Tobacco and pregnancy: Overview of exposures and effects

Effectiveness of a Pregnancy Smoking Intervention

Despite the known dangers of pregnancy smoking, rates remain high, especially in the rural, Southern United States. Interventions are effective, but few have been developed and tested in regions with high rates of pregnancy smoking, a culture that normalizes smoking, and a hard-to-reach prenatal population. The goals were to describe a smoking cessation intervention, the Tennessee Intervention for Pregnant Smokers program, and examine the impact on quit rates compared to usual care. Additionally we sought to examine reduction in smoking levels and number of quit attempts related to the intervention and finally to examine the impact of the intervention on birth outcomes. Intervention and historical control group participants, all smokers at entry to prenatal care, were recruited from five medical practices providing prenatal care in rural, South-Central Appalachia. The intervention, an expanded 5A’s (Ask, Advise, Assess, Assist, Arrange) model, was delivered by trained health educators. Over 28% of intervention group women quit smoking, compared to 9.8% in the control group. Two thirds of intervention group women significantly reduced smoking by delivery, with 40%+ attempting to quit at least once. Compared to controls, intervention group women saw significantly better birth outcomes, including newborns weighing 270g more and 50% less likely to have a neonatal intensive care unit admission. Among intervention group participants, those who quit smoking had significantly better birth outcomes than those who did not quit smoking. Findings point to the potential for appropriately tailored pregnancy smoking interventions to produce substantial improvements in birth outcomes within populations with health disparities.

A review of buprenorphine diversion and misuse: the current evidence base and experiences from around the world

Outpatient opioid addiction treatment with sublingual buprenorphine pharmacotherapy has rapidly expanded in the United States and abroad, and, with this increase in medication availability, there have been increasing concerns about its diversion, misuse, and related harms. This narrative review defines the behaviors of diversion and misuse, examines how the pharmacology of buprenorphine alone and in combination with naloxone influence its abuse liability, and describes the epidemiological data on buprenorphine diversion and intravenous misuse, risk factors for its intravenous misuse, and the unintended consequences of misuse and diversion. Physician practices to prevent, screen for, and therapeutically respond to these behaviors, which are a form of medication nonadherence, are discussed, and gaps in knowledge are identified. Outpatient opioid addiction treatment with sublingual buprenorphine pharmacotherapy experiences from other countries that have varied health care systems, public policies, and access to addiction treatment are shared to make clear that diversion and misuse occur across the world in various contexts, for many different reasons, and are not limited to buprenorphine. Comparisons are made with other opioids with known abuse liability and medications with no known abuse. The objective was to facilitate understanding of diversion and misuse so that all factors influencing their expression (patient and provider characteristics and public policy) can be appreciated within a framework that also recognizes the benefits of addiction treatment. With this comprehensive perspective, further careful work can help determine how to minimize these behaviors without eroding the current benefits realized through improved addiction treatment access and expansion.

Home smoking restrictions before, during and after pregnancy-a qualitative study in rural China

Worldwide, many nonsmokers (often women and children) are exposed to second-hand smoke (SHS) in home settings, as men retain their traditional power and control within their family and women and children have limited agency to intervene. This study, set up to explore home smoking management in rural China, found that some women were able to positively intervene to restrict men's smoking at three key stages: prior to conception, during their pregnancy and at the early years of their children's lives. By utilizing dominant social, health and political narratives about the importance of raising a healthy child supported by the One-Child Policy in China, combined with the fear of health risks of SHS to young children, the women were able to use their elevated status as bearer and carers of the only children to subvert the pre-eminence of men in domestic environments, enabling them to positively influence home smoking. While this study highlights the possibility for future smoking cessation initiatives in China by incorporating family carers' elevated awareness of protection of children's health in key stages of childhood, there is also a need for further health education, as family members were unsure why they needed to keep children smoke-free, which may partially explain why few households were smoke-free.

Does Maternal Country of Birth Matter for Understanding Offspring's Birthweight? A Multilevel Analysis of Individual Heterogeneity in Sweden

Background

Many public health and epidemiological studies have found differences between populations (e.g. maternal countries of birth) in average values of a health indicator (e.g. mean offspring birthweight). However, the approach based solely on population-level averages compromises our understanding of variability in individuals’ health around the averages. If this variability is high, the exclusive study of averages may give misleading information. This idea is relevant when investigating country of birth differences in health.

Methods and Results

To exemplify this concept, we use information from the Swedish Medical Birth Register (2002–2010) and apply multilevel regression analysis of birthweight, with babies (n = 811,329) at the first, mothers (n = 571,876) at the second, and maternal countries of birth (n = 109) at the third level. We disentangle offspring, maternal and maternal country of birth components of the total offspring heterogeneity in birthweight for babies born within the normal timespan (37–42 weeks). We found that of such birthweight variation about 50% was at the baby level, 47% at the maternal level and only 3% at the maternal countries of birth level.

Conclusion

In spite of seemingly large differences in average birthweight among maternal countries of birth (range 3290–3677g), knowledge of the maternal country of birth does not provide accurate information for ascertaining individual offspring birthweight because of the high inter-offspring heterogeneity around country averages. Our study exemplifies the need for a better understanding of individual health diversity for which group averages may provide insufficient and even misleading information. The analytical approach we outline is therefore relevant to investigations of country of birth (and ethnic) differences in health in general.

Smoking during pregnancy and vision difficulties in children: a systematic review

Cigarette smoking during pregnancy is a major public health concern. Intra-uterine exposure to maternal cigarette smoking is associated with increased risks of growth and neurodevelopmental problems during childhood and later life. Few studies have focussed on visual difficulties in children in the context of maternal smoking during pregnancy. A systematic search of online databases was carried out between February and May 2013 to examine the trend in visual outcomes in children exposed to maternal cigarette smoking during intra-uterine life. Twenty-four non-randomized studies were identified. Each study was rated for quality using the Newcastle-Ottawa Scale. Most studies (n = 18) reported fetal exposure to active or passive maternal cigarette smoking to be associated with an increased risk of adverse visual outcomes in children. In particular, there were higher rates of strabismus, refractive errors and retinopathy among children of women who smoked during pregnancy. These findings suggest that fetal exposure to cigarette smoke is a significant risk factor for visual problems during later life and that certain visual faculties, such as the intraocular muscles and retinal neurons, are more affected than others. The findings provide evidence in support of public health policies aimed at reducing fetal exposure to smoking by advising both women and their partners to quit smoking during pregnancy.

Month-wise estimates of tobacco smoking during pregnancy for the United States, 2002-2009

The timing of prenatal exposure to tobacco cigarette smoking can be crucial for the developing fetus. Pushing the field beyond prior pregnancy trimester-focused smoking estimates, we estimated month-specific prevalence proportions for tobacco cigarette smoking among pregnant and non-pregnant women of the United States, with consideration of tobacco dependence (TD) as well. In advance, we posited that pregnancy onset might prompt smoking cessation in early months, before the end of the 1st trimester, and that TD might account for sustained smoking in later months, especially months 8-9, when there are added reasons to quit. Estimates are from the 2002-2009 National Surveys on Drug Use and Health Restricted-Data Analysis System (R-DAS), with large nationally representative samples of US civilians, including 12-44 year old women (n ~ 70,000) stratified by pregnancy status and month of pregnancy, with multi-item assessment of TD as well as recently active smoking. Age was held constant via the Breslow-Day indirect standardization approach, a methodological detail of potential interest to other research teams conducting online R-DAS analyses. Among 12-44 year old women in Month 1 of pregnancy, as well as non-pregnant women, just over one in four was a recently active smoker (26-27 %), and approximately one-half of these smokers qualified as a TD case (52 %). Corresponding estimates for women in Month 3 were 17.6 % and two-thirds, respectively, lending some support for our advance hypotheses. Nonetheless, our a priori TD hypothesis about Months 8-9 seems to be contradicted: an increased concentration of TD among smokers surfaced early in pregnancy. Evidence of a possible ameliorative pregnancy effect on smoking prevalence as well as TD's effect on smoking persistence might be seen quite early in pregnancy. Substitution of a month-specific view for the traditional trimester view sheds new light on how pregnancy might shape smoking behavior before the end of trimester 1, with TD seeming to thwart a public health goal of 100 % cessation, early in pregnancy.

Nuclear and mitochondrial DNA alterations in newborns with prenatal exposure to cigarette smoke

Newborns exposed to maternal cigarette smoke (CS) in utero have an increased risk of developing chronic diseases, cancer, and acquiring decreased cognitive function in adulthood. Although the literature reports many deleterious effects associated with maternal cigarette smoking on the fetus, the molecular alterations and mechanisms of action are not yet clear. Smoking may act directly on nuclear DNA by inducing mutations or epigenetic modifications. Recent studies also indicate that smoking may act on mitochondrial DNA by inducing a change in the number of copies to make up for the damage caused by smoking on the respiratory chain and lack of energy. In addition, individual genetic susceptibility plays a significant role in determining the effects of smoking during development. Furthermore, prior exposure of paternal and maternal gametes to cigarette smoke may affect the health of the developing individual, not only the in utero exposure. This review examines the genetic and epigenetic alterations in nuclear and mitochondrial DNA associated with smoke exposure during the most sensitive periods of development (prior to conception, prenatal and early postnatal) and assesses how such changes may have consequences for both fetal growth and development.

Effects of tobacco smoking during pregnancy on oxidative stress in the umbilical cord and mononuclear blood cells of neonates

Background

Although cigarette smoke is known to be a complex mixture of over 4000 substances that can lead to damage through active or passive smoking, its mechanisms and biochemical consequences in pregnancy and neonates are not yet fully understood. Therefore, in the present study, we propose to study the impact of smoking during gestation on the viability of blood mononuclear cells (MNC) from umbilical cords of newborns to assess the degree of oxidative stress and cell viability. After childbirth, the cord blood and the umbilical cord were immediately collected in public hospitals in Greater Vitoria, ES, Brazil. Flow cytometry was used to analyze the cord blood followed by biochemical and histological tests to analyze possible changes in the umbilical cord.

Results

Pregnant smokers had a reduction of MNC viability from the umbilical cord (10%), an increase in the production of reactive oxygen species (ROS) and an increase in cell apoptosis (~2-fold) compared to pregnant non-smokers. In the umbilical cord, it was observed an increase of advanced oxidation protein products - AOPP (~2.5-fold) and a loss of the typical architecture and disposition of endothelial cells from the umbilical artery.

Conclusions

These data suggest that maternal cigarette smoking during pregnancy (even in small amounts) may compromise the viability of MNC cells and damage the umbilical cord structure, possibly by excessive ROS bioavailability.

Effect of cigarette smoking on vascular flows in pregnancies complicated by intrauterine growth restriction

Exposure to tobacco smoke during pregnancy may result in intrauterine growth restriction (IUGR). In the study, the effect of tobacco smoke on vascular flows in the middle cerebral artery, umbilical artery, ductus venosus in fetuses and uterine artery in pregnancies complicated by IUGR was investigated. The study subjects were divided into three groups: smoking women with IUGR (n=31), women with idiopathic IUGR (n=28) and healthy controls (n=50). Fetal biometry and flow parameters were measured. Concentration of heavy metals and antioxidants was tested in maternal blood and fetal umbilical cord blood. The Student t test and multiple regression analysis were used. Cotinine and cadmium concentrations were significantly higher in smokers (55.23±54.23, 1.52±0.9), while metallothionein was significantly higher (22.94±8.64) in the idiopathic IUGR group. Strong correlations between cotinine and cadmium concentrations and cerebral-umbilical index were found. Long-term exposure to tobacco smoke deteriorates flows in vital fetal vessels.

Examining two different schedules of financial incentives for smoking cessation among pregnant women

OBJECTIVE

To examine whether an efficacious voucher-based incentives intervention for decreasing smoking during pregnancy and increasing fetal growth could be improved without increasing costs. The strategy was to redistribute the usual incentives so that higher values were available early in the quit attempt.

METHOD

118 pregnant smokers in greater Burlington, Vermont (studied December, 2006-June, 2012) were randomly assigned to the revised contingent voucher (RCV) or usual contingent voucher (CV) schedule of abstinence-contingent vouchers, or to a non-contingent voucher (NCV) control condition wherein vouchers were provided independent of smoking status. Smoking status was biochemically verified; serial sonographic estimates of fetal growth were obtained at gestational weeks 30-34.

RESULTS

RCV and CV conditions increased point-prevalence abstinence above NCV levels at early (RCV: 40%, CV: 46%, NCV: 13%, p=.007) and late-pregnancy (RCV: 45%; CV: 36%; NCV, 18%; p=.04) assessments, but abstinence levels did not differ between the RCV and CV conditions. The RCV intervention did not increase fetal growth above control levels while the CV condition did so (p<.05).

CONCLUSION

This trial further supports the efficacy of CV for increasing antepartum abstinence and fetal growth, but other strategies (e.g., increasing overall incentive values) will be necessary to improve outcomes further.

Damaging legacy: maternal cigarette smoking has long-term consequences for male offspring fertility

STUDY QUESTION

What are the effects on fertility of cigarette smoke-induced toxicity on male offspring exposed during the gestational/weaning period?

SUMMARY ANSWER

Maternal cigarette smoke exposure during the gestational/weaning period causes long-term defects in male offspring fertility.

WHAT IS KNOWN ALREADY

Cigarette smoke is a well-known reproductive toxicant which is particularly harmful to both fetal and neonatal germ cells. However, recent studies suggest a significant portion of young mothers in the developed world still smoke during pregnancy. In the context of male reproductive health, our understanding of the effects of in utero exposure on offspring fertility is limited.

STUDY DESIGN, SIZE, DURATION

In this study, 27 C57BL/6 5-week-old female mice were exposed via the nose-only to cigarette smoke (treatment) or 27 were exposed to room air (control) for 6 weeks before being housed with stud males to produce litters. In the treatment group, smoke exposure continued throughout mating, pregnancy and lactation until weaning of pups at 21 days post birth. Male offspring were examined at post-natal days 3, 6, 12, 21 and 98 (adult).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Approximately 108 maternal smoke-exposed C57BL/6 offspring and controls were examined. Spermatogenesis was examined using testicular histology and apoptosis/DNA damage was assessed using caspase immunohistochemistry and TUNEL. Sertoli cell morphology and fluctuations in the spermatogonial stem cell population were also examined using immunohistochemistry. Microarray and QPCR analysis were performed on adult testes to examine specific long-term transcriptomic alteration as a consequence of maternal smoke exposure. Sperm counts and motility, zona/oolemma binding assays, COMET analysis and mitochondrial genomic sequencing were also performed on spermatozoa obtained from adult treated and control mice. Fertility trials using exposed adult male offspring were also performed.

MAIN RESULTS AND THE ROLE OF CHANCE

Maternal cigarette smoke exposure caused increased gonocyte and meiotic spermatocyte apoptosis (P < 0.01) as well as germ cell depletion in the seminiferous tubules of neonatal and juvenile offspring. Aberrant testicular development characterized by abnormal Sertoli and germ cell organization, a depleted spermatogonial stem cell population (P < 0.01), atrophic seminiferous tubules and increased germ cell DNA damage (P < 0.01) persisted in adult offspring 11 weeks after exposure. Microarray analysis of adult offspring testes associated these defects with meiotic germ cell development, sex hormone metabolism, oxidative stress and Sertoli cell signalling. Next generation sequencing also revealed a high mitochondrial DNA mutational load in the testes of adult offspring (P < 0.01). Adult maternal smoke-exposed offspring also had reduced sperm counts with spermatozoa exhibiting morphological abnormalities (P < 0.01), affecting motility and fertilization potential. Odf2, a spermatozoa flagellum component required for coordinated ciliary beating, was also significantly down-regulated (P < 0.01) in maternal smoke-exposed adult offspring, with aberrant localization along the spermatozoa flagellum. Adult maternal smoke-exposed offspring took significantly longer to impregnate control females and had a slight but significant (P < 0.01) reduction in litter size.

LIMITATIONS, REASONS FOR CAUTION

This study examined only one species (mouse) using a smoking model which only simulates human cigarette smoke exposure.

WIDER IMPLICATIONS OF THE FINDINGS

This study represents the first comprehensive animal model of maternal smoking on male offspring reproductive function, suggesting that exposure during the gestational/weaning period causes long-term defects in male offspring fertility. This is due to a compromised spermatogonial stem cell population resulting from gonocyte apoptosis and impaired spermatogenic development. This results in significant germ cell damage and Sertoli cell dysfunction, impacting germ cell number, tubule organization, DNA damage and spermatozoa in adult offspring. This study strengthens the current literature suggesting that maternal exposure impairs male offspring fertility, which is currently debated due to conflicting studies.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the Australian Research Council, Hunter Medical Research Institute, National Health and Medical Research Council of Australia and the Newcastle Permanent Building Society Charitable Trust. The authors declare no conflict of interest.

Applying measures of discriminatory accuracy to revisit traditional risk factors for being small for gestational age in Sweden: a national cross-sectional study

OBJECTIVES

Small for gestational age (SGA) is considered as an indicator of intrauterine growth restriction, and multiple maternal and newborn characteristics have been identified as risk factors for SGA. This knowledge is mainly based on measures of average association (ie, OR) that quantify differences in average risk between exposed and unexposed groups. Nevertheless, average associations do not assess the discriminatory accuracy of the risk factors (ie, its ability to discriminate the babies who will develop SGA from those that will not). Therefore, applying measures of discriminatory accuracy rather than measures of association only, our study revisits known risk factors of SGA and discusses their role from a public health perspective.

DESIGN

Cross-sectional study. We measured maternal (ie, smoking, hypertension, age, marital status, education) and delivery (ie, sex, gestational age, birth order) characteristics and performed logistic regression models to estimate both ORs and measures of discriminatory accuracy, like the area under the receiver operating characteristic curve (AU-ROC) and the net reclassification improvement.

SETTING

Data were obtained from the Swedish Medical Birth Registry.

PARTICIPANTS

Our sample included 731 989 babies born during 1987-1993.

RESULTS

We replicated the expected associations. For instance, smoking (OR=2.57), having had a previous SGA baby (OR=5.48) and hypertension (OR=4.02) were strongly associated with SGA. However, they show a very small discriminatory accuracy (AU-ROC≈0.5). The discriminatory accuracy increased, but remained unsatisfactorily low (AU-ROC=0.6), when including all variables studied in the same model.

CONCLUSIONS

Traditional risk factors for SGA alone or in combination have a low accuracy for discriminating babies with SGA from those without SGA. A proper understanding of these findings is of fundamental relevance to address future research and to design policymaking recommendations in a more informed way.

Soy isoflavone intake and the likelihood of ever becoming a mother: the Adventist Health Study-2

Objectives

As little is known about the possible relationship between the intake of phytoestrogens and female fertility, we investigated the relationship between soy isoflavone intake and the risk of nulliparity and nulligravidity.

Methods

A cross-sectional study of 11,688 North American Adventist women aged 30–50 years old with data regarding childbearing. These women were, as a group, characterized by a high proportion (54%) of vegetarians and a healthy lifestyle with a very low prevalence of smoking and alcohol use.

Results

The mean isoflavone intake (17.9 mg per day) was very high compared to other Western populations. Only 6% of the women indicated no intake of isoflavones. We found, after adjustment for age, marital status, and educational level, an inverse relationship (P=0.05) between isoflavone intake and the likelihood of ever having become a mother. In women with high (≥40 mg/day) isoflavone intake (12% of this group of women), the adjusted lifetime probability of giving birth to a live child was reduced by approximately 3% (95% CI: 0, 7) compared to women with low (<10 mg/day) intake. No relationships were found between the isoflavone intake and parity or age at first delivery in parous women. A similar inverse relationship (P=0.03) was found between the isoflavone intake and the risk of nulligravidity with a 13% (95% CI: 2, 26) higher risk of never have been pregnant in women with high (≥40 mg/day) isoflavone intake. These relationships were found mainly in women who reported problems becoming pregnant.

Conclusion

The findings suggest that a high dietary isoflavone intake may have significant impact on fertility.

Systematic review and meta-analysis of miscarriage and maternal exposure to tobacco smoke during pregnancy

We conducted a systematic review and meta-analysis to characterize the relationship between smoking and miscarriage. We searched the PubMed database (1956-August 31, 2011) using keywords and conducted manual reference searches of included articles and reports of the US Surgeon General. The full text of 1,706 articles was reviewed, and 98 articles that examined the association between active or passive smoking and miscarriage were included in the meta-analysis. Data were abstracted by 2 reviewers. Any active smoking was associated with increased risk of miscarriage (summary relative risk ratio = 1.23, 95% confidence interval (CI): 1.16, 1.30; n = 50 studies), and this risk was greater when the smoking exposure was specifically defined as during the pregnancy in which miscarriage risk was measured (summary relative risk ratio = 1.32, 95% CI: 1.21, 1.44; n = 25 studies). The risk of miscarriage increased with the amount smoked (1% increase in relative risk per cigarette smoked per day). Secondhand smoke exposure during pregnancy increased the risk of miscarriage by 11% (95% CI: 0.95, 1.31; n = 17 studies). Biases in study publication, design, and analysis did not significantly affect the results. This finding strengthens the evidence that women should not smoke while pregnant, and all women of reproductive age should be warned that smoking increases the risk of miscarriage.

Understanding tobacco-related attitudes among college and noncollege young adult hookah and cigarette users

OBJECTIVE

To examine differences in tobacco-related attitudes and hookah and cigarette use among college and noncollege young adults.

PARTICIPANTS

Time-location samples of young adult bar patrons in San Diego, California (N = 2,243), Tulsa (N = 2,095) and Oklahoma City (N = 2,200), Oklahoma, Albuquerque (N = 1,044) and Las Cruces (N = 894), New Mexico, between September 2009 and July 2011.

METHODS

Multinomial logistic regression examined associations between hookah and cigarette use and tobacco-related attitudes.

RESULTS

Current college students and graduates are less likely to smoke cigarettes, but more likely to use hookah. Among current hookah users, 22.6% were hookah-only users and 77.4% were dual users (cigarettes and hookah). College status is associated with different hookah use patterns, and those with anti-tobacco industry attitudes were more likely to smoke hookah.

CONCLUSIONS

Novel interventions are needed for college students using hookah. Existing strategies targeting smokers with anti-tobacco industry messages may be irrelevant to hookah users.

Using twitter to examine smoking behavior and perceptions of emerging tobacco products

BACKGROUND

Social media platforms such as Twitter are rapidly becoming key resources for public health surveillance applications, yet little is known about Twitter users' levels of informedness and sentiment toward tobacco, especially with regard to the emerging tobacco control challenges posed by hookah and electronic cigarettes.

OBJECTIVE

To develop a content and sentiment analysis of tobacco-related Twitter posts and build machine learning classifiers to detect tobacco-relevant posts and sentiment towards tobacco, with a particular focus on new and emerging products like hookah and electronic cigarettes.

METHODS

We collected 7362 tobacco-related Twitter posts at 15-day intervals from December 2011 to July 2012. Each tweet was manually classified using a triaxial scheme, capturing genre, theme, and sentiment. Using the collected data, machine-learning classifiers were trained to detect tobacco-related vs irrelevant tweets as well as positive vs negative sentiment, using Naïve Bayes, k-nearest neighbors, and Support Vector Machine (SVM) algorithms. Finally, phi contingency coefficients were computed between each of the categories to discover emergent patterns.

RESULTS

The most prevalent genres were first- and second-hand experience and opinion, and the most frequent themes were hookah, cessation, and pleasure. Sentiment toward tobacco was overall more positive (1939/4215, 46% of tweets) than negative (1349/4215, 32%) or neutral among tweets mentioning it, even excluding the 9% of tweets categorized as marketing. Three separate metrics converged to support an emergent distinction between, on one hand, hookah and electronic cigarettes corresponding to positive sentiment, and on the other hand, traditional tobacco products and more general references corresponding to negative sentiment. These metrics included correlations between categories in the annotation scheme (phihookah-positive=0.39; phi(e-cigs)-positive=0.19); correlations between search keywords and sentiment (χ²₄=414.50, P<.001, Cramer's V=0.36), and the most discriminating unigram features for positive and negative sentiment ranked by log odds ratio in the machine learning component of the study. In the automated classification tasks, SVMs using a relatively small number of unigram features (500) achieved best performance in discriminating tobacco-related from unrelated tweets (F score=0.85).

CONCLUSIONS

Novel insights available through Twitter for tobacco surveillance are attested through the high prevalence of positive sentiment. This positive sentiment is correlated in complex ways with social image, personal experience, and recently popular products such as hookah and electronic cigarettes. Several apparent perceptual disconnects between these products and their health effects suggest opportunities for tobacco control education. Finally, machine classification of tobacco-related posts shows a promising edge over strictly keyword-based approaches, yielding an improved signal-to-noise ratio in Twitter data and paving the way for automated tobacco surveillance applications.

Use of selective serotonin reuptake inhibitors and lifestyle among women of childbearing age: a Danish cross-sectional survey

OBJECTIVE

To examine the use of selective serotonin reuptake inhibitors (SSRIs) among Danish women of childbearing age according to lifestyle factors.

DESIGN

Cross-sectional survey.

SETTING

The Central Denmark Region.

PARTICIPANTS

4234 women (71.5% of the invited women) aged 25-44 years who participated in a public health survey in 2006.

OUTCOME MEASURES

Prevalence and prevalence ratios (PRs) of current and former SSRI use among women characterised by selected lifestyle factors. We obtained information on SSRI use through linkage to the Aarhus University Prescription Database covering all pharmacies in the region.

RESULTS

Of the 4234 women in the study, 161 (3.8%) were current SSRI users, 60 (1.4%) were recent users, 223 (5.3%) were former users and 3790 (89.5%) were never users. Current use of SSRIs was more prevalent in obese women than in non-obese women (PR 1.5, 95% CI 1.0 to 2.3), in current smokers compared with non-current smokers (PR 1.6, 95% CI 1.1 to 2.2), in women who drank more than seven alcoholic drinks weekly compared with women who drank seven or fewer drinks weekly (PR 1.8, 95% CI 1.2 to 2.8) and in women with an unhealthy diet compared with women with a healthy diet (PR 1.7, 95% CI 1.2 to 2.6). Prevalence of former use of SSRIs was similarly increased except in those with an unhealthy diet (PR 1.1, 95% CI 0.8 to 1.7). SSRI use did not differ according to participation in regular physical activity.

CONCLUSIONS

Women with an unhealthy lifestyle were about 1.5-fold more likely to be current or former users of SSRIs than those with a healthy lifestyle. These findings may be useful for quantitative assessment of the contribution of lifestyle factors to uncontrolled confounding in studies of SSRI use in pregnancy.

The effect of Swedish snuff (snus) on offspring birthweight: a sibling analysis

Current observational evidence indicates that maternal smoking during pregnancy is associated with reduced birthweight in offspring. However, less is known about the effect of smokeless tobacco on birthweight and about the possible mechanisms involved in this relationship. This paper studies the effect of Swedish smokeless tobacco (snus) on offspring birthweight comparing the results obtained from a conventional linear regression analysis and from a quasi-experimental sibling design using a multilevel linear regression analysis. From the Swedish Medical Birth Register, we investigated 604,804 singletons born between 2002 and 2010. From them, we isolated 8,861 siblings from 4,104 mothers with discrepant snus-use habits (i.e., women who had at least one pregnancy during which they used snus and at least one other pregnancy in which they did not). The conventional analysis shows that continuous snus use throughout the pregnancy reduces birthweight in 47 g while quitting or relapsing snus has a minor and statistically non-significant effect (−6 g and −4 g, respectively). However, using a sibling analysis the effect observed for mothers who continue to use snus during pregnancy is less intense than that observed with previous conventional analyses (−20 g), and this effect is not statistically significant. Sibling analysis shows that quitting or relapsing snus use after the first trimester slightly reduces birthweight (14 g).However, this small change is not statistically significant. The sibling analysis provides strong causal evidence indicating that exposure to snus during pregnancy has a minor effect on birthweight reduction. Our findings provide a new piece of causal evidence concerning the effect of tobacco on birthweight and support the hypothesis that the harmful effect of smoking on birthweight is not mainly due to nicotine.

Body mass index at age 20 and subsequent childbearing: the Adventist Health Study-2

BACKGROUND

Some epidemiological, clinical, and laboratory studies suggest that underweight and obesity impact fertility.

METHODS

This is cross-sectional study of 33,159 North American Adventist women, who were nulliparous at age 20 years and who, as a group, have a healthy lifestyle. Logistic regression analysis was used to assess how body mass index (BMI, kg/m(2)) at age 20 was related to never becoming pregnant, never giving birth to a living child, or not giving birth to a second or third child.

RESULTS

A total of 4954 (15%) of the women reported never becoming pregnant (nulligravidity) and 7461 (23%) women remained nulliparous. Underweight (BMI<18.5 kg/m(2)) at age 20 was associated with approximately 13% increased risk of nulligravidity or nulliparity. Women with BMI≥32.5 kg/m(2) when aged 20 had 2.5 (95% CI: 2.0, 3.1) times increased odds of nulliparity compared to women with BMI 20-24.9 kg/m(2). Increased risk was found for all groups of overweight women (BMI≥25 kg/m(2)). However, if the women gave birth to one live child after age 20, BMI≥32.5 kg/m(2) at age 20 had less impact (OR 1.6 [95% CI: 1.2, 2.2]) on the likelihood of not delivering a second child. In women who delivered two living children, obesity at age 20 had no bearing on the odds of having a third child.

CONCLUSIONS

Obesity and, to a lesser extent, underweight at age 20 increases the nulliparity rate. The results underscore the importance of a healthy weight in young women.

Revisiting the effect of maternal smoking during pregnancy on offspring birthweight: a quasi-experimental sibling analysis in Sweden

Maternal smoking during pregnancy (SDP) seems associated with reduced birthweight in the offspring. This observation, however, is based on conventional epidemiological analyses, and it might be confounded by unobserved maternal characteristics related to both smoking habits and offspring birth weight. Therefore, we apply a quasi-experimental sibling analysis to revisit previous findings. Using the Swedish Medical Birth Register, we identified 677,922 singletons born between 2002 and 2010 from native Swedish mothers. From this population, we isolated 62,941 siblings from 28,768 mothers with discrepant habits of SDP. We applied conventional and mother-specific multilevel linear regression models to investigate the association between maternal SDP and offspring birthweight. Depending on the mother was light or heavy smoker and the timing of exposition during pregnancy (i.e., first or third trimester), the effect of smoking on birthweight reduction was between 6 and 78 g less marked in the sibling analysis than in the conventional analysis. Sibling analysis showed that continuous smoking reduces birthweight by 162 grams for mothers who were light smokers (1 to 9 cigarettes per day) and 226 g on average for those who were heavy smokers throughout the pregnancy in comparison to non-smoker mothers. Quitting smoking during pregnancy partly counteracted the smoking-related birthweight reduction by 1 to 29 g, and a subsequent smoking relapse during pregnancy reduced birthweight by 77 to 83 g. The sibling analysis provides strong evidence that maternal SDP reduces offspring birthweight, though this reduction was not as great as that observed in the conventional analysis. Our findings support public health interventions aimed to prevent SDP and to persuade those who already smoke to quit and not relapse throughout the pregnancy. Besides, further analyses are needed in order to explain the mechanisms through which smoking reduces birthweight and to identify other maternal characteristics that are common causes of both birthweight reduction and maternal smoking.

Long-term health consequences of early-life exposure to substance abuse: an epigenetic perspective

A growing body of evidence highlights the importance of the nutritional or other environmental stimuli during critical periods of development in the long-term programming of organ systems and homeostatic pathways of the organism. The adverse influences early in development and particularly during intrauterine life have been shown to programme the risks for adverse health outcomes in adult life. The mechanisms underlying developmental programming remain still unclear. However, increasing evidence has been accumulated indicating the important role of epigenetic regulation including DNA methylation, histone modifications and non-coding RNAs in the developmental programming of late-onset pathologies, including cancer, neurodegenerative diseases, and type 2 diabetes. The maternal substance abuse during pregnancy, including smoking, drinking and psychoactive drug intake, is one of the important factors determining the process of developmental programming in modern human beings. The impact of prenatal drug/substance exposure on infant and early childhood development is currently in the main focus. The long-term programming effects of such exposures on aging and associated pathologies, however, have been reported only rarely. The purpose of this review is to provide a summary of recent research findings which indicate that maternal substance abuse during pregnancy and/or neonatal period can programme not only a child's health status, but also can cause long-term or even life-long health outcomes via mechanisms of epigenetic memory.

Exposure of pregnant women to waterpipe and cigarette smoke

INTRODUCTION

Throughout the Eastern Mediterranean region, tobacco is used primarily in 2 forms: cigarette smoking and waterpipe smoking. Despite the fact that tobacco use is considered as a global public health threat, waterpipe smoking is reported to be growing in popularity, particularly among women. The objectives of this study are to determine the prevalence and patterns of cigarette, waterpipe, and passive smoking among pregnant women in Jordan, and to assess their perception of harmful effects of cigarette and waterpipe smoking.

METHODS

A total of 500 pregnant women were randomly recruited from maternity clinics in North and Middle of Jordan and surveyed regarding exposure to waterpipe tobacco and cigarette smoking.

RESULTS

The results showed that 7.9% of women were current cigarette smokers and 8.7% were current waterpipe smokers. About 82.4% of all women reported that they are exposed to cigarette smoke and 32.8% reported that they are exposed to waterpipe smoke. The most common place where women are exposed to cigarette and waterpipe smoke was their house (50.4% and 48.7%, respectively) followed by public places (31.4% and 21.4%, respectively). In addition, the husband was the main source for exposure to cigarette and waterpipe smoke (48.5% and 42.7%, respectively). Approximately, 74% of women believed that cigarette smoking is addictive, whereas only 55.1% reported that waterpipe smoking leads to addiction.

CONCLUSIONS

Exposure of pregnant women to tobacco smoke is a public health problem in Jordan that requires immediate action.

Obesity at age 20 and the risk of miscarriages, irregular periods and reported problems of becoming pregnant: the Adventist Health Study-2

In a group of 46,000 North-American Adventist women aged 40 and above, we investigated the relationships between body mass index (BMI, kg/m²) at age 20 and the proportion of women who reported at least one miscarriage, periods with irregular menstruation or failing to become pregnant even if trying for more than one straight year. Approximately 31, 14 and 17 %, respectively, reported the three different problems related to reproduction. Positive age- and marital status adjusted relationships were found between BMI at age 20 and periods with irregular menstruation or failing to become pregnant even if trying for more than 1 year, but not with the risk of miscarriages. Women with BMI ≥ 32.5 kg/m² when aged 20 had approximately 2.0 (95 % CI: 1.6, 2.4) and 1.5 (95 % CI: 1.3, 1.9) higher odds for irregular periods or failing to get pregnant, respectively, than women with BMI in the 20–24.9 kg/m² bracket. These relationships were consistently found in a number of strata of the population, including the large proportion of the women who never had smoked or never used alcohol. Underweight (BMI < 18.5 kg/m²) when aged 20 marginally (approximately 15 %) increased the risk of failing to get pregnant within a year. Thus, obesity at age 20 increases the risk of reporting some specific reproductive problems, but not the risk of miscarriages.

Implementation of routine biochemical validation and an 'opt out' referral pathway for smoking cessation in pregnancy

AIMS

To introduce an 'opt out' referral pathway for smoking cessation in pregnancy and to compare different methods for identifying pregnant smokers in maternity care.

DESIGN

Pilot study that analysed routine data from maternity and smoking cessation services with biochemical validation of smoking status.

SETTING

Dudley and South Birmingham, England.

PARTICIPANTS

A total of 3712 women who entered the referral pathway-1498 in Dudley and 2214 in South Birmingham.

MEASUREMENTS

Routine monitoring data on smoking at maternity booking, referral to smoking cessation services, number of women who set quit dates set and short-term (4-week) self-report smoking status. Comparison of self-report, carbon monoxide (CO)-validated and urinary cotinine-validated smoking status for a subsample (n = 1492) of women at maternity booking.

FINDINGS

In Dudley 27% of women who entered the opt out referral pathway were identified as smokers following CO testing. Of those referred to the smoking cessation services, 19% reported stopping smoking at 4-week follow-up. In South Birmingham 17% were smokers at booking, with 5% of those referred recorded as non-smokers at 4 weeks. The number of women quitting did not increase during the study when compared with the previous year, despite higher referral rates in both areas. An optimum cut-off CO measurement of 4 parts per million (p.p.m.) was identified for sensitivity and specificity.

CONCLUSION

The introduction of an opt out referral pathway between maternity and stop smoking services resulted in more women being referred for support to quit but not higher numbers of quitters, suggesting that automatic referral may include women who are not motivated to stop and who may not engage with services. Routine carbon monoxide monitoring introduced as part of a referral pathway should involve a cut-off of 4 p.p.m. to identify smoking in pregnancy.

Steroidogenic enzyme expression in the human fetal liver and potential role in the endocrinology of pregnancy

The human feto-maternal unit produces large amounts of steroid hormones, particularly estrogens, during the second and third trimesters. The fetal adrenal gland and the placenta are considered the principal tissues driving steroid production but the fetal liver is likely to play an essential role in this process. This study was designed to measure transcript expression of proteins involved in steroid synthesis, metabolism, conjugation and signalling in the human fetal liver and to examine sex differences and effects of maternal smoking. Liver samples were taken from 55 normal fetuses from women undergoing second trimester elective termination. Levels of 23 mRNA transcripts encoding steroid synthesis/metabolic/conjugation enzymes and steroid receptors were measured by real-time PCR. The expression of representative proteins was confirmed by western blotting and immunohistochemistry. The human fetal livers expressed high levels of CYP19A1, SULT2A1, SULT1E1, HSD17B2, SRD5A3 and CYP3A7. Lower levels of SULT1A1, STS, UGT2B17, GPER, AKR1C3, UGT2B15, AR, CYP11A1, CYP21A2, HSD17B3, HSD17B1 and SRD5A1 were also detectable. The expression of ESR, ESR2, CYP17A1 and HSD3B transcripts was undetectable in most fetal livers, although HSD3B was shown to be present by western blotting. Sex differences were limited to SRD5A3 (lower in females) and UGT2B17 (higher in females). Maternal smoking increased the expression of CYP19A1, SULT2A1, UGT2B17, HSD17B2 and AKR1C3 and reduced the expression of SRD5A3 in the male fetal liver. This study shows that the human fetal liver is likely to have an extensive effect on circulating steroid levels in the human fetus and mother. The most important of these effects will be alterations to the species, conjugation and availability of estrogens in the fetus. Maternal smoking is likely to reduce circulating androgen bioactivity in male fetuses.

Assessment of DNA damage using chromosomal aberrations assay in lymphocytes of waterpipe smokers

OBJECTIVES

The aim of this study was to investigate the genotoxicity of waterpipe smoking in the lymphocytes of waterpipe smokers using chromosomal aberrations (CAs) assay.

MATERIALS AND METHODS

Fifty waterpipe smokers and 18 healthy non-smokers volunteered to participate in the study. Additionally, 18 heavy cigarette smokers were recruited for comparison. Chromosomal aberrations (CAs) assay was used to evaluate DNA damage in the lymphocytes.

RESULTS

The results showed that similarly to cigarette smoking, waterpipe smoking significantly increased the frequencies of CAs (p < 0.01). In addition, the frequencies of CAs increased with more waterpipe use.

CONCLUSIONS

Waterpipe smoking causes DNA damage to lymphocytes and the damage increases with more waterpipe use.

Investigating maternal risk factors as potential targets of intervention to reduce socioeconomic inequality in small for gestational age: a population-based study

BACKGROUND

The major aim of this study was to investigate whether maternal risk factors associated with socioeconomic status and small for gestational age (SGA) might be viable targets of interventions to reduce differential risk of SGA by socioeconomic status (socioeconomic SGA inequality) in the metropolitan area of Vancouver, Canada.

METHODS

This study included 59,039 live, singleton births in the Vancouver Census Metropolitan Area (Vancouver) from January 1, 2006 to September 17, 2009. To identify an indicator of socioeconomic SGA inequality, we used hierarchical logistic regression to model SGA by area-level variables from the Canadian census. We then modelled SGA by area-level average income plus established maternal risk factors for SGA and calculated population attributable SGA risk percentages (PAR%) for each variable. Associations of maternal risk factors for SGA with average income were investigated to identify those that might contribute to SGA inequality. Finally, we estimated crude reductions in the percentage and absolute differences in SGA risks between highest and lowest average income quintiles that would result if interventions on maternal risk factors successfully equalized them across income levels or eliminated them altogether.

RESULTS

Average income produced the most linear and statistically significant indicator of socioeconomic SGA inequality with 8.9% prevalence of SGA in the lowest income quintile compared to 5.6% in the highest. The adjusted PAR% of SGA for variables were: bottom four quintiles of height (51%), first birth (32%), bottom four quintiles of average income (14%), oligohydramnios (7%), underweight or hypertension, (6% each), smoking (3%) and placental disorder (1%). Shorter height, underweight and smoking during pregnancy had higher prevalence in lower income groups. Crude models assuming equalization of risk factors across income levels or elimination altogether indicated little potential change in relative socioeconomic SGA inequality and reduction in absolute SGA inequality for shorter height only.

CONCLUSIONS

Our findings regarding maternal height may indicate trans-generational aetiology for socioeconomic SGA inequalities and/or that adult height influences social mobility. Conditions affecting foetal and childhood growth might be viable targets to reduce absolute socioeconomic SGA inequality in future generations, but more research is needed to determine whether such an approach is appropriate.

Fetal programming of adult disease: implications for prenatal care

The obesity epidemic, including a marked increase in the prevalence of obesity among pregnant women, represents a critical public health problem in the United States and throughout the world. Over the past two decades, it has been increasingly recognized that the risk of adult health disorders, particularly metabolic syndrome, can be markedly influenced by prenatal and infant environmental exposures (ie, developmental programming). Low birth weight, together with infant catch-up growth, is associated with a significant risk of adult obesity and cardiovascular disease, as well as adverse effects on pulmonary, renal, and cerebral function. Conversely, exposure to maternal obesity or high birth weight also represents an increased risk for childhood and adult obesity. In addition, fetal exposure to select chemicals (eg, phytoestrogens) or environmental pollutants (eg, tobacco smoke) may affect the predisposition to adult disease. Animal models have confirmed human epidemiologic findings and provided insight into putative programming mechanisms, including altered organ development, cellular signaling responses, and epigenetic modifications (ie, control of gene expression without modification of DNA sequence). Prenatal care is transitioning to incorporate goals of optimizing maternal, fetal, and neonatal health to prevent or reduce adult-onset diseases. Guidelines regarding optimal pregnancy nutrition and weight gain, management of low- and high-fetal-weight pregnancies, use of maternal glucocorticoids, and newborn feeding strategies, among others, have yet to fully integrate long-term consequences on adult health.

Assessment of DNA damage using chromosomal aberrations assay in lymphocytes of waterpipe smokers

OBJECTIVES

The aim of this study was to investigate the genotoxicity of waterpipe smoking in the lymphocytes of waterpipe smokers using chromosomal aberrations (CAs) assay.

MATERIALS AND METHODS

Fifty waterpipe smokers and 18 healthy non-smokers volunteered to participate in the study. Additionally, 18 heavy cigarette smokers were recruited for comparison. Chromosomal aberrations (CAs) assay was used to evaluate DNA damage in the lymphocytes.

RESULTS

The results showed that similarly to cigarette smoking, waterpipe smoking significantly increased the frequencies of CAs (p < 0.01). In addition, the frequencies of CAs increased with more waterpipe use.

CONCLUSIONS

Waterpipe smoking causes DNA damage to lymphocytes and the damage increases with more waterpipe use.

Prenatal exposure to tobacco extract containing nicotinic alkaloids produces morphological and behavioral changes in newborn rats

Tobacco exposure is not only a health concern for adults but has also been shown to exert deleterious effects on the health of the fetus, newborn, child, and adolescent. Decreased cognitive function, lower Intellectual Quotient (IQ) and deficits in learning and memory in children have been associated with maternal smoking during pregnancy. In this study, we have studied the effect of a tobacco plant extract on the growth and development in the rat. The extract contained relative proportions of alkaloids, including nicotine, purified by chemical separation. Pregnant rats received oral doses of either control (NaCl) or tobacco extract during the entire gestational period. Offspring length and body weight were measured. Each day, the offspring were observed for the following physical parameters: hair growth, incisor eruption and eye opening. The day of appearance of these developments was recorded. Before weaning, the offspring were examined to test their cliff avoidance response (6 postnatal day (PN)), surface righting reflex (05, 07, 13 postnatal day), swimming development (10, 12 postnatal day), negative geotaxis response (7,9,13 and 17 postnatal day) and jumping down choice cage (15, 17 postnatal day). Administration of tobacco extract to dams during the entire gestation period affects behavior and development in pups. The observed effects were a delay in opening eyes, incisor eruption and hair appearance, behavioral developments and an alteration in the rate of success behavior. However, in the jumping down choice cage test there was no difference compared to control animals. The results suggest that tobacco extract has a significant effect on the development of behavioral patterns, orientation and motor coordination and function. They also suggest significant growth retardation and teratogenic effects.

A randomized trial of nicotine-replacement therapy patches in pregnancy

BACKGROUND

Nicotine-replacement therapy is effective for smoking cessation outside pregnancy and its use is widely recommended during pregnancy. We investigated the efficacy and safety of nicotine patches during pregnancy.

METHODS

We recruited participants from seven hospitals in England who were 16 to 50 years of age with pregnancies of 12 to 24 weeks' gestation and who smoked five or more cigarettes per day. Participants received behavioral cessation support and were randomly assigned to 8 weeks of treatment with active nicotine patches (15 mg per 16 hours) or matched placebo patches. The primary outcome was abstinence from the date of smoking cessation until delivery, as validated by measurement of exhaled carbon monoxide or salivary cotinine. Safety was assessed by monitoring for adverse pregnancy and birth outcomes.

RESULTS

Of 1050 participants, 521 were randomly assigned to nicotine-replacement therapy and 529 to placebo. There was no significant difference in the rate of abstinence from the quit date until delivery between the nicotine-replacement and placebo groups (9.4% and 7.6%, respectively; unadjusted odds ratio with nicotine-replacement therapy, 1.26; 95% confidence interval, 0.82 to 1.96), although the rate was higher at 1 month in the nicotine-replacement group than in the placebo group (21.3% vs. 11.7%). Compliance was low; only 7.2% of women assigned to nicotine-replacement therapy and 2.8% assigned to placebo used patches for more than 1 month. Rates of adverse pregnancy and birth outcomes were similar in the two groups.

CONCLUSIONS

Adding a nicotine patch (15 mg per 16 hours) to behavioral cessation support for women who smoked during pregnancy did not significantly increase the rate of abstinence from smoking until delivery or the risk of adverse pregnancy or birth outcomes. However, low compliance rates substantially limited the assessment of safety. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Current Controlled Trials number, ISRCTN07249128.).

The Experimental Use of Syrian Hamsters

The Syrian hamster (Mesocricetus auratus) is a widely used experimental animal model. This chapter focuses primarily on the most current research uses of the hamster. More classical uses are covered only as they pertain to these current uses. Hamsters possess unique anatomical and physiological features, which make them desirable research models. Unlike other commonly used laboratory rodents, hamsters possess a cheek pouch, which can be easily everted and examined at both the gross and microscopic level. The hamster's relative size also allows for better visualization of certain biological systems including the respiratory and reproductive systems when compared to the mouse. Further, laboratory hamsters develop a variety of inherited diseases, which display similarities to human conditions. Hamsters possessing some of these inherited traits are commercially available. They are susceptible to a variety of carcinogens and develop tumors that other research animals less commonly develop. Also they are susceptible to the induction of a variety of metabolic disorders through the use of dietary manipulations. The antagonistic nature of hamsters is used to study the effect of treatment on male aggressive and defensive behaviors. Syrian hamsters display several unique characteristics that make them desired models for carcinogenesis studies.

Consequences of prenatal substance use

BACKGROUND

Prenatal substance use is a major public health problem and a social morbidity, with consequences on the drug user and the offspring.

OBJECTIVE

This review focuses on the child and adolescent outcomes following in utero drug exposure.

METHODS

Studies on the effects of specific substances, legal and illegal; i.e., tobacco or nicotine, alcohol, marijuana, cocaine, opiates, and methamphetamine were evaluated and analyzed.

RESULTS

In general, manifestations of prenatal exposure to legal and illegal substances include varying deficits in birth anthropometric measurements, mild-to-moderate transient neurobehavioral alterations in infancy and long-term behavioral problems noted from early childhood to adolescence. Severity of expression of behavioral problems is influenced by environmental factors. Further, behavioral alterations following in utero drug exposure often exist with mental health co-morbidities.

CONCLUSION

Because of the long-term consequences of prenatal drug exposure on child and adolescent mental health, health providers need to promote substance use prevention, screen for exposure effects and provide or refer affected youths for intervention services. Preventive measures and treatment should consider other factors that may further increase the risk of psychopathology in the exposed children.

Enhancement of placental antioxidative function and P-gp expression by sodium ferulate mediated its protective effect on rat IUGR induced by prenatal tobacco/alcohol exposure

This study was aimed to explore the therapeutic effect of sodium ferulate (SF) on rats with intrauterine growth retardation (IUGR), and then to clarify the corresponding mechanism. Pregnant rats were divided into normal group, tobacco/alcohol exposure group, and tobacco/alcohol+SF groups. Fetal developmental indices, placental weight, histological alteration, oxidative and antioxidative-function (e.g. MDA, SOD, CAT) and Mdr1 levels were assayed. Results showed exposure to tobacco/alcohol resulted in reduced fetal developmental indices and placental histological alteration, as well as the increased MDA content, decreased SOD and CAT activities and decreased Mdr1a level. After SF treatment, fetal developmental indices, and placental weight, histological alteration, oxidative and antioxidative-function and mdr1a levels were reversed. Our study indicated SF may be effective in reversing IUGR production, and its underlying mechanism may be due to enhanced placental antioxidative function and P-gp expression, which may be related to IUGR formation by tobacco/alcohol exposure.

Evaluation of the representativeness of a Dutch non-malformed control group for the general pregnant population: are these controls useful for EUROCAT?

PURPOSE

A case-control study is the most powerful design to test the risk of specific congenital malformations associated with a specific drug. However, malformation registries often lack non-malformed controls. For the Dutch EUROCAT, we collected a non-malformed control group: the 'Healthy Pregnant'. The aim of this study was to evaluate the representativeness of this control group for the general pregnant population in the northern part of the Netherlands.

METHODS

The Healthy Pregnant data set includes data from two midwife practices. The baseline characteristics of mother and child including smoking status, drinking status, body mass index, maternal age, educational level, exposures to several drugs for chronic diseases and pregnancy related symptoms were evaluated.

RESULTS

Compared with the general population, mothers in Healthy Pregnant group (n = 556) were from either low or high education level, were more likely to have a body mass index > 25 kg/m² (26% versus 22%, p = 0.08) or to smoke (19% versus 10%, p < 0.01) but were less likely to consume alcohol (20% versus 29%, p < 0.01). The use of drugs for chronic conditions was lower in Healthy Pregnant group. Furthermore, drugs for occasional use were prescribed less frequently, and a significant underreporting of children with a low birth weight and a short duration of gestation was found.

CONCLUSION

The Healthy Pregnant data set was not representative of the general pregnant population in the northern part of the Netherlands. Specifically, the exposure to (chronic) drugs was underestimated, possibly a result of second-line care on the basis of medical indication. Thus, continuous investigation of options for improvement of the Healthy Pregnant database is required.

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.

Prenatal tobacco exposure influences cerebral oxygenation in preterm infants

AIM

Our aim was to determine the influence of prenatal tobacco exposure on regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) in preterm infants. We hypothesized that as a result of vasoconstriction caused by prenatal tobacco exposure r(c)SO(2) would be lower and FTOE would be higher during the first days after birth in infants exposed to tobacco during pregnancy.

METHODS

Sixty preterms were included in this prospective, observational cohort study (median gestational age 29.9 weeks, range 26.0-31.8, median birth weight 1248 g, range 615-2250). Fourteen infants had been exposed to tobacco during pregnancy. All mothers smoked more than five cigarettes a day till delivery. We measured r(c)SO(2) and transcutaneous arterial oxygen saturation (tcSaO(2)) in all infants on days 1-5, 8, and 15. FTOE was calculated: FTOE=(tcSaO(2)-r(c)SO(2))/tcSaO(2).

RESULTS

In preterm infants exposed to tobacco during pregnancy, r(c)SO(2) was lower during days 1, 2, and 8 after birth, median 73% versus 81%, 73% versus 80% and 71% versus 78% respectively. FTOE was higher during days 1 and 8 after birth, median 0.24 versus 0.15 and 0.26 versus 0.19 respectively. On the second day, FTOE tended to be higher, 0.18 versus 0.14.

CONCLUSIONS

During the first two days and day 8 after birth cerebral oxygen saturation is lower and oxygen extraction higher in preterm infants following prenatal tobacco exposure. Our data suggest that prenatal tobacco exposure may have an effect on cerebral oxygenation of the infant.

Periconceptional tobacco smoking and isolated congenital heart defects in the neonatal period

BACKGROUND

Tobacco use in pregnancy is considered a human developmental toxicant and potential teratogen. The aim of the study was to test for a possible association between periconceptional tobacco smoking and congenital heart disease (CHD) in the neonatal period.

METHODS

Maternal and infant characteristics of 157 neonates diagnosed with CHD at the University of Patras Medical School were collected and were compared with 208 normal neonates (aged 1-28 days) that were referred for echocardiography during a specified 3-year period.

RESULTS

In neonates with CHD 64 of 157 mothers (40.8%) reported smoking in pregnancy, whereas in the control group 41 of 208 mothers (19.7%) were smokers (p=0.000). Logistic regression analysis with pregestational diabetes, history of influenza-like illness in the first trimester, therapeutic drug exposure in pregnancy, maternal age, parity, family history of CHD, infant gender, prematurity and paternal smoking, as potential confounding factors showed that periconceptional tobacco smoking was associated with increased risk of CHD in the offspring (OR=2.750, 95% CI=1.659-4.476, p=0.00001). The incidence of neonatal heart disease in women who were non-smokers or smoked 1-10 and ≥11 cigarettes per day increased with the level of fetal tobacco exposure (35.8% versus 55.3% versus 64.3%, x2-test=20.303, p=0.000), suggesting a dose effect.

CONCLUSIONS

The results of the study are indicative of an association between periconceptional tobacco exposure and increased risk of CHD in the neonatal period. The potential role of gestational smoking as a risk factor for specific heart defect subgroups requires the conduction of large population based epidemiological studies.