Geographic patterns of low birth weight in Hawaii

This study examines areal variations in low birth weight, using the census tract as the unit of analysis. Reports from the 1980 U.S. census were used to develop summary indicators of environmental and socio-economic conditions, including poverty, employment, education and crowding, for 155 census tracts in the state of Hawaii. Maternal socio-demographic, prenatal care utilization, and medical risk indicators and low birth weight percentages for resident, single live births were extracted from the Hawaii 1979-1987 vital record live birth files and aggregated by census tract. Multiple regression analysis was used to develop a model that predicted 61% of the variation among census tracts in the percentage of low birth weight. Patterns of low birth weight were primarily associated with ethnic patterns of maternal residence and single marital status. There was no association between inadequate prenatal care and low birth weight at the census tract level.     

The impact of prenatal maternal stress and optimistic disposition on birth outcomes in medically high-risk women.

A sizable body of evidence indicates that prenatal maternal stress (PNMS) has an adverse impact on birth outcomes, including birth weight and gestational age at delivery. The authors hypothesized that effects of PNMS are attributable in part to dispositions such as pessimism that lead women to view their lives as stressful and that effects of PNMS and disposition on birth outcome are mediated by prenatal health behaviors. Using structural equations modeling procedures, the authors examined prospective impact of PNMS and dispositional optimism on birth weight and gestational age in a medically high-risk sample (N?=?129), controlling for effects of risk and ethnicity. After its strong inverse association with optimism was accounted for, PNMS had no impact on birth outcomes. Women who were least optimistic delivered infants who weighed significantly less, controlling for gestational age. Optimists were more likely to exercise, and exercise was associated with lower risk of preterm delivery. Results suggest that chronic stress in pregnancy may be a reflection of underlying dispositions that contribute to adverse birth outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pregnancy-specific stress, prenatal health behaviors, and birth outcomes.

Objective: Stress in pregnancy predicts earlier birth and lower birth weight. The authors investigated whether pregnancy-specific stress contributes uniquely to birth outcomes compared with general stress, and whether prenatal health behaviors explain this association. Design: Three structured prenatal interviews (N = 279) assessing state anxiety, perceived stress, life events, pregnancy-specific stress, and health behaviors. Main Outcome Measures: Gestational age at delivery, birth weight, preterm delivery (     

Racial differences in birth outcomes: The role of general, pregnancy, and racism stress.

Objective: This study examined the role of psychosocial stress in racial differences in birth outcomes. Design: Maternal health, sociodemographic factors, and 3 forms of stress (general stress, pregnancy stress, and perceived racism) were assessed prospectively in a sample of 51 African American and 73 non-Hispanic White pregnant women. Main Outcome Measures: The outcomes of interest were birth weight and gestational age at delivery. Only predictive models of birth weight were tested as the groups did not differ significantly in gestational age. Results: Perceived racism and indicators of general stress were correlated with birth weight and tested in regression analyses. In the sample as a whole, lifetime and childhood indicators of perceived racism predicted birth weight and attenuated racial differences, independent of medical and sociodemographic control variables. Models within each race group showed that perceived racism was a significant predictor of birth weight in African Americans, but not in non-Hispanic Whites. Conclusions: These findings provide further evidence that racism may play an important role in birth outcome disparities, and they are among the first to indicate the significance of psychosocial factors that occur early in the life course for these specific health outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress and low birth weight: a structural modeling approach using real life stressors

This study presents a structural equation model describing the influence of stressful life experiences on low birth weight. Data were gathered prospectively in two waves from 5295 inner-city women as part of a city-wide preterm birth prevention project. Using interviews and the medical record, over 200 measures were gathered on each mother and her infant, where each measure was included because of its relevance documented in the risk factor literature. Seventeen of these measures reflected real life stressful experiences and through measurement modeling, eleven of these measures were chosen to represent three underlying measures of stress: economic stress, family stress, and the lack of social support. This study incorporates these psychosocial stressors into a full structural equation model to show their influence on addictive behavior and low birth weight. The full model emerged from tests of alternative causal conceptualizations of how these stressors influence each other and low birth weight--whether their influence on low birth weight in simple and direct, or whether their influence is mediated by addictive behaviors. The model was tested on the first wave, a sample of 3205, and cross-validated on the second wave, a sample of 2090. The model shows that economic stress influences both social support and family stress, but has no direct influence on low birth weight: that social support, or its absence, influences addictive behavior, but has no direct influence on low birth weight, and that family stress influences addictive behavior, and consistent with 30 years of research on humans, has no direct influence on low birth weight. Finally, the mother's history of medical risks shows an independent influence on low birth weight, while her age does not. Age, however, shows a strong influence on addictive behavior. The study demonstrates how structural equation modeling can be used to create and test alternative conceptualizations of how stress affects low birth weight. There are strong implications for planners of prenatal care programs.     

Low birth weight and interactions between traditional risk factors

The effects of traditional risk factors on low birth weight were examined, using logistic regression analyses and adjusting for interactions between multiple factors. Data for 11,936 births were obtained from a state birth cohort file. The effect for maternal ethnicity was dependent on education and marital status; the effect of marital status was dependent on ethnicity, medical risk, and level of prenatal care; and the effect of prenatal care was dependent on marital status. Results suggest that examining only main effects and ignoring interactions can produce overgeneralized conclusions about the influence of individual risk factors on low birth weight.     

Prenatal and postnatal anxiety in Mexican women giving birth in Los Angeles.

Examined psychosocial factors related to pre- and postnatal anxiety in 291 pregnant Mexican women (aged 15–38 yrs). Ss completed the State-Trait Anxiety Inventory and questions designed to assess variables such as preferred characteristics of health care providers. Higher prenatal anxiety was associated with less desire for an active role during labor, lower assertiveness, higher pain expectation at delivery, lack of support from family members other than the husband, and preferences for health care providers who are female and Latino. All Ss preferred health care providers who provided good medical explanations and who were knowledgeable, friendly, and sympathetic. Postnatal anxiety was significantly lower than prenatal anxiety. Negative attitudes toward the baby and number of complications during labor and delivery were related to postnatal anxiety adjusted for prenatal anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of long-term pravastatin treatment on spermatogenesis and on adrenal and testicular steroidogenesis in male hypercholesterolemic patients

STUDY OBJECTIVE: To determine if there are significant differences in birth outcomes and survival for infants delivered by certified nurse midwives compared with those delivered by physicians, and whether these differences, if they exist, remain after controlling for sociodemographic and medical risk factors. DESIGN: Logistic regression models were used to examine differences between certified nurse midwife and physician delivered births in infant, neonatal, and postneonatal mortality, and risk of low birthweight after controlling for a variety of social and medical risk factors. Ordinary least squares regression models were used to examine differences in mean birthweight after controlling for the same risk factors. STUDY SETTING: United States. PATIENTS: The study included all singleton, vaginal births at 35-43 weeks gestation delivered either by physicians or certified nurse midwives in the United States in 1991. MAIN RESULTS: After controlling for social and medical risk factors, the risk of experiencing an infant death was 19% lower for certified nurse midwife attended than for physician attended births, the risk of neonatal mortality was 33% lower, and the risk of delivering a low birthweight infant 31% lower. Mean birthweight was 37 grams heavier for the certified nurse midwife attended than for physician attended births. CONCLUSIONS: National data support the findings of previous local studies that certified nurse midwives have excellent birth outcomes. These findings are discussed in light of differences between certified nurse midwives and physicians in prenatal care and labour and delivery care practices. Certified nurse midwives provide a safe and viable alternative to maternity care in the United States, particularly for low to moderate risk women.     

First-trimester growth and the risk of low birth weight

BACKGROUND: Previous studies have demonstrated a correlation between first-trimester size and birth weight. It is not known, however, whether low birth weight is related to first-trimester growth. We sought to determine whether the risk of low birth weight and birth weight that was low for gestational age is related to the size of the embryo or the fetus in the first trimester. METHODS: From a data base of ultrasound records of more than 30,000 pregnancies, we identified women who had no important medical problems, a normal menstrual history, and a first-trimester ultrasound scan in which the crown-rump length of the embryo or fetus had been measured. We examined the relation between the outcome of 4229 pregnancies and the difference between the measured and the expected crown-rump length in the first trimester, expressed as equivalent days of growth. RESULTS: A first-trimester crown-rump length that was two to six days smaller than expected was associated with an increased risk (as compared with a normal or slightly larger than expected crown-rump length) of a birth weight below 2500 g (relative risk, 1.8; 95 percent confidence interval, 1.3 to 2.4), a birth weight below 2500 g at term (relative risk, 2.3; 95 percent confidence interval, 1.4 to 3.8), a birth weight below the fifth percentile for gestational age (relative risk, 3.0; 95 percent confidence interval, 2.0 to 4.4), and delivery between 24 and 32 weeks of gestation (relative risk, 2.1; 95 percent confidence interval, 1.1 to 4.0), but not with delivery between 33 and 36 weeks (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.5). CONCLUSIONS: Suboptimal first-trimester growth may be associated with low birth weight, low birth-weight percentile, and premature delivery.     

Maternal risk factors in infants with very low birth weight

To determine whether maternal risk factors associated with the delivery of very low birth weight infants under 1501 g are different from those associated with low birth weight infants of 1501 to 2500 g, prenatal data on 12,247 deliveries were evaluated. The sample contained 302 very low birth weight infants. Maternal race, age, height, weight, gravidity, parity, past pregnancy performance, and pregnancy complications were analyzed. Factors related to very low birth weight but not to low birth weight infants were previous abortions, previous fetal deaths, and hypertensive vascular disease. Race, maternal height, and prepregnancy weight were not related to very low birth weight but were associated with an increase in low birth weight. There was no significant difference in the rate of very low birth weight or low birth weight by maternal age from 14 to 40 years. These results contradict the concept of a uniform set of predisposing factors for birth of all infants weighing 2500 g or less.     

Maternal corticotropin-releasing hormone levels in the early third trimester predict length of gestation in human pregnancy

OBJECTIVE: Corticotropin releasing hormone, a hypothalamic neuropeptide, plays a major role in regulating pituitary-adrenal function and the physiologic response to stress. During pregnancy corticotropin-releasing hormone is synthesized in large amounts by the placenta and released into the maternal and fetal circulations. Various endocrine, autocrine, and paracrine roles have been suggested for placental corticotropin-releasing hormone. The aim of this study was to prospectively assess the relationship between maternal plasma concentrations of corticotropin-releasing hormone in the early third trimester of pregnancy and the length of gestation in two groups of deliveries, with and without spontaneous labor. STUDY DESIGN: In a sample of 63 women with singleton intrauterine pregnancies, maternal plasma samples were collected between 28 and 30 weeks' gestation and corticotropin-releasing hormone concentrations were determined by radioimmunoassay. Each pregnancy was dated on the basis of last menstrual period and early ultrasonography. Parity, antepartum risk conditions, presence or absence of spontaneous labor, and birth outcomes were abstracted from the medical record. RESULTS: Maternal corticotropin-releasing hormone levels between 28 and 30 weeks' gestation significantly and negatively predicted gestational length (P < .01) after adjustment for antepartum risk. Moreover, subjects who were delivered preterm had significantly higher corticotropin-releasing hormone levels in the early third trimester (P < .01) than did those who were delivered at term. In deliveries preceded by spontaneous onset of labor, maternal third-trimester corticotropin-releasing hormone levels significantly and independently predicted earlier onset of labor (P < .01) and preterm labor (P < .05), whereas in deliveries effected by induction of labor or cesarean delivery, maternal corticotropin-releasing hormone levels were a marker of antepartum risk but not a statistically independent predictor of gestational length. CONCLUSION: These findings support the premise that placental corticotropin-releasing hormone is potentially implicated in the timing of human delivery in at least two ways. First, placental corticotropin-releasing hormone may play a role in the physiology of parturition. Premature or accelerated activation of the placental corticotropin-releasing hormone system, as reflected by precocious elevation of maternal corticotropin-releasing hormone levels, may therefore be associated with earlier onset of spontaneous labor and resultant delivery. Second, placental corticotropin-releasing hormone may be a marker of antepartum risk for preterm delivery and therefore an indirect predictor of earlier delivery. The implications of these findings are discussed in the context of the neuroendocrinology of placental corticotropin-releasing hormone and human parturition. Furthermore, the role of corticotropin-releasing hormone as a possible effector of prenatal stress in producing alterations in the timing of normal delivery is detailed.     

Identification of multiprotein complexes containing DNA replication factors by native immunoblotting of HeLa cell protein preparations with T-antigen-dependent SV40 DNA replication activity

Adequate prenatal care has been linked to improved birth outcomes in general populations but has not been assessed in HIV-infected women. We examined longitudinal claims files and vital statistics records for women in the New York State Medicaid HIV/AIDS data base delivering a singleton from 1985 through 1990. Adequacy of the self-reported number of prenatal visits was assessed by the Kessner index. In logistics models, we estimated the association of prenatal care, illicit drug use, and other maternal characteristics with three outcomes; low birth weight, preterm birth, and small-for-gestational-age. Of 2,254 singletons delivered by this HIV-infected cohort, 28% were low birth weight, 23% were preterm birth, and 20% were small for gestational age. Two-thirds had inadequate prenatal care. Non-drug users had 57 and 26% lower adjusted odds of low birth weight and preterm delivery than drug users. The adjusted odds of low birth weight and preterm birth for women with an adequate number of prenatal visits were, respectively, 48 and 21% lower than for women with inadequate care. Adequate prenatal care was also associated with a 43% reduction in the odds of small-for-gestational-age. An adequate number of prenatal visits by women in this HIV cohort was associated with a significant reduction in all three adverse birth outcomes, but most had inadequate prenatal care. These data support strengthening efforts to bring pregnant, HIV-infected women into care.     

Estimated gains in birth weight associated with reductions in smoking during pregnancy

OBJECTIVE: To compare the estimated effect on birth weight of reductions in maternal cigarette consumption and urinary cotinine during pregnancy. STUDY DESIGN: An observational study of 641 women with complete data on cigarette consumption, urinary cotinine and infant birth weight. Correlation and regression analyses were used to examine relationships between birth weight, cigarette consumption and urinary cotinine at first and last prenatal visits. RESULTS: Correlations of cigarette consumption and urinary cotinine with infant birth weight were -.23 and -.30 (first visit) and -.26 and -.31 (last visit); all P values were < .001. The regression equation relating urinary cotinine concentrations at first and last visits to infant birth weight explained a significantly larger proportion of the variability in birth weight than the equation relating cigarette consumption at these visits to infant birth weight, 11% vs. 7%, P = .04. Among continuing smokers, both equations predicted gains in birth weight in association with reductions in cigarette consumption, but quitting smoking before the first visit was associated with the most weight gain. As compared to the average infant birth weight of a woman who smoked 20 cigarettes per day throughout pregnancy, the estimated gain in birth weight would be 105 g if she cut down by 10 cigarettes per day after the first visit, 210 g if she quit after this visit and 310 g if she quit before the first visit. CONCLUSION: For women still smoking at their first prenatal visit, infant birth weight is already compromised, but subsequent reductions in cigarette consumption are associated with gains in birth weight. For women who cannot quit smoking, these reductions need to be substantial if increases in birth weight of > 100 g are to be achieved.     

Regulatory sequences required for hst-1 expression in embryonal carcinoma cells

OBJECTIVE: To examine the relationship of subfertility with miscarriage, low birth weight, and preterm delivery. DESIGN: Comparison of time to pregnancy distributions between pregnancies that had different outcomes. Three comparisons were made: (a) miscarriages with live births; within live births, (b) low birth weight infant (up to 2,500 grams) or not low birth weight; (c) preterm birth (37 weeks or less) or not preterm. Cox regression was used to adjust for covariates. POPULATION: All first pregnancies were analyzed from the National Child Development Study, a large survey of young adults aged 33 years, which is nationally representative of the British-born population. MAIN OUTCOME MEASURES: The distribution of the time taken to conceive (time to pregnancy), miscarriage, birth weight, and preterm delivery. RESULTS: Pregnancies that ended in miscarriage tended to take 23% longer to conceive, after adjustment for the other variables. Pregnancies that resulted in preterm delivery tended to take 15% longer to conceive. There was no statistically significant association with low birth weight. CONCLUSIONS: Delay in time to conception is a risk factor for poor obstetric outcome, irrespective of medical intervention.     

Social cognition and adjustment in children at risk for psychopathology.

This study tested two models of how social cognition affects the link between child adjustment and two family risk factors, maltreatment and parental psychopathology. The mediation model proposed that social cognition mediates the link between the risk factors and maladjustment. The compensation model proposed that social cognition compensates for the risk factors. Social cognitive measures were social problem-solving competency and hostile attributional and response biases. In 83 Ss (7 to 14 years of age), maltreatment, but not parental psychopathology, predicted aggression and peer rejection. The adjustment of Ss with a disturbed parent depended on maltreatment status. Risk status did not predict social cognition, so the mediation model was not supported. Consistent with the compensation model, Ss with high social cognitive skills were better adjusted regardless of risk status. Implications for high-risk research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stressful events and individual beliefs as correlates of economic disadvantage and aggression among urban children.

Examined 3 factors that were hypothesized to increase risk for aggression among urban children: economic disadvantage, stressful events, and individual beliefs. Ss were 1,935 African American, Hispanic, and White elementary-school boys and girls assessed over a 2-yr period. Individual poverty (INP) and aggression were only significant for the White Ss, with significant interactions between individual and community poverty for the other 2 ethnic groups. A linear structural model to predict aggression from the stress and beliefs variables, INP predicted stress for African American Ss and predicted beliefs supporting aggression for Hispanic Ss. For all ethnic groups, both stress and beliefs contributed significantly to the synchronous prediction of aggression, and for the Hispanic children, the longitudinal predictions were also significant. Findings are discussed in terms of their implications for preventive interventions in multiethnic, inner-city communities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological adaptation and birth outcomes: The role of personal resources, stress, and sociocultural context in pregnancy.

Prenatal psychosocial predictors of infant birth weight and length of gestation were investigated in a prospective study of 120 Hispanic and 110 White pregnant women. Hypotheses specifying that personal resources (mastery, self-esteem, optimism), prenatal stress (state and pregnancy anxiety), and sociocultural factors (income, education, ethnicity) would have different effects on birth outcomes were tested using structural equation modeling. Results confirmed that women with stronger resources had higher birth weight babies (β?=?–.21), whereas those reporting more stress had shorter gestations (β?=?–.20). Resources were also associated with lower stress (β?=?–.67), being married, being White, having higher income and education, and giving birth for the first time. There was no evidence that resources buffered the effects of stress. The importance of personal resources in pregnancy is highlighted along with implications for understanding the etiology of adverse birth outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Racial disparity in pregnancy outcomes: analysis of black and white teenage pregnancies

The pregnancies of black women are complicated by adverse outcomes such as prematurity and low birth weight at twice the rate of complications in pregnancies of white women. Although the cause of this racial disparity is unknown, it is most likely multifactorial. The disparity in outcomes has been found in many studies despite implementation of controls for the factors of age, socioeconomic status, and access to health care. We hypothesized that the increased incidence of adverse outcomes may be strongly affected by adequacy of prenatal care. We investigated the effects of comprehensive prenatal care delivered at the University of North Carolina-Chapel Hill Teenage Obstetric Clinic. The gestational age at the onset of prenatal care and the mean number of prenatal visits were the same for black and white teenagers. Among 183 teenagers we found no significant difference between black and white pregnancies for the outcomes of premature labor, premature delivery, fetal death, neonatal mortality, or hypertensive diseases. The mean gestational age at delivery was 38.3 weeks and 39.1 weeks for black and white women, respectively. The mean birth weight was 3126 gm and 3272 gm for black and white women, respectively. There was a trend (p < 0.09) toward more low birth weight infants in white women: 7% for black infants and 12% for white infants. We believe that comprehensive prenatal care significantly lessens the racial disparity in pregnancy outcomes between black and white adolescent women.     

Conceptual model for maternal behavior among polydrug cocaine-using mothers: The role of postnatal cocaine use and maternal depression.

This study examined the association between maternal cocaine use and maternal behavior and tested a conceptual model predicting maternal insensitivity during mother-infant interactions. Participants included 130 mother-infant dyads (68 cocaine-exposed and 62 noncocaine-exposed) who were recruited after birth and assessed at 4-8 weeks of infant age. Results of model testing indicated that when the effects of prenatal cocaine use were examined in the context of polydrug use, maternal psychopathology, maternal childhood history, and infant birth weight, only postnatal cocaine use and maternal depression/anxiety were unique predictors of maternal insensitivity during mother-infant interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)