Michael C. Lu

Racial and ethnic disparities in birth outcomes: a life-course perspective.

Background: In the United States, Black infants have significantly worse birth outcomes than do White infants. The cause of these persisting racial disparities remains unexplained. Most extant studies focus on differential exposures to protective and risk factors during pregnancy, such as current socioeconomic status, maternal risky behaviors, prenatal care, psychosocial stress, or perinatal infections. These risk factors during pregnancy, however, do not adequately account for the disparities. Methods: We conducted a literature review for longitudinal models of health disparities, and presented a synthesis of two leading models, using a life-course perspective. Traditional risk factors during pregnancy are then reexamined within their life-course context. We conclude with a discussion of the limitations and implications of the life-course perspective for future research, practice, and policy development. Results: Two leading longitudinal models of health disparities were identified and discussed. The early programming model posits that exposures in early life could influence future reproductive potential. The cumulative pathways model conceptualizes decline in reproductive health resulting from cumulative wear and tear to the bodys allostatic systems. We propose a synthesis of these two models, using the life-course perspective. Disparities in birth outcomes are the consequences of differential developmental trajectories set forth by early life experiences and cumulative allostatic load over the life course. Conclusions: Future research on racial disparities in birth outcomes needs to examine differential exposures to risk and protective factors not only during pregnancy, but over the life course of women. Eliminating disparities requires interventions and policy development that are more longitudinally and contextually integrated than currently prevail.

Lifecourse health development: past, present and future.

During the latter half of the twentieth century, an explosion of research elucidated a growing number of causes of disease and contributors to health. Biopsychosocial models that accounted for the wide range of factors influencing health began to replace outmoded and overly simplified biomedical models of disease causation. More recently, models of lifecourse health development (LCHD) have synthesized research from biological, behavioral and social science disciplines, defined health development as a dynamic process that begins before conception and continues throughout the lifespan, and paved the way for the creation of novel strategies aimed at optimization of individual and population health trajectories. As rapid advances in epigenetics and biological systems research continue to inform and refine LCHD models, our healthcare delivery system has struggled to keep pace, and the gulf between knowledge and practice has widened. This paper attempts to chart the evolution of the LCHD framework, and illustrate its potential to transform how the MCH system addresses social, psychological, biological, and genetic influences on health, eliminates health disparities, reduces chronic illness, and contains healthcare costs. The LCHD approach can serve to highlight the foundational importance of MCH, moving it from the margins of national debate to the forefront of healthcare reform efforts. The paper concludes with suggestions for innovations that could accelerate the translation of health development principles into MCH practice.

The Contribution of Maternal Stress to Preterm Birth: Issues and Considerations

Preterm birth represents the most significant problem in maternal-child health, with maternal stress identified as a variable of interest. The effects of maternal stress on risk of preterm birth may vary as a function of context. This article focuses on select key issues and questions highlighting the need to develop a better understanding of which particular subgroups of pregnant women may be especially vulnerable to the potentially detrimental effects of maternal stress, and under what circumstances and at which stages of gestation. Issues related to the characterization and assessment of maternal stress and candidate biologic mechanisms are addressed.

Preventing low birth weight: is prenatal care the answer?

Objectives: To review the evidence of effectiveness of prenatal care for preventing low birth weight (LBW). Methods: We reviewed original research, systematic reviews, meta-analyses and commentaries for evidence of effectiveness of the three core components of prenatal care - risk assessment, health promotion and medical and psychosocial interventions - for preventing the two constituents of LBW: preterm birth and intrauterine growth restriction (IUGR). Results: Clinical risk assessment will fail to identify the majority of pregnancies at risk for preterm delivery or IUGR. While biophysical and biochemical modalities appear promising, their cost-effectiveness has not been demonstrated, nor can their routine use be recommended in the absence of effective interventions. Smoking cessation programs appear to be modestly effective. There is insufficient evidence to conclude a benefit for nutrition interventions, work counseling or preterm birth education. Only antenatal corticosteroid therapy has demonstrated a clear benefit in the tertiary prevention of preterm delivery. Interventions for which there is insufficient evidence to conclude a benefit include bed rest, hydration, sedation, cerclage, progesterone supplementation, antibiotic treatment, tocolysis without concomitant use of corticosteroids, thyrotropin-releasing hormone, psychosocial support and home visitation. Additionally, there is a paucity of evidence supporting the effectiveness of prenatal interventions, such as low-dose aspirin, bed rest, maternal hyperoxygenation, plasma volume expansion and antenatal fetal assessment, in preventing IUGR or its associated morbidity and mortality. Conclusions: Neither preterm birth nor IUGR can be effectively prevented by prenatal care in its present form. Preventing LBW will require reconceptualization of prenatal care as part of a longitudinally and contextually integrated strategy to promote optimal development of womens reproductive health not only during pregnancy, but over the life course.

Provider encouragement of breast-feeding: evidence from a national survey.

Objective To examine the influence of provider encouragement on breast-feeding among women of different social and ethnic backgrounds in the United States. Methods A nationally representative sample of 2017 parents with children younger than 3 years was surveyed by telephone. The responses of the 1229 women interviewed were included in the analysis. Respondents were asked to recall whether their physicians or nurses had encouraged or discouraged them from breast-feeding. The effects of provider encouragement on breast-feeding initiation and duration were evaluated by multivariate logistic regression. The sample was then stratified to allow subset analyses by race and ethnicity, education, income class, age group, and marital status. Results More than one-third (34.4%) of respondents did not initiate breast-feeding. Three-fourths (73.2%) of women reported having been encouraged by their physicians or nurses to breast-feed; 74.6% of women who were encouraged initiated breast-feeding, compared with only 43.2% of those who were not encouraged (P < 0.001). Women who were encouraged to breast-feed were more than four times (relative risk 4.39; 95% confidence interval 2.96, 6.49) as likely to initiate breast-feeding as women who did not receive encouragement. The influence of provider encouragement was significant across all strata of the sample. In populations traditionally less likely to breast-feed, provider encouragement significantly increased breast-feeding initiation, by more than threefold among low-income, young, and less-educated women; by nearly fivefold among black women; and by nearly 11-fold among single women. Conclusion Provider encouragement significantly increases breast-feeding initiation among American women of all social and ethnic backgrounds.

Prenatal Programming of Childhood Overweight and Obesity

Objective: To review the scientific evidence for prenatal programming of childhood overweight and obesity, and discuss its implications for MCH research, practice, and policy.Methods: A systematic review of observational studies examining the relationship between prenatal exposures and childhood overweight and obesity was conducted using MOOSE guidelines. The review included literature posted on PubMed and MDConsult and published between January 1975 and December 2005. Prenatal exposures to maternal diabetes, malnutrition, and cigarette smoking were examined, and primary study outcome was childhood overweight or obesity as measured by body mass index (BMI) for children ages 5 to 21.Results: Four of six included studies of prenatal exposure to maternal diabetes found higher prevalence of childhood overweight or obesity among offspring of diabetic mothers, with the highest quality study reporting an odds ratio of adolescent overweight of 1.4 (95% CI 1.0–1.9). The Dutch famine study found that exposure to maternal malnutrition in early, but not late, gestation was associated with increased odds of childhood obesity (OR 1.9, 95% CI 1.5–2.4). All eight included studies of prenatal exposure to maternal smoking showed significantly increased odds of childhood overweight and obesity, with most odds ratios clustering around 1.5 to 2.0. The biological mechanisms mediating these relationships are unknown but may be partially related to programming of insulin, leptin, and glucocorticoid resistance in utero.Conclusion: Our review supports prenatal programming of childhood overweight and obesity. MCH research, practice, and policy need to consider the prenatal period a window of opportunity for obesity prevention.

Preconception Care Between Pregnancies: The Content of Internatal Care

For more than two decades, prenatal care has been a cornerstone of our nation’s strategy for improving pregnancy outcomes. In recent years, however, a growing recognition of the limits of prenatal care and the importance of maternal health before pregnancy has drawn increasing attention to preconception and internatal care. Internatal care refers to a package of healthcare and ancillary services provided to a woman and her family from the birth of one child to the birth of her next child. For healthy mothers, internatal care offers an opportunity for wellness promotion between pregnancies. For high-risk mothers, internatal care provides strategies for risk reduction before their next pregnancy. In this paper we begin to define the contents of internatal care. The core components of internatal care consist of risk assessment, health promotion, clinical and psychosocial interventions. We identified several priority areas, such as FINDS (family violence, infections, nutrition, depression, and stress) for risk assessment or BBEEFF (breastfeeding, back-to-sleep, exercise, exposures, family planning and folate) for health promotion. Women with chronic health conditions such as hypertension, diabetes, or weight problems should receive on-going care per clinical guidelines for their evaluation, treatment, and follow-up during the internatal period. For women with prior adverse outcomes such as preterm delivery, we propose an internatal care model based on known etiologic pathways, with the goal of preventing recurrence by addressing these biobehavioral pathways prior to the next pregnancy. We suggest enhancing service integration for women and families, including possibly care coordination and home visitation for selected high-risk women. The primary aim of this paper is to start a dialogue on the content of internatal care.

Severity of homelessness and adverse birth outcomes.

Predictors and the prevalence of adverse birth outcomes among 237 homeless women interviewed at 78 shelters and meal programs in Los Angeles in 1997 were assessed. It was hypothesized that they would report worse outcomes than national norms, that African Americans would report the worst outcomes because of their greater risk in the general population, and that homelessness severity would independently predict poorer outcomes beyond its association with other adverse conditions. Other predictors included reproductive history, behavioral and health-related variables, psychological trauma and distress, ethnicity, and income. African Americans and Hispanics reported worse outcomes than are found nationally, and African Americans reported the worst outcomes. In a predictive structural equation model, severity of homelessness significantly predicted low birth weight and preterm births beyond its relationship with prenatal care and other risk factors.

The clinical content of preconception care: preconception care for men.

Little attention has been given to mens preconception health and health care. This paper reviews the key elements of an approach to optimizing the preconception health status of men. Preconception care for men is important for improving family planning and pregnancy outcomes, enhancing the reproductive health and health behaviors of their female partners, and preparing men for fatherhood. Most importantly, preconception care offers an opportunity, similar to the opportunity it presents for women, for disease prevention and health promotion in men. Currently, no consensus exists on service delivery of preconception care for men--who should provide preconception care to whom, where, when, and how, and there are significant barriers to this care including the organization, financing, training, and demand. Finally, much more research on the content and how to effectively market and implement preconception care for men is needed.

Variations in the Incidence of Postpartum Hemorrhage Across Hospitals in California

Objective: Because postpartum hemorrhage may result from factors related to obstetrical practice patterns, we examined the variability of postpartum hemorrhage and related risk factors (obstetrical trauma, chorioamnionitis, and protracted labor) across hospital types and hospitals in California. Methods: Linked birth certificate and hospital discharge data from 507,410 births in California in 1997 were analyzed. Cases were identified using International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes. Comparisons were made across hospital types and individual hospitals. Risk adjustments were made using 1) sample restriction to a subset of 324,671 low-risk women, and 2) Bayesian hierarchical logistic regression model to simultaneously quantify the effects of patient-level and hospital-level risk factors. Results: Postpartum hemorrhage complicated 2.4% of live births. The incidence ranged from 1.6% for corporate hospitals to 4.9% for university hospitals in the full sample, and from 1.4% for corporate hospitals to 3.9% for university hospitals in the low-risk sample. Low-risk women who delivered at government, HMO and university hospitals had two- to threefold increased odds (odds ratios 1.98 to 2.71; 95% confidence sets ranged from 1.52 to 4.62) of having postpartum hemorrhage compared to women who delivered at corporate hospitals, irrespective of patient-level characteristics. They also had significantly higher rates of obstetrical trauma and chorioamnionitis. Greater variations were observed across individual hospitals. Conclusion: The incidence of postpartum hemorrhage and related risk factors varied substantially across hospital types and hospitals in California. Further studies using primary data sources are needed to determine whether these variations are related to the processesof care.