Determinants of postpartum sleep duration and sleep efficiency in minority women

Study ObjectivesTo examine demographic, psychosocial, and behavioral determinants of postpartum sleep duration and sleep efficiency among a cohort of black and Latina women.MethodsData were from 148 women (67% black, 32% Latina) at 5 months postpartum, recruited from an academic medical center in Philadelphia. Relevant demographic, psychosocial and behavioral predictors were assessed via questionnaire. Nocturnal sleep was objectively measured for 1 week using wrist actigraphy. Sleep duration was examined as a continuous variable and in categories (<7 versus ≥7 h per night); sleep efficiency was examined as a continuous variable. Independent multiple linear regression models were built to evaluate significant determinants of sleep.ResultsAdjusted models revealed that breastfeeding, having a bedtime after midnight, and being employed were associated with shorter sleep duration (–25–33 min, all p < 0.05). Multiparity, being unmarried, being employed, breastfeeding, having a bedtime after midnight, bedsharing, and responding to infant awakenings by getting up immediately rather than waiting a few minutes to see if the infant fell back asleep, were all significant determinants of sleeping <7 h per night (OR varying: 2.29–4.59, all p < 0.05). Bedsharing was the only variable identified from the multiple regression model that associated with poorer sleep efficiency (–3.8%, p < 0.05).ConclusionsFindings may inform interventions for improving postpartum sleep in socioeconomically disadvantaged, racial/ethnic minority postpartum women.     

Racial and Ethnic Disparities in Diabetes Complications in the Northeastern United States: The Role of Socioeconomic Status

The role of socioeconomic status (SES) in explaining racial/ethnic disparities in diabetes remains unclear. We investigated disparities in self-reported diabetes complications and the role of macro (eg, income, education) and micro (eg, owning a home or having a checking account) SES indicators in explaining these differences. The sample included individuals with a diagnosis of diabetes (N = 795) who were aged, on average, 55 years, and 55.6% non-Hispanic white, 25.0% African American, and 19.4% Hispanic. Approximately 8% reported nephropathy, 35% reported retinopathy, and 16% reported cardiovascular disease. There were significant disparities in the rates of complications among non-Hispanic white, African American, and Hispanic participants, with Hispanic participants having the highest rates of nephropathy, retinopathy, and cardiovascular disease. Macro SES indicators (eg, income) mediated racial differences (ie, non-Hispanic whites vs African Americans) in self-reported retinopathy, a combination of macro and more micro SES indicators (eg, education, income, and owning a home or having a checking account) mediated racial/ethnic differences (ie, non-Hispanic white vs Hispanic participants) in self-reported cardiovascular disease, and only micro SES indicators (eg, owning a home or having a checking account) mediated differences between lower-income SES racial/ethnic minority groups (ie, African American vs Hispanic participants) in self-reported retinopathy and cardiovascular disease. Findings underscore that indicators of SES must be sensitive to the outcome of interest and the racial/ethnic groups being compared.     

Maternal smoking during pregnancy and sleep problems in 2-month-old infants

Objective

The study aimed to assess possible association between maternal smoking during pregnancy and sleep disturbances in 2-month-old infants.

Subjects and methods

The study comprised 200 apparently healthy infants from community settings selected by chance (88 boys, 112 girls), aged 2 months, who were singletons born in St. Petersburg in 2007. The mothers were asked to complete the questionnaires addressing major infant, maternal and demographic characteristics with particular emphasis on maternal smoking during pregnancy. As a part of the interview, the mothers were requested to describe possible sleep disturbances in their infants, divided into five major sleep domains: bedtime problems, excessive daytime sleepiness, awakenings, regularity and duration of sleep as well as snoring.

Results

Of 200 mothers, 63 (31.5%) smoked during pregnancy. The babies born to smoking mothers more commonly were reported as having bedtime problems [odds ratio (OR)=2.75; 95% confidence interval (CI)=1.15–6.58], and this association remained significant after adjustment was made for major potential confounders. Maternal smoking after delivery did not significantly add to the risk. Babies born to smoking mothers more often had irregular sleep, but this association was markedly influenced by the confounding effect of maternal education. No statistically significant differences were found for total night time sleep duration, the frequency of night time awakenings, excessive night time waking and daytime sleepiness as well as for snoring and noisy breathing during sleep.

Conclusion

Maternal smoking during pregnancy should be considered as a risk factor for infant bedtime problems, emerging as early as 2 months of age.     

What are postpartum women doing while the rest of the world is asleep?

Large individual differences characterize maternal postpartum sleep and adjustment. Our goal was to explore aspects of mothers’ nocturnal environments and behaviours that may explain differences in postpartum adjustment. A total of 201 mothers of infants aged 0–6 months completed an online survey with demographics, number and duration of nocturnal awakenings, caretaking behaviours, environment and nocturnal activities during ‘one typical night during the past week’. Mothers reported 2.9 [standard deviation (SD) ± 1.7] nocturnal awakenings, each lasting 33.9 (SD ± 22.5) min. Infant age was related inversely to duration but unrelated to number of awakenings. Falling asleep while feeding was less frequent among exclusively formula‐feeders. Among the entire sample, mothers used a cellphone (59%), backlit tablet (25%), TV (20%) and computer (16%) during nocturnal awakenings. Watching TV and using a computer were each associated with longer nocturnal awakenings. Eighty‐nine per cent of women used ≥1 extra light source during nocturnal awakenings: night light (35%), light from a cracked door (28%), desk lamp (25%), electronic device (19%) or room light (14%). Light source(s) was unrelated to number or duration of nocturnal awakenings. These data suggest that, although supplemental light sources were not associated with awakenings, TV and computer use accounted for longer awakenings. Feeding method and technology use may help to explain individual differences in postpartum adjustments and may be targets for more effective interventions.     

Signaled night awakening and its association with social information processing and socio-emotional development across the first two years

Study ObjectivesNight awakening is common in infancy, and some infants continue to have signaled night awakenings throughout early childhood. However, the influence of signaled night awakening on children’s social development is less explored. In the present study, longitudinal associations between signaled night awakening, social information processing, and socio-emotional development were measured within the CHILD-SLEEP birth cohort in two groups formed based on parent-reported night awakenings.MethodsAt 8 months, there were 77 infants in the waking group (≥3 awakenings) and 69 infants in the nonwaking group (≤1 awakening). At 8 and 24 months, social information processing was measured as children’s attention to neutral and emotional faces, and at 24 months, parent-reported socio-emotional behavior was measured with the Brief Infant-Toddler Social and Emotional Assessment (BITSEA) questionnaire.ResultsThe two groups showed different patterns of attention to emotional faces. The waking group had a more pronounced attentional bias to fearful versus happy faces, whereas in the nonwaking group, attention to fearful and happy faces did not differ. In addition, at 24 months, the waking group had more dysregulation problems and lower social competence than the nonwaking group, but no clear differences in internalizing or externalizing problems were found.ConclusionsOur results contribute to the literature by showing that during the first 2 years of life, signaled night awakening is associated with social information processing and socio-emotional behavior.     

Sleep in Older African Americans and Caucasians at Risk for Sleep-Disordered Breathing

This study explored differences in sleep between older African Americans (AA) and Caucasians (CA) at risk for sleep-disordered breathing. Seventy AA and 70 CA were compared on ambulatory monitoring sleep variables and on self-reports on health and socioeconomic status (SES). After controlling for SES and health covariates, CA woke up significantly more often than AA (p = .018), but there were no other differences in sleep variables between the two groups. Time awake at night was related to being male, more depression, less walking, and lower income, whereas having more awakenings during the night was related to being CA, higher apnea-hypopnea index, and higher periodic leg movement index. Importance of inclusion of SES, health, and other covariates in studies exploring racial differences in sleep are discussed.     

Sleep in older African Americans and Caucasians at risk for sleep-disordered breathing

This study explored differences in sleep between older African Americans (AA) and Caucasians (CA) at risk for sleep-disordered breathing. Seventy AA and 70 CA were compared on ambulatory monitoring sleep variables and on self-reports on health and socioeconomic status (SES). After controlling for SES and health covariates, CA woke up significantly more often than AA (p = .018), but there were no other differences in sleep variables between the two groups. Time awake at night was related to being male, more depression, less walking, and lower income, whereas having more awakenings during the night was related to being CA, higher apnea-hypopnea index, and higher periodic leg movement index. Importance of inclusion of SES, health, and other covariates in studies exploring racial differences in sleep are discussed.     

Disparities in breast cancer incidence across racial/ethnic strata and socioeconomic status: a systematic review

OBJECTIVES: A higher incidence of breast cancer has been reported both in white women and women of higher socioeconomic status (SES) compared to women of other races and lower SES, respectively. We explored whether differences in SES can account for disparities in breast cancer incidence between races. METHODS: We identified several studies published between 1990 and 2007 that addressed disparities in breast cancer incidence across racial and socioeconomic strata. For each study, we calculated incidence rate ratios (IRRs) for breast cancer incidence in the highest strata to lowest strata of SES for white, black, Hispanic and Asian/Pacific-Islander populations. We then used these IRRs to compare trends in SES and breast cancer incidence between races and across studies. RESULTS: The studies we identified revealed that the magnitude of the disparity in breast cancer incidence between races decreases with increasing SES. While individual census-tract based studies' methods of assessing the association between SES and breast cancer incidence did not identify consistent trends between races, adjustment for risk factors closely correlated with SES eliminated the statistical differences in breast cancer incidence between women of white, Hispanic and Asian/Pacific-Islander, but not black, ethnicity. CONCLUSION: We found that racial differences in breast cancer incidence can largely be accounted for by ethnic differences in SES among white, Hispanic and Asian/Pacific-Islander women, but not between these populations and black women. We further highlight important differences in methodology between previously published studies that may account for their disparate findings.     

Sustained efficacy of eszopiclone over 6 months of nightly treatment: results of a randomized, double-blind, placebo-controlled study in adults with chronic insomnia

STUDY OBJECTIVES: To determine the long-term efficacy of eszopiclone in patients with chronic insomnia. DESIGN: Randomized, double-blind, multicenter, placebo-controlled. SETTING: Out-patient, with monthly visits. PATIENTS: Aged 21 to 69 years meeting DSM IV criteria for primary insomnia and reporting less than 6.5 hours of sleep per night, and/or a sleep latency of more than 30 minutes each night for at least 1 month before screening. INTERVENTIONS: Eszopiclone 3 mg (n = 593) or placebo (n = 195), nightly for 6 months MEASUREMENTS AND RESULTS: Efficacy was evaluated weekly using an interactive voice-response system. Endpoints included sleep latency; total sleep time; number of awakenings; wake time after sleep onset; quality of sleep; and next-day ratings of ability to function, daytime alertness, and sense of physical well-being. At the first week and each month for the study duration, eszopiclone produced significant and sustained improvements in sleep latency, wake time after sleep onset, number of awakenings, number of nights awakened per week, total sleep time, and quality of sleep compared with placebo (P < or = 0.003). Monthly ratings of next-day function, alertness, and sense of physical well-being were also significantly better with the use of eszopiclone than with placebo (P < or = 0.002). There was no evidence of tolerance, and the most common adverse events were unpleasant taste and headache. CONCLUSIONS: Throughout 6 months, eszopiclone improved all of the components of insomnia as defined by DSM-IV, including patient ratings of daytime function. This placebo-controlled study of eszopiclone provides compelling evidence that long-term pharmacologic treatment of insomnia is efficacious.     

Perinatal predictors of sleep disturbances in young infants

The study aimed to identify risk factors of sleep disturbances in 2-month-old infants. It comprised 198?infants (86?boys, 112?girls) who were singletons born in St. Petersburg, Russia, in?2007. The mothers were asked to complete questionnaires addressing major infant, maternal, and demographic characteristics. Preexisting medical records were scrutinized. The mothers were requested to describe infant sleep troubles. The baby was defined as having sleep disturbances, if he or she had five or more episodes per week characterized by settling difficulties at bedtime (could not fall asleep within 20?minutes after being put to bed) or frequent night awakenings (woke up more than twice during the night). Of 198?infants, 96?(48.5%) reportedly had sleep disturbances. In the univariate analysis, the factors associated with increased risk of sleep disturbances were (odds ratio, OR; (95%?CI)) first birth order 3.55 (1.90?C6.69), previous abortions 2.08 (1.14?C3.83), maternal vaginal bleedings during pregnancy 2.58 (1.07?C6.29), maternal allergies 2.44 (1.17?C5.14), and maternal smoking during pregnancy 2.45 (1.27?C4.77). Stepwise backward logistic regression analysis identified combinations of the factors that best predicted the risk of infant sleep disturbances: first birth order, previous abortions, and maternal smoking during pregnancy. After inclusion into the multiple logistic regression equation, these factors provided moderate prediction (pseudo R²=0.15). The receiver operating characteristic (ROC) curve was constructed, and the area under the ROC curve was equal to 0.6636 (95%?CI=0.5905?C0.7406), p_(area=0.5)?<0.05. Findings from the maternal history may help to predict sleep disturbances in young infants.     

Reference values and changes in infant sleep–wake behaviour during the first 12 months of life: a systematic review

This paper is a systematic review on the reference values and changes in infant sleep–wake behaviour during the first 12 months of life. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA). Seventy‐four papers were included, and the reference values and changes in sleep–wake behaviour during the first 12 months of life were identified. Sleep duration during the 24‐h period, and day and sleep periods during the night decreased over the first 12 months of life. Night wakings and bedtime/sleep‐onset time decreased, while the longest sleep period increased at night during the first 6 months. High discrepancy was noted between studies in the reference values of sleep–wake behaviour, while more congruence was noted regarding changes, especially those occurring in the first 6 months of life. Several methodological differences were identified between studies and may partially explain inconsistencies in the results, including the assessment of different sleep–wake behaviours, the focus on specific ages or age ranges, the use of self‐report, observational or direct measures, the recruitment of small or large representative samples, and the countries where the research was conducted. These aspects should be considered in future research and caution should be taken when generalizing results from studies with diverse methodological characteristics. Nonetheless, this review identifies normative reference values and the changes occurring in infant sleep–wake behaviour, and could inform both practitioners and researchers, helping them identify infants with sleep delays or problems.     

High incidence of HIV-associated mortality among black and Hispanic infants and women of childbearing age in the United States 1990-2001

This study examined HIV-associated mortality in infants and in women of childbearing age (15-44 years) in the United States from 1990-2001. HIV-associated deaths were identified from national vital records using multiple cause-of-death data. HIV-associated mortality was higher in black and Hispanic women than in white women (rate ratio(black) = 13.5, 95% CI = 13.2-13.8; rate ratio(Hispanic) = 2.4, 95% CI = 1.9-3.2). Racial/ethnic trends in infant mortality rates from HIV reflected trends observed in women (rate ratio(black) = 16.3, 95% CI = 13.5-19.7; rate ratio(Hispanic) = 3.4, 95% CI = 3.3-3.5). HIV-associated mortality decreased in infants and in women of childbearing age following the availability of highly active antiretroviral therapy, but the decrease was considerably less marked in black women than in women of other racial/ethnic groups. Our findings indicate the need for increased emphasis on prevention of HIV mortality in black and Hispanic women and infants. Reduction of HIV prevalence in young women may also prevent infant mortality from HIV by reducing mother-to-child transmission.     

Racial/ethnic disparities in sleep duration and sleep disturbances among pregnant and non‐pregnant women in the United States

Sleep disturbances among pregnant women are increasingly linked to suboptimal maternal/birth outcomes. Few studies in the USA investigating sleep by pregnancy status have included racially/ethnically diverse populations, despite worsening disparities in adverse birth outcomes. Using a nationally representative sample of 71,644 (2,349 pregnant) women from the National Health Interview Survey (2004–2017), we investigated relationships between self‐reported pregnancy and six sleep characteristics stratified by race/ethnicity. We also examined associations between race/ethnicity and sleep stratified by pregnancy status. We used average marginal predictions from fitted logistic regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for each sleep dimension, adjusting for sociodemographic and health characteristics. Pregnant women were less likely than non‐pregnant women to report short sleep (PR_Overall = 0.75; 95% CI, 0.68–0.82) and more likely to report long sleep (PR_Overall = 2.06; 95% CI, 1.74–2.43) and trouble staying asleep (PR_Overall = 1.34; 95% CI, 1.25–1.44). The association between pregnancy and sleep duration was less pronounced among women aged 35–49 years compared to those <35 years. Among white women, sleep medication use was less prevalent among pregnant compared to non‐pregnant women (PR_White = 0.45; 95% CI, 0.31–0.64), but this association was not observed among black women (PR_Black = 0.98; 95% CI, 0.46–2.09) and was less pronounced among Hispanic/Latina women (PR_{Hispanic/Latina} = 0.82; 95% CI, 0.38–1.77). Compared to pregnant white women, pregnant black women had a higher short sleep prevalence (PR_Black = 1.35; 95% CI, 1.08–1.67). Given disparities in maternal/birth outcomes and sleep, expectant mothers (particularly racial/ethnic minorities) may need screening followed by treatment for sleep disturbances. Our findings should be interpreted in the historical and sociocultural context of the USA.     

Associations of the residential built environment with adolescent sleep outcomes

Study ObjectivesOver 75% of US high school students obtain insufficient sleep, placing them at risk for adverse health outcomes. Identification of modifiable determinants of adolescent sleep is needed to inform prevention strategies, yet little is known about the influence of the built environment on adolescent sleep.MethodsIn this prospective study, actigraphy was used to assess sleep outcomes among 110 adolescents for 14 days each in eighth and ninth grades: duration (hours/night), onset and offset, and sleeping ≥8 hours. Home addresses were linked to built environment exposures: sound levels, tree canopy cover, street density, intersection density, population density, and housing density. Mixed-effects regression estimated associations of built environment measures with sleep outcomes, adjusting for sex, race, parent education, household income, household size, grade, weeknight status, and neighborhood poverty.ResultsA 1-standard deviation (SD) increase in neighborhood sound was associated with 16 minutes later sleep onset (β = 0.28; 95% confidence interval (CI): 0.06, 0.49) and 25% lower odds of sleeping for ≥8 hours (odds ratio (OR) = 0.75, 95% CI: 0.59, 0.96). A 1-SD increase in neighborhood tree canopy was associated with 18 minutes earlier sleep onset (β = −0.31, 95% CI: −0.49, −0.13) and 10 minutes earlier sleep offset (β= −0.17, 95% CI: −0.28, −0.05). No associations were observed for density-based exposures.ConclusionsHigher neighborhood sound level was associated with lower odds of sufficient sleep, while higher tree canopy cover was associated with more favorable sleep timing. Neighborhood sound levels and tree canopy cover are potential targets for policies and interventions to support healthier sleep among adolescents.     

Gender differences in the association of insomnia symptoms and coronary artery calcification in the multi-ethnic study of atherosclerosis

Study ObjectivesTo quantify the gender-specific associations between insomnia symptoms and subclinical atherosclerosis, measured by coronary artery calcium (CAC) scores, which has strong predictive value for incident cardiovascular disease.MethodsWe analyzed data from 1,429 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Participants completed standardized questionnaires and underwent polysomnography (PSG) and 7-day actigraphy. Insomnia symptoms were defined as: self-reported trouble falling, staying or returning to sleep, early-morning awakenings, or hypnotic use, for ≥5 nights/week. MESA assessed CAC using computed tomography. We employed multivariable linear regression to model the probability of CAC >0 overall and to model the linear continuous effect among those with nonzero CAC.ResultsOur sample was a mean age of 68.1 ± 9.1 years, 53.9% female, and 36.2% white, 28.0% black, 24.2% Hispanic, and 11.5% Chinese-American. Insomnia symptoms were present in 49.7% of men and 47.2% of women. In multivariable-adjusted analyses, insomnia symptoms was associated with an 18% higher prevalence of CAC (PR 1.18, 95% CI 1.04, 1.33) among females, but no association was observed among males (PR 1.00, 95% CI 0.91, 1.08). There was no evidence that the association between insomnia symptoms and prevalence of CAC >0 differed by objective sleep duration status (by single-night PSG or multi-night actigraphy) in females or males.ConclusionsWe found that among women, insomnia symptoms were associated with an 18% higher prevalence of CAC compared to no insomnia. Insomnia symptoms were not associated with CAC prevalence in men. Additionally, there was no evidence that the association between insomnia symptoms and CAC score >0 differed by objective short sleep duration status.     

Ethnic variation in the size of infant at birth

The impact of ethnicity and other maternal factors (BMI, parity, glucose tolerance, gestational age) on the size of the infant at birth was investigated in a relatively low socioeconomic status, multi-ethnic population at San Francisco General Hospital. A sample of 2,069 infants born to mothers of black, non-Hispanic white, Hispanic, and Chinese descent and whose mothers had received prenatal care at San Francisco General Hospital were studied. Maternal size, pregnancy history, and blood glucose were determined prenatally at 26–28 weeks gestation. Anthropometry was performed on the infant within 72 hours of birth. Black and Chinese infants were the lightest in weight, while Hispanic infants were the heaviest. When correction was made for maternal factors black infants were shown to be significantly (P < .05) lighter in birth weight than non-Hispanic white, Chinese, or Hispanic infants. Black infants were also significantly shorter in birth length and smaller in chest circumference. Chinese infants had significantly (P < .05) greater adiposity, as indicated by the sum of skinfold measurements, than both black and Hispanic infants. These findings are relevant to current practices in neonatal growth categories which are determined solely by birth weight and do not account for variations in body composition. Comparisons with a relatively higher socioeconomic status sample from Kaiser-Permanente Hospital (Oakland) shows a similar prevalence of low birth weight among blacks. These results support other results that ethnicity is a major independent influence on the weight of the newborn.     

Association between sleep duration and body size differs among three Hispanic groups

Objectives: Although numerous studies have reported negative associations between sleep duration and body size, no studies of this association have focused on Hispanic groups, which was the goal of this work. Methods: Data are from adults in the 1982–1984 Hispanic Health and Nutrition Examination Survey (HHANES), which enrolled Cuban‐Americans, Mexican‐Americans, and Puerto Ricans. HHANES included self‐reported sleep duration and several anthropometric measures. Principle component analysis extracted a single variable to represent body size. Linear regression models stratified by Hispanic group predicted body size from sleep duration adjusting for age, sex, education, income, marital status, household size, and acculturation. Results: Average age was 36–44 years and 52–64% were women. Average sleep duration was 7.3–7.7 h. Shorter sleep duration was associated with larger body size in Mexican‐Americans only. The regression coefficient indicated that on average a Mexican‐American adult who reported sleeping for 4 h would have a body size that was larger by 0.12 times the standard deviation for body size than a Mexican‐American adult reporting 8 h of sleep (all other covariates being equal). This effect was similar to the effect of 10 years of age, which would be associated with an increase in body size by 0.10 times the standard deviation of body size. Conclusions: These results underscore the importance of examining factors associated with obesity in different ethnic groups. It may be inappropriate to combine different Hispanic ethnicities together. Am. J. Hum. Biol., 2011. © 2010 Wiley‐Liss, Inc.     

Assessing sleep quality using self‐report and actigraphy in PTSD

Sleep disturbance is commonly reported by participants with post‐traumatic stress disorder, but objective evidence of poor sleep is often absent. Here we compared self‐report and actigraphic evaluations of sleep between veterans with post‐traumatic stress disorder and controls. Participants reported their sleep retrospectively for the month before the recording night and on the recording night. On the recording night, they wore an Actiwatch‐64 and were instructed to press the marker button upon getting into bed, each time they awoke, and at their final awakening. The post‐traumatic stress disorder group reported much worse sleep than controls on the Pittsburgh Sleep Quality Index for the previous month and somewhat poorer sleep on the recording night. However, on the recording night, neither diary nor actigraphic measures of number of awakenings, total time in bed, nor time lying awake after sleep onset differed between participants with and without post‐traumatic stress disorder. Diary‐reported number of awakenings was fewer than actigraphically captured awakenings. These results suggest a memory bias towards remembering worse sleep on the nights before the recording night.     

The influence of ethnicity, an atopic family history, and maternal ascariasis on cord blood serum IgE concentrations

Raised concentrations of cord blood serum (CBs) IgE have previously been demonstrated to reflect a hereditary predisposition for atopy in First World, predominantly white populations. A cross-sectional study of 53 black, 52 white, and 58 mixed race newborn infants and maternal pairs was performed in a multiethnic, mixed First and Third World society. The CBs IgE concentrations were measured with a modification of the standard IgE PRIST, which could reliably determine IgE concentrations to an accuracy of 0.01 kU/L. The black group had the highest geometric mean and median CBs IgE concentrations (0.21; 0.16 kU/L), followed by the white group (0.12; 0.12 kU/L) and the mixed group (0.10; 0.08 kU/L). If those newborn infants with an atopic family history and maternal ascariasis were excluded, the remainder had geometric mean and median CBs IgE concentrations of 0.20; 0.16 kU/L in the black subgroup, followed by values of 0.06; 0.05 kU/L in the mixed subgroup, and 0.05; 0.07 kU/L in the white subgroup. Statistically significant ethnic differences in the median CBs IgE concentrations of these subgroups were demonstrated between the black-white (p less than 0.05) and the black-mixed (p less than 0.005) ethnic groups. A positive family history of atopy influenced the CBs IgE concentrations in the white and mixed groups but not in the black group. Of those newborn infants with a CBs IgE concentration greater than 0.5 kU/L, a family history of atopy was found in 100% of the white newborn infants, in 58.3% of the mixed newborn infants, and only in 14.3% of the black newborn infants. Many of the black newborn infants without a family history of atopy had extremely high CBs IgE concentrations. The influence of maternal ascariasis was equivocal in the mixed group but of no significance in the black group. The high CBs IgE concentrations in the black newborn infants, independent of an atopic family history and maternal ascariasis, suggest that this atopic marker may therefore be of limited use in identifying the "high allergic-risk" newborn infant in black Third World populations who appear to represent a pool of genetic high IgE-responder phenotypes.