空气污染和低出生体重

空气污染与低出生体重之间的关系的研究在国外已有较多报道,通过回顾文献发现,孕期接触空气中的一氧化碳、可吸入颗粒、二氧化硫、二氧化氮、多环有机物、总悬浮颗粒等物质的污染可能与低出生体重的发生有关,但目前发生机制还不明确.     

Environmental inequities and low birth weight

The effects of environmental exposures to toxic agents, are related to different levels of exposure, genetic and biological susceptibility, risk perception and socioeconomic status (SES). In the present study we suggest that environmental influences on human reproduction should include investigations on SES, that can play an important role in embryo-foetal development. Low birth weight (LBW) is a risk factor for developing in adulthood coronary hearth disease, hypertension and type 2 diabetes. Maternal nutritional status and other hypothesis could explain LBW, however, environmental exposures are recognised as essential risk factors. Different studies evidenced an increased risk of LBW in relation to increased environmental air levels of particulate matter, carbon monoxide, and sulphur dioxide. Considering different risk possibilities and different risk perceptions, there is a need of a different scientific approach in which the scientific knowledge is connected with ethical and socioeconomic factors, for risk management, in order to overcome the environmental health inequities based on social contest.     

Outdoor air pollution, low birth weight, and prematurity

This study tested the hypothesis, suggested by several recent reports, that air pollution may increase the risk of adverse birth outcomes. This study analyzed all singleton live births registered by the Czech national birth register in 1991 in 67 districts where at least one pollutant was monitored in 1990-1991 (n = 108,173). Maternal exposures to sulfur dioxide (SO(2)), total suspended particles (TSP), and nitrous oxides (NO(x)) in each trimester of pregnancy were estimated as the arithmetic means of all daily measurements taken by all monitors in the district of birth of each infant. Odds ratios of low birth weight (< 2,500 g), prematurity (< 37 weeks of gestation), and intrauterine growth retardation (IUGR; < 10th percentile of birth weight for gestational age and sex) were estimated by robust logistic regression. The median (and 25th and 75th percentile) trimester exposures were 32 (18, 56) microg/m(3) for SO(2); 72 (55, 87) microg/m(3) for TSP; and 38 (23, 59) microg/m(3) for NO(x). Low birth weight (prevalence 5.2%) and prematurity (prevalence 4.8%) were associated with SO(2) and somewhat less strongly with TSP. IUGR was not associated with any pollutant. The effects on low birth weight and prematurity were marginally stronger for exposures in the first trimester, and were not attenuated at all by adjustment for socioeconomic factors or the month of birth. Adjusted odds ratios of low birth weight were 1.20 [95% confidence interval (CI), 1.11-1.30] and 1.15 (CI, 1.07-1.24) for a 50 microg/m(3) increase in SO(2) and TSP, respectively, in the first trimester; adjusted odds ratios of prematurity were 1.27 (CI, 1.16-1.39) and 1.18 (CI, 1.05-1.31) for a 50 microg/m(3) increase in SO(2) and TSP, respectively, in the first trimester. Low gestational age accounted for the association between SO(2) and low birth weight. These findings provide further support for the hypothesis that air pollution can affect the outcome of pregnancy.     

Race, family income, and low birth weight.

The relations among race, family income, and low birth weight were examined using information obtained from the National Longitudinal Survey of Youth, which conducted yearly interviews with a nationally representative sample of young women identified in the late 1970s. Data were available for these women and their offspring from 1979 through 1988. Maternal education, maternal age, age/parity risk, marital status, and smoking during pregnancy served as covariates in cross-sectional and longitudinal analyses. The risk of low birth weight among births to black women and white women who were poor was at similarly high levels regardless of whether poverty was determined prior to study entrance or during the study period. Longitudinal analyses showed an exceptionally large increase in risk of low birth weight among children born to women whose prior pregnancy ended in a low-birth-weight infant. These two findings emphasize the importance of factors antecedent to the pregnancy in the genesis of low birth weight.     

Environmental pollution, maternal residence and low birth weight

Case-control study, which aimed to analyze the risk factors associated with low birth weight of newborns of mothers from Rio Grande-RS that resided in the proximities of the industrial area. Mothers that gave birth in the maternities of the municipality were interviewed during the months of April to November of 2003. The sample comprehended 138 cases and 409 controls. It was performed the bivariate and multivariate statistical analysis. The Low Birth Weight (LBW) maintained itself positively associated with previous stillborns, previous LBWs, the presence of arterial hypertension during the pregnancy, and the threat of abortion during the current pregnancy. It was possible to identify the main factors of risk to which pregnant women are exposed and that interfere with birth weight of their children, which are in addition to those resulting from a greater exposure to pollutants, because they live near the industries.     

Education, infant mortality, and low birth weight in Sweden 1973-1990: emergence of the low birth weight paradox

AIMS: Educational differences in infant mortality, birth weight, and birth weight-specific infant mortality in Sweden were analysed. The "low birth weight paradox", where low birth weight infants have a lower mortality risk if born to women of lower rather than higher social strata, was addressed. METHODS: The study includes about a million single births 1973-90 to women born 1946-60. There were 6,544 infant deaths and 35,334 low birth weight infants. Analysis conducted on six-year time periods was restricted to 652,859 births to women aged 25-32 at the time of delivery. Odds ratios and 95% CI were estimated by logistic regression. Birth weight-specific infant mortality rates were calculated by education. RESULTS: Infants of women with low/low intermediate education had significantly higher odds ratios than those of highly educated women of being of low birth weight or of dying. If one compares only the infants of women with low and high education, these differences were accentuated over time. The low birth weight paradox appears over time. CONCLUSION: The widening differences in infant mortality and low birth weight over time may be caused by the decrease in women with low education, signifying increased selection and growing social disadvantage in this group. The emergence of the low birth weight paradox suggests that the distribution of causes of low birth weight differs between educational groups, and further that these causes are differently related to infant mortality. To disentangle these two groups of causes and their effects on infant mortality seems highly relevant.     

低出生体重儿液体配方奶对极低/超低出生体重儿生后早期生长发育的影响

目的:研究低出生体重儿液体配方奶对极低/超低出生体重早产儿生后早期生长发育的影响,进而评估其临床应用效果。方法:选择胎龄≤32周住院的极低/超低出生体重儿,分为观察组和对照组,分别给予低出生体重儿液体配方奶和普通早产儿配方奶粉喂养,观察喂养后体格发育指标、喂养相关指标、合并疾病等方面的差异,进行统计学分析。结果:应用低出生体重儿液体配方奶喂养的极低和超低出生体重早产儿体重增长速率高于对照组;体重增长所需热量、恢复至出生体重所需时间、喂养耐受时间、静脉营养应用时间均低于对照组;感染、贫血和高间接胆红素血症的发生率低于对照组,差异具有统计学意义(P<0.05)。结论:低出生体重儿液体配方奶由于可提供高热量,有效利用度高,肠道负荷小,且应用方便、能保证极低和超低出生体重儿生后早期良好的生长发育,同时可减少其并发症的发生。     

极低/超低出生体重儿母乳喂养的研究现状与进展

极低/超低出生体重儿的死亡人数占全部新生儿死亡人数的一半以上,相比低出生体重儿(即≥1 500 g),相关并发症发生率更高,预后相对更差,母乳喂养已被证实可以帮助改善其临床结局。本文对极低/超低出生体重儿母乳喂养的研究现状与进展进行综述。     

Association between violence during pregnancy and preterm birth and low birth weight in Colombia: Analysis of the demographic and health survey

Abstract

To explore the association between low birth weight and preterm birth with violence during pregnancy, we conducted a cross-sectional study by using the 2010 Colombian Demographic and Health Survey. We conducted bivariate analyses, binomial logistic regression, and stratified models by age, and 14,520 women were included. There was no association between violence and low birth weight. Nonetheless, an association with preterm birth in women aged over 35 was observed (OR 1.98, 95%CI 1.23, 3.17). Prenatal care appeared to be a protective factor for both outcomes. This research unexpectedly showed that supplementation with folic acid and iron was associated with preterm birth.     

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.     

Prevalence of low birth weight and its determinants in an urban resettlement area of Delhi

Birth weight remains an important factor affecting infant and child mortality. Many factors influence the occurrence of low birth weight (LBW). The present study was conducted to study the prevalence and determinants of LBW in an urban resettlement area of Delhi. A baseline survey was done to enroll all pregnant women in the area. These women were followed up every month till outcome. The prevalence of LBW was 39.1%. Occurrence of LBW was related to age, parity, weight and height of the mother. In multiple logistic regression analysis, mother's weight and parity alone emerged as significant variables. On further analysis, on adjusting for age, parity and birth weight were associated for the 20-35-year age group only. Thus, prevalence of LBW remains high in the urban under privileged of Delhi; maternal age, parity and weight and height are important determinants. Increasing age of first birth to more than 20 years can minimize effect of primi parity.     

城市低出生体重儿童学龄期主观生活质量评价

目的了解城市低出生体重儿童学龄期主观生活质量状况。方法从某城市已建立的出生队列中整群抽取6~12岁低出生体重儿童作为观察组,共随访101例,并按1:1匹配选择同性别和年龄的正常出生体重儿童作为对照,采用儿少主观生活质量问卷评价其主观生活质量水平。结果城市低出生体重儿童学龄期主观生活质量问卷平均得分为(161.670±16.567)分,生活质量的8个维度、认知成分、情感成分和总得分与正常出生体重儿童差异均无统计学意义。学龄儿童总的生活质量满意度集中在一般水平,且差异无统计学意义。结论城市低出生体重儿童学龄期主观生活质量与同龄正常出生体重儿童无明显差别。     

Demographic correlates of low birth weight

Data from 100,277 certificates of livebirths were analyzed in an attempt to uncover independent correlates of birthweight and gestation time. Without statistical control, each of these variables was shown to be significantly related to race, trimester of obtaining prenatal care, maternal age, parity, socioeconomic status, and legitimacy status. Regression analyses indicated that maternal race and the trimester in which she obtained prenatal care were the most significant correlates of birthweight and gestation time. It was suggested that race and trimester of obtaining prenatal care were not, in themselves, causes of low birthweight. Other indicess of socioeconomic, cultural, biological, medical, and psychological factors may be correlated with mother's race and the trimester in which she obtains prenatal care.