Environmental tobacco smoke and low birth weight: a hazard in the workplace?

Polycyclic aromatic hydrocarbon (PAH) exposure during pregnancy and child anthropometry from birth to 10 years of age: Sex-specific evidence from a cohort study in rural Bangladesh

Polycyclic aromatic hydrocarbons (PAHs) have endocrine disrupting properties and they cross the placental barrier, but studies on gestational exposure and child anthropometry are inconclusive. We aimed to elucidate the impact of early gestational PAH exposure on anthropometry from birth to 10 years of age in 1295 mother-child pairs from a nested sub-cohort of the MINIMat trial in Bangladesh. Several PAH metabolites [1-hydroxyphenanthrene (1-OH-Phe), Σ2-,3-hydroxyphenanthrene (Σ2-,3-OH-Phe), 4-hydroxyphenanthrene (4-OH-Phe), 1-hydroxypyrene (1-OH-Pyr), Σ2-,3-hydroxyfluorene (Σ2-,3-OH-Flu)] were quantified in spot urine collected around gestational week 8 using LC-MS/MS. Child weight and height were measured at 19 occasions from birth to 10 years. Multivariable-adjusted regression models were used to assess associations of maternal PAH metabolites (log₂-transformed) with child anthropometry. The median concentration of 1-OH-Phe, Σ2-,3-OH-Phe, 4-OH-Phe, 1-OH-Pyr and Σ2-,3-OH-Flu was 1.5, 1.9, 0.14, 2.5, and 2.0 ng/mL, respectively. All maternal urinary PAH metabolites were positively associated with newborn weight and length and all associations were more pronounced in boys than in girls (p interaction for all <0.14). In boys, the strongest associations were observed with Σ2-,3-OH-Phe and Σ2-,3-OH-Flu for which each doubling increased mean birth weight by 41 g (95% CI: 13; 69 and 12; 70) and length by 0.23 cm (0.075; 0.39) and 0.21 cm (0.045; 0.37), respectively. Maternal urinary PAH metabolites were not associated with child anthropometry at 10 years. In longitudinal analysis, however, maternal urinary PAH metabolites were positively associated with boys' weight-for-age (WAZ) and height-for-age Z-scores (HAZ) from birth to 10 years, but only the association of 4-OH-Phe with HAZ was significant (B: 0.080 Z-scores; 95% CI 0.013, 0.15). No associations were observed with girls' WAZ or HAZ. In conclusion, gestational PAH exposure was positively associated with fetal and early childhood growth, especially in boys. Further studies are needed to confirm causality and to explore long-term health effects.

The Effect of Active and Passive Maternal Smoking During Pregnancy on the Uterine Artery Blood Flow and Obstetric Outcomes: A Prospective Study

BACKGROUND AND AIM

Maternal smoking is associated with an increased risk of obstetric and neonatal complications during pregnancy. We aimed to investigate the effects of active and passive smoking on fetal-maternal blood flow and fetal complications in mid-trimester pregnant women.

METHODS

This prospective study was conducted at Zekai Tahir Burak Women's Research and Training Hospital and included women who were 20 to 22 weeks old, with no fetal anomalies, and with a singleton pregnancy. The data used in the analysis were obtained from a total of 168 pregnant women (50 smokers, 50 passive smokers, and 68 non-smokers). Starting from their 20^th week of pregnancy, the women were examined at least once in each trimester. Fetal and maternal pregnancy results were evaluated. Fetal biometry, umbilical, and uterine artery Doppler ultrasonography were performed. To evaluate the flow in these veins, the pulsatility index, resistance index, and systole/diastole (S/D) ratio were performed.

RESULTS

The mean age of study patients was 25.06 ± 4.36 years and the mean gestational week was 20.03 ± 0.6 weeks. In terms of the umbilical artery pulsatility index (UMBAPI), umbilical artery systolic/diastolic ratio (UMBAS/D),uterine artery resistance index (UARI), uterine artery pulsatility index (UAPI), and uterine artery systolic/diastolic ratio (UAS/D) levels, the mean value of the smoker group was significantly higher compared to the non-smoker group (p<0.001, p=0.043, p=0.021, p=0.020, and p=0.037, respectively). The birth weight of the fetus was significantly lower in the active and passive smoker groups than in the non-smoker group (p=0.009 and p=0.006, respectively). The number of patients diagnosed with intrauterine growth restriction (IUGR) and oligohydramnios were significantly higher in the smoker group than in the passive smoker and non-smoker groups (p=0.003 and p<0.001, respectively). The risk of low birth weight (OR, (95% CI): 3.38 (2.05 - 5.57); p=0.024), oligohydramnios (OR (95% CI): 13.44 (5.22 - 34.57); p=0.001), IUGR (OR (95% CI): 9.33 (4.50 - 19.33); p=0.001), and preterm birth (OR (95% CI): 4.56 (1.25 - 17.32); p=0.001) increased significantly in the active and passive cigarette exposure groups, compared to the non-smokers.

CONCLUSION

During pregnancy, both smoking and passive exposure to cigarette smoke adversely affect the fetus and the newborn. Uterine and umbilical artery Doppler measurements in pregnant women who smoke are significantly higher than the pregnant women who do not smoke.

Association between maternal lifestyle factors and low birth weight in preterm and term births: a case-control study

Background

It has been reported that lifestyle factors may affect birth weight; however, few studies have explored the association between lifestyle factors and low birth weight in preterm and term births in China. The objective of this study was to explore the effect of lifestyle on low birth weight in preterm and term births.

Methods

This case-control study was conducted in fourteen hospitals in Jiangmen, Guangdong Province. Data were collected from August 2015 to May 2016 using a standard questionnaire. Data were analysed using logistic regression.

Results

Women who delivered preterm and were physically active (1–3 times per week and ≥ 4 times per week) had reduced odds of having low birth weight babies (aOR = 0.584, 95%CI = 0.394–0.867 and, aOR = 0.516, 95%CI = 0.355–0.752, respectively). Pregnant women who had insufficient gestational weight gain had increased odds of having low birth weight babies (aOR = 2.272, 95%CI = 1.626–3.176). Women exposed to passive smoking had an increased risk of delivering low birth weight infants (aOR = 1.404, 95%CI = 1.057–1.864). Insufficient gestational weight gain and excessive gestational weight gain were both significantly associated with low birth weight (aOR = 1.484, 95%CI = 1.103–1.998 and aOR = 0.369, 95%CI = 0.236–0.577, respectively) for term deliveries. In addition, parity, history of low birth weight, antenatal care and gestational hypertension were significantly associated with the likelihood of low birth weight.

Conclusion

Pregnant women without exercise contraindications should remain physically active. Pregnant women should be aware of the negative effects of smoke and be aware of strategies to protect themselves from passive smoke exposure. Hospitals should inform pregnant women of the importance appropriate gestational weight gain. These recommendations should be put into practice to decrease the prevalence of low birth weight infants.

Arsenic and birth outcomes in a predominately lower income Hispanic pregnancy cohort in Los Angeles

Prenatal arsenic exposure has been associated with reduced fetal growth and increased risk for preterm birth, but most studies have been conducted in highly exposed populations outside the U.S. or in non-Hispanic populations in the rural U.S. The objectives of the current study were to: 1) examine the impact of early pregnancy exposure to arsenic on birth weight and gestational age at birth in a predominately lower income Hispanic pregnancy cohort in urban Los Angeles and 2) compare multiple biomarkers of arsenic exposure (blood, urine, and hair) assessed in early pregnancy (mean ± SD gestational age at biospecimen collection: 14 ± 4 weeks). Total arsenic (blood, hair) was measured by ICP-MS and speciated arsenic (urine) was measured by HPLC coupled to ICP-MS. Associations between log₂-transformed arsenic measures and birth outcomes were evaluated using multivariable linear regression. A doubling in hair arsenic was associated with a 72.2 g (95% CI: -144.3, -0.1, P = 0.05) lower birth weight, after adjusting for potential confounders and gestational age at birth. A similar but non-significant trend was observed for blood arsenic, but not urine arsenic. The inverse association between hair arsenic and birth weight was more pronounced among infants whose mothers gained greater amounts of weight during pregnancy (P_interaction = 0.02). The association between urinary monomethyl arsenic and GA at birth differed by pre-pregnancy BMI (P_interaction<0.01). This study provides evidence that even at relatively low levels of exposure, arsenic exposure (measured in hair samples collected in early pregnancy) may adversely affect fetal growth in this understudied population, particularly in combination with greater gestational weight gain. Future studies with larger sample sizes are needed to confirm these findings and to further investigate some of the inconsistencies observed for the different arsenic biomarkers evaluated.

Social determinants of smoke exposure during pregnancy: Findings from waves 1 & 2 of the Population Assessment of Tobacco and Health (PATH) Study

Maternal smoking during pregnancy (MSDP) and secondhand smoke (SHS) exposure are associated with a myriad of negative health effects for both mother and child. However, less is known regarding social determinants for SHS exposure, which may differ from those of maternal smoking during pregnancy (MSDP). To identify social determinants for SHS exposure only, MSDP only, and MSDP and SHS exposure, data were obtained from all pregnant women (18-54 years; N = 726) in waves 1 and 2 of the Population Assessment of Tobacco and Health Study (2014-2015). Multiple logistic regressions were conducted using SAS 9.4. Smoke exposure during pregnancy was common; 23.0% reported SHS exposure only, 6.1% reported MSDP only, and 11.8% reported both SHS exposure and MSDP. Results demonstrate that relationships between smoke exposure during pregnancy and social determinants vary by type of exposure. Women at risk for any smoke exposure during pregnancy include those who are unmarried and allow the use of combustible tobacco products within the home. Those who are at higher risk for SHS exposure include those who are younger in age, and those who are earlier in their pregnancy. Those who are at higher risk for maternal smoking include those with fair/poor mental health status and those who believe that others' view tobacco use more positively. These results suggest the need for implementing more comprehensive policies that promote smoke-free environments. Implementing these strategies have the potential to improve maternal and fetal health outcomes associated with tobacco smoke exposure.

Correlation between tobacco control policies and preterm births and low birth weight in Europe

OBJECTIVE

To assess the correlation between tobacco control policies- particularly smoking bans in work and public places-and the prevalence of preterm births and low birth weight in the European countries.

METHODS

This is an ecological study and the unit of analysis set at the country level. Tobacco control data in Europe were obtained for the years 2010 and 2013 as measured by the Tobacco Control Scale (TCS), which reflects the level of implementation of tobacco control policies. Prevalence data for preterm births and low birth weight were obtained from two sources: the European Perinatal Health Report (EPHR), which provides data for 2010, and the Eurostat data, which includes the years 2013 and 2014. We analyzed the correlation between the TCS score and the prevalence of preterm birth and low birth weight in the European countries by means of Spearman (rsp) rank-correlation coefficients and their 95% confidence intervals (95%CI).

RESULTS

The 2010 TCS was negatively correlated with the prevalence of preterm births before week 37 (rsp = -0.51; 95% CI: -0.77, -0.15; p = 0.006) and week 32 (rsp = -0.42; 95%CI: -0.73, -0.01; p = 0.030) and with the prevalence of the low birth weight (< 2500g, (rsp = -0.42; 95% CI: -0.66, -0.09; p = 0.028) in European countries in 2010. We found a statistically significant inverse correlation between the level of restrictions on smoking in public places and the prevalence of low birth weight (< 2500g rsp: -0.54; 95%CI: -0.72, -0.10; p = 0.017).

CONCLUSION

The level of smoke-free legislation in European countries correlates with lower preterm birth prevalence rates at the ecological level. Given the important negative effects of premature births for the public health system, these data support greater implementation of smoke-free policies and tend to support the implementation of tobacco control policies, but more research is needed.

Low-level maternal exposure to nicotine associates with significant metabolic perturbations in second-trimester amniotic fluid

Decades of public health research have documented that smoking in pregnancy poses significant health risks to both mother and child. More recent studies have shown that even passive maternal exposure to secondhand smoke associates with negative birth outcomes. However, the mechanisms linking exposure to outcomes have remained obscure. As a first step toward defining the metabolic consequence of low-level nicotine exposure on fetal development, we conducted an untargeted metabolomic analysis of 81 paired samples of maternal serum and amniotic fluid collected from karyotypically normal pregnancies in the second trimester. By comparing the m/z and retention times of our mass spectral features with confirmed standards, we identified cotinine, a nicotine derivative, and used the calculated cotinine concentrations to classify our maternal serum samples into exposure groups using previously defined cut-offs. We found that cotinine levels consistent with low-level maternal exposure to nicotine associated with distinct metabolic perturbations, particularly in amniotic fluid. In fact, the metabolic effects in amniotic fluid of ostensibly low-level exposed mothers showed greater overlap with perturbations previously observed in the sera of adult smokers than did the perturbations observed in the corresponding maternal sera. Dysregulated fetal pathways included aspartate and asparagine metabolism, pyrimidine metabolism, and metabolism of other amino acids. We also observed a strong negative association between level of maternal serum cotinine and acetylated polyamines in the amniotic fluid. Combined, these results confirm that low-level maternal nicotine exposure, indicated by a maternal serum cotinine level of 2-10ng/mL, is associated with striking metabolic consequences in the fetal compartment, and that the affected pathways overlap those perturbed in the sera of adult smokers.

Patterns of Smoking Behaviour in Low-Income Pregnant Women: A Cohort Study of Differential Effects on Infant Birth Weight

Maternal smoking accounts for 20%-30% of low birth weight (BW). Second-Hand Smoke (SHS) also negatively affects BW. This cohort study explored the differential effect of smoking patterns during pregnancy on infant BW. Smoking status for 652 self-reported smokers attending public ante-natal clinics was assessed at baseline (V1 first ante-natal visit), 28-32 weeks (V2) and one week after birth (V3). Multivariable generalised linear regression models tested smoking patterns (continuing to smoke, sustained quitting, partial quitting) on BW adjusting for household smoking and other co-variates. Total quitting showed a median increase of 288 g in BW (95% CI (confidence intervals): 153.1-423 g, p < 0.001), compared to partial quitting (147 g, (95% CI: 50-244 g), p < 0.003). In partial quitters, increased BW was observed only in females 218 g, (95% CI: 81-355 g), p = 0.002). Household SHS showed a specific negative influence on pre-term but not term BW. This study suggests that, for low-income women, quitting or partial quitting during pregnancy both have a positive influence on infant BW. Whether others in the household smoke is also important.

Air Pollution Impact on Pregnancy Outcomes in Como, Italy

OBJECTIVE

This retrospective observational study investigates the association between maternal exposure to air pollutants and pregnancy adverse outcomes in low urbanization areas.

METHODS

We used multivariate regression analysis to estimate, in the Como province (2005-2012), the effects of NO(x), NO2, SO2, O3, CO, and PM10 on low birth weight (LBW), babies small for gestational age (SGA), and preterm birth (PTB).

RESULTS

PTB was inversely associated with high (5.5 μg/m³) exposure to SO2 (adjusted odds ratio [aOR] = 0.74, 95% confidence interval [95% CI] = 0.58-0.95) and to CO (1.8 mg/m³, aOR = 0.84, CI = 0.72-0.99). PTB risk increased with second trimester exposure to NO(x) (118.3 μg/m³, aOR = 1.53, CI = 1.25-1.87), while LBW risk increased with third trimester PM10 (56.1 μg/m³, aOR = 1.44, CI = 1.03-2.02). SGA was inversely associated with third trimester NO(x) (115.8 μg/m³, aOR = 0.89, CI = 0.79-0.99).

CONCLUSIONS

Exposure to SO2 and CO seems to postpone delivery: a longer gestation could compensate for maternal hypoxemic-hypoxic damage.

Prenatal Arsenic Exposure and Birth Outcomes among a Population Residing near a Mining-Related Superfund Site

BACKGROUND

Limited epidemiologic data exist on prenatal arsenic exposure and fetal growth, particularly in the context of co-exposure to other toxic metals.

OBJECTIVE

We examined whether prenatal arsenic exposure predicts birth outcomes among a rural U.S. population, while adjusting for exposure to lead and manganese.

METHODS

We collected maternal and umbilical cord blood samples at delivery from 622 mother-infant pairs residing near a mining-related Superfund site in Northeast Oklahoma. Whole blood arsenic, lead, and manganese were measured using inductively coupled plasma mass spectrometry. We modeled associations between arsenic concentrations and birth weight, gestational age, head circumference, and birth weight for gestational age.

RESULTS

Median (25th-75th percentile) maternal and umbilical cord blood metal concentrations, respectively, were as follows: arsenic, 1.4 (1.0-2.3) and 2.4 (1.8-3.3) μg/L; lead, 0.6 (0.4-0.9) and 0.4 (0.3-0.6) μg/dL; manganese, 22.7 (18.8-29.3) and 41.7 (32.2-50.4) μg/L. We estimated negative associations between maternal blood arsenic concentrations and birth outcomes. In multivariable regression models adjusted for lead and manganese, an interquartile range increase in maternal blood arsenic was associated with -77.5 g (95% CI: -127.8, -27.3) birth weight, -0.13 weeks (95% CI: -0.27, 0.01) gestation, -0.22 cm (95% CI: -0.42, -0.03) head circumference, and -0.14 (95% CI: -0.24, -0.04) birth weight for gestational age z-score units. Interactions between arsenic concentrations and lead or manganese were not statistically significant.

CONCLUSIONS

In a population with environmental exposure levels similar to the U.S. general population, maternal blood arsenic was negatively associated with fetal growth. Given the potential for relatively common fetal and early childhood arsenic exposures, our finding that prenatal arsenic can adversely affect birth outcomes is of considerable public health importance.

CITATION

Claus Henn B, Ettinger AS, Hopkins MR, Jim R, Amarasiriwardena C, Christiani DC, Coull BA, Bellinger DC, Wright RO. 2016. Prenatal arsenic exposure and birth outcomes among a population residing near a mining-related Superfund site. Environ Health Perspect 124:1308-1315; http://dx.doi.org/10.1289/ehp.1510070.

Parental smoking during pregnancy shortens offspring's legs

One of the most severe detrimental environmental factors acting during pregnancy is foetal smoke exposure. The aim of this study was to assess the effect of maternal, paternal and parental smoking during pregnancy on relative leg length in 7- to 10-year-old children. The research conducted in the years 2001-2002 included 978 term-born children, 348 boys and 630 girls, at the age of 7-10 years. Information concerning the birth weight of a child was obtained from the health records of the women. Information about the mother's and the father's smoking habits during pregnancy and about the mothers' education level was obtained from a questionnaire. The influence of parental smoking on relative leg length, controlled for age, sex, birth weight and the mother's education, as a proxy measure of socioeconomic status, and controlled for an interaction between sex and birth weight, was assessed by an analysis of covariance, where relative leg length was the dependent variable, smoking and sex were the independent variables, and birth weight as well as the mother's education were the covariates. Three separate analyses were run for the three models of smoking habits during pregnancy: the mother's smoking, the father's smoking and both parents' smoking. Only both parents' smoking showed a significant effect on relative leg length of offspring. It is probable that foetal hypoxia caused by carbon monoxide contained in smoke decelerated the growth of the long bones of foetuses.

Comparative Evaluation of the Impact of Subacute Exposure of Smokeless Tobacco and Tobacco Smoke on Rat Testis

This study investigated the effects of 30-day exposure to tobacco smoke (TS), smokeless tobacco (ST), and nicotine on reproductive parameters and oxidative biomarkers in prepubertal and adult male rats. Sperm motility was reduced by 77.5 and 89.0% in TS and ST exposed prepubertal rats and 71.1 and 86.4% in adult rats, respectively. Sperm count was also reduced by 64.7 and 89.9% in prepubertal rats and 64.9 and 47.0% in adult rats, respectively. Nicotine decreased sperm motility (82.2%) and count (62.6%) in prepubertal rats but caused no effect in adult rats. There were no changes in sperm morphology; testosterone was decreased, while LH and FSH were increased in exposed rats, when compared with control. Malondialdehyde levels in testes of exposed rats were increased, and GSH, SOD, and catalase were altered. Results indicate that subacute exposure of tobacco products alters sperm characteristics in a rank order of ST > TS > nicotine, which may be linked to increase in oxidative stress in the testis.

Genetic variation affects congenital heart defect susceptibility in offspring exposed to maternal tobacco use

BACKGROUND

Congenital heart defects (CHDs) are among the most prevalent and serious birth defects, occurring in 8 to 10 of every 1000 live births in the United States. Epidemiologic studies have reported an association between CHDs and maternal smoking, but it remains unknown how genes impact the susceptibility of offspring to CHDs in the presence of maternal tobacco use.

METHODS

Using data from 403 case- and 219 control-parental triads enrolled in the National Birth Defects Prevention Study between 1998 and 2008, we investigated the association between CHDs and maternal and infant genetic variants involved in the tobacco metabolism and DNA repair pathways among mothers who smoked prenatally.

RESULTS

The maternal genotypes of single nucleotide polymorphisms in the excision repair cross-complementation group 1 (ERCC1), poly (ADP-ribose) polymerase 2 (PARP2), and ERCC5 genes were identified to be significantly associated with the occurrence of CHDs in the presence of maternal tobacco use. Our analysis also revealed a moderate association between the infant genotypes of polymorphisms in the O-sialoglycoprotein endopeptidase (OSGEP) gene and increased risk of CHDs among mothers who smoked.

CONCLUSION

Our study provides evidence that maternal and infant polymorphisms within the ERCC1, PARP2, ERCC5, and OSGEP genes are associated with CHD risk in the presence of maternal tobacco use. These results may provide insight into the susceptibility of having a pregnancy affected by CHDs among women who smoke.

Inequities in workplace secondhand smoke exposure among nonsmoking women of reproductive age

OBJECTIVES

We characterized workplace secondhand smoke exposure among nonsmoking women of reproductive age as a proxy for workplace secondhand smoke exposure during pregnancy.

METHODS

We included nonsmoking women aged 18 to 44 years employed during the past 12 months who participated in the 2010 National Health Interview Survey. We estimated the prevalence of workplace secondhand smoke exposure and its associations with sociodemographic and workplace characteristics.

RESULTS

Nine percent of women reported workplace secondhand smoke exposure. Prevalence decreased with increasing age, education, and earnings. Workplace secondhand smoke exposure was associated with chemical exposure (prevalence odds ratio [POR] = 3.3; 95% confidence interval [CI] = 2.3, 4.7); being threatened, bullied, or harassed (POR = 3.2; 95% CI = 2.1, 5.1); vapors, gas, dust, or fume exposure (POR = 3.1; 95% CI = 2.3, 4.4); and worrying about unemployment (POR = 3.0; 95% CI = 1.8, 5.2), among other things.

CONCLUSIONS

Comprehensive smoke-free laws covering all workers could eliminate inequities in workplace secondhand smoke exposure, including during pregnancy.

Influence of maternal environmental tobacco smoke exposure assessed by hair nicotine levels on birth weight

BACKGROUND

While the perinatal outcomes of active maternal smoking are well documented, results of the effects of environmental tobacco smoke (ETS) exposure during pregnancy are inconsistent. We aimed to examine the effect of ETS exposure, assessed by maternal hair nicotine levels at 35th week of gestation, on birth weight and the risk of small for gestational age (SGA) and low birth weight (LBW).

MATERIALS AND METHODS

A total of 871 non-smoking healthy pregnant women were recruited by one Korean hospital between 1 October 2006 and 31 July 2007. Hair samples were collected and anthropometric questionnaires administered at 35th week of gestation. The primary outcome was birth weight and secondary outcomes were the risk of babies being SGA and LBW.

RESULTS

Log-transformed hair nicotine concentrations were inversely related with birth weight after adjusting for confounding variables (β=-0.077, p=0.037). After stratifying hair nicotine levels by tertiles (T1, low [0.0-0.28 ng/mg]; T2, medium [0.29-0.62 ng/mg]; and T3, high [0.63-5.99 ng/mg]), the mean birth weight in each groups were 3,342 g (T1) 3,296 g (T2) and 3,290 g (T3), respectively. However the difference between groups was not statistically significant by analysis of co-variance (ANCOVA) adjusting for covariates (p=0.062). In logistic regression analysis, the risk of SGA was higher in the T3 (OR=1.59, 95%CI 1.05-2.42) than in the reference group (T1), after controlling for confounding variables. The risk of low birth weight (<2,500 g, LBW) was not significantly higher (OR=1.44, 95%CI 0.95-2.19), but the risk of babies being below 3,000g birth weight was increased in the T3 group (OR=1.53, 95%CI 1.00-2.36) compared with that in the T1 group.

CONCLUSIONS

Maternal ETS exposure during pregnancy was inversely related with birth weight. The risk of SGA increased in the highest ETS exposure group compared with in the low exposure group. To prevent ETS exposure during pregnancy, more comprehensive tobacco control policies are needed.

Adverse effects of parental smoking during pregnancy in urban and rural areas

Background

Parental smoking during pregnancy is associated with lower birthweight and gestational age, as well as with the risks of low birthweight (LBW) and preterm birth. The present study aims to assess the association of parental smoking during pregnancy with birth outcomes in urban and rural areas.

Methods

This was a secondary analysis of data collected in the Indonesia Family Life Survey, between 1993 and 2007, the first national prospective longitudinal cohort study in Indonesia. Retrospective data of parental smoking habits, socioeconomic status, pregnancy history and birth outcomes were collected from parents with children aged 0 to 5 years (n = 3789). We assessed the relationships between the amount of parental smoking during pregnancy with birthweight (LBW) and with gestational age (preterm birth).

Results

We found a significant reduction in birthweight to be associated with maternal smoking. Smoking (except for paternal smoking) was associated with a decrease in the gestational age and an increased risk of preterm birth. Different associations were found in urban area, infants born to smoking fathers and both smoking parents (>20 cigarettes/day for both cases) had a significant reduction in birthweight and gestational age as well as an increased risk of LBW and preterm birth.

Conclusions

Residence was found to be an effect modifier of the relation between parental smoking during pregnancy, amount of parental smoking, and birth outcomes on their children. Smoking cessation/reduction and smoking intervention program should be advised and prioritized to the area that is more prone to the adverse birth outcomes.

Prenatal risk factors for depression: a critical review of the evidence and potential mechanisms

Exposure to adverse experiences in early life increases the risk of depression during adulthood. Recent findings have highlighted that exposure of a fetus to an adverse intrauterine environment may also have implications for later offspring depression. This review considers the status of the evidence for these associations and the potential mechanisms underlying prenatal developmental risks for later depression, addressing the challenging possibility that environmental predisposition to depression may begin before birth.

The Effect of Second-Hand Smoke Exposure during Pregnancy on the Newborn Weight in Malaysia

BACKGROUND

There was strong evidence from studies conducted in developed countries that second-hand smoke (SHS) exposure is detrimental to the birth weight of newborn. This study was conducted to determine the effect of exposure to SHS smoke during pregnancy on the weight of newborns.

METHODS

A retrospective cohort study was conducted. The exposed group consists of 209 postnatal women who experienced SHS exposure at home because of a husband or other housemate who smoked inside the house throughout the pregnancy. The non-exposed group included 211 women who did not experience SHS exposure at home or at work during pregnancy. We excluded non-Malay ethnicity, multiple births, and congenital defects.

RESULTS

There was a significant difference in the adjusted mean birth weight between exposed infants [2893.0 g (95% confidence interval (CI): 2781.3, 3004.7)] and not exposed infants to SHS [3046.1 g (95% CI 2929.5, 3162.6) (P < 0.001)] after controlling for significant maternal factors. There was a 12.9 g (95% CI: 7.01, 18.96) reduction in birth weight for a corresponding increase in the exposure to the smoke of one cigarette (P < 0.001). The incidence of low birth weight (LBW) was higher in exposed women, [10% (95% CI: 5.94, 14.06)] compared to non-exposed women [4.7% (95% CI: 1.85, 7.55)].

CONCLUSION

This study found a significant association between SHS exposure during pregnancy and decreased birth weight.

Parental smoking during pregnancy and its association with low birth weight, small for gestational age, and preterm birth offspring: a birth cohort study

BACKGROUND

Intrauterine exposure to tobacco smoke has been discerned as an important risk factor for low birth weight (LBW), small for gestational age (SGA), and preterm birth infants. In this cohort study, we investigated the association of the amount of parental smoking during the different pregnancy stages with birth weight and the incidence of preterm delivery.

METHODS

Our study population was acquired from the Taiwan Birth Cohort Study. Between June 2005 and July 2006, 21,248 postpartum women were interviewed 6 months after their deliveries by a structured questionnaire. The parents were divided into four groups according to the amount of smoking during preconception, the first trimester, and the second and third trimesters. The relationships of parental smoking with gestational age and birth weight during the different pregnancy stages were assessed using multivariate linear regression. Multiple logistic regression analyses were performed to estimate the odds ratios and 95% confidence intervals of preterm delivery, LBW, and SGA infants during the different parental smoking status and the different pregnancy stages.

RESULTS

After adjusting for the physical and socioeconomic status of the parents and for paternal smoking during the same period, we found that maternal smoking decreased birth weight. Compared with the nonsmoking groups, all the maternal smoking groups had higher incidences of LBW, SGA, and preterm birth infants, especially when the mothers smoked >20 cigarettes/day. The association of paternal smoking with LBW, SGA, and preterm birth infants was insignificant.

CONCLUSION

Maternal smoking is responsible for increased incidences of LBW and preterm delivery of babies, and therefore, smoking cessation/reduction should be advised to pregnant women to reduce morbidities in their neonates. Further studies are needed to clarify the correlation of fetal health with passive smoking, including exposure to environmental tobacco smoke and to other smokers in the family.

Educational inequalities in perinatal outcomes: the mediating effect of smoking and environmental tobacco exposure

OBJECTIVE

Socioeconomic status (SES) is adversely associated with perinatal outcomes. This association is likely to be mediated by tobacco exposure. However, previous studies were limited to single perinatal outcomes and devoted no attention to environmental tobacco exposure. Therefore, this study aimed firstly to explain the role of maternal smoking in the association between maternal education and preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA), and secondly to explain whether environmental tobacco smoke mediates these associations further.

STUDY DESIGN

This study was nested in a population-based cohort study in the Netherlands, the Amsterdam Born Children and their Development (ABCD) study. Analyses were done in a sample of 3821 pregnant women of Dutch origin, using logistic regression analysis.

RESULTS

Least educated women, who were more often smoking and exposed to environmental tobacco smoke, had a significantly higher risk of PTB (OR 1.95 [95% CI: 1.19-3.20]), LBW (OR 2.41 [95% CI: 1.36-4.27]) and SGA (OR 1.90 [95% CI 1.32-2.74]) than highly educated women. The mediating effect of smoking in the least educated women was 43% for PTB, 55% for LBW and 66% for SGA. Environmental tobacco smoke did not explain these associations further. After adjustment for maternal smoking, the association between lower maternal education and pregnancy outcomes was no longer significant.

CONCLUSIONS

Smoking explains to a considerable extent the association between lower maternal education and adverse perinatal outcomes. Therefore, tobacco-interventions in lower educated women should be primarily focussed on maternal smoking to reduce PTB, LBW, and SGA. Additional attention to environmental tobacco exposure does not seem to reduce educational inequalities in perinatal outcomes.

A citywide smoking ban reduced maternal smoking and risk for preterm births: a Colorado natural experiment

BACKGROUND

Few reports exist on the association of a public smoking ban with fetal outcomes and maternal smoking in the United States. We sought to evaluate the effect of a citywide smoking ban in comparison to a like municipality with no such ban in Colorado on maternal smoking and subsequent fetal birth outcomes.

METHODS

A citywide smoking ban in Colorado provided a natural experiment. The experimental citywide smoking ban site was implemented in Pueblo, Colorado. A comparison community was chosen that had no smoking ban, El Paso County, with similar characteristics of population, size, and geography. The two sites served as their own controls, as each had a preban and postban retrospective observation period: preban was April 1, 2001, to July 1, 2003; postban was April 1, 2004, to July 1, 2006. Outcomes were maternal smoking (self-report), low birth weight (LBW) (defined as <2500 g or as <3000 g), and preterm births (<37 weeks gestation) in singleton births from mothers residing in these cities and reported to the State Department of Public Health. A difference-in-differences estimator was used to account for site and temporal trends in multivariate models.

RESULTS

Compared to El Paso County preban, the odds of maternal smoking and preterm births were, respectively, 38% (p<0.05) and 23% (p<0.05) lower in Pueblo. The odds for LBW births decreased by 8% for <3000 g and increased by 8.4% for <2500 g; however, neither was significant.

CONCLUSIONS

This is the first evidence in the United States that population-level intervention using a smoking ban improved maternal and fetal outcomes, measured as maternal smoking and preterm births.

Recruitment of α7 nicotinic acetylcholine receptor to caveolin-1-enriched lipid rafts is required for nicotine-enhanced Escherichia coli K1 entry into brain endothelial cells

AIM

We investigate how the α7 nicotinic acetylcholine receptor (α7 nAChR), an essential regulator of inflammation, contributes to the α7 agonist nicotine-enhanced Escherichia coli K1 invasion of human brain microvascular endothelial cells (HBMECs) through lipid rafts/caveolae-mediated signaling.

MATERIALS & METHODS

α7 nAChR-mediated signaling and bacterial invasion were defined by lipid raft fractionation, immunofluorescence microscopy and siRNA knockdown.

RESULTS

Nicotine-enhanced bacterial invasion was dose-dependently inhibited by two raft-disrupting agents, nystatin and filipin. Significant accumulation of the lipid raft marker GM3 was observed in HBMEC induced by E. coli K1 and nicotine. The recruitment of α7 nAChR and related signaling molecules, including vimentin, and Erk1/2, to caveolin-1 enriched lipid rafts was increased upon treatment with E44 or E44 plus nicotine. Erk1/2 activation (phosphorylation), which is required for α7 nAChR-mediated signaling and E44 invasion, was associated with lipid rafts and nicotine-enhanced bacterial infection. Furthermore, E44 invasion, E44/nicotine-induced activation of Erk1/2 and clustering of α7 nAChR and caveolin-1 was specifically blocked by both siRNAs.

CONCLUSION

α7 nAChR-mediated signaling through lipid rafts/caveolae is required for nicotine-enhanced E. coli K1 invasion of HBMEC.

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.

Smoking prevalence in early pregnancy: comparison of self-report and anonymous urine cotinine testing

OBJECTIVE

Societal pressures against smoking during pregnancy may lead to a reduction in disclosure of smoking status. The objective of this study was to compare prevalence of smoking at prenatal intake by self-report with anonymous biochemical validation.

METHODS

Women receiving care at the Duke Obstetrics Clinic from February 2005 through January 2006 were eligible for evaluation. Self-reported smoking and urine samples were obtained anonymously at prenatal intake. The NicCheck™ I semi-quantitative dipstick was used to detect urinary nicotine, cotinine, and 3-hydroxycotinine. The difference, with 95% confidence interval, between the proportions of smokers by self-report and urine testing was calculated for (1) high-positive vs. low-positive and negative results combined and (2) any positive vs. negative results.

RESULTS

Among 297 subjects, self-reported smoking was 18.2 vs. 14.8% for low-positive and negative results combined with an absolute difference of 3.4%, [-2.9%, 9.6%]. When comparing self-report with any positive result (43.1%), the absolute difference was 24.9%, [17.4%, 32.1%].

CONCLUSIONS

Our findings suggest that most pregnant women disclose their smoking and many nonsmokers may have significant second-hand exposure. Universal urinary cotinine screening of pregnant women could aid in appropriately counseling women about second-hand exposure as well as monitoring women at high risk for adverse pregnancy outcomes.

An intervention to reduce environmental tobacco smoke exposure improves pregnancy outcomes

OBJECTIVE

We tested the efficacy of a cognitive-behavioral intervention in reducing environmental tobacco smoke exposure (ETSE) and improving pregnancy outcomes among black women.

METHODS

We recruited 1044 women to a randomized, controlled trial during 2001-2004 in Washington, DC. Data on 691 women with self-reported ETSE were analyzed. A subset of 520 women with ETSE and salivary cotinine levels (SCLs) of <20 ng/mL were also analyzed. Individually tailored counseling sessions, adapted from evidence-based interventions for ETSE and other risks, were delivered to the intervention group. The usual-care group received routine prenatal care as determined by their provider. Logistic regression models were used to predict ETSE before delivery and adverse pregnancy outcomes.

RESULTS

Women in the intervention were less likely to self-report ETSE before delivery when controlling for other covariates (odds ratio [OR]: 0.50 [95% confidence interval (CI): 0.35-0.71]). Medicaid recipients were more likely to have ETSE (OR: 1.97 [95% CI: 1.31-2.96]). With advancing maternal age, the likelihood of ETSE was less (OR: 0.96 [95% CI: 0.93-0.99]). For women in the intervention, the rates of very low birth weight (VLBW) and very preterm birth (VPTB) were significantly improved (OR: 0.11 [95% CI: 0.01-0.86] and OR: 0.22 [95% CI: 0.07-0.68], respectively). For women with an SCL of <20 ng/mL, maternal age was not significant. Intimate partner violence at baseline significantly increased the chances of VLBW and VPTB (OR: 3.75 [95% CI: 1.02-13.81] and 2.71 [95% CI: 1.11-6.62], respectively). These results were true for mothers who reported ETSE overall and for those with an SCL of <20 ng/mL.

CONCLUSIONS

This is the first randomized clinical trial demonstrating efficacy of a cognitive-behavioral intervention targeting ETSE in pregnancy. We significantly reduced ETSE as well as VPTB and VLBW, leading causes of neonatal mortality and morbidity in minority populations. This intervention may reduce health disparities in reproductive outcomes.

The influence of secondhand smoke exposure on birth outcomes in Jordan

This study investigates how secondhand smoke (SHS) exposure influences neonatal birth weight in Jordan, a country with high smoking prevalence. The findings revealed that as the average number of SHS exposure hours per week increased in the second trimester, the neonatal birth weight decreased while holding all covariates constant. Women who reported a higher average number of SHS exposure hours per week from work in the second trimester, home in the third trimester, and outside in the third trimester were at greater risk for having a low birth weight neonate than women who reported a lower average number of SHS exposure hours.

Is pregnancy a teachable moment for smoking cessation among US Latino expectant fathers? A pilot study

OBJECTIVE

Pregnancy may be a time when US Latino expectant fathers consider quitting smoking. A 'teachable moment' is theorized to increase motivation to change a behavior through increased risk perceptions, emotional responses, and changes in self-image.

DESIGN

We recruited 30 Spanish-speaking expectant fathers through their pregnant partners. We assessed expectant fathers' diet, exercise, and smoking and teachable moment constructs (risk perceptions, emotional responses, and self-image).We also tested correlations between teachable moment constructs and motivation to change behaviors.

RESULTS

Latino expectant fathers had high-risk perceptions that their smoking harmed the pregnancy (M=4.4, SD=0.5 on five-point scale) and strong emotional responses about their smoking during pregnancy (M=3.9, SD=1.1). They also felt it was their role to make the pregnancy healthy (M=4.4, SD=0.8). They felt less strongly that their diet and exercise affected the pregnancy. The teachable moment constructs for smoking were strongly correlated with motivation to quit smoking; the same was not true for diet and exercise.

CONCLUSIONS

Latino expectant fathers seem aware that their smoking could harm the pregnancy but seem less concerned about the effect of their diet and exercise on the pregnancy. Pregnancy may be a time to help Latino expectant fathers quit smoking.

Low birthweight and preterm birth rates 1 year before and after the Irish workplace smoking ban

OBJECTIVE

It is well-established that maternal smoking has adverse birth outcomes (low birthweight, LBW, and preterm births). The comprehensive Irish workplace smoking ban was successfully introduced in March 2004. We examined LBW and preterm birth rates 1 year before and after the workplace smoking ban in Dublin.

DESIGN

A cross-sectional observational study analysing routinely collected data using the Euroking K2 maternity system.

SETTING

Coombe University Maternal Hospital.

POPULATION

Only singleton live births were included for analyses (7593 and 7648, in 2003 and 2005, respectively).

METHODS

Detailed gestational and clinical characteristics were collected and analysed using multivariable logistic regression analyses and subgroup analyses.

MAIN OUTCOME MEASURES

Maternal smoking rates, mean birthweights, and adjusted odds ratios (ORs) of LBW and preterm births in 2005 versus 2003.

RESULTS

There was a 25% decreased risk of preterm births (OR, 0.75; 95% CI, 0.59-0.96), a 43% increased risk of LBW (OR, 1.43; 95% CI, 1.10-1.85), and a 12% fall in maternal smoking rates (from 23.4 to 20.6%) in 2005 relative to 2003. Such patterns were significantly maintained when specific subgroups were also analysed. Mean birthweights decreased in 2005, but were not significant (P=0.99). There was a marginal increase in smoking cessation before pregnancy in 2005 (P=0.047).

CONCLUSIONS

Significant declines in preterm births and in maternal smoking rates after the smoking ban are welcome signs. However, the increased LBW birth risks might reflect a secular trend, as observed in many industrialised nations, and merits further investigations.

The design, implementation and acceptability of an integrated intervention to address multiple behavioral and psychosocial risk factors among pregnant African American women

BACKGROUND

African American women are at increased risk for poor pregnancy outcomes compared to other racial-ethnic groups. Single or multiple psychosocial and behavioral factors may contribute to this risk. Most interventions focus on singular risks. This paper describes the design, implementation, challenges faced, and acceptability of a behavioral counseling intervention for low income, pregnant African American women which integrated multiple targeted risks into a multi-component format.

METHODS

Six academic institutions in Washington, DC collaborated in the development of a community-wide, primary care research study, DC-HOPE, to improve pregnancy outcomes. Cigarette smoking, environmental tobacco smoke exposure, depression and intimate partner violence were the four risks targeted because of their adverse impact on pregnancy. Evidence-based models for addressing each risk were adapted and integrated into a multiple risk behavior intervention format. Pregnant women attending six urban prenatal clinics were screened for eligibility and risks and randomized to intervention or usual care. The 10-session intervention was delivered in conjunction with prenatal and postpartum care visits. Descriptive statistics on risk factor distributions, intervention attendance and length (i.e., with < 4 sessions considered minimal adherence) for all enrolled women (n = 1,044), and perceptions of study participation from a sub-sample of those enrolled (n = 152) are reported.

RESULTS

Forty-eight percent of women screened were eligible based on presence of targeted risks, 76% of those eligible were enrolled, and 79% of those enrolled were retained postpartum. Most women reported a single risk factor (61%); 39% had multiple risks. Eighty-four percent of intervention women attended at least one session (60% attended > or = 4 sessions) without disruption of clinic scheduling. Specific risk factor content was delivered as prescribed in 80% or more of the sessions; 78% of sessions were fully completed (where all required risk content was covered). Ninety-three percent of the subsample of intervention women had a positive view of their relationship with their counselor. Most intervention women found the session content helpful. Implementation challenges of addressing multiple risk behaviors are discussed.

CONCLUSION

While implementation adjustments and flexibility are necessary, multiple risk behavioral interventions can be implemented in a prenatal care setting without significant disruption of services, and with a majority of referred African American women participating in and expressing satisfaction with treatment sessions.

Low maternal concentrations of soluble vascular endothelial growth factor receptor-2 in preeclampsia and small for gestational age

OBJECTIVES

Preeclampsia is considered an anti-angiogenic state. A role for the anti-angiogenic factors soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble endoglin in preeclampsia has been proposed. Soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) has been detected in human plasma, and the recombinant form of this protein has anti-angiogenic activity. There is a paucity of information about maternal plasma sVEGFR-2 concentrations in patients with preeclampsia and those without preeclampsia with small for gestational age (SGA) fetuses. This study was conducted to determine whether: (1) plasma sVEGFR-2 concentration changes throughout pregnancy; and (2) preeclampsia and SGA are associated with abnormalities in the maternal plasma concentration of sVEGFR-2.

STUDY DESIGN

This cross-sectional study included non-pregnant women (n = 40), women with normal pregnancies (n = 135), women with an SGA fetus (n = 53), and women with preeclampsia (n = 112). SGA was defined as an ultrasound-estimated fetal weight below the 10(th) percentile for gestational age that was confirmed by neonatal birth weight. Plasma concentrations of sVEGFR-2 were determined by ELISA.

RESULTS

(1) There was no significant difference in the mean plasma concentration of sVEGFR-2 between non-pregnant women and those with normal pregnancies (p = 0.8); (2) patients with preeclampsia and those without preeclampsia with SGA fetuses had a lower mean plasma concentration of sVEGFR-2 than that of women with normal pregnancies (p < 0.001 for both); and (3) there was no significant difference in the mean plasma concentration of sVEGFR-2 between patients with preeclampsia and those without preeclampsia with SGA (p = 0.9).

CONCLUSIONS

Preeclampsia and SGA are associated with low plasma concentrations of sVEGFR-2. One interpretation of the findings is that plasma sVEGFR-2 concentration could reflect endothelial cell function.

Maternal smoking and congenital heart defects

OBJECTIVES

In a population-based case-control study, we investigated the association between congenital heart defects and maternal smoking.

METHODS

The National Birth Defects Prevention Study enrolled 3067 infants with nonsyndromic congenital heart defects and their parents and 3947 infants without birth defects and their parents. Affected infants had > or = 1 of the following defects: conotruncal, septal, anomalous pulmonary venous return, atrioventricular septal defects, and left-sided or right-sided obstructive heart defects. Mothers of case and control infants were asked if they smoked during the periconceptional period, defined as 1 month before pregnancy through the first trimester. Maternal home and workplace exposure to tobacco smoke during the same period was also determined. Logistic regression was used to compute odds ratios and 95% confidence intervals while controlling for potential confounders.

RESULTS

Case infants were more likely to be premature and have lower birth weight than control infants. Women who smoked anytime during the month before pregnancy to the end of the first trimester were more likely to have infants with septal heart defects than women who did not smoke during this time period. This association was stronger for mothers who reported heavier smoking during this period. This relation was independent of potential confounding factors, including prenatal vitamin use, alcohol intake, maternal age, and race or ethnicity. Women who smoked > or = 25 cigarettes per day were more likely than nonsmoking mothers to have infants with right-sided obstructive defects. There was no increased risk of congenital heart defects with maternal exposure to environmental tobacco smoke.

CONCLUSIONS

Maternal smoking during pregnancy was associated with septal and right-sided obstructive defects. Additional investigation into the timing of tobacco exposure and genetic susceptibilities that could modify this risk will provide a more precise evidence base on which to build clinical and public health primary prevention strategies.

Environmental tobacco smoke: respiratory and other health effects

Involuntary exposure to environmental tobacco smoke (ETS) is a serious and entirely preventable public health hazard. It has become clear that ETS adversely affects the health of all who breathe its toxins. Independent of active smoking, ETS exposure is a modifiable risk factor for chronic obstructive pulmonary disease. The expanding body of research presented in this article provides evidence that the damaging consequences of ETS reach far beyond the lungs. Having been determined the third leading cause of preventable death in this country, this is a problem that must be addressed aggressively.

Epidemiology of prenatal smoking and perinatal outcomes

During the previous two decades smoking among pregnant women in the developed world declined by about 60-75%. Nevertheless, prenatal smoking remains a common habit and accounts for a significant proportion of fetal morbidity and mortality through both a direct (fetal) and an indirect (placental) effect. The most important smoking-induced placental pathology is placental abruption with reported risk estimates ranging from 1.4 to 4.0. It is almost a consensus that prenatal smoking is a causative factor for placental abruption. Although the evidence is less compelling, smoking mothers are at an increased risk for placenta previa and placenta-previa-accreta combination. There is no association between maternal smoking and the syndrome of idiopathic uterine bleeding. The relationship between maternal smoking and fetal growth is causal, and includes significant reduction in growth of head circumference, abdominal circumference and femur length, with the largest reduction in size observed for femur length. Prenatal smoking is associated with a 20-30% higher likelihood for stillbirth, a 40% elevation in the risk for infant mortality and a 2-fold increase in the incidence of SIDS.

CONCLUSION

Despite a temporal decline in maternal smoking, it still accounts for significant feto-infant morbidity and mortality, and efforts to discourage prenatal smoking need to be intensified.

Associations among genetic susceptibility, DNA damage, and pregnancy outcomes of expectant mothers exposed to environmental tobacco smoke

This study determined the effects of environmental tobacco smoke (ETS) on fetal growth by measuring neonatal birth outcomes and the extent of maternal DNA damage, and investigating the relationships among gene polymorphisms, genotoxicity, and pregnancy outcomes of expectant mothers who had exposed to tobacco smoke. This prospective study enrolled 685 pregnant women who completed an initial questionnaire at three central Taiwan hospitals between 2003 and 2004. Genotype analyses of CYP1A1, GSTT1, GSTM1, and NAT2 were performed from 421 women. A total of 398 women completed the follow-up analysis and successfully delivered a live single baby (n=384). Comet assay was performed for 18 smokers, 143 ETS-exposed subjects and 130 non-smokers to measure DNA damage. Analytical findings indicated that the levels of DNA damage among smokers and ETS-exposed subjects were significantly higher than that of non-smokers. DNA damage score in the ETS-exposed group was 84.3+/-44.3 and 63.5+/35.0 [corrected] for the nonsmoking group (p<0.001). Risk of DNA damage (DNA strand breakage, sister chromatid exchange, cell transformation and escalation of cytotoxicity) for subjects exposed to ETS was 7.49 times (adjusted odds ratio; 95% CI, 1.27-44.20) [corrected] greater than that of non-exposed to tobacco smoke at home. Average birth weight of neonates born to subjects with extremely serious DNA damage (within the 90th percentile, DNA damage score >or =129.5) was 141 g lighter than that of those with DNA damage score <129.5 (p=0.068) [corrected] The degree of DNA lesion was not related to metabolic polymorphic genes. The results of this study suggest that comet assay are reliable biomarkers for monitoring pregnant women exposed to tobacco smoke and indicate fetal growth effects from environmental exposure to tobacco smoke.

Prevalence of maternal smoking and environmental tobacco smoke exposure during pregnancy and impact on birth weight: retrospective study using Millennium Cohort

Background

Meta-analyses of studies investigating the impact of maternal environmental tobacco smoke (ETS) on birth weight have not produced robust findings. Although, ante natal ETS exposure probably reduces infant's birth weights, the scale of this exposure remains unknown. We conducted a large, cohort study to assess the impact of ETS exposure on birth weight whilst adjusting for the many factors known to influence this.

Method

Retrospective study using interview data from parents of 18,297 children born in 2000/2001 and living in the UK 9 months afterwards (the Millennium Cohort Survey). Comparison of birth weight, sex and gestational age specific (SGA) z score, birth before 37 weeks and birth weight < 2.5 Kg (LBW) in infants born to women exposed to: i) no tobacco smoke, ii) ETS only and iii) maternal smoking whilst pregnant.

Results

13% of UK infants were exposed to ETS and 36% to maternal smoking ante natally. Compared to no ante natal tobacco smoke exposure, domestic ETS lowered infants' adjusted mean birth weights by 36 g (95% CI, 5 g to 67 g) and this effect showed a dose-response relationship. ETS exposure also caused non-significant increases in the adjusted risks of Low Birth Weight (<2.5 Kg) [OR 1.23 (95% CI, 0.96 to 1.58) and premature birth [OR 1.21 (95% CI, 0.96 to 1.51)], whilst the impacts of maternal smoking were greater and statistically significant.

Conclusion

UK prevalences of domestic ETS exposure and maternal smoking in pregnancy remain high and ETS exposure lowers infants' birth weights.

Parental smoking and children's respiratory health: independent effects of prenatal and postnatal exposure

OBJECTIVES

Adverse effects have been reported of prenatal and/or postnatal passive exposure to smoking on children's health. Uncertainties remain about the relative importance of smoking at different periods in the child's life. We investigate this in a pooled analysis, on 53,879 children from 12 cross-sectional studies--components of the PATY study (Pollution And The Young).

METHODS

Effects were estimated, within each study, of three exposures: mother smoked during pregnancy, parental smoking in the first two years, current parental smoking. Outcomes were: wheeze, asthma, "woken by wheeze", bronchitis, nocturnal cough, morning cough, "sensitivity to inhaled allergens" and hay fever. Logistic regressions were used, controlling for individual risk factors and study area. Heterogeneity between study-specific results, and mean effects (allowing for heterogeneity) were estimated using meta-analytical tools.

RESULTS

There was strong evidence linking parental smoking to wheeze, asthma, bronchitis and nocturnal cough, with mean odds ratios all around 1.15, with independent effects of prenatal and postnatal exposures for most associations.

CONCLUSIONS

Adverse effects of both pre- and postnatal parental smoking on children's respiratory health were confirmed. Asthma was most strongly associated with maternal smoking during pregnancy, but postnatal exposure showed independent associations with a range of other respiratory symptoms. All tobacco smoke exposure has serious consequences for children's respiratory health and needs to be reduced urgently.

Acute effects of environmental tobacco smoke and dried dung smoke on lung histopathology in rabbits

AIMS

To compare the effects of cigarette smoke and dried dung smoke exposure on the histopathology of lungs.

METHODS

Three groups each with five rabbits were formed. The cigarette smoke group was exposed to cigarette smoke, the biomass group was exposed to dried dung smoke and the control group was exposed to dry air 1 hour daily for 1 month. At the end of 1 month, animals were sacrificed and lung tissues were examined histopathologically.

RESULTS

Histopathological evaluation of rabbits' lungs revealed that intraparenchymal vascular congestion and thrombosis, intraparenchymal haemorrhage, respiratory epithelial proliferation, number of macrophages in the alveolar and bronchial lumen, alveolar destruction, emphysematous changes and bronchoalveolar haemorrhage scores were significantly increased in rabbits exposed to cigarette smoke compared with the control group. Respiratory epithelial proliferation, alveoli destruction and emphysematous change scores were significantly increased in rabbits exposed to dried dung smoke compared with the control group.

CONCLUSION

Although less than the effects of cigarette smoke, dried dung smoke had severe histopathological effects on rabbits' lungs.

Smoking habits, nicotine use, and congenital malformations

OBJECTIVE

We examined whether maternal smoking and use of nicotine substitutes during the first 12 weeks of pregnancy increased the prevalence of congenital malformations in general and of certain congenital malformations in particular.

METHODS

In the Danish National Birth Cohort (1997-2003) we identified 76,768 pregnancies (and their subsequent singleton births); 20,603 were exposed to tobacco smoking during the first 12 weeks of pregnancy. Birth outcomes were collected by linkage to the Central Population Register, the National Patients Register, and the National Birth Register. We identified congenital malformations from the Hospital Medical Birth Registry as they were recorded at birth or in the first year of follow-up.

RESULTS

Smoking mothers were younger, weighed less, consumed more alcohol, and had received less education. Children exposed to prenatal tobacco smoking had no increase in congenital malformations prevalence compared with the nonexposed children in both crude and adjusted analyses. Children born to nonsmokers, but who used nicotine substitutes, had a slightly increased relative congenital malformations prevalence ratio; relative prevalence rate ratio was 1.61 (95% confidence interval 1.01-2.58), which represents a 60% increased risk. When the analysis was restricted to musculoskeletal malformations, the relative prevalence rate ratio was 2.63 (95% confidence interval 1.53-4.52).

CONCLUSION

Our results showed no increase in congenital malformations related to prenatal tobacco smoking. However, we identified an increase of malformations risk in nonsmokers using nicotine substitutes. This finding needs to be replicated in other data sources.

LEVEL OF EVIDENCE

II-2.

Smoking and reproduction: the oviduct as a target of cigarette smoke

The oviduct is an exquisitely designed organ that functions in picking-up ovulated oocytes, transporting gametes in opposite directions to the site of fertilization, providing a suitable environment for fertilization and early development, and transporting preimplantation embryos to the uterus. A variety of biological processes can be studied in oviducts making them an excellent model for toxicological studies. This review considers the role of the oviduct in oocyte pick-up and embryo transport and the evidence that chemicals in both mainstream and sidestream cigarette smoke impair these oviductal functions. Epidemiological data have repeatedly shown that women who smoke are at increased risk for a variety of reproductive problems, including ectopic pregnancy, delay to conception, and infertility. In vivo and in vitro studies indicate the oviduct is targeted by smoke components in a manner that could explain some of the epidemiological data. Comparisons between the toxicity of smoke from different types of cigarettes, including harm reduction cigarettes, are discussed, and the chemicals in smoke that impair oviductal functioning are reviewed.

Ambient air pollution and pregnancy outcomes: a review of the literature

Over the last decade or so, a large number of studies have investigated the possible adverse effects of ambient air pollution on birth outcomes. We reviewed these studies, which were identified by a systematic search of the main scientific databases. Virtually all reviewed studies were population based, with information on exposure to air pollution derived from routine monitoring sources. Overall, there is evidence implicating air pollution in adverse effects on different birth outcomes, but the strength of the evidence differs between outcomes. The evidence is sufficient to infer a causal relationship between particulate air pollution and respiratory deaths in the postneonatal period. For air pollution and birth weight the evidence suggests causality, but further studies are needed to confirm an effect and its size and to clarify the most vulnerable period of pregnancy and the role of different pollutants. For preterm births and intrauterine growth retardation (IUGR) the evidence as yet is insufficient to infer causality, but the available evidence justifies further studies. Molecular epidemiologic studies suggest possible biologic mechanisms for the effect on birth weight, premature birth, and IUGR and support the view that the relation between pollution and these birth outcomes is genuine. For birth defects, the evidence base so far is insufficient to draw conclusions. In terms of exposure to specific pollutants, particulates seem the most important for infant deaths, and the effect on IUGR seems linked to polycyclic aromatic hydrocarbons, but the existing evidence does not allow precise identification of the different pollutants or the timing of exposure that can result in adverse pregnancy outcomes.

The New York City Smoke-Free Air Act: second-hand smoke as a worker health and safety issue

BACKGROUND

Despite the provisions of a Smoke-Free Air Act (SFAA) enacted in 1995, more than 415,000 non-smoking New York City workers reported exposure to second-hand smoke in the workplace all or most of the time in 2002. Continued exposure to second-hand smoke in New York City prompted a renewed debate about a broader smoke-free air law.

METHODS

The approach taken by the New York City Department of Health and Mental Hygiene to make the case for workplace protection from second-hand smoke, counter the opposition's arguments, and ultimately win the support of policymakers and the public for comprehensive smoke-free workplace legislation is described.

RESULTS

On December 30, 2002, New York City's Mayor signed the SFAA of 2002 into law, making virtually all workplaces, including restaurants and bars, smoke-free.

CONCLUSIONS

Proponents for a stronger law prevailed by defining greater protection from second-hand smoke as a matter of worker health and safety. Efforts to enact smoke-free workplace laws will inevitably encounter strong opposition, with the most common argument being that smoke-free measures will harm businesses. These challenges, however, can be effectively countered and public support for these measures is likely to increase over time by focusing the debate on worker protection from second-hand smoke exposure on the job.

Environmental tobacco smoke in the workplace: markers of exposure, polymorphic enzymes and implications for disease state

Studies focusing directly on tobacco smoke have tended to center on the differences in effect between smokers and non-smokers and many hundreds of such studies have been performed. In this review, we examine the current literature specifically concerning workplace exposure to environmental tobacco smoke (ETS) and its impact on individuals, particularly non-smokers and never smokers. The paper deals with quantifying and minimizing ETS exposures in a working environment, the effect of polymorphisms and other genetic factors that influence health outcomes after exposure to ETS and the association of occupational ETS exposure to disease-specific biomarkers.

Drug abuse's smallest victims: in utero drug exposure

The social and economic impact of drug use on our global population continues to increase leaving no geographical, social or cultural group untouched. The National Institute on Drug Abuse (NIDA), in one of the few large surveys of maternal abuse, found that 5.5% of mothers reported taking an illicit substance during gestation. These figures certainly are underestimates due to the stigma of drug use during pregnancy and the accompanying legal, ethical and economic issues. Although drugs of choice and routes of administration vary by country, exposure of our most valuable resource, our children, to the developmental effects of drugs is an enormous problem. In utero drug exposure can have a severe impact not only on the development of the fetus, but also on the child during later stages of life. More than 75% of infants exposed to drugs have major medical problems as compared to 27% of unexposed infants. The cost of treating drug-affected infants was twice the cost of non-affected infants. Obstetrical complications including placental insufficiency, miscarriage, intrauterine death, and increased incidence of infectious and sexually-transmitted diseases are higher in the drug-abusing mother. Treatment for pregnant addicts should be a high priority for our governments. Increased awareness and improvement in our understanding of drug abuse in the medical, legal and social realms will enable us to reduce the barriers to treatment for this important population.Accurate identification of in utero drug exposure has important implications for the care of the mother and child, but can raise difficult legal issues. Society discourages prenatal care with the infliction of harsh criminal penalties. Maternal drug use during pregnancy can be monitored with urine, sweat, oral fluid and/or hair testing. Detection of in utero drug exposure has traditionally been accomplished through urine testing; however, the window of detection is short, reflecting drug use for only a few days before delivery. Monitoring exposure through testing of alternative matrices, such as neonatal meconium and hair, offers advantages including non-invasive collection and detection earlier in gestation. There are many unresolved issues in monitoring in utero drug exposure that urgently require research. These can be divided into research to definitively differentiate drug exposed and non-drug-exposed fetuses, determine the most efficient methods to routinely monitor women's drug use, and determine how these drug test results relate to neonatal and maternal outcomes. Research in this area is difficult and expensive to perform, but necessary to assess accurately drug effects on the fetus. By increasing our understanding of the physiological, biochemical and behavioral effects of gestational drug exposure, we may ultimately provide solutions for better drug prevention, treatment and a reduction in the number of drug-exposed children.

[Prematurity and low birth weight: effects of active and passive smoking during pregnancy]

Among the risk factors inevitably associated with low birthweights and premature births, tobacco remains the factor most often cited. From 1997 to 1998, a study was conducted in a Quebec City hospital centre in order to determine the prevalence of smoking among pregnant women as well as their exposure to passive smoking at home and at work. The percentage of women who smoke before pregnancy is 40.2%, while that of women who smoke during pregnancy is 37.3%. The analysis of characteristics of pregnant women who smoke and do not smoke shows strong variations according to age, education, matrimonial status and income. The relative risk linked to smoking is 1.54 for premature birth and 2.21 for low birthweight.

Genetic susceptibility of term pregnant women to oxidative damage

Genetic polymorphisms involved in the activation and detoxification of exogenous chemicals and in the production and scavenging of reactive oxygen species may modulate the levels of oxidative injury biomarker. We investigated 81 pregnant women in Inchon, Korea. In addition to a questionnaire survey, urinary concentrations of 8-hydroxydeoxyguanosine (8-OH-dG) and malondialdehyde (MDA) were measured as oxidative injury biomarkers. Cytochrome P-450(CYP)1A1, CYP2E1, glutathione S-transferase (GST)M1 and GSTT1 polymorphisms and myeloperoxidase (MPO) and manganese superoxide dismutase (MnSOD) polymorphisms were evaluated to determine the effect of genetic modification on urinary 8-OH-dG and MDA. The concentrations of urinary 8-OH-dG were significantly elevated in the presence of the MnSOD variant genotype (P=0.04) and in the case of GSTM1 null status (P=0.02) by multivariate regression. The concentrations of urinary MDA were not affected significantly by the genetic polymorphisms. This result shows that oxidative stress injury is modified by some heritable polymorphisms, including GSTM1 and MnSOD.

Relation between ambient air pollution and low birth weight in the Northeastern United States

We evaluated the relation between term low birth weight (LBW) and ambient air levels of carbon monoxide (CO), particulate matter up to 10 microm in diameter (PM(10)), and sulfur dioxide (SO(2)). The study population consisted of singleton, term live births (37-44 weeks of gestation) born between 1 January 1994 and 31 December 1996 in six northeastern cities of the United States: Boston, Massachusetts; Hartford, Connecticut; Philadelphia, Pennsylvania; Pittsburgh, Pennsylvania; Springfield, Massachusetts; and Washington, DC. Birth data were obtained from National Center for Health Statistics Natality Data Sets. Infants with a birth weight < 2,500 g were classified as LBW. Air monitoring data obtained from the U.S. Environmental Protection Agency were used to estimate average trimester exposures to ambient CO, PM(10), and SO(2). Our results suggest that exposures to ambient CO and SO(2) increase the risk for term LBW. This risk increased by a unit increase in CO third trimester average concentration [adjusted odds ratio (AOR) 1.31; 95% confidence interval (CI) 1.06,1.62]. Infants with SO(2) second trimester exposures falling within the 25 and < 50th (AOR 1.21; CI 1.07,1.37), the 50 to < 75th (AOR 1.20; CI 1.08,1.35), and the 75 to < 95th (AOR 1.21; CI 1.03,1.43) percentiles were also at increased risk for term LBW when compared to those in the reference category (< 25th percentile). There was no indication of a positive association between prenatal exposures to PM(10) and term LBW. Increased ambient levels of air pollution may be associated with an increased risk for LBW.