by ART

BACKGROUND AND OBJECTIVES

Although racial and ethnic disparities in adverse birth outcomes have been well documented, it is unknown whether such disparities diminish in women who use medically assisted reproduction (MAR). We examined differences in the association between maternal race and ethnicity and adverse birth outcomes among women who conceived spontaneously and those who used MAR, including assisted reproduction technology (ART), eg, in-vitro fertilization, and also non-ART MAR, eg, fertility drugs.

METHODS

We conducted a population-based retrospective cohort study using data on all singleton births (N = 7 545 805) in the United States from 2016 to 2017. The outcomes included neonatal and fetal death, preterm birth, and serious neonatal morbidity, among others. Modified Poisson regression was used to estimate adjusted rate ratios (aRR) and 95% confidence intervals (CI) and to assess the interactions between race and ethnicity and mode of conception.

RESULTS

Overall, 93 469 (1.3%) singletons were conceived by MAR. Neonatal mortality was twofold higher among infants of non-Hispanic Black versus non-Hispanic White women in the spontaneous-conception group (aRR = 1.9, 95% CI: 1.8-1.9), whereas in the ART-conception group, neonatal mortality was more than fourfold higher in infants of non-Hispanic Black women (aRR = 4.1, 95% CI: 2.9-5.9). Racial and ethnic disparities between Hispanic versus non-Hispanic White women were also significantly larger among women who conceived using MAR with regard to preterm birth (&lt;34 weeks) and perinatal mortality.

CONCLUSIONS

Compared to women who conceived spontaneously, racial and ethnic disparities in adverse perinatal outcomes were larger in women who used MAR. More research is needed to identify preventive measures for reducing risks among vulnerable women who use medically assisted reproduction.

Machine learning to predict pregnancy outcomes: a systematic review, synthesizing framework and future research agenda

Machine Learning (ML) has been widely used in predicting the mode of childbirth and assessing the potential maternal risks during pregnancy. The primary aim of this review study is to explore current research and development perspectives that utilizes the ML techniques to predict the optimal mode of childbirth and to detect various complications during childbirth. A total of 26 articles (published between 2000 and 2020) from an initial set of 241 articles were selected and reviewed following a Systematic Literature Review (SLR) approach. As outcomes, this review study highlighted the objectives or focuses of the recent studies conducted on pregnancy outcomes using ML; explored the adopted ML algorithms along with their performances; and provided a synthesized view of features used, types of features, data sources and its characteristics. Besides, the review investigated and depicted how the objectives of the prior studies have changed with time being; and the association among the objectives of the studies, uses of algorithms, and the features. The study also delineated future research opportunities to facilitate the existing initiatives for reducing maternal complacent and mortality rates, such as: utilizing unsupervised and deep learning algorithms for prediction, revealing the unknown reasons of maternal complications, developing usable and useful ML-based clinical decision support systems to be used by the expecting mothers and health professionals, enhancing dataset and its accessibility, and exploring the potentiality of surgical robotic tools. Finally, the findings of this review study contributed to the development of a conceptual framework for advancing the ML-based maternal healthcare system. All together, this review will provide a state-of-the-art paradigm of ML-based maternal healthcare that will aid in clinical decision-making, anticipating pregnancy problems and delivery mode, and medical diagnosis and treatment.

Joint effects of prenatal exposure to per- and poly-fluoroalkyl substances and psychosocial stressors on corticotropin-releasing hormone during pregnancy

BACKGROUND

Prenatal exposure to per- and poly-fluoroalkyl substances (PFAS) and psychosocial stressors has been associated with adverse pregnancy outcomes, including preterm birth. Previous studies have suggested that joint exposure to environmental chemical and social stressors may be contributing to disparities observed in preterm birth. Elevated corticotropin-releasing hormone (CRH) during mid-gestation may represent one biologic mechanism linking chemical and nonchemical stress exposures to preterm birth.

METHODS

Using data from a prospective birth cohort (N = 497), we examined the cross-sectional associations between five individual PFAS (ng/mL; PFNA, PFOA, PFOS, PFHxS, and Me-PFOSA-AcOH) and CRH (pg/mL) using linear regression. PFAS and CRH were measured during the second trimester in serum and plasma, respectively. Coefficients were standardized to reflect change in CRH associated with an interquartile range (IQR) increase in natural log-transformed PFAS. We additionally examined if the relationship between PFAS and CRH was modified by psychosocial stress using stratified models. Self-reported depression, stressful life events, perceived stress, food insecurity, and financial strain were assessed using validated questionnaires during the second trimester and included as binary indicators of psychosocial stress.

RESULTS

An IQR increase in PFNA was associated with elevated CRH (β = 5.17, 95% confidence interval [CI] = 1.79, 8.55). Increased concentrations of PFOA were also moderately associated with CRH (β = 3.62, 95% CI = -0.42, 7.66). The relationship between PFNA and CRH was stronger among women who experienced stressful life events, depression, food insecurity, and financial strain compared to women who did not experience these stressors.

CONCLUSIONS

This cross-sectional study is the first to examine the relationship between PFAS exposure and CRH levels in mid-gestation. We found that these associations were stronger among women who experienced stress, which aligns with previous findings that chemical and nonchemical stressor exposures can have joint effects on health outcomes.

Early Association Factors for Depression Symptoms in Pregnancy: A Comparison between Spanish Women Spontaneously Gestation and with Assisted Reproduction Techniques

Women with assisted reproduction techniques (ART) have a different psychological profile than women with a spontaneous pregnancy. These differences may put the former group at higher risk for depressive symptomatology. Our aim was to determine what sociodemographic factors and psychological variables interact with early depressive symptoms in pregnant women with ART. This is a cross-sectional, non-interventional, and observational study where a total of 324 women were analyzed in the first trimester of pregnancy at the Hospital Universitario Central de Asturias (Spain). Women completed a sociodemographic questionnaire, the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder 7-item Scale, the Resilience inventory, the General concerns (ad hoc scale), the Stressful life events, and the prenatal version of Postpartum Depression Predictors Inventory-Revised (PDPI-R), including socioeconomic status, pregnancy intendedness, self-esteem, partner support, family support, friends support, marital satisfaction, and life stress. According to our models, women undergoing ART had significantly increased the PHQ-9 scores (β = 6.75 ± 0.74; p-value < 0.001). Being single also increased the PHQ-9 score. Related to the psychological variables, anxiety (β = 0.43 ± 0.06; p-value < 0.001) and stressful life events (β = 0.17 ± 0.06; p-value = 0.003) increased PHQ-9 scores. In contrast, resilience (β = -0.05 ± 0.02; p-value = 0.004), self-esteem (β = -1.21 ± 0.61; p-value = 0.048), and partner support (β = -1.50 ± 0.60; p-value = 0.013) decreased PHQ-9 scores. We concluded that women undergoing ART need interventions to reduce anxiety and stressful life events, and to improve resilience, self-esteem, and emotional partner support to prevent depressive symptomatology during this important phase in their lives.

Cumulative life stressors and stress response to threatened preterm labour as birth date predictors

PURPOSE

Preterm birth represents one of the main causes of neonatal morbimortality and a risk factor for neurodevelopmental disorders. Appropriate predictive methods for preterm birth outcome, which consequently would facilitate prevention programs, are needed. We aim to predict birth date in women with a threatened preterm labour (TPL) based on stress response to TPL diagnosis, cumulative life stressors, and relevant obstetric variables.

METHODS

A prospective cohort of 157 pregnant women with TPL diagnosis between 24 and 31 weeks gestation formed the study sample. To estimate the stress response to TPL, maternal salivary cortisol, α-amylase levels, along with anxiety and depression symptoms were measured. To determine cumulative life stressors, previous traumas, social support, and family functioning were registered. Then, linear regression models were used to examine the effect of potential predictors of birth date.

RESULTS

Lower family adaptation, higher Body Mass Index (BMI), higher cortisol levels and TPL diagnosis week were the main predictors of birth date. Gestational week at TPL diagnosis showed a non-linear interaction with cortisol levels: TPL women with middle- and high-cortisol levels before 29 weeks of gestation went into imminent labour.

CONCLUSION

A combination of stress response to TPL diagnosis (salivary cortisol) and cumulative life stressors (family adaptation) together with obstetric factors (TPL gestational week and BMI) was the best birth date predictor. Therefore, a psychosocial therapeutic intervention program aimed to increase family adaptation and decrease cortisol levels at TPL diagnosis as well as losing weight, may prevent preterm birth in symptomatic women.

Explaining the Black-White Disparity in Preterm Birth: A Consensus Statement From a Multi-Disciplinary Scientific Work Group Convened by the March of Dimes

In 2017–2019, the March of Dimes convened a workgroup with biomedical, clinical, and epidemiologic expertise to review knowledge of the causes of the persistent Black-White disparity in preterm birth (PTB). Multiple databases were searched to identify hypothesized causes examined in peer-reviewed literature, 33 hypothesized causes were reviewed for whether they plausibly affect PTB and either occur more/less frequently and/or have a larger/smaller effect size among Black women vs. White women. While definitive proof is lacking for most potential causes, most are biologically plausible. No single downstream or midstream factor explains the disparity or its social patterning, however, many likely play limited roles, e.g., while genetic factors likely contribute to PTB, they explain at most a small fraction of the disparity. Research links most hypothesized midstream causes, including socioeconomic factors and stress, with the disparity through their influence on the hypothesized downstream factors. Socioeconomic factors alone cannot explain the disparity's social patterning. Chronic stress could affect PTB through neuroendocrine and immune mechanisms leading to inflammation and immune dysfunction, stress could alter a woman's microbiota, immune response to infection, chronic disease risks, and behaviors, and trigger epigenetic changes influencing PTB risk. As an upstream factor, racism in multiple forms has repeatedly been linked with the plausible midstream/downstream factors, including socioeconomic disadvantage, stress, and toxic exposures. Racism is the only factor identified that directly or indirectly could explain the racial disparities in the plausible midstream/downstream causes and the observed social patterning. Historical and contemporary systemic racism can explain the racial disparities in socioeconomic opportunities that differentially expose African Americans to lifelong financial stress and associated health-harming conditions. Segregation places Black women in stressful surroundings and exposes them to environmental hazards. Race-based discriminatory treatment is a pervasive stressor for Black women of all socioeconomic levels, considering both incidents and the constant vigilance needed to prepare oneself for potential incidents. Racism is a highly plausible, major upstream contributor to the Black-White disparity in PTB through multiple pathways and biological mechanisms. While much is unknown, existing knowledge and core values (equity, justice) support addressing racism in efforts to eliminate the racial disparity in PTB.

Posttraumatic stress in NICU mothers: modeling the roles of childhood trauma and infant health

OBJECTIVE

To evaluate acute stress disorder (ASD) symptoms and their predictors in Neonatal Intensive Care Unit (NICU) mothers.

STUDY DESIGN

In this cross-sectional study, 119 mothers (~72% Medicaid) completed surveys during the first month of their infants' hospitalizations. Correlations and structural equation models (SEMs) evaluated relations among mothers' childhood trauma history, infant health appraisals, objective infant health, and ASD.

RESULT

ASD symptoms (~55%) and childhood trauma (~33%) were prevalent. ASD was correlated with childhood trauma, infant health, and infant health appraisals. All SEMs had good fit, indicating that (a) infant health appraisals partially mediated relations between childhood trauma and ASD, and (b) infant health appraisals fully mediated relations between objective infant health and ASD.

CONCLUSION

ASD symptoms are prevalent among NICU mothers regardless of infant health severity. Recognition of childhood trauma history and appraisals of infant health is critical for trauma-informed care.

The impact of prenatal stressful life events on adverse birth outcomes: A systematic review and meta-analysis

BACKGROUND

Stressful life events as important stressors have gradually been recognized as the potential etiology that may lead to adverse birth outcomes such as preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA). However, researches on this topic have shown relatively inconsistent results. This systematic review and meta-analysis was performed to synthesize available data on the association between prenatal stressful life events and increased risks of PTB, LBW, and SGA.

METHODS

Electronic databases were searched from their inception until September 2020. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated to assess the association between prenatal stressful life events and PTB, LBW, and SGA using random effects models. In addition, subgroup analyses, cumulative meta-analyses, sensitivity analyses, and publication bias diagnosis were conducted. STATA 14.0 was applied for statistical analyses.

RESULTS

Totally 31 cohort studies involving 5,665,998 pregnant women were included. Prenatal stressful life events were associated with a 20% higher risk of PTB (RR = 1.20, 95%CI = 1.10-1.32), a 23% increased risk for LBW (RR = 1.23, 95%CI = 1.10-1.39), and a 14% higher risk of SGA (RR = 1.14, 95%CI = 1.08-1.20). Sensitivity analysis indicated the results were stable.

CONCLUSIONS

Findings indicated that pregnant women experiencing prenatal stressful life events were at increased risk of PTB, LBW, and SGA. This information provided additional supports that pregnant women experiencing prenatal stressful life events would benefit from receiving assessment and management in prenatal care services.

Pregnant Mexican American Biopsychosocial/Cultural risks for adverse infant outcomes

Aims

To test a model of psychosocial/cultural/biological risk factors for poor birth outcomes in Latina pregnant women.

Design

An observational study measuring acculturation, progesterone, cortisol, cotinine, age, marital status, income, stress, depressive symptoms and coping. We tested a structural equation model to predict risk.

Methods

We obtained a convenience sample (N = 515) of low medical risk pregnant Mexican American Hispanic women at 22–24 weeks of gestation. Bilingual research nurses collected data from blood, urine and questionnaires. Self‐report measures were the Beck Depression Inventory‐II, the Perceived Stress Scale, the Acculturation Rating Scale for Mexican Americans‐II and the Brief Cope. We measured progesterone and cortisol in plasma and cotinine levels in urine by enzyme‐linked immunoassays.

Results

A PLS‐SEM model revealed that Mexican American Hispanic pregnant women who were younger, single, lower income, more acculturated and who had greater negative coping, stress and depression were most at risk for having earlier and smaller babies.

Periconceptional stressors and social support and risk for adverse birth outcomes

Background

The prevalence of preterm birth and low birth weight has been increasing slightly in recent years. A few studies have suggested that psychosocial stress during pregnancy may increase risk for these adverse birth outcomes. To extend those observations, we analyzed various major life event stressors separately and cumulatively as potential risk factors for preterm birth and low birth weight using granular categories of each outcome in a large, population-based study. Additionally, we assessed if greater social support buffered any effects.

Methods

Data were from a nested prevalence study of 4395 women in the National Birth Defects Prevention Study who delivered live-born non-malformed infants (controls) between 2006 and 2011. Participants completed a standardized, computer-assisted interview between 6 weeks and 24 months after delivery that included questions on stress and social support from 3 months before pregnancy to the 3rd month of pregnancy. Cumulative stress and support indices were also calculated. Preterm birth was divided into “early preterm” (< 32 weeks), “late preterm” (32–36 weeks) and “term.” Low birthweight was divided into “very low birth weight” (< 1500 g), “low birth weight” (1500–2499 g) and “normal birth weight” (≥2500 g). Relative risks and 95% confidence intervals (95% CI) were calculated using Poisson regression.

Results

For women reporting relationship difficulties, there was a suggestive risk of early preterm birth (RR: 1.9, 95%CI: 0.9–3.9) and very low birthweight (RR: 2.0, 95%CI: 0.9–4.4). For women reporting that they or someone close to them were victims of abuse, violence, or crime, there was an increased risk of low birthweight (RR: 1.8, 95%CI: 1.1–2.7) and late preterm birth (RR: 1.5, 95%CI: 1.0–2.2). There were no strong associations observed between social support questions and the various outcomes.

Conclusions

Our results add some support to prior evidence that certain stressors may be associated with increase selected adverse birth outcomes risk. We did not find strong evidence that social support buffered the observed risks in our study.

Stressful life events, the incidence of infertility, and the moderating effect of maternal responsiveness: a longitudinal study

Although the association between stress and poor reproductive health is well established, this association has not been examined from a life course perspective. Using data from the National Longitudinal Survey of Youth 1997 cohort (N = 1652), we fit logistic regression models to test the association between stressful life events (SLEs) (e.g., death of a close relative, victim of a violent crime) during childhood, adolescence, and early adulthood and later experiences of infertility (inability to achieve pregnancy after 12 months of intercourse without contraception) reported by female respondents. Because reactions to SLEs may be moderated by different family life experiences, we stratified responses by maternal responsiveness (based on the Conger and Elder Parent-Youth Relationship scale) in adolescence. After adjusting for demographic and environmental factors, in comparison to respondents with one or zero SLEs, those with 3 SLEs and ≥ 4 SLEs had 1.68 (1.16, 2.42) and 1.88 (1.38, 2.57) times higher odds of infertility, respectively. Respondents with low maternal responsiveness had higher odds of infertility that increased in a dose-response manner. Among respondents with high maternal responsiveness, only those experiencing four or more SLEs had an elevated risk of infertility (aOR = 1.53; 1.05, 2.25). In this novel investigation, we demonstrate a temporal association between the experience of SLEs and self-reported infertility. This association varies by maternal responsiveness in adolescence, highlighting the importance of maternal behavior toward children in mitigating harms associated with stress over the life course.

Stressful life events, hypertensive disorders, and high blood sugar during pregnancy

The objective of this study was to examine the association of life events stressors with risk of gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) by using the multilevel sample from the 2007 Los Angeles Mommy and Baby (LAMB) survey. Four multilevel logistic regression models were applied while accounting for the multilevel design of the LAMB study. The following demographic variables were used as covariates: maternal age, race/ethnicity, maternal educational attainment, household income level in the previous year, physical exercise, and prepregnancy body weight status. The scale for total number of stressors was positively associated with GDM in Model 1, but the association did not reach the significance threshold of 0.05. In Model 2 where four specific domains of stressors (financial, traumatic, spousal, and emotional stressors) were used as the key exposure variables, the number of financial stressors during pregnancy was significantly associated with a higher risk of GDM. The scale for total number of stressors was associated with HDP in Model 3. Experience of financial stressors during pregnancy was significantly associated with a higher risk of HDP in Model 4. In conclusion, exposure to higher number of financial stressors was associated with an elevated risk of GDM and HDP.

Pregnancies Among the First Generation of Survivors of Perinatal HIV Infection

OBJECTIVE

Little is known about pregnancy outcomes among women who have acquired human immunodeficiency virus (HIV) through perinatal infection and survived into adulthood. The objectives of this study were to describe pregnancy outcomes among women with perinatal HIV infection (PHIV) in Canada and to identify potential challenges in the prevention of perinatal HIV transmission in this population.

METHODS

A retrospective review of all pregnancies among women with PHIV who were previously followed as children at two tertiary care centres in Montréal, Québec, was conducted. Data were extracted from pediatric and obstetrical records.

RESULTS

There were 21 pregnancies among 11 women, and 18 of these pregnancies were unintentional. Mean age at first pregnancy was 19.5 years (range 15-29 years). At the first prenatal visit, 79% had a detectable viral load, 36% were immunosuppressed (CD4 T cell count <200 mm³), and only 36% were receiving antiretroviral therapy (ART). At the time of delivery, although all were prescribed ART, 50% of these women still had a detectable viral load, and 36% remained immunosuppressed. All of the women harboured mutations conferring drug resistance to zidovudine and lamivudine, and the majority (73%) were also resistant to nevirapine. None of the infants were HIV infected, although all received prophylaxis with agents to which their mother's virus was resistant.

CONCLUSION

Unplanned pregnancies, difficulties with adherence to ART, and drug resistance were identified challenges in the management of pregnancies among women with PHIV. This study highlights a gap in the reproductive counselling of adolescents with PHIV and the need for close follow-up and adherence support during pregnancy in this population.

Interleukin-17A and Chronic Stress in Pregnant Women at 24-28 Weeks Gestation

BACKGROUND

Allostatic load (AL) is a biopsychosocial model that suggests chronic psychosocial stress leads to physiological dysregulation and poor outcomes. The purpose of this study was to examine AL in pregnant women operationalized using proinflammatory cytokines and psychosocial indicators and perinatal outcomes.

OBJECTIVES

The aim of the study was to identify relationships between circulating cytokines/chemokines and the Prenatal Distress Questionnaire, the Maternal Antenatal Attachment Scale, the Emotional Quotient Inventory, the Life Experiences Scale, and demographics in pregnant women.

METHODS

A cross-sectional design was used to recruit pregnant women between 24 and 28 weeks of gestation. Blood and stress/emotional indicators were obtained after informed consent. Plasma was abstracted to simultaneously measure 29 cytokines/chemokines using a multiplex array. Cytokine/chemokine levels were compared with continuous variables using Spearman's rho and with categorical variables using Mann-Whitney U.

RESULTS

Twenty-five women with medically high-risk (n = 16) and low-risk (n = 9) pregnancies consented. Most women were White (68%) with a mean age of 29 years (SD = 5.9). Although several cytokines and chemokines showed significant correlations with the stress/emotional indicators, only interleukin-17A (IL-17A) was significantly associated with all of the indicators (Prenatal Distress Questionnaire: rs = .528, p = .012; Maternal Antenatal Attachment Scale: rs = -.439, p = .036; Emotional Quotient Inventory total: rs = -.545, p = .007), Life Experiences Scale (rs = .458, p = .032), birth weight (rs = -.499, p = .013), and race (p = .01).

DISCUSSION

Increased levels of IL-17A, a known cytokine associated with chronic stress and with poor perinatal outcomes, were associated with high prenatal distress, low maternal attachment, and lower emotional intelligence in pregnant women. Increased levels of IL-17A also were associated with lower birth weight and non-White race. Results support the model of AL in pregnant women and highlight IL-17A as a potential biomarker of AL during pregnancy.

Polarization-sensitive optical coherence tomography with a conical beam scan for the investigation of birefringence and collagen alignment in the human cervix

By measuring the phase retardance of a cervical extracellular matrix, our in-house polarization-sensitive optical coherence tomography (PS-OCT) was shown to be capable of (1) mapping the distribution of collagen fibers in the non-gravid cervix, (2) accurately determining birefringence, and (3) measuring the distinctive depolarization of the cervical tissue. A conical beam scan strategy was also employed to explore the 3D orientation of the collagen fibers in the cervix by interrogating the samples with an incident light at 45° and successive azimuthal rotations of 0-360°. Our results confirmed previous observations by X-ray diffraction, suggesting that in the non-gravid human cervix collagen fibers adjacent to the endocervical canal and in the outermost areas tend to arrange in a longitudinal fashion whereas in the middle area they are oriented circumferentially. PS-OCT can assess the microstructure of the human cervical collagen in vitro and holds the potential to help us better understand cervical remodeling prior to birth pending the development of an in vivo probe.

Stressor landscapes, birth weight, and prematurity at the intersection of race and income: Elucidating birth contexts through patterned life events

Women of color and women in poverty experience disproportionately high rates of adverse birth outcomes in the United States (US). We use an intersectionality-based approach to examine how maternal life events (LE's) preceding childbirth are patterned and shape birth outcomes at the intersection of race and income. Using population data from the Pregnancy Risk Assessment Monitoring System we uncover common maternal LE clusters preceding births in 2011-2015, offering a description and measurement of what we call "stressor landscapes" that go beyond standard measures by frequency or type alone. Three landscapes emerge: (1) Protected, characterized by very few LE's; (2) Illness/Isolated, with very few LE's and most commonly involving an illness or death of someone close; and (3) Toxic/Cumulative, comprising more frequent and acute LE's. Mothers in the toxic landscape experience on average 107-g lighter birth weights and a 27%, 49%, and 57% greater risk of PTB, LBW, and VLBW, respectively, compared to in the protected landscape. Low-income and non-Hispanic black (NHB), Hispanic, American Indian (AI), and Alaska Native (AN) mothers are among the groups disproportionately exposed to toxic stressor landscapes. The association between landscape and birth outcomes additionally varies by race and income. Among non-Hispanic white mothers, toxic landscapes are linked to poor birth outcomes at lower incomes. Among NHB mothers, illness-related stressors are additionally linked to worse outcomes and stressor landscapes disproportionately harm middle-income mothers. Toxic stressors may contribute to worse outcomes among middle- and high-income Hispanic and AI/AN mothers, but these patterns are less clear. Our study offers a new approach to measuring LE's that match common conceptions of exposure clustering and applies it to US population data to reveal LE patterns underlying persistent social disparities in maternal and child health.

Changing trends of adverse pregnancy outcomes with maternal age in primipara with singleton birth: A join point analysis of a multicenter historical cohort study in China in 2011-2012

INTRODUCTION

Adverse pregnancy outcomes are related to two opposite maternal factors, youth and aging. However, the change in trend of specific outcomes with childbearing age is unknown. The aim of this study was to investigate the changing trend of various maternal and neonatal outcomes with maternal age from 17 to 44 years.

MATERIAL AND METHODS

Data were extracted from the medical records from 2011-2012 of 39 public hospitals of 14 cities in China. The eligibility criteria were primiparity and singleton birth. Join point regression analysis was used to estimate the percent change per year of age (PCA) to explore the trends of adverse pregnancy outcomes with regard to maternal age and to identify the join point of maternal age when the trend was changed.

RESULTS

A total of 89 171 women were eligible for analysis. There were four categories of trend styles. Continuously increasing trends were linear for placenta previa (PCA, 0.1%), placenta implantation (PCA, 0.09%) and postpartum hemorrhage (PCA, 0.22%), and nonlinear for gestational diabetes mellitus with one join point of 23 years (PCA, 0.17% and 0.71%) and cesarean section with four join points of 25, 28, 31 and 36 years (PCA, 1.39%, 0.34%, 1.51%, 3.49% and 0.94%). Continuously decreasing trends were linear for intrahepatic cholestasis (PCA, -0.02%) and nonlinear for anemia with one join point of 28 years (PCA, -0.49% and -0.04%). The bidirective trends were downward to upward for preterm birth (PCA, -2.93%, -0.36% and 0.38%), hypertension in pregnancy (PCA, -0.09%, 0.47%), low birthweight (PCA 0.51% and 0.38%), low 1-minute Apgar score (PCA, -0.28% and 0.07%), low 5-minute Apgar score at (PCA, -0.10% and 0.06%) and neonatal intensive care unit admission (PCA, -1.92%, -0.07% and 0.12%) with a nadir age of 28 years. The bidirective trend was upward to downward for macrosomia (PCA, 0.39% and -0.11%), with a peak age of 30 years.

CONCLUSIONS

The changes in the trend of specific outcomes were different with maternal age, which means that youth, aging or both could affect the outcomes.

Assessing the risk factors before pregnancy of preterm births in Iran: a population-based case-control study

Background

Preterm birth is a major cause of prenatal and postnatal mortality particularly in developing countries. This study investigated the maternal risk factors associated with the risk of preterm birth.

Methods

A population-based case-control study was conducted in several provinces of Iran on 2463 mothers referred to health care centers. Appropriate descriptive and analytical statistical methods were used to evaluate the association between maternal risk factors and the risk of preterm birth. All tests were two-sided, and P values < 0.05 were considered to be statistically significant.

Results

The mean gestational age was 31.5 ± 4.03 vs. 38.8 ± 1.06 weeks in the case and control groups, respectively. Multivariate regression analysis showed a statistically significant association between preterm birth and mother’s age and ethnicity. Women of Balooch ethnicity and age ≥ 35 years were significantly more likely to develop preterm birth (OR: 1.64; 95% CI: 1.01–-2.44 and OR: 9.72; 95% CI: 3.07–30.78, respectively). However, no statistically significant association was observed between preterm birth and mother’s place of residence, level of education, past history of cesarean section, and BMI.

Conclusion

Despite technological advances in the health care system, preterm birth still remains a major concern for health officials. Providing appropriate perinatal health care services as well as raising the awareness of pregnant women, especially for high-risk groups, can reduce the proportion of preventable preterm births.

Perinatal Navigator Approach to Smoking Cessation for Women With Prevalent Opioid Dependence

Women who smoke during pregnancy face psychosocial barriers to cessation, and women with opioid use disorder (OUD) face amplified barriers. We pilot tested a Perinatal Wellness Navigator (PWN) program for a group of high-risk perinatal women (N = 50; n = 42 with OUD) that consisted of (a) one-on-one tobacco treatment, (b) comprehensive assessment of cessation barriers, and (c) linkage to clinical/social services. Outcome measures were assessed at baseline and postintervention. Participants smoked 10 fewer cigarettes per day (p = .05) at postintervention and were less dependent on nicotine (p < .01). Mean postnatal depression scores (p = .03) and perceived stress (p = .03) decreased postintervention. Participants received at least one referral at baseline (n = 106 total), and 10 participants received an additional 18 referrals at postintervention to address cessation barriers. The PWN program was minimally effective in promoting total tobacco abstinence in a high-risk group of perinatal women, but participants experienced reductions in cigarettes smoked per day, nicotine dependence, stress, and depression.

Periodontal condition is associated with adverse perinatal outcomes and premature rupture of membranes in low-income pregnant women in Bogota, Colombia: a case-control study

Objectives: To assess the periodontal condition as a factor associated with adverse perinatal outcomes, premature rupture of membranes (PRM), and preeclampsia in low-income pregnant women treated at public hospitals in Bogotá, Colombia.Methods: Pregnant women with preterm birth (PTB) and low birth weight (LBW) or both conditions (n = 107/428), or only PTB (n = 73/292) or LBW (n = 74/296) or with PRM (n = 98/392) or preeclampsia (n = 76/304) in a ratio of four controls for each case, coming from three hospitals of the public Northern Network of Bogotá, Colombia were studied. Sociodemographic, perinatal adverse outcome history, antenatal care, chronic infections, periodontal condition, threatened abortion, bleeding in the second half of pregnancy, oligohydramnios, diabetes, gestational diabetes, alcohol consumption, hypertension, smoking, alcohol during pregnancy were determined. Logistic regression was conducted to establish factors associated to perinatal adverse outcomes. Multiple correspondence analysis was conducted as secondary analysis.Results: Threatened abortion, absence of antenatal care, hypertension, chronic infections, and periodontal condition were the most important factors associated with perinatal adverse outcomes. The presence of periodontal pockets was associated with LBW OR 2.52 (IC_95% 1.36-4.70), PTB OR 2.04 (IC_95% 1.10-3.64), PTB-LBW or both OR 2.08 (IC_95% 1.18-3.31), PRM OR 2.04 (IC_95% 1.17-3.56). Periodontal pockets presence was not associated with preeclampsia. Multiple correspondence analyses showed high correlation between PRM with chronic infection and presence of periodontal pockets.Conclusions: Periodontal condition is a factor independent of other important risk factors for a perinatal adverse outcome and PRM. Prevention of periodontal disease should be included in preconception and prenatal care programs.

Life Course Adversity and Prior Miscarriage in a Pregnancy Cohort

BACKGROUND

Prior studies indicate associations between preconception adversities and risk of miscarriage, but few have considered type (e.g., financial, substance use, abuse) or timing (e.g., childhood, adulthood) of adversities. We examined relationships between life course adversities in multiple domains and probability of miscarriage.

METHODS

Data came from women with at least one previous pregnancy in the Pregnancy Outcomes and Community Health (1998-2004) study (n = 2,106). Life course adversities in domains of abuse/witnessing violence, loss of someone close, economic hardship, and substance abuse were assessed via questionnaire and categorized as occurring during childhood only, adulthood only, both childhood and adulthood, or neither. We also calculated a cumulative adversity score. We used logistic regression models to estimate associations between life course adversity measures and the probability of miscarriage, and examined effect modification by race/ethnicity and maternal education. All models were adjusted for maternal age, race/ethnicity, education, and marital status.

RESULTS

The odds of miscarriage were higher among women experiencing legal adversities during both childhood and adulthood (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.3-2.8) compared with women not experiencing legal adversities, and higher among women experiencing substance use adversities in childhood only (OR, 1.4; 95% CI, 1.1-1.7) compared with women not experiencing substance use adversities. Each additional adversity was marginally significantly associated with a 10% increase in odds of preterm birth (OR, 1.1; 95% CI, 1.0-1.1). Among women with only one prior miscarriage, no adversity measures were associated with miscarriage.

CONCLUSIONS

Exposure to adversity in certain domains and across the life course modestly increased the odds of miscarriage.

Evidence of validity of the Stress-Producing Life Events (SPLE) instrument

OBJECTIVE Evaluate the construct validity of a list of eight Stressful Life Events in pregnant women. METHODS A cross-sectional study was conducted with 1,446 pregnant women in São Luís, MA, and 1,364 pregnant women in Ribeirão Preto, SP (BRISA cohort), from February 2010 to June 2011. In the exploratory factorial analysis, the promax oblique rotation was used and for the calculation of the internal consistency, we used the compound reliability. The construct validity was determined by means of the confirmatory factorial analysis with the method of estimation of weighted least squares adjusted by the mean and variance. RESULTS The model with the best fit in the exploratory analysis was the one that retained three factors with a cumulative variance of 61.1%. The one-factor model did not obtain a good fit in both samples in the confirmatory analysis. The three-factor model called Stress-Producing Life Events presented a good fit (RMSEA < 0.05; CFI/TLI > 0.90) for both samples. CONCLUSIONS The Stress-Producing Life Events constitute a second order construct with three dimensions related to health, personal and financial aspects and violence. This study found evidence that confirms the construct validity of a list of stressor events, entitled Stress-Producing Life Events Inventory.

Stress and the HPA Axis: Balancing Homeostasis and Fertility

An organism’s reproductive fitness is sensitive to the environment, integrating cues of resource availability, ecological factors, and hazards within its habitat. Events that challenge the environment of an organism activate the central stress response system, which is primarily mediated by the hypothalamic–pituitary–adrenal (HPA) axis. The regulatory functions of the HPA axis govern the cardiovascular and metabolic system, immune functions, behavior, and reproduction. Activation of the HPA axis by various stressors primarily inhibits reproductive function and is able to alter fetal development, imparting a biological record of stress experienced in utero. Clinical studies and experimental data indicate that stress signaling can mediate these effects through direct actions in the brain, gonads, and embryonic tissues. This review focuses on the mechanisms by which stress activation of the HPA axis impacts fertility and fetal development.

Worry about racial discrimination: A missing piece of the puzzle of Black-White disparities in preterm birth?

OBJECTIVES

The causes of the large and persistent Black-White disparity in preterm birth (PTB) are unknown. It is biologically plausible that chronic stress across a woman's life course could be a contributor. Prior research suggests that chronic worry about experiencing racial discrimination could affect PTB through neuroendocrine, vascular, or immune mechanisms involved in both responses to stress and the initiation of labor. This study aimed to examine the role of chronic worry about racial discrimination in Black-White disparities in PTB.

METHODS

The data source was cross-sectional California statewide-representative surveys of 2,201 Black and 8,122 White, non-Latino, U.S.-born postpartum women with singleton live births during 2011-2014. Chronic worry about racial discrimination (chronic worry) was defined as responses of "very often" or "somewhat often" (vs. "not very often" or "never") to the question: "Overall during your life until now, how often have you worried that you might be treated or viewed unfairly because of your race or ethnic group?" Prevalence ratios (PRs) with 95% Confidence Intervals (CI) were calculated from sequential logistic regression models, before and after adjustment for multiple social/demographic, behavioral, and medical factors, to estimate the magnitude of: (a) PTB risks associated with chronic worry among Black women and among White women; and (b) Black-White disparities in PTB, before and after adjustment for chronic worry.

RESULTS

Among Black and White women respectively, 36.9 (95% CI 32.9-40.9) % and 5.5 (95% CI 4.5-6.5) % reported chronic worry about racial discrimination; rates were highest among Black women of higher income and education levels. Chronic worry was significantly associated with PTB among Black women before (PR 1.73, 95% CI 1.12-2.67) and after (PR 2.00, 95% CI 1.33-3.01) adjustment for covariates. The unadjusted Black-White disparity in PTB (PR 1.59, 95%CI 1.21-2.09) appeared attenuated and became non-significant after adjustment for chronic worry (PR 1.30, 95% CI 0.93-1.81); it appeared further attenuated after adding the covariates (PR 1.17, 95% CI 0.85-1.63).

CONCLUSIONS

Chronic worry about racial discrimination may play an important role in Black-White disparities in PTB and may help explain the puzzling and repeatedly observed greater PTB disparities among more socioeconomically-advantaged women. Although the single measure of experiences of racial discrimination used in this study precluded examination of the role of other experiences of racial discrimination, such as overt incidents, it is likely that our findings reflect an association between one or more experiences of racial discrimination and PTB. Further research should examine a range of experiences of racial discrimination, including not only chronic worry but other psychological and emotional states and both subtle and overt incidents as well. These dramatic results from a large statewide-representative study add to a growing-but not widely known-literature linking racism-related stress with physical health in general, and shed light on the links between racism-related stress and PTB specifically. Without being causally definitive, this study's findings should stimulate further research and heighten awareness of the potential role of unmeasured social variables, such as diverse experiences of racial discrimination, in racial disparities in health.

Theoretical Insights into Preconception Social Conditions and Perinatal Health: The Role of Place and Social Relationships

Recent efforts to explain the stark social and racial disparities in adverse birth outcomes that have persisted for decades in the U.S. have looked beyond prenatal factors, to explore preconception social conditions that may influence perinatal health via dysregulation of physiologic processes. The extant evidence supporting this link however remains limited, both due to a lack of data and theory. To address the latter, this manuscript generates a structured set of theoretical insights that further develop the link between two preconception social conditions - place and social relationships - and perinatal health. The insights propose the following.

PLACE

necessarily encompasses all social contexts to which females are exposed from infancy through young adulthood; encompasses a variety of related exposures that, when possible, should be jointly considered; and may compound the effect of poverty-in childhood, adolescence, or young adulthood-on perinatal health. Social relationships: span relationships from early life through adulthood, and extend to intergenerational associations; often involve (or induce) major changes in the lives of individuals and should be examined with an emphasis on the developmental stage in which the change occurred; and necessarily encompass a lack of social integration, or, social isolation. We also identify potential biological and social-structural mechanisms linking these preconception social conditions to perinatal health, and conclude by identifying promising directions for future research.

Stressors Across the Life-Course and Preterm Delivery: Evidence From a Pregnancy Cohort

Objectives Growing evidence suggests that pre-conception stressors are associated with increased risk of preterm delivery (PTD). Our study assesses stressors in multiple domains at multiple points in the life course (i.e., childhood, adulthood, within 6 months of pregnancy) and their relation to PTD. We also examine heterogeneity of associations by race/ethnicity, PTD timing, and PTD clinical circumstance. Methods We assessed stressors retrospectively via mid-pregnancy questionnaires in the Pregnancy Outcomes and Community Health Study (1998-2004), a Michigan pregnancy cohort (n = 2559). Stressor domains included abuse/witnessing violence (hereafter "abuse"), loss, economic stress, and substance use. We used logistic and multinomial regression for the following outcomes: PTD (<37 weeks' gestation), PTD by timing (≤34 weeks, 35-36 weeks) and PTD by clinical circumstance (medically indicated, spontaneous). Covariates included race/ethnicity, education, parity, and marital status. Results Stressors in the previous 6 months were not associated with PTD. Experiencing abuse during both childhood and adulthood increased adjusted odds of PTD among women of white or other race/ethnicity only (aOR 1.6, 95 % CI 1.1, 2.5). Among all women, abuse in childhood increased odds of late PTD (aOR 1.5, 95 % CI 1.0, 2.2) while abuse in both childhood and adulthood non-significantly increased odds of early PTD (aOR 1.6, 95 % CI 0.9, 2.7). Sexual, but not physical, abuse in both childhood and adulthood increased odds of PTD (aOR 1.9, 95 % CI 1.0, 3.5). Conclusions Experiences of abuse-particularly sexual abuse-across the life-course may be important considerations when assessing PTD risk. Our results motivate future studies of pathways linking abuse and PTD.

Subgroup identification of early preterm birth (ePTB): informing a future prospective enrichment clinical trial design

BACKGROUND

Despite the widely recognized association between the severity of early preterm birth (ePTB) and its related severe diseases, little is known about the potential risk factors of ePTB and the sub-population with high risk of ePTB. Moreover, motivated by a future confirmatory clinical trial to identify whether supplementing pregnant women with docosahexaenoic acid (DHA) has a different effect on the risk subgroup population or not in terms of ePTB prevalence, this study aims to identify potential risk subgroups and risk factors for ePTB, defined as babies born less than 34 weeks of gestation.

METHODS

The analysis data (N = 3,994,872) were obtained from CDC and NCHS' 2014 Natality public data file. The sample was split into independent training and validation cohorts for model generation and model assessment, respectively. Logistic regression and CART models were used to examine potential ePTB risk predictors and their interactions, including mothers' age, nativity, race, Hispanic origin, marital status, education, pre-pregnancy smoking status, pre-pregnancy BMI, pre-pregnancy diabetes status, pre-pregnancy hypertension status, previous preterm birth status, infertility treatment usage status, fertility enhancing drug usage status, and delivery payment source.

RESULTS

Both logistic regression models with either 14 or 10 ePTB risk factors produced the same C-index (0.646) based on the training cohort. The C-index of the logistic regression model based on 10 predictors was 0.645 for the validation cohort. Both C-indexes indicated a good discrimination and acceptable model fit. The CART model identified preterm birth history and race as the most important risk factors, and revealed that the subgroup with a preterm birth history and a race designation as Black had the highest risk for ePTB. The c-index and misclassification rate were 0.579 and 0.034 for the training cohort, and 0.578 and 0.034 for the validation cohort, respectively.

CONCLUSIONS

This study revealed 14 maternal characteristic variables that reliably identified risk for ePTB through either logistic regression model and/or a CART model. Moreover, both models efficiently identify risk subgroups for further enrichment clinical trial design.

Racial/Ethnic Disparities in Measures of Self-reported Psychosocial States and Traits during Pregnancy

Background The aim of this study was to determine whether racial/ethnic differences in psychosocial measures, independent of economic status, exist among a large population of pregnant nulliparas. Methods Between October 2010 and September 2013, nulliparous women at eight U.S. medical centers were followed longitudinally during pregnancy and completed validated instruments to quantify several psychosocial domains: Cohen Perceived Stress Scale, trait subscale of the Spielberger Anxiety Inventory, Connor-Davidson Resilience Scale, Multidimensional Scale of Perceived Social Support, Krieger Racism Scale, Edinburgh Postnatal Depression Scale, and the Pregnancy Experience Scale. Scores were stratified and compared by self-reported race, ethnicity, and income. Results Complete data were available for 8,128 of the 10,038 women enrolled in the study. For all measures, race and ethnicity were significantly associated (p < 0.001) with survey scores. Non-Hispanic black (NHB) women were most likely to score in the most unfavorable category for all measures, with the exception of the Pregnancy Experience Scale. The magnitude of these differences did not differ by income status (interaction, p > 0.05) except on the Krieger racism survey and the Edinburgh depression survey, which were exacerbated among NHB women with higher income (interaction, p < 0.001). Conclusion Significant racial/ethnic disparities, independent of income status, exist in psychosocial measures during pregnancy.

Born early and born poor: An eco-bio-developmental model for poverty and preterm birth

Poverty is associated with adverse long-term cognitive outcomes in children. Poverty is also linked with preterm delivery which, in turn, is associated with adverse cognitive outcomes. However, the extent of the effect of poverty on preterm delivery, as well as proposed mechanisms by which they occur, have not been well described. Further, the impact of poverty on preterm school readiness has not been reviewed. As the childhood poverty level continues to increase in the U.S., we examine the evidence around physiological, neurological, cognitive and learning outcomes associated with prematurity in the context of poverty. We use the evidence gathered to suggest an Eco-Bio-Developmental model, emphasizing poverty as a toxic stress which predisposes preterm birth and which, via epigenetic forces, can continue into the next generation. Continued postnatal social disadvantage for these developmentally high-risk preterm infants is strongly linked with poor neurodevelopmental outcomes, decreased school readiness, and decreased educational attainment which can perpetuate the poverty cycle. We suggest social remedies aimed at decreasing the impact of poverty on mothers, fathers, and children which may be effective in reducing the burden of preterm birth.

Maternal and neonatal factors related to prematurity

ABSTRACT OBJECTIVE To identify maternal and neonatal factors associated with prematurity in the municipality of Porto Alegre. METHOD This was a population-based case-control study. The cases were newborns under 37 weeks of gestation and the controls were newborns over 37 weeks. The data came from the records of 19,457 births in the city of Porto Alegre in the year 2012 from the Information System on Live Births of the Municipal Health Department. The analysis was carried outand adjusted by a Logistic Regression according to a hierarchical model. The variables studied were allocated into three hierarchy levels: sociodemographic variables; reproductive history; and gestational and birth factors. RESULTS There were 767 cases allocated and 1,534 controls in a design of a case for two controls (1:2) by simple randomization. In the final model, a statistically significant association was found for prematurity for the following variables: mother's age under 19 years old (OR=1.32; CI 95%: 1.02-1.71) or over 34 years old (OR=1.39; CI 95%: 1.12-1.72); inadequate maternal schooling for age (OR=2.11; CI 95%: 1.22-3.65); multiple pregnancies (OR=1.14; CI 95%: 1.01-1.29); C-section (OR=1.15; CI 95%: 1.03-1.29); birth weights under 2,500g (OR=4.04; CI 95%: 3.64-4.49); Apgar score at five minutes between zero and three (OR=1.47; CI 95%: 1.12-1.91); and inadequate prenatal care (OR=1.18; CI 95%: 1.02-1.36). CONCLUSION The present study showed the most immediate consequence of prematurity for newborns by evidencing its association with worse Apgar scores and low birth weight. The following factors were also shown as possible more distal determinants of prematurity: mother's age; inadequate maternal education; multiple gestation; inadequate prenatal care; and C-section.

Infant birthweight in the US: the role of preconception stressful life events and substance use

The purpose of this study was to determine the relationships among preconception stressful life events (PSLEs), women's alcohol and tobacco use before and during pregnancy, and infant birthweight. Data were from the Early Childhood Longitudinal Study-Birth Cohort (n = 9,350). Data were collected in 2001. Exposure to PSLEs was defined by indications of death of a parent, spouse, or previous live born child; divorce or marital separation; or fertility problems prior to conception. Survey data determined alcohol and tobacco usage during the 3 months prior to and in the final 3 months of pregnancy. We used staged multivariable logistic regression to estimate the effects of women's substance use and PSLEs on the risk of having a very low (<1,500 g, VLBW) or low (1,500-2,499 g, LBW) birthweight infant, adjusting for confounders. Women who experienced any PSLE were more likely to give birth to VLBW infants (adjusted odds ratio [AOR] = 1.35; 95 % confidence interval [CI] = 1.10-1.66) than women who did not experience any PSLE. Compared to women who never smoked, women who smoked prior to conception (AOR = 1.31; 95 % CI = 1.04-1.66) or during their last trimester (AOR = 1.98; 95 % CI = 1.56-2.52) were more likely to give birth to LBW infants. PSLEs and women's tobacco use before and during pregnancy are independent risk factors for having a lower birthweight baby. Interventions to improve birth outcomes may need to address women's health and health behaviors in the preconception period.

Do Physical Activity Patterns Across the Lifecourse Impact Birth Outcomes?

The significant impact of physical activity during, or immediately prior to pregnancy on a range of pregnancy and birth outcomes has been established. However, lifecourse theory posits that the antecedents of poor outcomes occur across a larger trajectory of time. The objective of this study was to examine whether physical activity patterns over the lifecourse impact birth outcomes. The sample (n = 1,713) was derived from Waves I, III, and IV of the National Longitudinal Study of Adolescent Health and limited to women who had their first, singleton live birth between Waves III and IV; respondents who had missing data were excluded. Outcome variables included preterm birth (<37 weeks) and low birth weight (<5.5 pounds). Physical activity was categorized as follows: long-term physically active (active at Waves I and III); short-term physically active (active at only Wave I or III); and not physically active (not active at Waves I and III). Survey-weighted logistic regression controlled for socio-demographic and established predictors of poor birth outcomes. Women categorized as long-term physically active had lower rates of preterm births (12.2 vs. 18.7 %) and low birth weight (9.1 vs. 11.1 %) compared to women categorized as not physically active. However, when controlling for covariates, adjusted analysis revealed that physical activity consistency only predicted preterm birth (aOR = 0.55, 95 % CI = 0.33-0.91). Findings suggest that physical activity patterns across the lifecourse may decrease risk of preterm birth. Implications include efforts supporting patterns of physical activity over longer periods of time prior to pregnancy.

Examining the link between women's exposure to stressful life events prior to conception and infant and toddler health: the role of birth weight

BACKGROUND

The life course perspective suggests a pathway may exist among maternal exposure to stressful life events prior to conception (PSLEs), infant birth weight and subsequent offspring health, whereby PSLEs are part of a 'chains-of-risk' that set children on a certain health pathway. No prior study has examined the link between PSLEs and offspring health in a nationally representative sample of US mothers and their children. We used longitudinal, nationally representative data to evaluate the relation between maternal exposure to PSLEs and subsequent measures of infant and toddler health, taking both maternal and obstetric characteristics into account.

METHODS

We examined 6900 mother-child dyads participating in 2 waves of the nationally representative Early Childhood Longitudinal Study-Birth Cohort (n=6900). Infant and toddler health outcomes assessed at 9 and 24 months included overall health status, special healthcare needs and severe health conditions. Adjusted path analyses examined associations between PSLEs, birth weight and child health outcomes.

RESULTS

In adjusted analyses, PSLEs increased the risk for very low birth weight (VLBW, <1500 g), which, in turn, predicted poor health at both 9 and 24 months of age. Path analyses demonstrated that PSLEs had small indirect effects on children's subsequent health that operated through VLBW.

CONCLUSIONS

Our analysis suggests a chains-of-risk model in which women's exposure to PSLEs increases the risk for giving birth to a VLBW infant, which, in turn, adversely affects infant and toddler health. Addressing women's preconception health may have important downstream benefits for their children, although more research is needed to replicate these findings.

Parental Leave Policy as a Strategy to Improve Outcomes among Premature Infants

Although gains have been made in premature birth rates among racial and ethnic minority and low socioeconomic status populations, tremendous disparities still exist in both prematurity rates and health outcomes for preterm infants. Parental involvement is known to improve health outcomes for preterm babies. However, a gap in evidence exists around whether parental involvement can help ameliorate the disparities in both short- and long-term out-comes for their preterm children. Families more likely to experience preterm birth are also less likely to have access to paid leave and thus experience significant systemic barriers to involvement, especially when their newborns are hospitalized. This article describes the research gap in this area and explores pathways by which social workers may ameliorate disparities in preterm birth outcomes through practice, policy, and research.

The Feto-Maternal Health Cost of Intimate Partner Violence Among Delivery-Related Discharges in the United States, 2002-2009

Our purpose was to estimate the national prevalence of intimate partner violence (IPV) among delivery-related discharges and to investigate its association with adverse feto-maternal birth outcomes and delivery-related cost. A retrospective cross-sectional analysis of delivery-related hospital discharges from 2002 to 2009 was conducted using the Nationwide Inpatient Sample (NIS). We used ICD-9-CM codes to identify IPV, covariates, and outcomes. Multivariable logistic regression modeling was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the associations between IPV and each outcome. Joinpoint regression was used for trend analysis. During the study period, 3,649 delivery-related discharges were diagnosed with IPV (11.2 per 100,000; 95% CI = [10.0, 12.4]). IPV diagnosis during delivery is associated with stillbirth (AOR = 4.12, 95% CI = [2.75, 6.17]), preterm birth (AOR = 1.97, 95% CI = [1.59, 2.44]), fetal death (AOR = 3.34, 95% CI = [1.99, 5.61]), infant with poor intrauterine growth (AOR = 1.55, 95% CI = [1.01, 2.40]), and increased inpatient hospital care cost (US$5,438.2 vs. US$4,080.1) per each discharge, incurring an additional cost of US$4,955,707 during the study period. IPV occurring during pregnancy has a significant health burden to both the mother and infant. Education about IPV; screening at periodic intervals, including during obstetric visits; and ongoing clinical care could help to reduce or eliminate adverse effects of pregnancy-related IPV. Preventing the lifelong consequences associated with IPV can have a positive effect on the overall health of all women and delivery-related health care cost.

Comparison of black-white disparities in preterm birth between Canada and the United States

BACKGROUND

A higher risk of preterm birth among black women than among white women is well established in the United States. We compared differences in preterm birth between non-Hispanic black and white women in Canada and the US, hypothesizing that disparities would be less extreme in Canada given the different historical experiences of black populations and Canada's universal health care system.

METHODS

Using data on singleton live births in Canada and the US for 2004-2006, we estimated crude and adjusted risk ratios and risk differences in preterm birth (< 37 wk) and very preterm birth (< 32 wk) among non-Hispanic black versus non-Hispanic white women in each country. Adjusted models for the US were standardized to the covariate distribution of the Canadian cohort.

RESULTS

In Canada, 8.9% and 5.9% of infants born to black and white mothers, respectively, were preterm; the corresponding figures in the US were 12.7% and 8.0%. Crude risk ratios for preterm birth among black women relative to white women were 1.49 (95% confidence interval [CI] 1.32 to 1.66) in Canada and 1.57 (95% CI 1.56 to 1.58) in the US (p value for heterogeneity [pH] = 0.3). The crude risk differences for preterm birth were 2.94 (95% CI 1.91 to 3.96) in Canada and 4.63 (95% CI 4.56 to 4.70) in the US (pH = 0.003). Adjusted risk ratios for preterm birth (pH = 0.1) were slightly higher in Canada than in the US, whereas adjusted risk differences were similar in both countries. Similar patterns were observed for racial disparities in very preterm birth.

INTERPRETATION

Relative disparities in preterm birth and very preterm birth between non-Hispanic black and white women were similar in magnitude in Canada and the US. Absolute disparities were smaller in Canada, which reflects a lower overall risk of preterm birth in Canada than in the US in both black and white populations.

Preconception Maternal Bereavement and Infant and Childhood Mortality: A Danish Population-Based Study

OBJECTIVES

Preconception maternal bereavement may be associated with an increased risk for infant mortality, although these previously reported findings have not been replicated. We sought to examine if the association could be replicated and explore if risk extended into childhood.

METHODS

Using a Danish population-based sample of offspring born 1979 to 2009 (N = 1,865,454), we analyzed neonatal (0-28 days), postneonatal infant (29-364 days), and early childhood (1-5 years) mortality after maternal bereavement in the preconception (6-0 months before pregnancy) and prenatal (between conception and birth) periods. Maternal bereavement was defined as death of a first-degree relative of the mother. Analyses were conducted using logistic and log-linear Poisson regressions that were adjusted for offspring, mother, and father sociodemographic and health factors.

RESULTS

We identified 6541 (0.004%) neonates, 3538 (0.002%) postneonates, and 2132 (0.001%) children between the ages of 1 and 5 years who died. After adjusting for covariates, bereavement during the preconception period was associated with increased odds of neonatal (adjusted odds ratio = 1.87, 95% confidence interval = 1.53-2.30) and postneonatal infant mortality (adjusted odds ratio = 1.52, 95% confidence interval = 1.15-2.02). Associations were timing specific (6 months before pregnancy only) and consistent across sensitivity analyses. Bereavement during the prenatal period was not consistently associated with increased risk of offspring mortality; however, this may reflect relatively low statistical power.

CONCLUSIONS

Results support and extend previous findings linking bereavement during the preconception period with increased odds of early offspring mortality. The period immediately before pregnancy may be a sensitive period with potential etiological implications and ramifications for offspring mortality.

Induced abortions and birth outcomes of women with a history of severe psychosocial problems in adolescence

OBJECTIVE

To increase knowledge on the reproductive health of women who have been placed in a residential school, a child welfare facility for adolescents with severe psychosocial problems.

METHODS

All women (n=291) who lived in the Finnish residential schools on the last day of the years 1991, 1996, 2001 and 2006 were included in this study and compared with matched general population controls. Register-based information on induced abortions and births was collected until the end of the year 2011.

RESULTS

Compared to controls, women with a residential school history had more induced abortions. A higher proportion of their births took place when they were teenagers or even minors. They were more often single, smoked significantly more during pregnancy and had a higher risk of having a preterm birth or a baby with a low birth weight.

CONCLUSIONS

The findings have implications for the planning of preventive and supportive interventions that aim to increase the well-being of women with a residential school history and their offspring.

Predictors of alcohol and tobacco use prior to and during pregnancy in the US: the role of maternal stressors

The purpose of the study was to understand the association between stressful life events prior to conception (PSLEs) and women's alcohol and tobacco use prior to and during pregnancy, and the continuation of such use through pregnancy. Data were from the Early Childhood Longitudinal Study-Birth Cohort (n = 9,350). Data were collected in 2001. Exposure to PSLEs was defined by indications of death of a parent, spouse, or previous live born child, divorce or marital separation, or fertility problems prior to conception. Survey data determined alcohol and tobacco usage during the 3 months prior to and in the final 3 months of pregnancy. Weighted regressions estimated the effect of PSLEs on alcohol and tobacco use at each time point and on the continuation of use, adjusting for confounders. Experiencing any PSLE increased the odds of tobacco use prior to (adjusted odds ratio [AOR] 1.52, 95 % confidence interval (CI) 1.23-1.87) and during pregnancy (AOR 1.57, 95 % CI 1.19-2.07). Women exposed to PSLEs smoked nearly five additional packs of cigarettes in the 3 months prior to pregnancy (97 cigarettes, p = 0.011) and consumed 0.31 additional alcoholic drinks during the last 3 months of pregnancy than unexposed women. PSLEs are associated with tobacco use before pregnancy and alcohol and tobacco use during pregnancy. Alcohol and tobacco screening and cessation services should be implemented prior to and during pregnancy, especially for women who have experienced PSLEs.

Neighborhood disadvantage, preconception stressful life events, and infant birth weight

OBJECTIVES

We sought to determine whether the effects of preconception stressful life events (PSLEs) on birth weight differed by neighborhood disadvantage.

METHODS

We drew our data from the Early Childhood Longitudinal Study, Birth Cohort (2001-2002; n = 9300). We created a neighborhood disadvantage index (NDI) using county-level data from the 2000 US Census. We grouped the NDI into tertiles that represented advantaged, middle advantaged, and disadvantaged neighborhoods. Stratified multinomial logistic regressions estimated the effect of PSLEs on birth weight, controlling for confounders.

RESULTS

We found a gradient in the relationship between women's exposure to PSLEs and having a very low birth weight (VLBW) infant by NDI tertile; the association was strongest in disadvantaged neighborhoods (adjusted odd ratio [AOR] = 1.62; 95% confidence interval [CI] = 1.04, 2.53), followed by middle (AOR = 1.39; 95% CI = 1.00, 1.93) and advantaged (AOR = 1.29; 95% CI = 0.91, 1.82) neighborhoods. We observed a similar gradient for women with chronic conditions and among minority mothers.

CONCLUSIONS

Women who experienced PSLEs, who had chronic conditions, or were racial/ethnic minorities had the greatest risk of having VLBW infants if they lived in disadvantaged neighborhoods; this suggests exacerbation of risk within disadvantaged environments. Interventions to reduce rates of VLBW should focus on reducing the deleterious effects of stressors and on improving neighborhood conditions.

Determinants of cesarean delivery in the US: a lifecourse approach

This study takes a lifecourse approach to understanding the factors contributing to delivery methods in the US by identifying preconception and pregnancy-related determinants of medically indicated and non-medically indicated cesarean section (C-section) deliveries. Data are from the Early Childhood Longitudinal Study-Birth Cohort, a nationally representative, population-based survey of women delivering a live baby in 2001 (n = 9,350). Three delivery methods were examined: (1) vaginal delivery (reference); (2) medically indicated C-section; and (3) non-medically indicated C-sections. Using multinomial logistic regression, we examined the role of sociodemographics, health, healthcare, stressful life events, pregnancy complications, and history of C-section on the odds of medically indicated and non-medically indicated C-sections, compared to vaginal delivery. 74.2 % of women had a vaginal delivery, 11.6 % had a non-medically indicated C-section, and 14.2 % had a medically indicated C-section. Multivariable analyses revealed that prior C-section was the strongest predictor of both medically indicated and non-medically indicated C-sections. However, we found salient differences between the risk factors for indicated and non-indicated C-sections. Surgical deliveries continue to occur at a high rate in the US despite evidence that they increase the risk for morbidity and mortality among women and their children. Reducing the number of non-medically indicated C-sections is warranted to lower the short- and long-term risks for deleterious health outcomes for women and their babies across the lifecourse. Healthcare providers should address the risk factors for medically indicated C-sections to optimize low-risk delivery methods and improve the survival, health, and well-being of children and their mothers.

A protocol to identify non-classical risk factors for preterm births: the Brazilian Ribeirão Preto and São Luís prenatal cohort (BRISA)

Background

Preterm birth is the main cause of morbidity and mortality during the perinatal period. Classical risk factors are held responsible for only 1/3 of preterm births and no current intervention has produced an appreciable reduction of this event. It is necessary to explore new hypotheses and mechanisms of causality by using an integrated approach, collaboration among research groups and less fragmented theoretical-methodological approaches in order to detect new risk factors and to formulate more effective intervention strategies.

Methods

The study will be conducted on a convenience cohort of Brazilian pregnant women recruited at public and private prenatal health services. A total of 1500 pregnant women in São Luís, and 1500 in Ribeirão Preto, will be invited for an interview and for the collection of biological specimens from the 22nd to the 25th week of gestational age (GA). At the time of delivery they will be reinterviewed. GA will be determined using an algorithm based on two criteria: date of last menstruation (DLM) and obstetric ultrasound (OUS) performed at less than 20 weeks of GA. Illicit drug consumption during pregnancy will be determined using a self-applied questionnaire and the following instruments will be used: perceived stress scale, Beck anxiety scale, screening for depression of the Center of Epidemiological Studies (CES-D), experiences of racial discrimination, social network and social support scale of the Medical Outcomes Study and violence (Abuse Assessment Screening and violence questionnaire of the WHO). Bacterial vaginosis, urinary tract infection and periodontal disease will also be identified. Neuroendocrine, immunoinflammatory and medical intervention hypotheses will be tested. The occurrence of elective cesarean section in the absence of labor will be used as a marker of medical intervention.

Conclusion

Psychosocial, genetic and infectious mechanisms will be selected, since there are indications that they influence preterm birth (PTB). The studies will be conducted in two Brazilian cities with discrepant socioeconomic conditions. The expectation is to identify risk factors for PTB having a greater predictive power than classically studied factors. The final objective is to propose more effective interventions for the reduction of PTB, which, after being tested, might subsidize health policies.

Electronic supplementary material

The online version of this article (doi:10.1186/1742-4755-11-79) contains supplementary material, which is available to authorized users.