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.     

Perinatal Outcomes Among Foreign-Born and US-Born Chinese Americans, 1995–2000

This paper examines nativity differences in adverse perinatal outcomes of Chinese-American mothers. Singleton live births to US-resident Chinese women (150,620 foreign-born, 15,040 US-born) and a random sample of 150,620 non-Hispanic White mothers were selected from 1995 to 2000 national linked birth/infant death certificate files. Associations between maternal nativity status and adverse perinatal outcomes were assessed using multivariable logistic regressions. Compared to US-born Chinese mothers, foreign-born Chinese mothers were less likely to be unmarried, teen mothers, have a non-Hispanic White or other race partner, be rural residents, and more likely to be less educated, or utilize prenatal care inadequately. Controlling for these factors, foreign-born Chinese-American mothers had significantly lower risks for low birth weight, preterm birth, and small-for-gestational age, whereas risks for infant mortality, neonatal mortality, and post-neonatal mortality did not differ significantly from those of infants of US-born Chinese mothers. Chinese Americans exhibited clear nativity differentials for adverse birth outcomes.     

Pregnancy outcomes of US-born and foreign-born Japanese Americans.

OBJECTIVES: This study investigated the birth outcomes of Japanese Americans, focusing on the role of the mother's place of birth. METHODS: Single live births to US-resident Japanese American mothers (n = 37,941) were selected from the 1983 through 1987 US linked live birth-infant death files. RESULTS: US-born mothers were more likely than foreign-born mothers to be less than 18 years old and not married, to start prenatal care early, and to more adequately use prenatal care. Infants of foreign-born Japanese Americans had a slightly lower risk of low birthweight.No significant differences were found between nativity groups for very low birthweight or neonatal, postneonatal, and infant mortality. The mortality rates of infants of US-born (6.2) and foreign-born (5.4) Japanese American women were below the US Year 2000 objective but still exceeded Japan's 1990 rate (4.6). However, low-birthweight percentages of the US-born group (5.7%) and the foreign-born group (5.0%) were similar to that of Japan (5.5%). CONCLUSIONS: The infants of foreign-born Japanese-American women exhibited modestly better low-birthweight percentages than those of US-born Japanese Americans. This finding supports theories of the healthy immigrant.     

Differing First Year Mortality Rates of Term Births to White, African-American, and Mexican-American US-Born and Foreign-Born Mothers

To determine whether maternal nativity (US-born versus foreign-born) is associated with the first year mortality rates of term births. Stratified and multivariable binomial regression analyses were performed on the 2003–2004 National Center for Health Statistics linked live birth-infant death cohort files. Only term (37–42 weeks) infants with non-Latina White, African-American, and Mexican-American mothers were studied. The infant mortality rate (<365 days, IMR) of births to US-born non-Latina White mothers (n = 3,684,569) exceeded that of births to foreign-born White mothers (n = 226,621): 2.4/1,000 versus 1.3/1,000, respectively; relative risk (RR) = 1.8 [95 % confidence interval (CI) 1.6–2.0]. The IMR of births to US-born African-American mothers (n = 787,452) exceeded that of births to foreign-born African-American mothers (n = 118,246): 4.1/1,000 versus 2.2/1,000, respectively; RR = 1.8 (1.6–2.1). The IMR of births to US-born Mexican-American mothers (n = 338,337) exceeded that of births to Mexican-born mothers (n = 719,837): 2.4/1,000 versus 1.8/1,000, respectively; RR = 1.3 (1.2–1.4). These disparities were not limited to a singular cause of death and were widest among deaths due to Sudden Infant Death Syndrome. In multivariable binomial regression models, the adjusted RR of infant mortality for non-LBW, term births to US-born (compared to foreign-born) for White, African-American, and Mexican-American mothers equaled 1.5 (1.3–1.7), 1.7 (1.5–2.1) and 1.6 (1.4–1.8), respectively. The IMR of term births to White, African-American, and Mexican-American mothers exceeds that of their counterparts with foreign-born mothers independent of traditional individual level risk factors.     

Perinatal outcomes in native Chinese and Chinese-American women

This study aimed to compare perinatal outcomes in native Chinese, foreign-born and US-born Chinese-American women by analysing a cohort of 950,624 singleton pregnancies in south-east China and 293,849 singleton births from the US live and stillbirth certificates from 1995 to 2004. Only births at 28 weeks or later were included. Compared with US-born Chinese-American women, native Chinese and foreign-born Chinese-American women had substantially lower risks of having a small-for-gestational age (SGA) infant (adjusted relative risk [aRR] ranging from 0.46 to 0.66) or preterm birth (aRR ranging from 0.53 to 0.82). While having a White or Black father had a reduced risk of SGA (aRR=0.45 and 0.62, respectively), it has an increased risk for preterm birth (aRR=1.13 and 1.57, respectively). Infants with Chinese father and foreign-born mother were heavier than those with Chinese father and US-born mothers. All findings were statistically significant. Our findings demonstrated the protective role of foreign-born status on low birthweight and preterm delivery. The paternal contribution to fetal size is substantial.     

Exploring Weathering: the Relation of Age to Low Birth Weight Among First Generation and Established United States-Born Mexican–American Women

To determine the age-related patterns of low birth weight, preterm birth, and intrauterine growth retardation among first generation and established US-born Mexican?CAmerican mothers. We performed stratified analyses on an Illinois transgenerational dataset of Mexican?CAmerican infants (1989?C1991) and their mothers (1956?C1976) with appended U.S. census income information. In Cook County, Illinois established (second or higher generation) US-born Mexican?CAmerican women (N?=?2,006) had a low birth weight (<2,500?g) rate of 6.2% compared to 4.8% for first generation US-born Mexican?CAmerican women (N?=?1,450), RR?=?1.3 (1.0?C1.6). In both subgroups, low birth weight, preterm, and intrauterine growth retarded components rates did not increase with advancing maternal age. First generation 30?C35?year old US-born Mexican?CAmerican women (N?=?159) had a low birth weight rate of 3.1% compared to 4.2% for their teen counterparts (N?=?386), RR?=?0.8 (0.3?C2.0). Established 30?C35?year old US-born Mexican?CAmerican women (N?=?330) had a low birth weight rate of 4.9% compared to 7.4% for their teen counterparts (N?=?459), RR?=?0.7 (0.4?C1.2). There was no evidence of weathering among US-born Mexican?CAmerican mothers with a lifelong residence in lower income neighborhoods, with a general downward trend in low birth weight rates with increasing age until age 30?C35. Rates of low birth weight, preterm birth, and intrauterine growth retardation do not increase with advancing age among first generation and established US-born 15?C35?year old Mexican?CAmerican women. This trend persists among both generations of women with a lifelong residence in lower income neighborhoods.     

Reproductive health differences among Latin American- and US-born young women

Investigations of reproductive health within Lationos living in the United States suggest that sexual behaviors and contraception use practices vary by ethnicity and between foreign- and US-born adolescents. This article compares high-risk sexual behaviors and reproductive health among foreign-born Latinas, US-born Latinas, and US-born non-Latinas aged 15–24 years. We recruited 361 females from reproductive health clinics in the San Francisco Bay Area of California between 1995 and 1998; these women completed an interview that assessed sexual risk behaviors and history of pregnancy, abortion, and sexually transmitted infections. Current chlamydial and gonococcal infections were detected through biological testing. Among participants aged 15–18 years, US-born Latinas were more likely to have been pregnant (odds ratio [OR] comparing US-born Latinas and US-born non-Latinas=3.9, 95% confidence interval [CI] 1.3, 11.4), whereas among respondents aged 19–24 years, foreign-born Latinas were more likely to have been pregnant than US-born Latinas (OR=11.3, 95% CI 1.0, 130.8) and US-born non-Latinas (OR=64.2, 95%CI 9.9, 416.3). US-born Latinas were most likely to have had an abortion (OR comparing US-born Latinas and US-born non-Latinas=2.0, 95% CI 0.9, 4.7). They were also most likely to have chlamydial infection at study enrollment (8.2% prevalence compared to 2.2% and 1.0% for foreign-born Latinas and US-born non-Latinas, respectively; P=0.009). Reproductive health differences between foreign and US-born females and within the US-born population warrant further examination and highlight the need for targeted prevention.     

Maternal ethnicity and pre-eclampsia in New York City, 1995-2003

Studies on ethnic differences in the risk of pre-eclampsia are limited. We linked birth records for 902,460 singleton births for the period 1995-2003 in New York City with hospital discharge data to evaluate the association between ethnicity and the risk of pre-eclampsia and compare risks between US-born and foreign-born women. Logistic regression models adjusted for maternal age, maternal education, parity, self-reported pre-pregnancy maternal weight, smoking during pregnancy and year of delivery were used to compare each ethnic group with non-Hispanic White women. The prevalence of pre-eclampsia in this study population was 3.2%. Among the major ethnic groups considered in our study, East Asian women had the lowest risk of pre-eclampsia (1.4%) and Mexican women had the highest risk (5.0%). Compared with non-Hispanic White women, there was a slightly decreased risk for East Asian women (adjusted OR = 0.8, [95% CI 0.7, 0.8]), similar risk for North African women (adjusted OR = 1.1, [95% CI 0.9, 1.3]), and increased risk for all other major ethnic groups (adjusted ORs: 1.3, 2.9), with the highest risk for Mexican women (adjusted OR = 2.9, [95% CI 2.7, 3.1]). No difference in risks was observed for US- vs. foreign-born women with the exception that foreign-born South-East Asian and Pacific Islanders had an increased risk of pre-eclampsia (adjusted OR = 1.8, [95% CI 1.0, 3.1]) relative to those born in the US. We concluded that there was ethnic heterogeneity in the development of pre-eclampsia among women in New York City and that Asian subgroups should be examined separately in future studies on ethnicity. Our results should contribute to screening for pre-eclampsia taking ethnic variation into account, and may help to suggest leads for the study of the aetiology of the condition.     

US Black vs White disparities in foetal growth: physiological or pathological?

BACKGROUND: Birthweight for gestational age is lower in US Black infants than in US White infants. It is unknown, however, whether this difference is 'normal' (i.e. physiological) or reflects pathological foetal growth restriction. METHODS: We applied an analytic approach based on foetuses at risk to compare gestational age-specific rates of live birth, 'revealed' small-for-gestational-age (SGA), and neonatal mortality among singleton infants >or=22 weeks of gestation and >or=500 g born in 1998-2000 to US White (n = 9 012 194), US-born Black (n = 1 554 382), and foreign-born Black (n = 200 395) mothers. Graphical methods and Cox proportional hazards regression analyses were used to compare outcomes in the three ethnic groups. RESULTS: Rates of live birth and neonatal mortality were highest at all gestational ages in US-born Blacks, lowest in Whites, and intermediate in foreign-born Blacks. The revealed SGA pattern cohered much more closely with the observed pattern for neonatal mortality when SGA was defined based on a single, overall standard of birthweight for gestational age than when based on ethnic group-specific standards. CONCLUSION: The closer coherence of revealed SGA and neonatal mortality rates based on a single standard and the intermediate pattern among foreign-born Blacks strongly suggest that Black-White differences in birthweight for gestational age are pathological, rather than physiological.     

Higher Mortality Rate Among Infants of US-Born Mothers Compared to Foreign-Born Mothers in New York City

This study is to compare infant mortality rates (IMRs) between US- and foreign-born mothers in New York City. The linked live birth-infant death records from 1995 to 1998 were analyzed. Overall US-born mothers had a higher IMR than foreign-born mothers, though there were great variations in IMRs by country of maternal birth among foreign-born mothers. US-born mothers had higher IMRs compared to foreign-born mothers for several maternal/infant characteristics. Logistic regression analyses indicated that infants of foreign-born mothers were less likely to die from prematurity, Sudden Infant Death Syndrome and external causes, but were more likely to die of congenital anomalies than those of US-born mothers. Further analyses on the interactions of maternal race/ethnicity and country of birth showed variations in the IMRs of leading causes of death. Infant mortality reduction strategies should be differentially targeted to minority mothers of different countries of birth, particularly for potentially preventable causes of deaths.     

Neighborhood support and the birth weight of urban infants

Differences in maternal characteristics only partially explain the lower birth weights of infants of African-American women. It is hypothesized that economic and social features of urban neighborhoods may further account for these differences. The authors conducted a household survey of 8,782 adults residing in 343 Chicago, Illinois, neighborhoods to assess mean levels of perceived social support and used US Census data to estimate neighborhood economic disadvantage. Data on birth weight and maternal risk factors were gathered from 95,711 birth certificates (1994-1996). Before statistical adjustment of the data, infants born to African-American mothers were found to be, on average, 297 g lighter than those born to White mothers. After adjustment for individual-level risk factors, this difference was reduced to 154 g. For African-American mothers only, mean birth weight decreased significantly as the neighborhood level of economic disadvantage increased. For White mothers only, a significant positive association was found between perceived levels of neighborhood social support and infant birth weight. Adding these neighborhood-level predictors to the model reduced the adjusted White versus African-American difference in birth weight to 124 g. Results support the hypothesis that neighborhood-level factors are significantly associated with infant birth weight.     

Secular change in birthweight among southeast Asian immigrants to the United States.

We analyzed the Washington State births in 1980-1986 to Southeast Asian parents whose birth place was coded as being outside of the US. The mean birthweight increased from 3188 grams in 1980-81 to 3283 grams in 1986, an annual increment of about 18 grams (95% CI = 11, 25 grams). The prevalence of low birthweight (less than 2500 grams) decreased from 7.2 percent in 1980-81 to 5.4 percent in 1986, an annual reduction of 6.4 percent (95% CI = 1.3, 11.2 percent). In an analysis of information ascertained from the birth certificate, the change of paternal occupational status (from student to employed) was associated with 27 percent of the reduction in the prevalence of low birthweight, independent of maternal age, infant sex, and prior gravidity. A similar temporal change of birthweight during the same period of time was not observed among infants of US-born Asian mothers. Among the women who had two consecutive births from 1984 to 1986, the improvement of birthweight for the second birth compared to the first birth was much greater in infants born to the Southeast Asian mothers than that to White mothers. Our study suggests that living in the United States after immigration from their native countries has had a positive impact on the birthweight of infants born to Southeast Asian immigrants.     

Women’s Lifelong Exposure to Neighborhood Poverty and Low Birth Weight: A Population-Based Study

Objective To determine whether women’s lifelong residential environment is associated with infant low birth weight. Methods We performed race-specific stratified and multivariate binomial regression analyses on an Illinois vital record dataset of non-Latino White and African-American infants (1989–1991) and their mothers (1956–1975) with appended United States census income information. Results Non-Latino White women (N = 267) with a lifelong residence in low-income neighborhoods had a low birth weight (<2,500 g) incidence of 10.1% vs. 5.1% for White women (N = 10,647) with a lifelong residence in high-income neighborhoods; RR = 2.0 (1.4–2.9). African-American women (N = 18,297) with a lifelong residence in low-income neighborhoods had a low birth weight incidence of 17% vs. 11.7% for African-American women (N = 546) with a lifelong residence in high-income areas; RR = 1.5 (1.2–1.8). The adjusted population attributable risk (PAR) percent of LBW for lifelong residence in low-income neighborhoods was 1.6% for non-Latino White and 23.6% for African-American women. Conclusions Non-Latino White and African-American women’s lifelong residence in low-income neighborhoods is a risk factor for LBW; however, African-Americans experience a greater public health burden from this phenomenon.     

Lower Rates of Preterm Birth in Women of Arab Ancestry: An Epidemiologic Paradox—Michigan, 1993–2002

Objective: Preterm birth (PTB), <37 weeks gestation, occurs in 12.1% of live births annually and is associated with significant morbidity and mortality in the United States. Racial/ethnic subgroups are disproportionately affected by PTB. Michigan is home to one of the largest Arab-American communities in the country; however, little is known about PTB in this population. This study examined the maternal demographic profile and risk factors of preterm birth (PTB) among foreign-born and US-born women of Arab ancestry relative to US-born Whites in Michigan. Methods: Using Michigan Vital Statistics data, we examined correlates of PTB for primiparous U.S.-born white (n = 205,749), U.S.-born Arab (n=1,697), and foreign-born Arab (n=5,997) women who had had a live-born singleton infant during 1993–2002. We examined variables commonly reported to be associated with PTB, including mother's age and education; insurance type; marital status of parents; receipt of prenatal care; mother's chronic hypertension, diabetes, and tobacco use; and infant sex. Results: Foreign-born Arabs are less educated and more likely to be on Medicaid, and they receive less prenatal care than US-born Whites. Prevalence of PTB was 8.5, 8.0, and 7.5% for US-born Whites, US-born Arabs, and foreign-born Arabs, respectively. Pregnancy-related hypertension was the only predictor of PTB that these three groups had in common: Adjusted Odds Ratio (AOR)=2.1 (95% Confidence Interval (CI)=1.99, 2.21), AOR=2.6 (95% CI=1.24, 5.51), and AOR=2.6 (95% CI=1.55, 4.31) for US-born whites, US-born Arabs, and foreign-born Arabs, respectively. Conclusions: Foreign-born Arab women in Michigan have a higher-risk maternal demographic profile than that of their US-born white counterparts; however, their prevalence of PTB is lower, which is consistent with the epidemiologic paradox reported among foreign-born Hispanic women.     

Low Birth Weight Across Generations

Objectives: This study sought to determine the relationship between maternal birth weight, prenatal care usage, and infant birth weight. Methods: Stratified and logistic regression analyses were performed on a dataset of computerized Illinois vital records of White (N = 187,074) and African-American (N = 58,856) infants born between 1989 and 1991 and their mothers born between 1956 and 1975. Results: Among White mothers who received adequate prenatal care, the low birth weight (<2500 g) rate was 4% for infants of former low birth weight mothers (N = 5230) compared to 2.1% for infants of former nonlow birth weight mothers (N = 93,011), relative risk equaled 1.9(1.7–2.2); the population attributable risk of maternal low birth weight was 4.1%. Among African American mothers who received adequate prenatal care, the low birth weight rate was 15% for infants of former low birth weight mothers (N = 2196) compared to 7.2% for infants of former nonlow birth weight mothers (N = 14,607), relative risk equaled 2.1(1.9–2.4); the population attributable risk of maternal low birth weight was 10.9%. The maternal–infant birth weight associations were consistent across all maternal age, education, marital status, and prenatal care categories. Conclusions: Maternal low birth weight is a risk factor for infant low birth weight independent of risk status during the current pregnancy. A greater percentage of low birth weight African American (compared to White) infants are attributable to maternal low birth weight.     

Pregnancy risk factors and birth outcomes in Washington State: a comparison of Ethiopian-born and US-born women.

This study compared birth outcomes of three cohorts of women with singleton live births in Washington State between 1980 and 1991: all Black Ethiopian-born women (n = 264) and samples of US-born Black (n = 526) and White (n = 546) women. Ethiopians were older, more likely to be married, and less likely to smoke than were US-born women, and they were less likely to have anemia than US-born Blacks. The adjusted low-birthweight risk among Ethiopians was similar to that of US-born Blacks (relative risk [RR] = 0.9) and Whites (RR = 1.1). Ethiopians were more likely to have high-birthweight infants than were US-born Blacks (RR = 4.0). Cultural and behavioral etiologies may explain these favorable birth outcomes.     

Differences in the self-reported racism experiences of US-born and foreign-born Black pregnant women

Differential exposure to minority status stressors may help explain differences in United States (US)-born and foreign-born Black women's birth outcomes. We explored self-reports of racism recorded in a survey of 185 US-born and 114 foreign-born Black pregnant women enrolled in Project Viva, a prospective cohort study of pregnant women in Boston, Massachusetts, USA. Self-reported prevalence of personal racism and group racism was significantly higher among US-born than foreign-born Black pregnant women, with US-born women having 4.1 and 7.8 times the odds, respectively, of childhood exposure. In multivariate analyses, US-born women's personal and group racism exposure also was more pervasive across the eight life domains we queried. Examined by immigrant subgroups, US-born women were more similar in their self-reports of racism to foreign-born women who moved to the US before age 18 than to women who immigrated after age 18. Moreover, US-born women more closely resembled foreign-born women from the Caribbean than those from Africa. Differential exposure to self-reported racism over the life course may be a critically important factor that distinguishes US-born Black women from their foreign-born counterparts.     

Suburban Migration and the Birth Outcome of Chicago-Born White and African–American Women: The Merit of the Healthy Migrant Theory?

The healthy migrant theory posits that women who migrate before pregnancy are intrinsically healthier and therefore have better birth outcomes than those who don’t move. Objective. To determine whether migration to the suburbs is associated with lower rates of preterm (<37 weeks) birth among Chicago-born White and African–American mothers. We performed stratified and multilevel logistic regression analyses on an Illinois transgenerational dataset of non-Latino White and African–American infants (1989–1991) and their mothers (1956–1976) with appended US census income information. Forty percent of Chicago-born White mothers (N = 45,135) migrated to Suburban Cook County and 30 % migrated to the more geographically distant collar counties. In contrast, 10 % of Chicago-born African–American mothers (N = 41,221) migrated to Suburban Cook and only two percent migrated to the collar counties. Chicago-born White and African–American migrant mothers to Suburban Cook County had lower preterm birth rates than their non-migrant counterparts; RR = 0.8 (0.8–0.9) and 0.8 (0.7–0.8), respectively. When neighborhood income was singularly taken into account, the protective association of suburban migration and preterm birth disappeared among Chicago-born Whites. In race-specific multilevel multivariate regression models which included neighborhood income, the adjusted odds ratio of preterm birth, low birth weight, and small for gestational-age for Chicago-born White and African–American migrant (compared to non-migrant) mothers approximated unity. Neighborhood income underlies the protective association of suburban migration and birth outcome among Chicago-born White and African–American mothers. These findings do not support the healthy migrant hypothesis of reproductive outcome.     

Low birthweight among US Hispanic/Latino subgroups: the effect of maternal foreign-born status and education

We investigated whether maternal foreign-born status confers a protective effect against low birthweight (LBW) across US Hispanic/Latino subgroups (i.e., Mexicans, Puerto Ricans, Cubans and Central/South Americans) in the USA, and whether the association between maternal education and LBW varies by Hispanic/Latino subgroup and by foreign-born status. We conducted logistic regression analyses of the 2002 US Natality Detail Data (n=634,797). Overall, foreign-born Latino women are less likely to have LBW infants than US-born Latino women. The protective effect of foreign-born status is stronger among Latino women with less than high school education. The maternal education gradient is significantly flatter among foreign-born Latino women than among their US-born counterparts (p<0.001). Patterns among Mexican-origin women account for the overall trends among all Latinos.Foreign-born status (main effect) reduces the risk of LBW among Mexicans by about 21% but does not protect against LBW among other Latino subgroups (i.e., Puerto Ricans, Cubans and Central/South Americans). Among Mexicans and Central South Americans, the protective effect of foreign-born status is stronger among women with low education (i.e., 0-11 and 12 years) than among women with more education (i.e., 13-15 and 16+ years). The educational gradient in LBW is less pronounced among foreign-born Mexicans and Central/South Americans than among their US-born counterparts. As such, maternal foreign-born status and education are associated with LBW, though the direction and strength of these associations vary across Latino subgroups. A "health paradox" is apparent for foreign-born Mexican and Central/South American women among whom there is a weak maternal educational gradient in LBW. Future research may test hypotheses regarding the mechanisms underlying these variations in LBW among Latino subgroups, i.e., different gradients in sending countries, health selection of immigrants, cultural factors, and social support.     

Racial/Ethnic and Nativity Differences in Birth Outcomes Among Mothers in New York City: The Role of Social Ties and Social Support

Immigrants have lower rates of low birth weight (LBW) and to some extent preterm birth (PTB), than their US-born counterparts. This pattern has been termed the ‘immigrant health paradox’. Social ties and support are one proposed explanation for this phenomenon. We examined the contribution of social ties and social support to LBW and PTB by race/ethnicity and nativity among women in New York City (NYC). The NYC Pregnancy Risk Assessment Monitoring System survey (2004–2007) data, linked with the selected items from birth certificates, were used to examine LBW and PTB by race/ethnicity and nativity status and the role of social ties and social support to adverse birth outcomes using bivariate and multivariable analyses. SUDAAN software was used to adjust for complex survey design and sampling weights. US- and foreign-born Blacks had significantly increased odds of PTB [adjusted odds ratio (AOR) = 2.43, 95 % CI 1.56, 3.77 and AOR = 2.6, 95 % CI 1.66, 4.24, respectively] compared to US-born Whites. Odds of PTB among foreign-born Other Latinas, Island-born Puerto Ricans’ and foreign-born Asians’ were not significantly different from US-born Whites, while odds of PTB for foreign-born Whites were significantly lower (AOR = 0.47, 95 % CI 0.26, 0.84). US and foreign-born Blacks’ odds of LBW were 2.5 fold that of US-born Whites. Fewer social ties were associated with 32–39 % lower odds of PTB. Lower social support was associated with decreased odds of LBW (AOR 0.69, 95 % CI 0.50, 0.96). We found stronger evidence of the immigrant health paradox across racial/ethnic groups for PTB than for LBW. Results also point to the importance of accurately assessing social ties and social support during pregnancy and to considering the potential downside of social ties.