Moderate alcohol drinking and risk of preterm birth

OBJECTIVE: We have analysed the association between alcohol drinking before and during the three trimesters of pregnancy and risk of preterm birth of babies with normal weight for gestational age or with low weight for gestational age (SGA). DESIGN: Case-control study. SETTING: General and university hospitals in Italy. SUBJECTS: Cases were 502 women who delivered preterm births <37 weeks gestation. The controls included 1966 women who gave birth at term (>/=37 weeks of gestation) to healthy infants of normal weight (ie between 10th and 90th centile according to the Italian standard) on randomly selected days at the hospitals where cases had been identified. INTERVENTIONS: Interview. RESULTS: No increased risk of preterm birth was observed in women drinking one or two drinks/die in pregnancy, but three or more drinks/die increased the risk (multivariate odds ratios (OR) 2.0 for >/=3 drinks during the first trimester, 1.8 during the second and 1.9 during the third). When the analysis was conducted separately for preterm births with normal weight or SGA, the increased risk was observed in preterm SGA only (multivariate OR for >/=3 drinks/die during the first trimester=3.6, 95% confidence interval (CI) 1.3-11.1); the estimated multivariate OR for >/=3 drinks/die during the first trimester of preterm babies with normal weight for gestational age was only slightly above unity and not statistically significant (multivariate OR 1.4, 95% CI 0.5-3.7). CONCLUSIONS: The study shows an increased risk in mothers who drink >/=3 die units alcohol in pregnancy of preterm births.     

Cigarettes, coffee, and preterm premature rupture of the membranes.

Premature (prior to 37 completed weeks of gestation) rupture of the membranes (preterm PROM) is one of the most common underlying causes of preterm delivery. However, there have been few epidemiologic studies of this obstetric complication. The authors studied the relation of maternal cigarette smoking and coffee consumption to both preterm PROM and spontaneous preterm labor not complicated by premature rupture of the membranes (preterm NONPROM) in a large cross-sectional data base. The 307 preterm PROM and 488 preterm NONPROM cases who delivered during 1977-1980 at the Boston Hospital for Women were compared with 2,252 randomly selected women who delivered at term at that institution. Multiple logistic regression techniques were used to derive maximum likelihood estimates of adjusted odds ratios (OR) and 95% confidence intervals (CI). After confounders had been adjusted for, the relative risk of preterm PROM for women who reported ever having smoked during pregnancy, as compared with nonsmokers, was 1.6 (95% CI 1.1-2.4). However, no gradient between the number of cigarettes smoked per day and the risk of preterm PROM was observed. Similar results were observed for preterm NONPROM. Women who consumed three or more cups of coffee daily during the first trimester had a 2.2-fold greater risk of preterm PROM than did women who drank two or fewer cups (95% CI 1.5-3.3). Among coffee drinkers, there was some evidence of a linear trend in the risk of preterm PROM as coffee consumption increased. Consumption of three or more cups of coffee per day was less strongly associated with the occurrence of preterm NONPROM (adjusted OR = 1.4, 95% CI 1.0-1.9).     

Breast cancer in relation to the occurrence and time of induced and spontaneous abortion

The authors evaluated whether an induced or spontaneous abortion during the first six months of gestation, particularly if it occurs before the first term pregnancy, increases the risk of breast cancer. Data from a case-control study of women under 70 years of age were used: 3,200 cases of breast cancer were compared with 4,844 controls with nonmalignant nongynecologic conditions. Among both nulliparous and parous women, the risk of breast cancer was not related to the number of induced or spontaneous abortions. After allowance for all identified potential confounding factors, the estimated relative risk for nulliparous women with an induced abortion relative to those who had never been pregnant was 1.3 (95% confidence interval (CI) 0.8-2.2), and for spontaneous abortion, the corresponding estimate was 0.9 (95% CI 0.5-1.5). Among parous women, the estimated relative risks were 1.2 (95% CI 0.9-1.6) for an induced abortion and 0.9 (95% CI 0.8-1.0) for a spontaneous abortion, relative to never having had an abortion of any type. The time of the abortion had little effect: The relative risk estimates were 0.9 (95% CI 0.5-1.4) for induced abortion before the first term birth, 1.4 (95% CI 1.0-1.9) for induced abortion first occurring after the first term birth, 0.9 (95% CI 0.7-1.2) for spontaneous abortion before the first term birth, and 0.9 (95% CI 0.7-1.0) for spontaneous abortion first occurring after the first term birth. Similar results were evident for women under age 40, among whom the frequency of induced abortion was relatively high. These data suggest that the risk of breast cancer is not materially affected by abortion, regardless of whether it occurs before or after the first term birth.     

Chemical hair treatments and adverse pregnancy outcome among Black women in central North Carolina

Several studies suggest that toxic chemicals in hair products may be absorbed through the scalp in sufficient amounts to increase the risks of adverse health effects in women or their infants. This case-control study of 525 Black women from three counties in North Carolina who had delivered a singleton, liveborn infant examined whether exposure to chemicals used in hair straightening and curling increased the odds that the infant was preterm or low birth weight. Cases consisted of 188 preterm and 156 low birth weight births (for 123 women, their infant was both low birth weight and preterm). Controls were 304 women who delivered term and normal birth weight infants. Women who used a chemical hair straightener at any time during pregnancy or within 3 months prior to conception had an adjusted odds ratios (OR) of 0.7 (95% confidence interval (CI) 0.4-1.1) for preterm birth and 0.6 (95% CI 0.4-1.1) for low birth weight. Exposure to chemical curl products was also not associated with preterm delivery (adjusted OR = 0.9, 95% CI 0.5-1.8) or low birth weight (adjusted OR = 1.0, 95% CI 0.5-1.9). Despite this failure to find an association, continued search for risk factors to which Black women are uniquely exposed is warranted.     

Does lack of multinutrient supplementation during early pregnancy increase vulnerability to alcohol-related preterm or small-for-gestational-age births?

The objective of this study was to assess whether women who do not take multinutrient supplements during early pregnancy are more susceptible to the effects of low-to-moderate alcohol consumption on preterm birth and small-for-gestational-age birth (SGA) compared to women who do take multinutrients. This analysis included 800 singleton live births to mothers from a cohort of pregnant women recruited for a population-based cohort study conducted in the Kaiser Permanente Medical Care Program in Northern California. Participants were recruited in their first trimester of pregnancy and information about their alcohol use and supplement intake during pregnancy was collected. Preterm birth (n = 53, 7%) was defined as a delivery prior to 37 completed weeks of gestation and SGA birth (n = 124, 16%) was defined as birth weight less than the 10th percentile for the infant’s gestational age and sex compared to US singleton live births. A twofold increase in the odds of SGA birth attributed to low-to-moderate alcohol intake was found among multinutrient supplement non-users (95% CI: 1.1, 5.3). Yet, among multinutrient supplement users, there was no increased risk of an SGA birth for women who drank low-to-moderately compared to women who abstained (aOR: 0.97, 95% CI: 0.6, 1.6). Similar results emerged for preterm birth. Our findings provide marginal evidence that multinutrient supplementation during early pregnancy may modify the risk of SGA births and preterm birth associated with alcohol consumption during pregnancy and may have important implications for pregnant women and women of child-bearing age. However, future research needs to be conducted.     

Coffee drinking and risk of preterm birth

OBJECTIVES: We analysed the association between coffee drinking before and during the three trimesters of pregnancy and the risk of preterm birth of babies normal for gestational age (NGA) or small for gestational age (SGA). METHODS: Case-control study conducted in University clinics of North Italy. Cases were 502 women who delivered at <37 weeks of gestation. The controls included 1966 women who gave birth at term (>or=37 weeks of gestation) to healthy infants on randomly selected days at the hospitals where cases had been identified. RESULTS: There was inverse association for coffee consumption in the third trimester of pregnancy in SGA cases compared to NGA (heterogeneity test between OR: chi1(2)=5.6811 P<0.05). In comparison with not drinkers, all the ORs of overall intake of caffeine were closed near the unity for both SGA and NGA preterm birth. CONCLUSION: Compared with no consumption, a low consumption of coffee during pregnancy may not have significant effects on preterm birth.     

Does inadequate prenatal care contribute to growth retardation among second-born African-American babies?

The authors evaluated the relation between adequacy of prenatal care and risk of delivery of full term small-for-gestational-age (SGA) infants. Data were derived from maternally linked birth certificates for 6,325 African-American women whose first two pregnancies ended in singleton, full term live births in Georgia from 1989 through 1992. The authors used stratified analysis to assess the effect of prenatal care on the risk of having an SGA baby in the second pregnancy among women with and without an SGA baby in their first pregnancy. The group of women with a history of SGA birth may be more likely to include persons for whom SGA delivery is related to factors, such as genetics, that are not amenable to intervention by prenatal care. Inadequate prenatal care was not associated with the risk of SGA delivery among women who had previously delivered an SGA baby. In unadjusted analyses, inadequate prenatal care was associated with an increased risk of delivering a full term SGA baby in the second pregnancy among women whose first baby was not SGA (risk ratio = 1.28; 95% confidence interval: 1.05, 1.55). The association did not persist when data were adjusted for confounding variables (odds ratio = 1.11; 95% confidence interval: 0.89, 1.38). Regardless of outcome in the first pregnancy, adequate prenatal care did not reduce the risk of full term SGA birth among second pregnancies in this population.     

Preconception homocysteine and B vitamin status and birth outcomes in Chinese women

BACKGROUND: The associations between homocysteine, B vitamin status, and pregnancy outcomes have not been examined prospectively. OBJECTIVE: We assessed the associations of preconception homocysteine and B vitamin status with preterm birth and birth of low-birth-weight (LBW) and small-for-gestational-age (SGA) infants in Chinese women. DESIGN: This was a case-control study of women aged 21-34 y. Preterm cases (n = 29) delivered living infants at <37 wk gestation; term controls (n = 405) delivered infants at > or =37 wk. LBW cases (n = 33) had infants weighing <2500 g; normal-birth-weight controls (n = 390) had infants weighing > or =2500 g. SGA cases (n = 65) had infants below the 10th percentile of weight-for-gestational-age; appropriate-for-gestational-age controls (n = 358) had infants above this cutoff. Nonfasting plasma concentrations of homocysteine, folate, and vitamins B-6 and B-12 were measured before conception. RESULTS: Elevated homocysteine (> or =12.4 micro mol/L) was associated with a nearly 4-fold higher risk of preterm birth (OR: 3.6; 95% CI: 1.3, 10.0; P < 0.05). The risk of preterm birth was 60% lower among women with vitamin B-12 > or =258 pmol/L than among vitamin B-12-deficient women (OR: 0.4; 95% CI: 0.2, 0.9; P < 0.05) and was 50% lower among women with vitamin B-6 > or =30 nmol/L than among vitamin B-6-deficient women (OR: 0.5; 95% CI: 0.2, 1.2; NS). Folate status was not associated with preterm birth, and homocysteine and B vitamin status were not associated with LBW or SGA status. CONCLUSIONS: Elevated homocysteine and suboptimal vitamin B-12 and B-6 status may increase the risk of preterm birth. These results need to be confirmed in larger prospective studies.     

Preconception Hemoglobin Concentration and Risk of Low Birth Weight and Small-for-Gestational-Age: A Large Prospective Cohort Study in China

Less is known about the impact of maternal preconception anemia on birth outcomes. We aimed to examine associations between preconception hemoglobin (Hb) concentrations with risk of low birth weight (LBW) and small-for-gestational-age (SGA). This study was from a large population-based prospective cohort in China and included 124,725 women with singleton live births delivered at gestational ages of 28–45 weeks who were registered before pregnancy. Maternal Hb concentrations were measured during registration, and other health-related information was recorded prospectively. Logistic regression was used to evaluate the associations between preconception Hb concentrations with risk of LBW and SGA, adjusting for potential confounders. The results showed women with preconception anemia accounted for 22.28%. The incidences of LBW/SGA were 2.37%/6.30% among anemic women, and 2.01%/5.48% among non-anemic women, respectively. Preconception mild anemia increased by 17% (95% confidence interval (CI): 1.06, 1.28) and 14% (95% CI: 1.07, 1.21) the risk for LBW and SGA, while moderate-to-severe anemia had no significant association with LBW and SGA. Compared with the 120–129 g/L group, a U-shaped association was observed between preconception Hb concentrations with LBW and SGA. In conclusion, not only maternal anemia but also elevated Hb concentrations before pregnancy contribute to an increased risk of LBW and SGA.     

Caffeinated coffee, decaffeinated coffee and endometrial cancer risk: a prospective cohort study among US postmenopausal women

There is plausible biological evidence as well as epidemiologic evidence to suggest coffee consumption may lower endometrial cancer risk. We evaluated the associations between self-reported total coffee, caffeinated coffee and decaffeinated coffee, and endometrial cancer risk using the Women's Health Initiative Observational Study Research Materials obtained from the National Heart, Lung, and Blood Institute Biological Specimen and Data Repository Coordinating Center. Our primary analyses included 45,696 women and 427 incident endometrial cancer cases, diagnosed over a total of 342,927 person-years of follow-up. We used Cox-proportional hazard models to evaluate coffee consumption and endometrial cancer risk. Overall, we did not find an association between coffee consumption and endometrial cancer risk. Compared to non-daily drinkers (none or <1 cup/day), the multivariable adjusted hazard ratios for women who drank ≥4 cups/day were 0.86 (95% confidence interval (CI) 0.63, 1.18) for total coffee, 0.89 (95% CI 0.63, 1.27) for caffeinated coffee, and 0.51 (95% CI 0.25, 1.03) for decaf coffee. In subgroup analyses by body mass index (BMI) there were no associations among normal-weight and overweight women for total coffee and caffeinated coffee. However among obese women, compared to the referent group (none or <1 cup/day), the hazard ratios for women who drank ≥2 cups/day were: 0.72 (95% CI 0.50, 1.04) for total coffee and 0.66 (95% CI 0.45, 0.97) for caffeinated coffee. Hazard ratios for women who drank ≥2 cups/day for decaffeinated coffee drinkers were 0.67 (0.43-1.06), 0.93 (0.55-1.58) and 0.80 (0.49-1.30) for normal, overweight and obese women, respectively. Our study suggests that caffeinated coffee consumption may be associated with lower endometrial cancer risk among obese postmenopausal women, but the association with decaffeinated coffee remains unclear.     

Spontaneous abortions and birth defects related to tap and bottled water use, San Jose, California, 1980-1985.

We recently studied pregnancies occurring during 1980-1985 in four study areas in Santa Clara County, California. Two of the areas were exposed to solvent-contaminated drinking water during 1980 and 1981, and two were unexposed. There was an overall excess of spontaneous abortions among women who reported any tapwater consumption during the first trimester of pregnancy compared with those who reported no tapwater consumption [odds ratio (OR) = 4.0; 95% confidence interval (CI) = 1.8-9.1)], regardless of exposure to the contaminated water. The odds ratio for spontaneous abortion for women reporting any vs no tapwater was 6.9 (95% CI = 2.7-17.7) after adjustment for numerous potential confounders using multiple logistic regression analyses. The elevated odds ratio of spontaneous abortion was seen among tapwater drinkers who used no filters or softener-type filters but not among women who reported use of active filters. Spontaneous abortion rates were reduced in women who reported any vs no bottled water consumption (OR = 0.26; 95% CI = 0.16-0.43). Among women who reported no tapwater consumption, no birth defects occurred among 263 live births; in comparison, among women who reported tapwater consumption, 4% of 908 live births had defects (P = 0.0001). We observed no relation between birth defects and bottled water use.     

Parental occupational exposure to pesticides and childhood germ-cell tumors

In a recently completed US case-control study (Children's Oncology Group, 1993-2001) with 253 cases and 394 controls, the authors investigated the association between parental occupational exposure to pesticides and risk of childhood germ-cell tumors. Information on occupational pesticide exposure was collected using job-specific module questionnaires and assessed by an experienced industrial hygienist. Odds ratios for childhood germ-cell tumors associated with maternal exposures before pregnancy, during pregnancy, and after the birth of the index child were 1.0 (95% confidence interval (CI): 0.8, 1.4), 1.1 (95% CI: 0.7, 1.6), and 1.3 (95% CI: 0.9, 1.8), respectively. Paternal exposures before pregnancy, during pregnancy, and after the birth of the index child were not related to germ-cell tumors (odds ratios (ORs) were 0.9 (95% CI: 0.7, 1.2), 0.8 (95% CI: 0.5, 1.2), and 0.8 (95% CI: 0.5, 1.3), respectively). When both parents had ever been occupationally exposed to pesticides before the index pregnancy, the odds ratio was 0.8 (95% CI: 0.4, 1.3). Subgroup analyses showed a positive association between maternal exposure to herbicides during the postnatal period and risk of germ-cell tumors in girls (OR = 2.3, 95% CI: 1.0, 5.2) and an inverse association between paternal exposure to pesticides during the index pregnancy and germ-cell tumors in boys (OR = 0.2, 95% CI: 0.1, 1.0). This study did not provide strong evidence supporting a relation between parental pesticide exposure in the workplace and risk of germ-cell tumors among offspring.     

Coffee consumption and risk of myocardial infarction among older Swedish women

Numerous studies have examined the association between coffee consumption and risk of myocardial infarction (MI), but results have been inconsistent. Case-control studies generally suggest a harmful effect of coffee drinking, whereas cohort studies have mostly shown no association. Recent studies found that coffee may lower the risk of diabetes, a major coronary risk factor. The authors prospectively examined the effect of coffee consumption on MI risk in 32,650 older Swedish women, aged 40-74 years, participating in the Swedish Mammography Cohort; 459 cases of MI developed during 165,896 person-years of follow-up from 1997 to 2002. After adjustment for age, coronary heart disease risk factors, and dietary variables, the relative risk of MI associated with drinking >/=5 cups/week versus 0-4 cups/week was 0.68 (95% confidence interval (CI): 0.43, 1.07). The authors observed a nonsignificant trend toward lower risk with higher consumption levels. Compared with that for 0-4 cups/week, the relative risks of MI were 0.84 (95% CI: 0.51, 1.38) for 5-7 cups/week, 0.65 (95% CI: 0.41, 1.03) for 2-3 cups/day, 0.64 (95% CI: 0.39, 1.04) for 4-5 cups/day, and 0.65 (95% CI: 0.37, 1.12) for >/=6 cups/day (p-trend = 0.07). Contrary to previous case-control studies, the authors concluded that coffee consumption does not increase MI risk. Coffee consumption of >/=5 cups/week was nonsignificantly inversely associated with MI risk among older Swedish women.     

Effect of maternal smoking and coffee consumption on the risk of having a recognized Down syndrome pregnancy

To evaluate the possible effects of maternal smoking and caffeine or coffee consumption on the occurrence of a recognized pregnancy with Down syndrome, the authors analyzed data from a case-control study of 997 liveborn infants or fetuses with Down syndrome ascertained in California from 1991 to 1993 and 1,007 liveborn controls without a birth defect. Interviews with mothers covered demographic information, pregnancy, and medical history, with detailed questions on the use of tobacco, alcohol, and caffeinated beverages. All analyses were age-adjusted. High alcohol consumption (> or =4 drinks/week) in the first month of pregnancy was associated with reduced risk for a recognized Down syndrome conceptus (odds ratio (OR) = 0.54; 95% confidence interval (CI): 0.34, 0.85). Maternal smoking during the periconceptional period was not associated with risk of recognized Down syndrome (OR = 1.04; 95% CI: 0.79, 1.37), but maternal consumption of four or more cups of coffee per day was inversely associated (OR = 0.63; 95% CI: 0.41, 0.96). In multivariate analysis, a significant interaction between coffee drinking and smoking was observed. The inverse association remained only for nonsmoking mothers who drank four or more cups of coffee per day (OR = 0.48; 95% CI: 0.28, 0.82). These results suggest that among nonsmoking mothers, high coffee consumption is more likely to reduce the viability of a Down syndrome conceptus than that of a normal conceptus.     

Are there associations between coffee consumption and glucose tolerance in elderly subjects?

OBJECTIVE: To describe the associations between coffee consumption and glucose tolerance among elderly subjects. DESIGN: A survey among an unselected non-institutionalized elderly population. Diabetes was assessed on the basis of self-reports and 2-h oral glucose tolerance test for the subjects on diet treatment or with normal glucose tolerance (NGT). Coffee consumption was assessed by a questionnaire. SETTING: Three municipalities in Northern Finland Subjects: All non-institutionalized subjects with baseline normal glucose tolerance or impaired glucose tolerance (IGT) aged 70 years or over. MAIN OUTCOME MEASURES: Incidence, persistence or impairment of abnormal glucose tolerance (AGT). RESULTS: Forty-two percent of those with NGT and 0-5 cups of coffee daily developed AGT, whereas the corresponding figure was 25% for those who drank more than five cups coffee daily. Fifty-five percent of the subjects with IGT or NGT who drank 0-5 cups coffee daily either persisted in IGT or developed AGT. The corresponding figure was 30% for those drinking more than five cups coffee daily. After adjustment for age, body mass index, cardiovascular disease, smoking, alcohol consumption and physical exercise, among those with NGT, the odds ratio (OR) for developing AGT was 2.3 for those drinking 0-5 cups compared to those drinking more than five cups of coffee daily (95% confidence interval (CI) 0.7-7.2). Correspondingly, low coffee consumption was the most powerful predictor associated with the persistence of IGT or the development of AGT (OR 2.9; 95% CI 1.2-6.9). CONCLUSIONS: Low coffee consumption predicts impairment of AGT or persistence of IGT among elderly subjects.     

Low birth weight in relation to multiple induced abortions.

BACKGROUND. Most studies report that a single induced abortion does not increase risk for delivering a low birth weight infant in a subsequent pregnancy. However, the effect of multiple abortions has not been adequately evaluated. METHODS. This relationship was studied in 6541 White women who delivered their first child between 1984 and 1987. We compared the frequencies of low birth weight (less than 2500 g) among infants born to 1999 women without prior induced abortion and 1999 women with one abortion with the frequencies of low birth weight among infants born to women with two (n = 1850), three (n = 520), and four or more (n = 173) prior induced abortions. RESULTS. After adjustment for confounding variables, we found no linear relationship in risk of low birth weight among women with one (relative risk [RR] = 1.2, 95% confidence interval [CI] = 0.9-1.5), two (RR = 1.5, 95% CI = 1.1-2.0), three (RR = 1.3, 95% CI = 0.8-1.9), or four or more (RR = 1.6, 95% CI = 0.9-2.9) prior induced abortions. CONCLUSIONS. These findings confirm earlier reports of little or no evidence of harmful effects on birth weight by one or by two or more induced abortions. We further report that risk is not significantly elevated even in women with three, four, or more prior terminations of pregnancy when compared with women with one or two abortions.     

Alcohol drinking and risk of small for gestational age birth

OBJECTIVE: To assess if alcohol drinking is a risk factor for small for gestational age (SGA) birth. METHODS: Case-control study. Cases were 555 women (mean age 31 years, range 16-43) who delivered SGA babies at the Clinica Luigi Mangiagalli and the Obstetric and Gynecology Clinic of the University of Verona. The controls were 1966 women (mean age 31 years, range 14-43) who gave birth at term (> or =37 weeks of gestation) to healthy infants of normal weight at the hospitals where cases had been identified. RESULTS: No increase in the risk of SGA birth was observed in women drinking one or two drinks/day in pregnancy, but three or more per day increased the risk: odds ratios (OR) were 3.2 (1.7-6.2) for > or =3 drinks during the first trimester, 2.7 (1.4-5.3) during the second and 2.9 (1.5-5.7) during the third. CONCLUSIONS: The study shows an increased risk of SGA births in mothers who drink > or =3 units/day of alcohol in pregnancy.     

The use of data set of the Hungarian case-control surveillance of congenital abnormalities for evaluation of birth outcomes beyond birth defects

AIMS: To use the data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities (HCCSCA) for the evaluation of birth outcomes beyond congenital abnormalities and to show as example the study of 49 antimicrobial drugs used in Hungary for the reduction of preterm births. METHODS: The population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996, included 38,151 newborn infants without birth defects and this sample represented 1.8% of Hungarian births. Medically recorded gestational age at delivery and birthweight, in addition the rate of preterm births and low birthweight newborns born to mothers with or without different antimicrobial drugs used at least by ten pregnant women were analysed. RESULTS: Of 49 antimicrobial drugs, two: ampicillin (adjusted POR with 95% CI: 0.8, 0.7-0.9) and clotrimazole (0.8, 0.7-0.9) showed a preterm birth preventive effect. This preterm preventive effect was found mainly after the use of ampicillin and clotrimazole during the first trimester of pregnancy. CONCLUSIONS: Ampicillin and clotrimazole may be effective for the reduction of preterm births due to infectious diseases of pregnant women in general but particularly caused by genital infections. However, the limitation of the data set did not allow the appropriate evaluation of some antimicrobial drugs (e.g. clindamycin).     

Traffic-related atmospheric pollutants levels during pregnancy and offspring's term birth weight: a study relying on a land-use regression exposure model

BACKGROUND: Some studies have suggested that particulate matter (PM) levels during pregnancy may be associated with birth weight. Road traffic is a major source of fine PM (PM with aero-dynamic diameter < 2.5 microm; PM(2.5)). OBJECTIVE: We determined to characterize the influence of maternal exposure to atmospheric pollutants due to road traffic and urban activities on offspring term birth weight. METHODS: Women from a birth cohort [the LISA (Influences of Lifestyle Related Factors on the Human Immune System and Development of Allergies in Children) cohort] who delivered a non-premature baby with a birth weight > 2,500 g in Munich metropolitan area were included. We assessed PM(2.5), PM(2.5) absorbance (which depends on the blackness of PM(2.5), a marker of traffic-related air pollution), and nitrogen dioxide levels using a land-use regression model, taking into account the type and length of roads, population density, land coverage around the home address, and temporal variations in pollution during pregnancy. Using Poisson regression, we estimated prevalence ratios (PR) of birth weight < 3,000 g, adjusted for gestational duration, sex, maternal smoking, height, weight, and education. RESULTS: Exposure was defined for 1,016 births. Taking the lowest quartile of exposure during pregnancy as a reference, the PR of birth weight < 3,000 g associated with the highest quartile was 1.7 for PM(2.5) [95% confidence interval (CI), 1.2-2.7], 1.8 for PM(2.5) absorbance (95% CI, 1.1-2.7), and 1.2 for NO(2) (95% CI, 0.7-1.7). The PR associated with an increase of 1 microg/m(3) in PM(2.5) levels was 1.13 (95% CI, 1.00-1.29). CONCLUSION: Increases in PM(2.5) levels and PM(2.5) absorbance were associated with decreases in term birth weight. Traffic-related air pollutants may have adverse effects on birth weight.