Biomedical subjects

R J David

Publications and source records attributed to R J David.

At least 19 recordsLinked to original sources

PubMed2000

Enigma of maternal race and infant birth weight: a population-based study of US-born Black and Caribbean-born Black women.

The authors used 1985-1990 Illinois' vital records to determine the low birth weight components of infants delivered to US-born Black women, Caribbean-born Black women, and US-born White women. The moderately low birth weight rate (1,500-2,499 g) was 10% for infants with US-born Black mothers (n = 67,357) and 6% for infants with Caribbean-born mothers (n = 2,265) compared with 4% for infants with US-born White mothers (n = 34,124); the relative risk equaled 2.7 (95% confidence interval (CI): 2.5, 2.8) and 1.7 (95% CI: 1.4, 2.0), respectively. The very low birth weight rate (<1,500 g) was 2.6% for infants delivered to US-born Black women and 2.4% for infants to Caribbean-born women compared with 0.7% for infants to US-born White women; the relative risk equaled 3.6 (95% CI: 3.1, 4.1) and 3.3 (95% CI: 2.5, 4.4), respectively. Among the lowest risk mothers, the relative risk of moderately low birth weight for infants with US-born Black mothers and Caribbean-born mothers (compared with US-born White mothers) was 2.7 (95% CI: 2.1, 3.4) and 1.2 (95% CI: 0.4, 3.1), respectively; the relative risk of very low birth weight for infants with US-born Black mothers and Caribbean-born mothers was 6.7 (95% CI: 3.8, 12) and 4.2 (95% CI: 1.0, 18), respectively. The authors conclude that Caribbean-born women and US-born Black women have disparate moderate rates but equivalent very low birth weight rates.

Adult↗

PubMed2000

Low-income African-American mothers' perception of exposure to racial discrimination and infant birth weight.

We performed a hospital-based case-control study of African-American mothers to explore the relation between a mother's perception of exposure to racial discrimination during pregnancy and very low birth weight. We administered a structured questionnaire to low-income mothers of very low birth weight (<1500 gm; N = 25) and non-low birth weight (>2500 gm; N = 60) infants. The unadjusted and adjusted odds ratio of very low birth weight for maternal exposure to racial discrimination were 1.9 (0.5-6.6) and 3.2 (0.9-11.3), respectively. We conclude that maternal perception of exposure to racial discrimination during pregnancy may be associated with very low birth weight in their infants.

Black or African American↗

PubMed1998

African-American mothers' perception of their residential environment, stressful life events, and very low birthweight.

We performed a hospital-based case-control study of African-American mothers to explore the relation between a mother's perception of her own residential environment and very low birthweight. We administered a structured questionnaire to mothers of very-low-birthweight (<1,500 gm; N = 28) and critically ill non-low-birthweight (>2,500 gm; N = 52) infants. The groups had similar sociodemographic characteristics. The vast majority of participants were unmarried and had no private medical insurance. The odds ratios of very low birthweight fluctuated between 1.7 and 3.2 for African-American mothers who rated their neighborhoods (in terms of police protection, protection of property, personal safety, friendliness, delivery of municipal services, cleanliness, quietness, and schools) unfavorably. Additionally, the odds ratio of very low birthweight for mothers exposed to three or more stressful life events during pregnancy was 3.1 (95% confidence interval = 1.2-8.2). We conclude that African-American mothers' perception of their residential environment and frequency of stressful life events are associated with very low birthweight in their infants.

Adolescent↗

PubMed1997

Relation of parental birth weights to infant birth weight among African Americans and whites in Illinois: a transgenerational study.

The authors used a transgenerational data set of Illinois vital records to ascertain the relation between parental birth weights and infant birth weight. The infant generation consisted of all African Americans and whites born in Illinois during 1989-1991. The parent generation included the mothers and fathers who were also born in Illinois between 1956 and 1975. In the infant cohort, the rate of low birth weight (LBW) (<2,500 g) was 11.7% for African Americans (n = 15,287) versus 5.0% for whites (n = 117,708) (relative risk (RR) = 2.3, 95% confidence interval (CI) 2.2-2.5). For African Americans, the LBW rate was 17.9% among those born to LBW mothers (n = 1,943) compared with 10.8% among those born to non-LBW mothers (n = 13,344) (RR = 1.8, 95% CI 1.6-1.9). For whites, the LBW rate was 8.5% among those born to LBW mothers (n = 2,174) compared with 4.8% among those born to non-LBW mothers (n = 115,534) (RR = 1.7, 95% CI 1.6-2.0). A weaker association was observed between paternal birth weight and infant birth weight. The authors conclude that parental birth weights are important risk factors for LBW in both African Americans and whites.

Adult↗

PubMed1997

Differing birth weight among infants of U.S.-born blacks, African-born blacks, and U.S.-born whites.

BACKGROUND: In the United States, the birth weights of infants of black women are lower than those of infants of white women. The extent to which the lower birth weights among blacks are related to social or genetic factors is unclear. METHODS: We used vital records for 1980 through 1995 from Illinois to determine the distribution of birth weights among infants born to three groups of women -- U.S.-born blacks, African-born blacks, and U.S.-born whites. RESULTS: The mean birth weight of 44,046 infants of U.S.-born white women was 3446 g, that of 3135 infants of African-born black women was 3333 g, and that of 43,322 infants of U.S.-born black women was 3089 g. The incidence of low birth weight (weight less than 2500 g) was 13.2 percent among infants of U.S.-born black women and 7.1 percent among infants of African-born black women, as compared with 4.3 percent among infants of U.S.-born white women (relative risks, 3.1 and 1.6, respectively). Among the women at lowest risk (those 20 to 39 years old, with 12 years of education for themselves and their spouses, early prenatal care, gravida 2 or 3, and no previous fetal loss), the rate of low birth weight in infants of African-born black women (3.6 percent) was closer to the rate in infants of U.S.-born white women (2.4 percent), and the rate in infants of U.S.-born black women remained high (7.5 percent). CONCLUSIONS: The birth-weight patterns of infants of African-born black women and U.S.-born white women are more closely related to one another than to the birth weights of infants of U.S.-born black women.

Africa↗

PubMed1997

Very-low-birthweight infants and income incongruity among African American and white parents in Chicago.

OBJECTIVES: Illinois vital records for 1982/1983 and US census income data for 1980 were analyzed to ascertain the relationship of income incongruity, race, and very low birthweight. METHODS: Positive income incongruity was considered present when study infants resided in wealthier neighborhoods than non-Latino Whites at the same level of parental education attainment and marital status. RESULTS: The odds ratios of very low birthweight for African Americans (n = 44,266) and Whites (n = 27,139) who experienced positive income incongruity were 0.7 (95% confidence interval [CI] = 0.5, 0.9) and 0.6 (95% CI = 0.5, 0.9), respectively. CONCLUSIONS: Positive income incongruity is associated with lower race-specific rates of very low birthweight.

Adolescent↗

PubMed1997

Adequacy of prenatal care utilization, maternal ethnicity, and infant birthweight in Chicago.

This study examines the extent to which the Adequacy of Prenatal Care Utilization Index explains the racial disparity in infant birthweight. A stratified analysis was performed on all African-American, Mexican-American, and non-Latino white singleton infants born in Chicago, Illinois between 1982 and 1983. This older cohort was chosen to avoid the confounding effect of cocaine associated with its increased local availability after 1985. The adequacy of prenatal care utilization varied by race and place of residence. However, in moderate-income areas (median family annual income of $20,001 to $30,000), the African-American birthweight disadvantage persisted among infants born to mothers who received adequate and adequate-plus prenatal care. Similarly, although race-specific term (gestational age > 37 weeks) low birthweight rates declined as prenatal care usage rose, the position of African Americans relative to Mexican Americans and whites was essentially unchanged. These findings indicate that maternal race or some factor closely related to it affects pregnancy outcome regardless of the adequacy of prenatal care utilization.

Black or African American↗

PubMed1997

Urban violence and African-American pregnancy outcome: an ecologic study.

OBJECTIVES: To ascertain the extent to which residence in violent communities is an independent risk factor for adverse pregnancy outcomes among impoverished (census tract median family income < $10,000/year) African-American mothers. DESIGN: A cross-sectional study was performed. METHODS: We performed multivariate analyses on 1983 Illinois vital records, Chicago Police Department violent crime rates, and 1980 United States Census income data. RESULTS: African-American mothers who resided in the most violent communities had a low birth weight rate of 16% compared to 12% for infants (N = 315) with mothers who lived in the least violent communities; odds ratio = 1.5 (1.0-2.1). The proportion of small-for-gestational-age infants was substantially elevated in mothers who resided in the most violent communities compared to mothers who lived in the least violent communities: 7% vs. 3%; odds ratio = 2.6 (1.5-2.1). In multivariate logistic regression models that controlled for individual risk factors, the adjusted odds ratios for low birth weight and small-for-gestational-age infants among mothers who resided in the most (compared to the least) violent communities were 1.1 (0.9-1.2) and 1.5 (1.1-2.1), respectively. CONCLUSION: We conclude that a community's violent crime rate is associated with intrauterine growth retardation among infants born to African-American women.

Adolescent↗

PubMed1996

Birth weight has increased over a generation.

The authors examined secular trends in birth weight for a geographically defined population over 40 years, controlling for migration effects. The study was an analysis first of all Illinois births between 1950 and 1990 and second of a subset of births for which two succeeding generations were born in the state. For the latter analysis, the authors created a transgenerational birth file by linking infant birth records to the birth records of their parents. Shifts toward bigger babies were observed in both data sets. For black births, the shift was larger in the transgenerational file; but for white infants, similar magnitude shifts were observed in the two files. In both analyses, there were larger birth weight shifts for whites than for blacks. Mean birth weight increases within families ranged from 33 g (black male infants compared with their fathers) to 74 g (white female infants and their mothers). The rate of births at very low birth weight (< 1,500 g) decreased by 6% in the white population but increased by 56% in blacks. Results presented in this study demonstrate that even when migratory effects are eliminated, a secular increase in birth weight is observed. Moreover, the left tall of the birth weight distribution does not always follow the same temporal trend observed for the mode.

Black or African American↗

PubMed1993

Race and birthweight in biracial infants.

OBJECTIVES: The purpose of the study was to determine the role of infant race as a determinant of the Black-White disparity in low birthweight (< 2500 g). METHODS: Univariate analysis and multivariate logistic regression were performed on Illinois vital records from 1982 and 1983 and on 1980 United States census income data. RESULTS: Fourteen percent of the infants born to Black mothers and White fathers were of low birthweight, compared with 9% of infants born to White mothers and Black fathers and 6% of a random sample of White infants. Both groups of biracial infants were more likely to have been born to unmarried mothers and to reside in very low-income (< $10,000 per year) census tracts than were White infants. When all confounding variables were entered into a logistic model, the adjusted odds ratio of low birthweight for biracial infants born to Black mothers and White fathers equaled 1.4. When biracial infants born to White mothers and Black fathers were compared with White infants, the adjusted odds ratio of low birthweight equaled 1.0. CONCLUSIONS: Paternal and consequent infant race does not affect the birthweight distribution of those born to White mothers and Black fathers. Unidentified factors closely related to maternal race underlie the Black-White disparity in infant birthweight.

Adult↗

PubMed1992

Differences in neonatal mortality by race, income, and prenatal care.

To determine the extent to which the social and physical environment affects the association between prenatal care and black pregnancy outcome in Chicago, we performed a stratified analysis of 1982-1983 Illinois vital records and 1980 United States census income data. Median family income of the mother's census tract was used as the ecologic variable. In very-low-income census tracts (less than $10,000 per year), 40% of blacks and 47% of whites received adequate prenatal care. There was no racial disparity in the percentage of low-birth-weight infants attributed to inadequate prenatal care among poor mothers. For mothers who resided in moderate-income areas ($20,001 to $30,000 per year), 50% of blacks and 67% of whites received adequate prenatal care. Although adequate (compared to inadequate) prenatal care was associated with improved birthweight distribution independent of community income, only in moderate-income areas was it related to black neonatal survival. For term black infants who received adequate prenatal care, residence in impoverished areas was associated with a nearly fourfold greater neonatal mortality rate (deaths per 1000 live births): 5/1000 vs 1/1000; RR = 3.8 (1.3-11.0). We conclude that place of residence is an important risk factor for black neonatal mortality.

Black or African American↗

PubMed1991

Bad outcomes in black babies: race or racism?

The gap between black and white infant death rates in the United States has grown over the last three decades. Epidemiologic and medical studies by investigators seeking to understand and reverse this adverse trend have been unsuccessful. Researchers have looked in vain for the combination of social and environmental risk factors that are more common among blacks and would therefore explain this group's poor reproductive outcomes. The implicit alternate hypothesis is genetic differences between blacks and whites. In fact, there is more of a gap between black and white mothers of higher socioeconomic position than between overall black and white rates without socioeconomic stratification. An alternative to the genetic theory explains these results, however, on the basis of social risk factors that, because of the presence of widespread discrimination in the society under study, apply only to blacks. Such factors are the effects of racism, not race per se. Several lines of research are needed to investigate the effects of racism on perinatal outcomes, including studies on psychophysiological reactions to racial discrimination and on ethnic group differences in coping mechanisms, social supports, and physical environment. Analysis of trends over the past 37 years indicates that improvements in white (and total US) infant mortality rates cannot be anticipated until the racial gap is closed.

Black or African American↗

PubMed1990

Differential survival rates among low-birth-weight black and white infants in a tertiary care hospital.

Birth-weight-specific mortality is lower for black prematures than white prematures of similar low birth weight. The reason for this well-recognized phenomenon is unknown. We investigated the extent to which black and white infants differ in their gestational maturity and incidence of potentially lethal risk factors, and the effect these factors might have on differential mortality risk. The population studied comprised babies born alive in a tertiary care hospital with birth weights from 700 to 1800 g over a 4 1/2-year period. Univariate analysis showed no important difference between races for the incidence of lung disease, Apgar scores, birth weight, or gestational age. Infants with a birth weight below the 10th percentile (small for gestational age) were more likely to be black, and infants with a birth weight above the 90th percentile (large for gestational age) who had a survival disadvantage were usually white. The crude odds ratio for the white race was 1.79 (1.18-2.73). When the demographic, morbidity, and growth variables were put into a logistic model, the odds ratio changed only slightly, to 1.52 (1.14-2.03). We conclude that the majority of the black-white difference in birth-weight-specific survival is not due to a higher incidence of black small-for-gestational-age infants, nor is it due to differences in major morbidities associated with death.

Academic Medical Centers↗

PubMed1990

The differential effect of traditional risk factors on infant birthweight among blacks and whites in Chicago.

We analyzed 103,072 White and Black births in Chicago from the 1982 and 1983 Illinois vital records, using 1980 median family income of mother's census tract as an ecologic variable. Thirty-one percent of Blacks and 4 percent of Whites resided in census tracts with median family incomes less than or equal to $10,000/year. Only 2 percent of Black mothers, compared to 16 percent of White mothers, lived in areas where the median family income was greater than $25,000/year. Among Blacks with incomes less than or equal to $10,000/year, maternal age, education, and marital status had minimal predictive power on the incidence of low birthweight (LBW) infants. Among high-risk mothers in the poorest areas the proportion of LBW infants in Blacks and Whites was less divergent than in higher income areas. Independent of residential area, low-risk Whites had half the occurrence of LBW infants as Blacks. We conclude that the extremes of residential environments show dramatic racial disparity in prevalence, yet the few low-risk Blacks still do less well than low-risk Whites. Traditional risk factors do not completely explain racial differences in neonatal outcome.

Adult↗

PubMed1988

The Northwestern University Triplet Study. III: Neonatal outcome.

Limited data suggest that cesarean section (CS) may be the preferred method of delivery for triplets. Despite this, it is also felt that the third triplet is at great risk at delivery. We reviewed our experience of 14 triplet pregnancies at Northwestern University between 1981 and 1985. All deliveries were attended by neonatal teams in sufficient number to resuscitate each infant. Of the 14 pregnancies, two ended in previable loss. Thirty-six infants were born from 12 pregnancies of a mean gestational age of 33 weeks (28-38 weeks). The overall survival was 97.3%. Two women delivered vaginally. While the first was successful, the second resulted in vaginal delivery of the first two triplets followed by emergency CS for the third. That infant had a cord blood pH of 6.96 (BE-19), was resuscitated and survived. All 10 CS were successful. The mean cord blood gas tensions and pH were normal. In addition, Apgar scores, the requirement for mechanical ventilation or supplemental oxygen, and mortality did not differ between the first and third-born triplet. These observations suggest that CS was beneficial. Our very low mortality rate supports the concept that CS delivery and aggressive neonatal resuscitation and therapy greatly enhances survival.

Birth Order↗

PubMed1986

Effects of birth weight and ethnicity on incidence of sudden infant death syndrome.

Sudden infant death syndrome occurs with increased frequency in low birth weight infants and in black infants. The degree to which the higher LBW rate among blacks might explain this higher SIDS rate is unknown. To address this question, we analyzed the 1233 SIDS deaths that occurred among 252,376 neonatal survivors in Cook County from 1975 to 1980, using computer-coded matched infant birth and death records. Birth weight and ethnic group were identified. The overall SIDS rates in blacks, Hispanics, and whites were 5.1, 1.2, and 1.3/1000 neonatal survivors, respectively. Within each ethnic group, the SIDS rates increased progressively with decreasing birth weight. Within the less than or equal to 1500 gm birth weight groups, the SIDS rates were 16.4, 3.9, and 5.5/1000 neonatal survivors in blacks, Hispanics, and whites. Using direct standardization, we found that 27% of the SIDS rate disparity between blacks and whites could be explained by the higher LBW rate in blacks (14% vs 6% in whites). The good outcomes in both LBW and SIDS rates for the Hispanic population were unexpected because, like blacks, Hispanics are socioeconomically disadvantaged. Findings for this group suggest that the remaining 73% of the increased SIDS rate in blacks cannot be attributed in a straightforward manner to differences in income or educational attainment.

Black or African American↗

PubMed1986

Did low birthweight among US blacks really increase?

The low birthweight (LBW) rate among reported United States non-White births increased 32 per cent from 1950 to 1967. States with large increments in non-White LBW rates over the period 1950-67 ("rising LBW states") were compared to states with more stable LBW rates. Paradoxically, states with the most deterioration in LBW rates had the most improvement in LBW risk factors (low income, mothers under age 20 or over age 35, birth order over four). In 1950, at least 9.7 per cent of non-White births in rising LBW states went unreported, and underreporting was biased, with out-of-hospital LBW births who die young least likely to be reported. From 1950 to 1967, non-White out-of-hospital births for the US declined from 42 per cent to 7 per cent, and yearly values for per cent of non-White births in hospital and LBW rates were highly correlated (r = .98). These data suggest that the observed rise in non-White LBW rates from 1950 to 1967 was due in large part to systematic underreporting of LBW births among non-White out-of-hospital deliveries in the 1950s. This underreporting essentially ceased when hospital delivery for non-Whites became nearly universal in the late 1950s and 1960s.

Adult↗

PubMed1986

Arginine:glycine amidinotransferase. A comparative study in lizard and mouse tissues.

Kidney transamidinase activity in the lizard (Calotes versicolor), like that in the mouse, showed the pH optimum at 7.4. The lizard enzyme was inhibited to a greater degree than the mouse enzyme at high concentrations (greater than 20 mM) of L-arginine and glycine. Kidney and liver in the lizard and kidney and pancreas in the mouse were the tissues with high transamidinase activity. While transamidinase activity was widely distributed in mouse tissues, the enzyme was found to be restricted only to a few tissues in the lizard. Hydrocortisone administration into male lizards did not significantly alter the transamidinase levels in kidney and liver.

Amidinotransferases↗