Odds Of Low Birth Weight Research Articles

Adverse birth outcomes among native-born and foreign-born mothers in Taiwan: A population-based birth cohort study

BackgroundThe number of children born to foreign-born mothers in Taiwan has significantly increased since the 1990s. These foreign-born mothers are mainly from China and Southeast Asia. Children born to foreign-born mothers, according to media reports, are subject to inferior health. This study sought to determine whether socioeconomic disparities in birth outcomes exist between native and foreign-born mothers in Taiwan.MethodsAnalysis data were obtained from the Taiwan Birth Cohort Study of 20,090 nationally representative 6-month-old babies, born in 2005. The data on the babies were divided into two groups, those of foreign-born mothers and those of Taiwanese mothers. The health outcome variables that were examined included two adverse birth outcomes: low birth weight and preterm birth. Multiple logistic regression was used to examine the association between income and foreign-born status, as well as birth outcomes among both groups.ResultsChildren of native Taiwanese mothers had a higher prevalence of low birth weight (6.9%) than did children of China-born (4.7%) and Southeast Asia-born mothers (5.2%). The prevalence of preterm birth was also higher among children of native Taiwanese mothers (8.4%) than among children of Southeast Asia-born (7.2%) and China-born mothers (6.3%). Foreign-born status was associated with lower odds of low birth weight among families with a monthly family income < NT$30,000 (adjusted odds ratio (AOR) = 0.24, 95% confidence interval (CI) = 0.14–0.42, p < 0.001), and lower odds of preterm birth among families with a monthly family income < NT$30,000 and NT$30,000–69,999 (AOR = 0.63, CI = 0.40–0.99, p < 0.05, and AOR = 0.68, CI = 0.53–0.88, p < 0.01, respectively). Having a higher monthly family income (NT$70,000+ and NT$30,000–69,999) was associated with lower odds of low birth weight (AOR = 0.59, CI = 0.46–0.77, p < 0.001 and AOR = 0.75, CI = 0.60–0.94, p < 0.05, respectively) among Taiwanese mothers, but not among foreign-born mothers.ConclusionForeign-born mothers from China and Southeast Asia did not experience worse birth outcomes than native Taiwanese mothers did, regardless of the disadvantaged socioeconomic position of their families.

Proximity to roadways and pregnancy outcomes

Adverse birth outcomes are associated with exposure to air pollution during pregnancy. Road proximity is a simple, widely available metric for capturing local variation in exposure to traffic-related air pollution. We characterized maternal exposure to traffic-related air pollution during pregnancy using residential proximity to major roadways among 2004-2008 singleton births in NC. Controlling for maternal race, age, education, nativity, marital status, and tobacco use, and season of birth, parity, infant sex, and Census tract-level urbanization and income, we evaluated the association between road proximity and pregnancy outcomes using generalized linear mixed models with a random intercept for each Census tract. Birth weight, birth weight percentile for gestational age, gestational hypertension, and small-for-gestational age were not associated with road proximity; however, women residing within 250 m of a major roadway were at 3-5% increased odds of low birth weight, preterm birth, and late preterm birth compared with women residing beyond 250 m (P<0.05). Our analyses demonstrate an association between proximity to major roadways and pregnancy outcomes using a large sample. Road proximity may represent a relatively straightforward method for assessing maternal risk from exposure to traffic-related air pollution, with results offering guidance for studies that can more accurately characterize air pollution exposures.

Maternal mid-upper arm circumference is associated with birth weight among HIV-infected Malawians.

The authors examined the relationship of maternal anthropometry to fetal growth and birth weight among 1005 human immunodeficiency virus (HIV)-infected women in Lilongwe, Malawi, who consented to enrollment in the Breastfeeding, Antiretrovirals, and Nutrition Study (www.thebanstudy.org). Anthropometric assessments of mid-upper arm circumference (MUAC), arm muscle area (AMA), and arm fat area (AFA) were collected at the baseline visit between 12 and 30 weeks' gestation and in up to 4 follow-up prenatal visits. In longitudinal analysis, fundal height increased monotonically at an estimated rate of 0.92 cm/wk and was positively and negatively associated with AMA and AFA, respectively. These latter relationships varied over weeks of follow-up. Baseline MUAC, AMA, and AFA were positively associated with birth weight (MUAC: 31.84 g/cm(2), 95% confidence interval [CI], 22.18-41.49 [P < .01]; AMA: 6.88 g/cm(2), 95% CI, 2.51-11.26 [P < .01]; AFA: 6.97 g/cm(2), 95% CI, 3.53-10.41 [P < .01]). In addition, MUAC and AMA were both associated with decreased odds for low birth weight (LBW; <2500 g) (MUAC: odds ratio [OR] = 0.85, 95% CI, 0.77-0.94 [P < .01]; AMA: OR = 0.95, 95% CI, 0.91-0.99 [P < .05]). These findings support the use of MUAC as an efficient, cost-effective screening tool for LBW in HIV-infected women, as in HIV-uninfected women.

Maternal religious attendance and low birth weight

We use data from the U.S. Fragile Families and Child Wellbeing study to test whether maternal religious attendance is protective against low birth weight. Building on previous research, we also consider the mediating influence of mental health, cigarette use, alcohol use, illicit drug use, poor nutrition, and prenatal care. Our results indicate that maternal religious attendance is protective against low birth weight. In fact, each unit increase in the frequency of religious attendance reduces the odds of low birth weight by 15%. Religious attendance is also associated with lower odds of cigarette use and poor nutrition, but is unrelated to mental health, alcohol use, illicit drug use, and prenatal care. Although lower rates of cigarette use help to mediate or explain 11% of the association between maternal religious attendance and low birth weight, we find no evidence to substantiate the mediating influence of mental health, alcohol use, illicit drug use, poor nutrition, or prenatal care. Our results suggest that the health benefits of religious involvement may extend across generations (from mother to child); however, additional research is needed to fully explain the association between maternal religious attendance and low birth weight. It is also important for future research to consider the extent to which the apparent health advantages of religious adults might be attributed to health advantages in early life, especially those related to healthy birth weight.

Birth outcomes for African and Caribbean babies in England and Wales: retrospective analysis of routinely collected data

ObjectivesTo compare mean birth weights, gestational ages and odds of preterm birth and low birth weight of live singleton babies of black African or Caribbean ethnicity born in 2005 or...

Early rise in human chorionic gonadotropin (hCG) is associated with maternal and perinatal outcome

hCG levels in early pregnancy are hypothesized to reflect trophoblast function and placental health. The goal of this study was to examine the association between serial hCG levels and maternal and perinatal outcomes. Retrospective cohort study. Patients with symptomatic unassisted pregnancies were followed with early first trimester serial hCGs. Only singleton live births were included. The slope for daily rate of increase in log transformed hCG levels (hCG rise) was estimated and analyzed as a continuous variable and by quartile (Q). Primary outcomes were birth weight and gestational age at delivery. Secondary outcomes were preterm birth, low birth weight (<2,500g), and hypertensive disorders. The relationship of hCG rise with each outcome was assessed with t-tests, chi-square tests, and linear and logistic regression. 159 singleton live births were analyzed. The median two-day increase in hCG was 105% (lower Q 70%; upper Q 142%). Linear regression models demonstrated no significant association between hCG rise and birth weight or gestational age. However, quartile of hCG rise was significantly associated with low birth weight (P=0.002). Compared to the first Q (slowest), subjects with a more rapid hCG rise (second-fourth Qs) had increased odds of low birth weight (OR 18.78, 6.54, and 5.14, respectively). A composite outcome, including small for gestational age, low birth weight, preterm birth, and preeclampsia was also more prevalent in higher Qs of hCG rise (P=0.006, OR 5.83, 3.75, and 1.54, respectively). A similar trend was observed for a composite adverse infant outcome (P=0.023, OR 4.62, 7.93, and 3.26, respectively). The rise in hCG may reflect trophoblast cell differentiation and function. A fast rise may indicate suboptimal placental function. These findings could lead to an early method to identify women at risk for later pregnancy complications.

Particulate Pollutants and Racial/Ethnic Disparity in Feto-Infant Morbidity Outcomes

We sought to assess the association between air particulate pollutants and feto-infant morbidity outcomes across racial/ethnic subgroups. This is a retrospective cohort study from 2000 through 2007 based on three linked databases: (1) The Florida Hospital Discharge database; (2) The vital statistics records of singleton live births in Florida; (3) Air pollution and meteorological data from the Environmental Protection Agency. Using computerized mathematical modeling, we assigned exposure values of the air pollutants of interest (PM(2.5), PM(10) and the PM coarse fraction [PM(10)-PM(2.5)]) to mothers over the period of pregnancy based on Euclidean minimum distance from the air pollution monitoring sites. The primary outcomes of interest were: low birth weight, very low birth weight, preterm birth, very preterm birth, and small for gestational age (SGA). We used adjusted odds ratios to approximate relative risks. We observed increased risk for overall feto-infant morbidity outcome in women exposed to any of the three particulate pollutants (values above the median). Exposed women had increased odds for low birth weight, very low birth weight and preterm birth with the greatest risk being that for very low birth weight (AOR=1.27, 95% CI=1.08-1.49). Black women exposed to any particulate pollutant had the greatest odds for all the morbidity outcomes, most pronounced for very low birth weight (AOR=3.32, 95% CI=2.56-4.30). Environmental particulate pollutants are associated with adverse feto-infant outcomes among exposed women, especially blacks. Black-white disparity in adverse fetal outcomes is widened in the presence of these pollutants, which provide a target for intervention.

The Potential Contribution of Marital-Cohabitation Status to Racial, Ethnic, and Nativity Differentials in Birth Outcomes in Texas

Disparities in infant mortality by race/ethnicity and nativity are widely known. Patterns of marriage and union formation also vary by race, ethnicity and nativity and may contribute to disparities in birth outcomes. Using population level data, we build on previous research of race/ethnic disparities in birth outcomes by investigating the role of union status. Data come from the 2006 Birth Record from Texas Vital Statistics. The final sample size included 369,839 births to Texas women aged 18 and older. Birth outcomes were constructed from indicators of low birth weight and preterm birth. Logistic regression estimates odds of low birth weight and preterm birth by race/ethnicity and nativity and union status. Race/ethnicity/nativity and union status are significant and independent predictors of birth outcomes. US born Black and Mexican Origin mothers had higher odds of preterm birth and low birth weight babies compared to US born White mothers. Unmarried mothers had higher odds of adverse birth outcomes compared to married women. There was only modest support that the association between race/ethnicity/nativity status and birth outcomes could be explained by divergent patterns in union status. Though disparities in birth outcomes are persistent across race, ethnicity and nativity, the results suggest that union status at birth is a very weak factor in accounting for these disparities. Differing patterns in union status did not account for the Black-White and Mexican Origin-White gaps in infant health outcomes. Additional research aimed at uncovering the processes that put these mothers and infants at higher risk is needed.

Pregnancy and Neonatal Outcomes of Aboriginal Women: A Systematic Review and Meta-Analysis

Purpose Inadequate prenatal care and higher incidences of higher-risk behaviors and gestational diabetes, in addition to other significant determinants of health, place aboriginal women at increased risk of adverse pregnancy outcomes. We conducted a systematic review and meta-analyses of pregnancy and neonatal outcomes among aboriginal women. Methods We searched Medline, Embase, and CINAHL for English-language studies reporting rates of pregnancy and neonatal outcomes among aboriginal women. Data were extracted by three reviewers in duplicate. Study quality was assessed for biases in selection, exposure assessment, confounder adjustment, analyses, outcomes assessment, and attrition. Data were synthesized using random effect model. Subgroup analyses were performed based on the country of origin of the aboriginal women. Results Thirty-eight studies of low to moderate risk of biases were included. Adjustment for confounding factors was performed in eight studies. Unadjusted odds of low birth weight (LBW), preterm birth (PTB), stillbirth, neonatal and perinatal mortality were increased among infants born to aboriginal women. However, adjusted odds were only increased for PTB and stillbirths. Subgroup analyses revealed higher unadjusted odds of LBW, PTB, stillbirth, and neonatal and perinatal mortality among Australian aboriginals; PTB, macrosomia, stillbirth and neonatal and perinatal mortality among Canadian aboriginals, and PTB and neonatal mortality among American Indians and Alaskan Native women. Conclusion Aboriginal women are at increased risk of adverse pregnancy outcomes especially PTB; however, future studies assessing confounders adjusted estimates are needed. Differences in outcomes exist based on the country of origin of aboriginal women, reasons for which should be investigated.

Birth Outcomes Among Offspring of Women Exposed to the September 11, 2001, Terrorist Attacks

To evaluate the effects of the September 11, 2001, World Trade Center attacks on birth outcomes. Live singleton births between September 11, 2001, and October 31, 2002, to women enrolled in a World Trade Center Health Registry (the Registry, n=446) were compared with births to women residing more than 5 miles from the World Trade Center (n=49,616). Birth weight, gestational age, low birth weight, and preterm delivery were evaluated using linear and logistic regression. Births before September 11, 2001, were analyzed to assess possible seasonal biases of associations with pregnancy trimester on September 11. Associations of birth outcomes with September 11-related psychologic stress and physical exposures were assessed among births to women within the Registry (n=499). Birth weight and gestational age distributions were similar for births to women enrolled in the Registry and comparison births. Although mean gestational age and birth weight varied with trimester on September 11, a similar association was found among births in previous years, consistent with a seasonal effect not related to exposure. Registry-linked births to mothers with probable posttraumatic stress disorder (n=61) had a higher odds of low birth weight (adjusted odds ratio [OR] 2.49, 95% confidence interval [CI] 1.02-6.08) and preterm delivery (adjusted OR 2.48, 95% CI 1.05-5.84) compared with births to women without posttraumatic stress disorder. Women who lived, worked, or were near the World Trade Center on or soon after September 11 had pregnancy outcomes similar to women residing more than 5 miles away. However, among exposed women, probable posttraumatic stress disorder was associated with low birth weight and preterm delivery. II.

Stroke during pregnancy: no increased risk of preterm delivery and low birth weight, a nationwide case-controlled study

ObjectivePopulation-based data regarding pregnancy outcomes for patients who experienced stroke during pregnancy is sparse and mainly from Western populations. The authors investigate the association between strokes and pregnancy outcomes in...

The Association Between Second Hand Smoke and Low Birth Weight and Preterm Delivery

To determine the association between maternal exposure to SHS and low birth weight and preterm delivery. This cross-sectional study was carried out in the four main governmental hospitals dealing with deliveries in the north of Jordan. A consecutive 8,490 women who delivered in these hospitals between April 2007 and September 2007 were included in the study after excluding those who reported active smoking during the current pregnancy. Pre-structured questionnaire and review of hospital records were used to collect data about maternal background, obstetric history, medical history, and data related to second hand smoke exposure. Overall, 13.8% of women gave birth to a preterm baby and 10.0% gave birth to a low birth weight baby. About 12.6% of women who were exposed to SHS delivered low birth weight babies compared to 7.7% for non exposed women. The rate of preterm delivery among the exposed group was significantly higher than that among the non-exposed group (17.2 vs. 10.6%). In the multivariate analysis, exposure to SHS during pregnancy was significantly associated with increased odds of low birth weight (OR = 1.56 (95% CI 1.31, 1.89)) and preterm delivery (OR = 1.61 (95% CI: 1.30, 1.99)). Exposure of women to SHS during pregnancy is associated with increased odds of low birth weight and preterm delivery. Health care professionals should carry out educational programs to increase awareness and understanding of pregnant women and their husbands about the harmful effects of second hand smoke on birth outcomes.

Residential Segregation and Birth Weight among Racial and Ethnic Minorities in the United States

Racial and ethnic minorities are often residentially segregated from whites in urban settings, a fact which has important health consequences. Research on the relationship between residential segregation and health outcomes lacks national-level investigation of racial and ethnic minority groups other than African Americans. I use multilevel analyses to examine the associations of residential isolation and clustering with birth weight among Asian, black, and Latino Americans using data from the National Center for Health Statistics' Natality Files and the U.S. Census. Findings indicate that segregation has a negative effect on the likelihood of having a low birth weight baby among Asian Americans, suggesting a possible concentration of social and structural resources in highly-segregated communities. On the contrary, segregation marginally increases the odds of low birth weight among African Americans, but only in the presence of higher poverty rates. Segregation does not affect birth weight among Latino Americans.

Maternal schizophrenia and pregnancy outcome: Does the use of antipsychotics make a difference?

Objective This study compared the risk of adverse pregnancy outcome—including preterm births, low birth weight (LBW), large-gestational-age (LGA), and small-gestational-age (SGA)—among mothers with schizophrenia receiving typical, atypical, and no antipsychotics during pregnancy. They were all compared with control subjects. Methods We used population-based data from the Taiwan National Health Insurance Research Database and birth certificate registry covering the years 2001 to 2003. In total, 696 mothers with schizophrenia and 3480 matched unaffected mothers were included for analysis. After adjusting for characteristics of mother, father, and infants, multivariate logistic regression analyses were performed to examine the risk of LBW, preterm gestation, SGA, and LGA, comparing mothers with schizophrenia and unaffected mothers. Results After adjusting for potential confounders, the odds of LBW and SGA for unaffected mothers respectively were 0.72 (95% CI = 0.50–0.88) and 0.81 (95% CI = 0.64–0.92) times those of mothers with schizophrenia who had not receiving antipsychotics during pregnancy. There was no significant difference in the risk of LBW, preterm births, LGA, and SGA babies compared to mothers with schizophrenia receiving atypical antipsychotics during pregnancy and those not receiving antipsychotics. However, mothers with schizophrenia receiving typical antipsychotics during pregnancy had higher odds of preterm birth (OR = 2.46, 95% CI = 1.50–4.11) compared to those not receiving antipsychotics. Conclusions The data suggest that the risks for LBW and SGA among mothers with schizophrenia are not affected by antipsychotic use. Women who receive treatment with typical antipsychotics during pregnancy are at slightly higher risk of preterm birth.

Ulcerative Colitis and Pregnancy Outcomes in an Asian Population

As the prevalence of ulcerative colitis (UC) is much higher in Western countries than in Asian countries, previous investigations of pregnancy outcomes for women with UC were limited to people of European descent. This study was aimed at examining the risk of adverse pregnancy outcomes (low birth weight (LBW), preterm birth, small for gestational age (SGA), and cesarean section (CS)) among Asian women with UC. Using a 3-year nationwide population-based database, we identified a total of 196 women who gave birth from 2001 to 2003, who were diagnosed with UC within 2 years before their index deliveries. A total of 1,568 unaffected pregnant women matched these cases according to age and year of delivery. Conditional logistic regression analyses were performed to estimate risk. There were significant differences between women with and without UC in terms of LBW (12.76% vs. 5.55, P<0.001) and preterm births (11.73% vs. 6.25%, P=0.004). After adjusting for infant gender, parity, maternal age, highest maternal educational level, parental age difference, maternal marital status, hypertension, diabetes, anemia, family monthly income, as well as conditioning on maternal age and year of delivery, the odds of LBW and preterm births for women with UC were 2.36 (95% confidence interval (CI)=1.45-3.82) and 1.90 (95% CI=1.16-3.11) times, respectively, those for unaffected women. Although UC often follows a milder disease course in Asians than in people of European descent, we demonstrated that Asian women suffering from UC were still at risk of having preterm and LBW babies, compared with unaffected mothers.

Segmented assimilation theory and perinatal health disparities among women of Mexican descent

A higher prevalence of infant low birth weight (<2500 g) has been observed among more acculturated mothers of Mexican descent living in the U.S. when compared to their less acculturated counterparts. Tests of the "acculturation hypothesis" have established that disparities in certain risks for low birth weight exist between subgroups of women of Mexican-origin. However, disparities observed by neighborhood of residence have yet to be explained. Most tests of the acculturation hypothesis assume a classical path of assimilation, whereby Mexican American health is expected to deteriorate with time spent residing in the U.S. and across the generations. The theory of segmented assimilation suggests that alternative paths are possible depending upon individual characteristics and the context of the neighborhood into which immigrant families and their children reside. This study tested the theory of segmented assimilation as a framework for examining the geographic, cultural, and socioeconomic underpinnings of population differences in infant low birth weight among women of Mexican descent in California using the 2000 U.S. Census and population-based data from the Maternal and Infant Health Assessment (1999-2005) (n=6442). Little support was found for the theory's hypotheses. Rather, increased odds for infant low birth weight were observed for English speakers residing in Latino immigrant neighborhoods when compared to English speakers in other neighborhoods, an effect attenuated for Spanish speakers. Elevated odds of low birth weight were also observed among English speakers residing in Latino immigrant neighborhoods when compared to Spanish speakers in the same neighborhoods. Findings suggest the transfer of health-specific social capital in ethnic neighborhoods may depend upon sociocultural consonance between individuals and neighborhood residents. The authors call for additional research that sheds light on the sociocultural dynamics of maternal and infant health at multiple levels.

Intention to Become Pregnant and Low Birth Weight and Preterm Birth: a Systematic Review

Increased stress, psychosocial problems, economic disadvantages, and lack of prenatal care are proposed to explain discrepancies in the outcome of unintended pregnancies. Studies of maternal intention and pregnancy outcomes have yielded varied results. Objective is to review studies of the risk of low birth weight (LBW)/preterm births (PTB) associated with unintended pregnancies ending in a live birth. We reviewed studies reporting on maternal intentions and outcomes from Medline, Embase, CINAHL, and bibliographies of identified articles. An unintended pregnancy was further classified as mistimed (not intended at that time) or unwanted (not desired at any time). Studies reporting an association between pregnancy intention and any of the outcomes were included. Study quality was assessed for biases in selection, exposure assessment, confounder adjustment, analyses, outcomes assessment, and attrition. Unadjusted and adjusted data from included studies were extracted by two reviewers. There were significantly increased odds of LBW among unintended pregnancies [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.25, 1.48] ending in a live birth. Within the unintended category, mistimed (OR 1.31, 95% CI 1.13, 1.52) and unwanted (OR 1.51, 95% CI 1.29, 1.78) pregnancies were associated with LBW. There were statistically significantly increased odds of PTB among unintended (OR 1.31, 95% CI 1.09, 1.58), and unwanted (OR 1.50, 95% CI 1.41, 1.61) but not for mistimed (OR 1.36, 95% CI 0.96, 1.93) pregnancies. Unintended, unwanted, and mistimed pregnancies ending in a live birth are associated with a significantly increased risk of LBW and PTB.

The impact of the First Steps prenatal care program on birth outcomes among women receiving Medicaid in Washington State

To evaluate the effectiveness of "First Steps", Washington State's expanded Medicaid prenatal and post-partum care program, we conducted a retrospective population-based cohort study using birth and hospital discharge records from Washington State for 1999-2002. Birth outcomes of 19,668 First Steps participants receiving Medicaid were compared to those of 56,728 non-participating mothers receiving Medicaid. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for the association between First Steps participation and low birth weight (<2500g), preterm birth (<37 weeks gestation), small for gestational age (<10th percentile in birth weight for Washington State infants of same gestational age and sex), and infant mortality (death prior to 12 months). Adjusted for potential confounders of maternal age, race/ethnicity, education, marital status, parity, place of residence, foreign birth, and participation in other benefit programs, infants of women participating in First Steps were less likely to be of low birth weight (OR=0.92, 95% CI: 0.84-1.00). Among Hispanic women, compared to non-participants, participants had a reduced odds of low birth weight (OR=0.79, 95% CI: 0.67-0.94) and preterm birth (OR=0.85, 95% CI: 0.74-0.98). These results suggest that participation in First Steps among Medicaid recipients may be particularly effective among Hispanic mothers.

Ethnic-Cultural Background, Maternal Body Size and Pregnancy Outcomes in a Diverse Swiss Cohort

ABSTRACT Objective: To investigate the influence of ethnic-cultural background and maternal body size on pregnancy outcomes in infants born at term. Study design: A retrospective cohort of 1,432 pregnant women who delivered a live newborn at term between 1999 and 2003 provided the data for the following study. We performed multivariable regression analyses for birth weight and rate of caesarean section controlling for body mass index (BMI), net weight gain, maternal age, parity, smoking, marital status and sex of infant. Results: Thirty percent of the women studied had a BMI ≥ 25; the proportion of mothers with a BMI ≥ 25 varied substantially by ethnic-cultural background (range: Far East 2.8% vs. Africa 50.0%). After adjustment for confounding variables, mothers from Sri Lanka and the Middle East had significantly lighter infants (Sri Lanka −145.5 g, 95% CI −59.3 g to −231.7 g, P = 0.001; Middle East −214.3 g, 95% CI −33.7 g to −395.0 g, P = 0.02) than mothers from Switzerland. Each unit increase in maternal pre-pregnancy BMI was associated with a 20.3 g increase in birth weight (95% CI 14.3 g to 26.4 g, P < 0.001). Muslim mothers from the former Yugoslavia had significantly lower odds of caesarean section than Swiss mothers (OR 0.63, 95% CI 0.41 to 0.96, P = 0.03). Conclusions: In this cohort, certain ethnic-cultural groups had increased odds for low birth weight and others had reduced odds of operative delivery compared with the Swiss comparison group. Given the strong association between ethnic-cultural background and overweight in this cohort, culturally appropriate support and counseling during prenatal care should be evaluated in the increasingly diverse environment in European countries.

Risk of Low Birth Weight Associated with Advanced Maternal Age Among Four Ethnic Groups in the United States

To examine and compare the risk of low birth weight associated with delayed childbearing in four ethnic groups using nationally representative data in the United States. We compared the risk of low (< 2.5 kg) birth weight among African Americans, Mexican Americans, Puerto Ricans, and non-Hispanic whites using birth data for the United States obtained from the National Center for Health Statistics. Comparisons were done separately for first births and births of second or higher order and in terms of odds ratios, risk differences and attributable fractions of very low (< 1.5 kg), middle low (1.5-2.5) and overall low birth weight. Statistical analysis included use of logistic regression models with likelihood ratio tests for interaction effects. African Americans and Puerto Ricans, and to a lesser extent Mexican Americans, had higher risk differences associated with advanced maternal age. For first births, the risk differences associated with advanced maternal age (> or = 35 years) in low birth weight were 5.3% (95% CI, 4.7-6.0), 4.3% (95% CI, 1.7-6.9), and 3.7% (95% CI, 2.8-4.5) for African Americans, Puerto Ricans, and Mexican Americans, respectively, as compared with 2.6% (95% CI, 2.4-2.7) for non-Hispanic whites. On the other hand, the odds ratios associated with advanced maternal age were more similar across the four ethnic groups. Differences were greater for all ethnic groups in the case of first births as compared with births of second or higher order. Advanced maternal age appears to be associated with for the most part similarly increased odds of low birth weight for African Americans, Mexican Americans, Puerto Ricans, and non-Hispanic whites. However, the age-related increments in the risk of low birth associated with advanced maternal age are greater for African Americans, Puerto Ricans and, to a lesser extent, Mexican Americans, as compared with non-Hispanic whites.