Maternal cigarette smoking and pregnancy outcome

National and regional economic inequalities in first- and second-hand tobacco consumption among women of reproductive ages in Iran

INTRODUCTION

The epidemic of tobacco consumption is one of the major public health threats the world has been facing so far. This study was performed to investigate the economic inequalities in tobacco consumption among women of reproductive ages at national and regional levels in Iran.

METHODS

We used data from 10,339 women of reproductive ages (18-49 years) who participated in Iran's 7th Non-Communicable Disease Risk Factor Surveillance (STEPS). Wagstaff normalized concentration index and decomposition method were applied to measure economic inequalities in first- and second-hand tobacco consumption and determine their corresponding contributory factors, respectively.

RESULTS

The prevalence of women's first-hand tobacco consumption, and their exposure to second-hand smoke in the home, and workplace were 3.6%, 28.3%, and 8.4%, respectively. First- and second-hand tobacco consumption was significantly more concentrated among low-economic women. Exposure to home second-hand smoke, education, and economic status had the largest contributions to the measured inequality in first-hand tobacco consumption (48.9%, 38.9%, and 30.8%, respectively). The measured inequality in women's secondhand smoke exposure at home was explained by their level of education (43.8%), economic status (30.3%), and residency in rural areas (18%), and at work by residency in rural areas (42.2%), economic status (38.8%), and level of education (32%). Our results also revealed diversity in the geographical distribution of inequalities in rural and urban areas and five regions of the country.

CONCLUSION

The present study highlighted the need for more enforcement of tobacco control rules and increasing tobacco taxes as general measures. Furthermore, there is a need for gender-sensitive initiatives at national and regional levels to educate, support, and empower low-economic women and households for tobacco cessation, and complying with restrictive smoking rules.

Interactions among maternal smoking, breastfeeding, and offspring genetic factors on the risk of adult-onset hypertension

BACKGROUND

Previous studies have reported that maternal smoking during pregnancy and breastfeeding may affect the occurrence of hypertension, but whether early life factors modify the impact of the offspring's genetic risk on hypertension is still unknown. The aim of this study was to investigate the relationships among maternal smoking and breastfeeding with adult-onset hypertension and the modified impact of offspring genetic susceptibility.

METHODS

This study included 437,185 participants from the UK Biobank who were initially free of hypertension and provided a prospective cohort of individuals aged 40 to 69 years. The association of maternal smoking during pregnancy and breastfeeding with hypertension was examined by using the Cox regression model. Then, a polygenic risk score (PRS) for hypertension was used to test the gene-environmental interaction on hypertension.

RESULTS

During a median follow-up period of 8.7 years, a total of 68,148 cases of hypertension were identified in this study. The hazard ratios (HRs) and 95% confidence intervals (CIs) of hypertension for maternal smoking and breastfeeding were 1.11 (1.09, 1.13) and 0.96 (0.94, 0.98), respectively. However, no evidence of an interaction between maternal smoking and breastfeeding was observed. Across all levels of genetic risk, including high genetic risk, maternal smoking and nonbreastfeeding had higher hypertension hazards than nonmaternal smoking and breastfeeding, respectively. The adjusted HRs (95% CIs) of hypertension were 1.80 (1.73, 1.87) in those who had high genetic predisposition plus maternal smoking and 1.67 (1.60-1.74) in those with nonbreastfeeding and high genetic risk. There were significant additive interactions between maternal smoking or breastfeeding and genetic factors on the incidence of hypertension.

CONCLUSIONS

Maternal smoking and nonbreastfeeding were associated with a higher risk of hypertension in adulthood and may attenuate the risk of hypertension related to genetic factors. These results suggested that adherence to nonmaternal smoking and breastfeeding was associated with a lower risk of hypertension among participants with all gradients of genetic risk.

Perinatal exposure to maternal smoking and adulthood smoking behaviors in predicting cardiovascular diseases: A prospective cohort study

BACKGROUND AND AIMS

Little is known about the associations between perinatal exposure to maternal smoking and cardiovascular disease (CVD) incidence in offspring, and whether such associations are modified by adulthood and genetically determined smoking behaviors.

METHODS

A total of 414,588 participants without CVD at baseline were included from the UK Biobank in 2006-2010 and followed up through 2018. Cox-proportional hazard models were used to examine the association of perinatal maternal smoking with CVD, and both multiplicative and additive interaction analyses were performed to investigate the modification effects of own smoking behaviors.

RESULTS

During a median follow-up of 8.93 years, we observed 10,860 incident CVD events, including 7006 myocardial infarction (MI) and 4147 stroke. We found that perinatal exposure to maternal smoking was associated with increased risks of CVD (HR: 1.10; 95% CI: 1.05-1.14), MI (1.10; 1.05-1.16) and stroke (1.10; 1.03-1.18). In addition, we observed significant interactions between perinatal exposure to maternal smoking and adulthood exposure to own smoking on CVD and MI on both the multiplicative and additive scales (all p < 0.05). The attributable proportions due to additive interaction between perinatal and adulthood exposure to smoking were 14% (9%-19%) for CVD and 16% (10%-22%) for MI, respectively. Perinatal exposure to maternal smoking also showed an interaction with genetically determined smoking on MI (p < 0.05), but no interactions were found on the total CVD and stroke.

CONCLUSIONS

Our results indicate that perinatal exposure to maternal smoking is associated with increased risks of CVD events, and such relations are modified by adulthood smoking behaviors.

Socioeconomic inequalities and adverse pregnancy outcomes in the UK and Republic of Ireland: a systematic review and meta-analysis

OBJECTIVE

There has been an unprecedented rise in infant mortality associated with deprivation in recent years in the United Kingdom (UK) and Republic of Ireland. A healthy pregnancy can have significant impacts on the life chances of children. The objective of this review was to understand the association between individual-level and household-level measures of socioeconomic status and adverse pregnancy outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Nine databases were searched (Medline, Embase, Scopus, ASSIA, CINAHL, PsycINFO, BNI, MIDRIS and Google Scholar) for articles published between 1999 and August 2019. Grey literature searches were also assessed.

STUDY SELECTION CRITERIA

Studies reporting associations between individual-level or household socioeconomic factors on pregnancy outcomes in the UK or Ireland.

RESULTS

Among the 82 353 search results, 53 821 titles were identified and 35 unique studies met the eligibility criteria. Outcomes reported were neonatal, perinatal and maternal mortality, preterm birth, birth weight and mode of delivery. Pooled effect sizes were calculated using random-effects meta-analysis. There were significantly increased odds of women from lower levels of occupation/social classes compared with the highest level having stillbirth (OR 1.40, 95% CI 1.23 to 1.59, I²98.62%), neonatal mortality (OR 1.39, 95% CI 1.22 to 1.57, I²97.09%), perinatal mortality (OR 1.39, 95% CI 1.23 to 1.57, I²98.69%), preterm birth (OR 1.41, 95% CI 1.33 to 1.50, I²70.97%) and low birth weight (OR 1.40, 95% CI 1.19 to 1.61, I²99.85%). Limitations relate to available data, unmeasured confounders and the small number of studies for some outcomes.

CONCLUSIONS

This review identified consistent evidence that lower occupational status, especially manual occupations and unemployment, were significantly associated with increased risk of multiple adverse pregnancy outcomes. Strategies to improve pregnancy outcomes should incorporate approaches that address wider determinants of health to provide women and families with the best chances of having a healthy pregnancy and baby and to decrease pregnancy-related health inequalities in the general population.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019140893.

Neural tube defects: Risk factors and preventive measures

For the last 25 years, it has been proven that the occurrence or recurrence of neural tube defects can be prevented with the administration of folic acid before and early pregnancy. At present, over 80 countries in the world, except Japan, have mandated the fortification of wheat flour and/or rice with folic acid, which has resulted in a significant reduction in the prevalence of neural tube defects. In 2000, the Japanese government recommended folic acid 400 μg daily for young women of childbearing age and women who are planning to conceive. In 2002, the government started to present information about the importance of folic acid in the development of fetuses in the Mother-Child Health Booklet annually. Despite these endeavors, the prevalence of neural tube defects has remained unchanged. We discuss the risk factors of neural tube defects and propose preventive measures to decrease the number of neonates with neural tube defects. We believe that the government should implement the fortification of staple food with folic acid very soon, which will eventually decrease not only the neonatal mortality and morbidity, but also the economic burden on our health care system.

Maternal Active Smoking During Pregnancy and Low Birth Weight in the Americas: A Systematic Review and Meta-analysis

Introduction

Smoking during pregnancy may negatively impact newborn birth weight. This study investigates the relationship between maternal active smoking during pregnancy and low birth weight in the Americas through systematic review and meta-analysis.

Methods

A literature search was conducted through indexed databases and the grey literature. Case-control and cohort studies published between 1984 and 2016 conducted within the Americas were included without restriction regarding publication language. The article selection process and data extraction were performed by two independent investigators. A meta-analysis of random effects was conducted, and possible causes of between-study heterogeneity were evaluated by meta-regressions and subgroup analyses. Publication bias was assessed by visual inspection of Begg's funnel plot and by Egger's regression test.

Results

The literature search yielded 848 articles from which 34 studies were selected for systematic review and 30 for meta-analysis. Active maternal smoking was associated with low birth weight, OR = 2.00 (95% CI: 1.77-2.26; I2 = 66.3%). The funnel plot and Egger's test (p = .14) indicated no publication bias. Meta-regression revealed that sample size, study quality, and the number of confounders in the original studies did not account for the between-study heterogeneity. Subgroup analysis indicated no significant differences when studies were compared by design, sample size, and regions of the Americas.

Conclusion

Low birth weight is associated with maternal active smoking during pregnancy regardless of the region in the Americas or the studies' methodological aspects.

Implications

A previous search of the major electronic databases revealed that no studies appear to have been conducted to summarize the association between maternal active smoking during pregnancy and low birth weight within the Americas. Therefore, this systematic review may help to fill the information gap. The region of the Americas contains some of the most populous countries in the world; therefore, this study may provide useful data from this massive segment of the world's population.

Maternal Smoking during Pregnancy, Household Smoking after the Child's Birth, and Childhood Proteinuria at Age 3 Years

BACKGROUND AND OBJECTIVES

Smoking is a well known risk factor of proteinuria in adults; however, clinical studies in children are limited. The purpose of this study is to clarify the associations of maternal smoking during pregnancy and household smoking after the child's birth with the risk of proteinuria at age 3 years old.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a population-based retrospective cohort study on 44,595 children using data on prenatal health checkups, home visit neonatal health checkups, and health checkups at 4, 9, and 18 months and 3 years of age in Kobe City, Japan. Maternal smoking status (nonsmoker, past smoker, or current smoker) was collected with standardized questionnaires. The outcome of interest was the presence of proteinuria at 3 years of age defined as urinary protein ≥1+. To evaluate the association between child proteinuria and smoking status, we performed multivariate logistic regression model analyses adjusted for confounding factors.

RESULTS

The prevalence rates of children in the maternal smoking groups (none, past, and current) were 78.9%, 4.4%, and 16.7%, respectively. The frequencies of child proteinuria defined as ≥1+ urinary protein were 1.7% in the current smoking group, 1.6% in the past smoking group, and 1.3% in the nonsmoking group. Maternal smoking during pregnancy was associated with child proteinuria (odds ratio, 1.24; 95% confidence interval, 1.00 to 1.52; P=0.05) in the multiple logistic regression model, although nonmaternal family smoking during pregnancy was not significantly associated with child proteinuria (odds ratio, 0.97; 95% confidence interval, 0.79 to 1.19; P=0.77). We also found a similar association with household smoking after the child's birth (odds ratio, 1.23; 95% confidence interval, 0.99 to 1.54; P=0.06), although this observation was not significant.

CONCLUSIONS

Maternal smoking during pregnancy was one of the risk factors of childhood proteinuria. We also found a similar association with household smoking after the child's birth, although this observation was not significant.

Maternal characteristics of pregnancies with intrauterine fetal demise

OBJECTIVE

To identify maternal characteristics independently associated with pregnancies resulting in intrauterine fetal demise (IUFD).

STUDY DESIGN

This was a population-based cohort study of all births taking place at the McGill University Health Centre in Montreal, Canada, between 2001 and 2007, using the McGill University Obstetrics and Neonatal Database. Maternal characteristics were compared between pregnancies that resulted in IUFD and control pregnancies resulting in live newborns. A logistic regression analysis was constructed to identify parameters independently associated with IUFD.

RESULTS

We identified 20,744 births during the study period, 87 of which were complicated by IUFD. Mothers with IUFD were more likely to be younger, with less formal education, higher rates of smoking during pregnancy, and more fetal anomalies (42.5% vs. 7.5%, P<0.001). After exclusion of pregnancies with congenital and/or chromosomal abnormalities, less formal education (7 vs. 13.6 school years, P<0.001) and smoking during pregnancy (24% vs. 7.7%, P<0.001) remained significantly more common in pregnancies resulting in IUFD. In the multivariable regression analysis both smoking and number of maternal school years were independently associated with IUFD pregnancies (OR 2.22 for smoking, P=0.007 and OR 0.865 for number of school years, P<0.001).

CONCLUSION

Lower levels of education and smoking during pregnancy are independent predictors of IUFD.

Prenatal nicotine exposure induces poor articular cartilage quality in female adult offspring fed a high-fat diet and the intrauterine programming mechanisms

Prenatal nicotine exposure (PNE) induces skeletal growth retardation and dyslipidemia in offspring displaying intrauterine growth retardation (IUGR). Cholesterol accumulation resulting from cholesterol efflux dysfunction may reduce the quality of articular cartilage through fetal programming. This study evaluated the quality of articular cartilage of female adult offspring fed a high-fat diet and explored the mechanisms using a rat IUGR model established by the administration of 2.0mg/kg/d of subcutaneous nicotine from gestational days 11-20. The results demonstrated an increased OARSI (Osteoarthritis Research Society International) score and total cholesterol content, decreased serum corticosterone, and increased IGF1 and dyslipidemia with catch-up growth in PNE adult offspring. Cartilage matrix, IGF1 and cholesterol efflux pathway expression were reduced in PNE fetuses and adult offspring. Therefore, PNE induced poor articular cartilage quality in female adult offspring fed a high-fat diet via a dual programming mechanism.

High levels of alcohol consumption in pregnant women from a touristic area of Southern Spain

The prevalence of alcohol intake in women who become pregnant is similar to that found in the general population, especially in cases of unplanned pregnancies. Consequently, foetal exposure is high during the period of maximum vulnerability. The present study was carried out to determine the prenatal level of exposure to alcohol in Málaga, a Mediterranean region whose economy is based on the touristic sector (Costa del Sol). A cross-sectional, observational design was used to investigate the consumption of alcohol during pregnancy, based on a self-reporting questionnaire. A total of 451 women in the first, second or third trimesters of pregnancy were recruited. Consumption prevalences in each trimester were 40.7%, 25.5% and 17.1%. A higher educational level was associated with greater exposure to alcohol (risk ratio, 1.87 [1.30-2.69]). These results should alert the providers of obstetric care in touristic areas to the need for the adoption of adequate preventive measures.

Maternal smoking and the risk of still birth: systematic review and meta-analysis

Background

Smoking in pregnancy is known to be associated with a range of adverse pregnancy outcomes, yet there is a high prevalence of smoking among pregnant women in many countries, and it remains a major public health concern. We have conducted a systematic review and meta-analysis to provide contemporary estimates of the association between maternal smoking in pregnancy and the risk of stillbirth.

Methods

We searched four databases namely MEDLINE, EMBASE, Psych Info and Web of Science for all relevant original studies published until 31^st December 2012. We included observational studies that measured the association between maternal smoking during pregnancy and the risk of stillbirth.

Results

1766 studies were screened for title analysis, of which 34 papers (21 cohorts, 8 case controls and 5 cross sectional studies) met the inclusion criteria. In meta-analysis smoking during pregnancy was significantly associated with a 47% increase in the odds of stillbirth (OR 1.47, 95% CI 1.37, 1.57, p < 0.0001). In subgroup analysis, smoking 1-9 cig/day and ≥10 cig/day was associated with an 9% and 52% increase in the odds of stillbirth respectively. Subsequently, studies defining stillbirth at ≥ 20 weeks demonstrated a 43% increase in odds for smoking mothers compared to mothers who do not smoke, (OR 1.43, 95% CI 1.32, 1.54, p < 0.0001), whereas studies with stillbirth defined at ≥ 24 weeks and ≥ 28 weeks showed 58% and 33% increase in the odds of stillbirth respectively.

Conclusion

Our review confirms a dose-response effect of maternal smoking in pregnancy on risk of stillbirth. To minimise the risk of stillbirth, reducing current smoking prevalence in pregnancy should continue to be a key public health high priority.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1552-5) contains supplementary material, which is available to authorized users.

Maternal and fetal metabonomic alterations in prenatal nicotine exposure-induced rat intrauterine growth retardation

Prenatal nicotine exposure causes adverse birth outcome. However, the corresponding metabonomic alterations and underlying mechanisms of nicotine-induced developmental toxicity remain unclear. The aims of this study were to characterize the metabolic alterations in biofluids in nicotine-induced intrauterine growth retardation (IUGR) rat model. In the present study, pregnant Wistar rats were intragastrically administered with different doses of nicotine (0.5, 1.0 and 2.0 mg/kg d) from gestational day (GD) 11-20. The metabolic profiles of the biofluids, including maternal plasma, fetal plasma and amniotic fluid, were analyzed using (1)H nuclear magnetic resonance (NMR)-based metabonomic techniques. Prenatal nicotine exposure caused noticeably lower body weights, higher IUGR rates of fetal rats, and elevated maternal and fetal corticosterone (CORT) levels compared to the controls. The correlation analysis among maternal, fetal serum CORT levels and fetal bodyweight suggested that the levels of maternal and fetal serum CORT presented a positive correlation (r=0.356, n=32, P<0.05), while there was a negative correlation between fetal (r=-0.639, n=32, P<0.01) and maternal (r=-0.530, n=32, P<0.01) serum CORT level and fetal bodyweight. The fetal metabonome alterations included the stimulation of lipogenesis and the decreased levels of glucose and amino acids. The maternal metabonome alterations involved the enhanced blood glucose levels, fatty acid oxygenolysis, proteolysis and amino acid accumulation. These results suggested that prenatal nicotine exposure is associated with an altered maternal and fetal metabonome, which may be related to maternal increased glucocorticoid level induced by nicotine.

Parental smoking during pregnancy and offspring cardio-metabolic risk factors at ages 17 and 32

OBJECTIVE

To examine the association of maternal and/or paternal smoking during pregnancy with offspring cardio-metabolic risk (CMR) factors at adolescence and early adulthood, taking into account socio-demographic, medical and lifestyle characteristics of parents and offspring, as well as offspring common genetic variation.

METHODS

We used a population-based cohort of all 17 003 births in Jerusalem during 1974-76, with available archival data on parental and birth characteristics. Measurements at age 17 were assessed at military induction examinations for 11 530 offspring. 1440 offspring from the original 1974-1976 birth cohort were sampled using a stratified sampling approach, and were interviewed and examined at age 32. Parental smoking during pregnancy (i.e. maternal, paternal and any parent) was primarily defined dichotomously (any number of cigarettes smoked daily by mother or father during pregnancy vs. non-smokers). Additionally, smoking was assessed by quantity of cigarettes smoked daily. Linear regression models were used to evaluate the associations of parental smoking during pregnancy with various offspring CMR factors, after controlling for potential confounders and for genetic variation in candidate genes.

RESULTS

Prevalence of exposure to parental smoking in-utero (i.e. smoking of any parent) was 53.2% and 48.4% among the 17 years old and 32 years old samples, respectively. At age 17, smoking of at least one parent during pregnancy was significantly associated with weight (B = 1.39), height (B = 0.59), BMI (B = 0.32) and pulse rate (B = -0.78) (p-values < 0.001). At age 32, parental smoking, adjusted for covariates, was associated with 2.22 kg higher mean offspring weight, 0.95 cm higher mean offspring height, 0.57 kg/m(2) higher BMI, and 1.46 cm higher waist-circumference (p-values ≤ 0.02). Similar results, reflecting a dose response, were observed when maternal and paternal smokings were assessed by number of cigarettes smoked daily.

CONCLUSIONS

This prospective study demonstrates a potential long-term adverse effect of parental smoking during pregnancy on offspring health and calls for increasing efforts to promote smoking cessation of both parents before pregnancy.

[Changes in life styles of pregnant women and risks for having a pregnancy afflicted with spina bifida]

AIMS

Though periconceptional intakes of folic acid could prevent the occurrence of spina bifida by 50 to 70%, the prevalence has not shown any decreasing tendency during the past 30 years in Japan. We aim to analyze various parameters through life style questionnaires and 3-day food records obtained from pregnant women the last 10 years, and to examine whether their life styles have been shifting to the direction of lowering the incidence of spina bifida.

MATERIALS AND METHODS

Life style questionnaires inquired of knowledge of folic acid in relation to preventing spina bifida during a pregnancy and other relevant parameters, which were collected from 11,861 participants during a period of from 2002 to 2011. Food records asked participants to semi-quantitatively describe diets and beverages they consumed for a 3-day period, which were collected from 1,081 pregnant women from 2003 to 2011.

RESULTS

Life style questionnaires demonstrated that knowledge of folic acid and the proportion of those who took folic acid supplements elevated from 15.3 and 9.1% in 2002 to 43.7 and 61.5% in 2011, respectively, that comparison of those who took folic acid supplements from 2008 to 2011 residing in one of 8 districts of Japan showed a significant difference, i.e., the proportion of those in the Chugoku or Kyushu district being significantly lower compared to that in the Hokkaido district, and that other life style parameters have not much altered the past 9 years, e.g., those who conceived as planed being 67%, those who confirmed own pregnancy within 6 weeks of pregnancy being 70%, those who took balanced diets being 65%, and those who did not smoke or drink being 95% and 96%, respectively. Three-day food records revealed that the mean dietary folate intakes ranged from 260 to 360 microg/day in each year which were less than the recommended dietary allowance (RDA) publicized by the government, but that the proportion of pregnant women in the first trimester who consumed folic acid supplements from 4 weeks prior to to 12 weeks after conception increased from 7.4% in 2003 to 69.6% in 2011.

CONCLUSIONS

As a whole it could be stated that life styles of pregnant women have been shifting toward the direction the past 10 years where the risk for having a pregnancy afflicted with spina bifida is to be decreased. Medical doctors, nurses, midwives, dietitians and pharmacists are asked to repeatedly supply important information on folic acid and to advise taking folic acid supplements 400 microg a day to women planning to conceive or women in the reproductive age.

Maternal smoking in pregnancy and birth defects: a systematic review based on 173 687 malformed cases and 11.7 million controls

BACKGROUND

There is uncertainty over whether maternal smoking is associated with birth defects. We conducted the first ever comprehensive systematic review to establish which specific malformations are associated with smoking.

METHODS

Observational studies published 1959–2010 were identified (Medline), and included if they reported the odds ratio (OR) for having a non-chromosomal birth defect among women who smoked during pregnancy compared with non-smokers. ORs adjusted for potential confounders were extracted (e.g. maternal age and alcohol), otherwise unadjusted estimates were used. One hundred and seventy-two articles were used in the meta-analyses: a total of 173 687 malformed cases and 11 674 332 unaffected controls.

RESULTS

Significant positive associations with maternal smoking were found for: cardiovascular/heart defects [OR 1.09, 95% confidence interval (CI) 1.02–1.17]; musculoskeletal defects (OR 1.16, 95% CI 1.05–1.27); limb reduction defects (OR 1.26, 95% CI 1.15–1.39); missing/extra digits (OR 1.18, 95% CI 0.99–1.41); clubfoot (OR 1.28, 95% CI 1.10–1.47); craniosynostosis (OR 1.33, 95% CI 1.03–1.73); facial defects (OR 1.19, 95% CI 1.06–1.35); eye defects (OR 1.25, 95% CI 1.11–1.40); orofacial clefts (OR 1.28, 95% CI 1.20–1.36); gastrointestinal defects (OR 1.27, 95% CI 1.18–1.36); gastroschisis (OR 1.50, 95% CI 1.28–1.76); anal atresia (OR 1.20, 95% CI 1.06–1.36); hernia (OR 1.40, 95% CI 1.23–1.59); and undescended testes (OR 1.13, 95% CI 1.02–1.25). There was a reduced risk for hypospadias (OR 0.90, 95% CI 0.85–0.95) and skin defects (OR 0.82, 0.75–0.89). For all defects combined the OR was 1.01 (0.96–1.07), due to including defects with a reduced risk and those with no association (including chromosomal defects).

CONCLUSIONS

Birth defects that are positively associated with maternal smoking should now be included in public health educational materials to encourage more women to quit before or during pregnancy.

Placental abruption: epidemiology, risk factors and consequences

Placental abruption, classically defined as a premature separation of the placenta before delivery, is one of the leading causes of vaginal bleeding in the second half of pregnancy. Approximately 0.4-1% of pregnancies are complicated by placental abruption. The prevalence is lower in the Nordic countries (0.38-0.51%) compared with the USA (0.6-1.0%). Placental abruption is also one of the most important causes of maternal morbidity and perinatal mortality. Maternal risks include obstetric hemorrhage, need for blood transfusions, emergency hysterectomy, disseminated intravascular coagulopathy and renal failure. Maternal death is rare but seven times higher than the overall maternal mortality rate. Perinatal consequences include low birthweight, preterm delivery, asphyxia, stillbirth and perinatal death. In developed countries, approximately 10% of all preterm births and 10-20% of all perinatal deaths are caused by placental abruption. In many countries, the rate of placental abruption has been increasing. Although several risk factors are known, the etiopathogenesis of placental abruption is multifactorial and not well understood.

From the American Academy of Pediatrics: Technical report--Secondhand and prenatal tobacco smoke exposure

Secondhand tobacco smoke (SHS) exposure of children and their families causes significant morbidity and mortality. In their personal and professional roles, pediatricians have many opportunities to advocate for elimination of SHS exposure of children, to counsel tobacco users to quit, and to counsel children never to start. This report discusses the harms of tobacco use and SHS exposure, the extent and costs of tobacco use and SHS exposure, and the evidence that supports counseling and other clinical interventions in the cycle of tobacco use. Recommendations for future research, policy, and clinical practice change are discussed. To improve understanding and provide support for these activities, the harms of SHS exposure are discussed, effective ways to eliminate or reduce SHS exposure are presented, and policies that support a smoke-free environment are outlined.

Maternal smoking and infant mortality: does quitting smoking reduce the risk of infant death?

BACKGROUND

Maternal smoking has repeatedly been associated with increased infant mortality rates. No study has investigated whether smoking cessation influences the risk of infant death. This study estimates infant mortality after the second pregnancy in relation to smoking behavior in both the first and the second pregnancy.

METHODS

We used the Swedish Medical Birth Register to identify women who delivered their first and second singleton infants during 1983-2002. Maternal smoking during the 2 pregnancies was categorized into (1) never smoker, (2) quitter, (3) starter, and (4) persistent smoker. In the second pregnancy, 555,046 live births (of at least 22 completed gestational weeks) were followed for infant death within 1 year. Cox regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Compared with infants born to never smokers, the HR (95% CI) of infant mortality in the second pregnancy was 2.0 (1.7-2.4) among infants born to persistently heavy smokers, whereas among women who stopped smoking in the second pregnancy, the HRs were 1.4 (1.0-2.0) among those who had been heavy smokers in the first pregnancy, and 1.0 (0.8-1.2) among those who had been light smokers. The association of smoking during pregnancy with infant mortality was modified by infant's age, and was strongest at 4-15 weeks after birth. The smoking effect on neonatal mortality, but not postneonatal mortality, was mediated by gestational age.

CONCLUSIONS

Smoking cessation reduced the risk of infant death. The smoking-related risk of neonatal mortality appears to be mediated by smoking effects on gestational age, a factor that only partly explains the association between smoking and postneonatal mortality.

Low maternal awareness of fetal movement is associated with small for gestational age infants

Our aim was to identify associations between information given to pregnant women about fetal activity, level of maternal awareness of fetal activity, maternal concern about decreased fetal movement, and pregnancy outcomes. This was a population-based cross-sectional study. Mothers with a singleton delivery were invited to answer an anonymous structured questionnaire before discharge from the delivery unit. Six hundred and ninety-one mothers participated (60.4% of eligible women). Women were highly aware of fetal activity. Yet, 25% did not receive any information from care providers about expected normal fetal activity. Receiving information about fetal activity was associated with increased maternal awareness (odds ratio, 2.0; 95% confidence interval [CI], 1.2-3.4). Low maternal awareness of fetal activity was associated with an increased risk of having a small for gestational age infant (odds ratio, 6.5; 95% CI, 3.5-12.3). Expectations about the normal frequency of fetal movements, as reported by the mothers, varied from 25 kicks/hour to 3 kicks/24 hours. Receiving information about expected fetal activity was associated with maternal concerns about decreased fetal movement, but not with improved outcomes. We conclude that receiving information about expected fetal activity was associated with maternal concerns, but not with improved outcomes.

Parental mental illness and fatal birth defects in a national birth cohort

BACKGROUND

Few large studies describe links between maternal mental illness and risk of major birth defect in offspring. Evidence is sparser still for how effects vary between maternal diagnoses and no previous study has assessed risk with paternal illnesses.

METHOD

A population-based birth cohort was created by linking Danish national registers. We identified all singleton live births during 1973-1998 (n=1.45 m), all parental psychiatric admissions from 1969 onwards, and all fatal birth defects until 1 January 1999. Linkage and case ascertainment were almost complete. Relative risks were estimated using Poisson regression.

RESULTS

Risk of fatal birth defect was elevated in relation to history of any maternal admission and also with affective disorders specifically, although the strongest effect found was with maternal schizophrenia. The rate was more than doubled in this group compared to the general population [relative risk (RR) 2.34, 95% confidence interval (CI) 1.45-3.77], which also represented a significant excess risk compared with all other admitted maternal disorders (p=0.018). Risk of death from causes other than birth defect was no higher with schizophrenia than with other maternal conditions. There was no elevation in risk of fatal birth defect if the father was admitted with schizophrenia or any other psychiatric diagnosis.

CONCLUSIONS

There are many possible explanations for a higher risk of fatal birth defect with maternal schizophrenia and affective disorder. These include genetic effects directly linked with maternal illness, lifestyle factors (diet, smoking, alcohol and drugs), poor antenatal care, psychotropic medication toxicity, and gene-environment interactions. Further research is needed to elucidate the causal mechanisms.

Health-risk behaviours: examining social disparities in the occurrence of stillbirth

While an association between low socio-economic status (SES) and increased risk of stillbirth has been observed consistently over several decades, the pathways through which SES exerts these effects have not been established. Given that some key health-risk behaviours for stillbirth, including smoking and pre-pregnancy obesity, have strong relationships with SES, health-risk behaviours may serve as a channel through which low SES contributes to stillbirth outcomes. The objective of this study was to estimate the proportion of the relationship between low SES and the occurrence of stillbirth that is explained by health-risk behaviours in populations of Eastern Ontario and Nova Scotia (112 stillbirth cases and 398 controls). Both area and individual level influences of SES were assessed. The study population consisted of 112 cases (women delivering stillborn infants) and 398 controls. Odds ratios and 95% confidence intervals estimated by multivariable logistic regression were used to approximate relative risks. The contribution of health-risk behaviours to relationships between SES and stillbirth was assessed by a change in the relative risk estimate following omission of each health-risk behaviour from the model. Of the three measures of individual level SES examined (household income, education, Blishen occupational index), only household income was a statistically significant predictor of stillbirth. After controlling for individual level SES, no community level SES effects were observed for stillbirth. Adjustments for key health-risk behaviours (smoking) resulted in an 18.5% reduction in the odds ratio estimate for low SES, from 3.31 to 2.79. This large unexplained SES effect that remained highlights the need for research into other potential pathways that may account for increased risk of stillbirth among those of lower SES.

Nicotine-induced prenatal overexposure to maternal glucocorticoid and intrauterine growth retardation in rat

Overexposure to glucocorticoid during fetal development can result in intrauterine growth retardation (IUGR) as well as other diseases after birth. The purpose of this study is to investigate the possibility of glucocorticoid disturbance-mediated nicotine-induced IUGR after chronic prenatal exposure. Nicotine at 1.0mg/kg twice a day was administered subcutaneously to pregnant rats from gestational day (GD) 8 to GD 15 (mid-gestation) or GD 21 (late-gestation). Placental weights and fetal developmental parameters were recorded. Corticosterone levels were determined by radioimmunoassay. The mRNA expressions of adrenal steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side chain cleavage (P450scc) and placental 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD-2) were determined using real-time quantitative RT-PCR. The results showed that prenatal chronic nicotine exposure causes IUGR in rats (P<0.01); in response to nicotine exposure, maternal serum corticosterone levels were elevated at mid- and late-gestations (P<0.05); mRNA expressions of StAR and P450scc increased in maternal adrenals (P<0.05 or 0.01) but decreased in fetal adrenals (P=0.16 or 0.11). Furthermore, the mRNA levels of placental 11 beta-HSD-2 were reduced at mid- and late-gestations (P<0.05). These results suggest that nicotine-induced IUGR is associated with the disturbances of glucocorticoid homeostasis in maternal and fetal rats. A possible underlying mechanism is that long term nicotine administration leads to fetal overexposure to maternal glucocorticoid by the combined effect of increased maternal glucocorticoid level and impaired placental barrier to it, all of which eventually leads to the fetal adrenocortical dysfunction and IUGR.

Do socioeconomic factors explain why maternal smoking during pregnancy is more frequent in a more developed city of Brazil?

The prevalence of smoking during pregnancy in Ribeirão Preto, a rich Brazilian city, was significantly higher (21.4%) than in São Luís (5.9%), a less developed city. To assess which variables explain the difference in prevalence of smoking during pregnancy, data from two birth cohorts were used, including 2846 puerperae from Ribeirão Preto, in 1994, and 2443 puerperae from São Luís, in 1997/98. In multivariable analysis, risk of maternal smoking during pregnancy was higher in São Luís for mothers living in a household with five or more persons (OR = 1.72, 95%CI = 1.12-2.64), aged 35 years or older (OR = 1.98, 95%CI = 0.99-3.96), who had five or more children (OR = 2.10, 95%CI = 1.16-3.81), and whose companion smoked (OR = 2.20, 95%CI = 1.52-3.18). Age of less than 20 years was a protective factor (OR = 0.55, 95%CI = 0.33-0.92). In Ribeirão Preto there was association with maternal low educational level (OR = 2.18, 95%CI = 1.30-3.65) and with a smoking companion (OR = 3.25, 95%CI = 2.52-4.18). Receiving prenatal care was a protective factor (OR = 0.24, 95%CI = 0.11-0.49). Mothers from Ribeirão Preto who worked outside the home were at a higher risk and those aged 35 years or older or who attended five or more prenatal care visits were at lower risk of smoking during pregnancy as compared to mothers from São Luís. Smoking by the companion reduced the difference between smoking rates in the two cities by 10%. The socioeconomic variables in the model did not explain the higher prevalence of smoking during pregnancy in the more developed city.

The influence of maternal cigarette smoking on placental pathology in pregnancies complicated by abruption

OBJECTIVE

The purpose of this study was to evaluate the effect of maternal cigarette smoking on placental histology in women with abruption.

STUDY DESIGN

Data were derived from the New Jersey-Placental Abruption Study (NJ-PAS)--an ongoing, case-control study, conducted since August 2002 in 2 large hospitals in NJ. Abruption cases were identified based on a clinical diagnosis. Histologic evaluations were performed by 2 perinatal pathologists who were blinded to the abruption status. Maternal smoking during pregnancy was determined based on patient's self-report. Among abruption cases, histologic findings were compared between smokers and nonsmokers, and the association expressed as odds ratio (OR) with 95% confidence interval (CI). All analyses were adjusted for potential confounders.

RESULTS

A total of 189 abruption cases were available for analysis, of which 10.6% (n = 20) were smokers. Intervillous thrombus was more common in women who smoked (20%) than in nonsmokers (3.0%) (OR, 17.5; 95% CI, 3.1-99.4). However, placental infarcts were seen less frequently among smokers than nonsmokers (10.0% vs 32.5%; OR, 0.2; 95% CI, 0.1-0.8).

CONCLUSION

These findings suggest that different pathologic mechanisms may be responsible for the histologic findings between smokers and nonsmokers diagnosed with placental abruption.

Impact of reproductive experience on women's smoking behaviour in Japanese nurses

OBJECTIVES

The objectives of this study were to describe current and past smoking behaviour of female Japanese nurses, to examine factors associated with developing and stopping a smoking habit, and to examine how their reproductive experiences affect their smoking behaviour.

STUDY DESIGN

A cross-sectional study. This study was a baseline survey of a prospective occupational cohort study.

METHODS

A self-administered survey of 1748 female Japanese nurses aged over 20 years was conducted in Gunma prefecture, Japan, in 1999.

RESULTS

Overall, 27.2% developed a smoking habit (current smokers, 19.8%; ex-smokers, 7.4%) and 72.2% were never smokers. Logistic regression analysis showed that the type of nursing certificate was statistically associated with developing a smoking habit. It also showed that the type of nursing certificate, work place, marital status and current pregnancy were statistically associated with smoking cessation. Currently pregnant women were more likely to stop smoking than non-pregnant women (adjusted odds ratio, 3.18; 95% confidence intervals, 1.25-8.06). For women aged 20-29 years, the proportions of current smokers, ex-smokers and never smokers among pregnant women were 11.5, 23.1 and 65.4%, respectively; among non-pregnant women of this age, the values were 22.3, 4.3 and 73.4%, respectively. There was a statistically significant difference in such proportions between the two groups (chi2=19.27; P<0.0001). More than half of the ex-smokers who were currently pregnant had stopped smoking in the last 12 months. Smoking behaviour showed no statistically significant difference between women who had had at least one delivery and women who had not.

CONCLUSIONS

The results suggest that pregnancy provides a good opportunity for smoking cessation, but a large proportion of women who successfully quit smoking during pregnancy relapse after delivery.

Major improvements, but persisting inequalities in infant survival in Estonia 1992-2002

BACKGROUND

Inequality in adult health increased in Estonia during the transition period after 1991. We examined inequality in infant survival from 1992 to 2002.

METHODS

All 132 854 singleton live births reported to the Estonian Medical Birth Registry in 1992-2001 were linked to the Estonian Mortality Database. The effect of mother's education, nationality, marital status, and place of residence on neonatal (0-27 days) and post-neonatal (28-364 days) death was evaluated in logistic regression with adjustments for maternal age, parity, smoking, sex of the infant, birth weight, and gestational age.

RESULTS

Infant mortality decreased substantially. Risk of death in neonatal period was lowest in Tartu, with a decline from 4.9/1000 in infants born in 1992-1996 to 2.1/1000 in those born in 1997-2001. Decline in neonatal mortality in other regions was from 9.2/1000 to 5.1/1000. Persisting regional differences were unexplained by mothers' nationality, education, or marital status, or the infants' length of gestation. Decline in post-neonatal mortality was less marked and although risk differences between different socio-economic groups decreased, mothers' marital status and education in particular remained strongly associated with risk of post-neonatal death [odds ratio for infants born to mothers with basic or lower education compared to university education 3.70 (95% confidence interval 2.34-5.85) in 1992-1996 and 3.56 (2.06-6.14) in 1997-2001].

CONCLUSIONS

Infant survival improved appreciably in Estonia after 1991 and risk differences between social groups decreased. The improvements were not accompanied by reduction in the strength of the effects of social characteristics on infant death measured as risk ratios.

Addiction – who is not affected?

Addiction and addiction-related behaviour increased during the past decades. Several substances with psychoactive attributes, like opioids, cocaine or alcohol, can lead to dependence with physical and/or mental symptoms. In addition to substance-related addiction, non-substance-related dependence requires special attention. Increasing numbers of workaholics and patients suffering from internet-addiction, gambling or eating-disorders can be observed. To meet international treatment standards for addiction, diversification of therapy is necessary and, additionally, gender-related aspects in development and treatment of dependence and addiction-related behaviour are essential for state-of-the-art therapy of this patient population.

Maternal Alcohol Abuse and Neonatal Infection

BACKGROUND

Since chronic alcohol use suppresses the adult immune system, we tested the hypothesis that maternal alcohol ingestion increases the risk of infection in term newborns.

METHODS

Analysis of a large case-control study of birth weight for gestational age was performed focusing on maternal alcohol ingestion and the development of infection in term newborns > or =36 weeks gestation. After delivery, mothers were asked about alcohol and tobacco use in the 3 months prior to conception, the 1st, 2nd, and 3rd trimester of pregnancy.

RESULTS

Eight hundred and seventy-two singleton newborns (872) > or = 36 weeks gestation were identified for analysis. A total of 51 (5.8%) had newborn infections. Gestational age, sex, and small for gestational age (SGA) were similar in the newborns with and without infection (p = NS). Infants whose mothers reported alcohol use, excessive drinking or smoking in pregnancy were more likely to have a newborn diagnosed with an infection than were mothers who reported abstaining from alcohol or cigarettes (p < 0.05). When controlling for race and smoking, SGA infants whose mothers used any alcohol had a 2.5-fold increase risk of infection, while excessive alcohol use increased the risk 3-4-fold. In a multivariable logistic regression analysis controlling for low maternal income, smoking, and SGA, excessive alcohol use during the 2 trimester increased the risk of newborn infection (OR 3.7 [1.1,12.8], p < 0.05).

CONCLUSIONS

Excessive maternal alcohol use is associated with an increased risk of newborn infection in this patient sample. Increased awareness and further clinical investigations are warranted to address the detrimental effects of fetal alcohol exposure on the developing immune system.

Pre-pregnancy weight and the risk of stillbirth and neonatal death

OBJECTIVE

To evaluate the association between maternal pre-pregnancy body mass index (BMI) and the risk of stillbirth and neonatal death and to study the causes of death among the children.

DESIGN

Cohort study of pregnant women receiving routine antenatal care in Aarhus, Denmark.

SETTING

Aarhus University Hospital, Denmark, 1989-1996.

POPULATION

A total of 24,505 singleton pregnancies (112 stillbirths, 75 neonatal deaths) were included in the analyses.

METHODS

Information on maternal pre-pregnancy weight, height, lifestyle factors and obstetric risk factors were obtained from self-administered questionnaires and hospital files. We classified the population according to pre-pregnancy BMI as underweight (BMI <18.5 kg/m(2)), normal weight (BMI 18.5-24.9 kg/m(2)), overweight (BMI 25-29.9 kg/m(2)) and obese (BMI 30.0 kg/m(2) or more).

MAIN OUTCOME MEASURES

Stillbirth and neonatal death and causes of death.

RESULTS

Maternal obesity was associated with a more than doubled risk of stillbirth (odds ratio = 2.8, 95% confidence interval [CI]: 1.5-5.3) and neonatal death (odds ratio = 2.6, 95% CI: 1.2-5.8) compared with women of normal weight. No statistically significantly increased risk of stillbirth or neonatal death was found among underweight or overweight women. Adjustment for maternal cigarette smoking, alcohol and caffeine intake, maternal age, height, parity, gender of the child, years of schooling, working status and cohabitation with partner did not change the conclusions, nor did exclusion of women with hypertensive disorders or diabetes mellitus. No single cause of death explained the higher mortality in children of obese women, but more stillbirths were caused by unexplained intrauterine death and fetoplacental dysfunction among obese women compared with normal weight women.

CONCLUSION

Maternal obesity more than doubled the risk of stillbirth and neonatal death in our study. The present and other studies linking maternal obesity to an increased risk of severe adverse pregnancy outcomes emphasise the need for public interventions to prevent obesity in young women.

Health-Related Behavior and Beliefs of Pregnant Smokers

To determine the association of smoking with other health-compromising behavior and beliefs during pregnancy, a cross-sectional survey of 1,203 women in the United Kingdom assessed smoking status, stage of change, fetal health locus of control, alcohol consumption, folic acid intake, and use of vitamin and iron supplements. Twenty percent were current smokers, and 33% were alcohol users. Pregnant smokers (especially those in the precontemplative stage) were less likely to increase folic acid intake, less likely to take vitamin and iron supplements, and less likely to feel personally responsible for the health of the fetus. Infants of smokers may be placed at an intrauterine disadvantage, not only in terms of smoking, but also in terms of nutrition.

Cigarette smoking during pregnancy in rural Nepal. Risk factors and effects of beta-carotene and vitamin A supplementation

OBJECTIVE

We examined risk factors of smoking and the association between smoking and pregnancy-related and 6-month infant mortality in rural Nepal, where 30% women reported smoking during pregnancy.

DESIGN

Cross-sectional analysis of risk factors associated with smoking status and health consequences of smoking, using prospective data collected as part of a randomized community trial to examine the effect of maternal vitamin A or beta-carotene supplementation on maternal mortality.

SETTING

Rural, southeastern plains of Nepal.

SUBJECTS AND METHODS

A total of 17 767 women contributed at least one pregnancy during 3.5 y of the study. Data on cigarette or bidi (rolled tobacco) smoking were collected using a 7-day recall, twice during pregnancy. Associations between smoking status and maternal diet, morbidity profile, household socioeconomic status and serum concentration of retinol, carotenoids and tocopherols were examined. Further, relative risk (RR) and 95% confidence intervals (CI) were calculated to estimate supplement effects on pregnancy-related mortality, stratified by smoking status during pregnancy.

RESULTS

Smokers were more likely to be older, illiterate and poor compared to nonsmokers. Fruit and vegetable consumption among smokers and nonsmokers did not vary. However, smokers were more likely to consume meat/fish/eggs and less likely to consume milk than nonsmokers. They were also more likely to report symptoms of vaginal bleeding, edema, severe headache and convulsions during pregnancy relative to nonsmokers. Mortality per 100,000 pregnancies appeared to be higher among smokers than nonsmokers in the placebo group (915 vs 584, RR=1.57, 95% CI: 0.80-3.08). beta-Carotene supplementation reduced pregnancy-related mortality both among smokers (RR=0.31 95% CI: 0.11-0.89) and nonsmokers (RR=0.41, 95% CI: 0.19-0.89). Similar results obtained with vitamin A supplementation were not statistically significant. Infant mortality up to 6 months was approximately 30% higher among smokers compared to nonsmokers in the placebo group both before and after adjusting for confounding factors. Neither supplement given to women reduced infant mortality.

CONCLUSIONS

Cigarette smoking during pregnancy is associated with an increased risk of maternal and infant mortality in rural Nepal. beta-Carotene and to some extent vitamin A may reduce the risk of pregnancy-related mortality, but not infant mortality, among both smokers and nonsmokers.

Levels of excess infant deaths attributable to maternal smoking during pregnancy in the United States

OBJECTIVES

The objectives of the study were: 1) To determine the risk of infant mortality associated with prenatal cigarette smoking; 2) To assess whether the relationship, if existent, was dose-dependent; 3) To explore the morbidity pathway that explains the effect of tobacco smoke on infant mortality, and 4) to compute excess infant deaths attributable to maternal smoking in the United States.

METHODS

Retrospective cohort study on 3,004,616 singleton live births that occurred in 1997 in the United States using the US national linked birth/infant death data. Excess infant deaths due to maternal smoking were computed using the population-attributable risk (PAR).

RESULTS

Overall, 13.2% of pregnant women who delivered live births in 1997 smoked during pregnancy. The rate of infant mortality was 40% higher in this group as compared to nonsmoking gravidas (P < 0.0001). This risk increased with the amount of cigarettes consumed prenatally in a dose-dependent fashion (p for trend < 0.0001). Small-for-gestational age rather than preterm birth is the main mechanism through which smoking causes excess infant mortality. We estimated that about 5% of infant deaths in the United States were attributable to maternal smoking while pregnant, with variations by race/ethnicity. The proportion of infant deaths attributable to maternal smoking was highest among American Indians at 13%, almost three times the national average. If pregnant smokers were to halt tobacco use a total of 986 infant deaths would be averted annually.

CONCLUSIONS

Smoking during pregnancy accounts for a sizeable number of infant deaths in the United States. This highlights the need for infusion of more resources into existing smoking cessation campaigns in order to achieve higher quit rates, and substantially diminish current levels of smoking-associated infant deaths.

Impact of maternal age on preterm delivery and low birthweight: a hospital-based collaborative study of nulliparous Lebanese women in Greater Beirut

OBJECTIVES

To analyze the impact of maternal age at first childbirth on the incidence of preterm delivery and low birthweight among single live births delivered to nulliparous Lebanese women in Greater Beirut.

STUDY DESIGN

Eligible subjects were selected from a consecutive sample of neonatal admissions to nine National Collaborative Perinatal Network participating hospitals over a three-year period (April 1, 1999 to March 31, 2002). Chi-square tests and logistic regression analyses were applied.

RESULTS

Out of 5556 nulliparous mothers, 5.4% had a preterm delivery and 5.2% a low-birthweight infant. In the multivariate analysis, preterm delivery was not significantly affected by old maternal age. Mothers aged 25 years or more remained a high-risk group for low birthweight even after controlling for potentially confounding characteristics.

CONCLUSIONS

Maternal age at first childbirth above 25 years is an independent risk factor for low birthweight, but not for preterm delivery, an outcome influenced mainly by obstetric complications.

The complex relationship between smoking in pregnancy and very preterm delivery. Results of the Epipage study

OBJECTIVE

To assess the relationship between cigarette smoking during pregnancy and very preterm births, according to the main mechanisms of preterm birth.

DESIGN

Case-control study (the French Epipage study).

SETTING

Regionally defined population of births in France.

POPULATION

Eight hundred and sixty-four very preterm live-born singletons (between 27 and 32 completed weeks of gestation) and 567 unmatched full-term controls.

METHODS

Data from the French Epipage study were analysed using a polytomous logistic regression model to control for social and demographic characteristics, pre-pregnancy body mass index and obstetric history. The main mechanisms of preterm delivery were classified as gestational hypertension, antepartum haemorrhage, premature rupture of membranes, spontaneous preterm labour and other miscellaneous mechanisms.

MAIN OUTCOME MEASURES

Odds ratios for very preterm birth for low to moderate (1-9 cigarettes/day) and heavy (>/=10 cigarettes/day) maternal smoking in pregnancy, estimated according to the main mechanisms leading to preterm birth.

RESULTS

Smokers were more likely to give birth to very preterm infants than non-smokers [adjusted odds ratio (aOR) 1.7, 95% confidence interval (CI) 1.3-2.2]. Heavy smoking significantly reduced the risk of very preterm birth due to gestational hypertension (aOR 0.5, 95% CI 0.3-1.0), whereas both low to moderate and heavy smoking increased the risk of very preterm birth due to all other mechanisms (aOR between 1.6 and 2.8).

CONCLUSION

These data from the Epipage study show that maternal smoking during pregnancy is a risk factor for very preterm birth. The impact of maternal smoking on very preterm birth appears to be complex: it lowers the risk of very preterm birth due to gestational hypertension, but increases the risk of very preterm birth due to other mechanisms. These findings might explain why maternal smoking is more closely related to preterm birth among multiparous women than among nulliparous women.

Risk factors of perinatal mortality in Lithuania, 1997-1998

AIM

The aim of this paper is to determine the risk factors of perinatal mortality in Lithuania during 1997-1998.

METHODS

The focus of the study is the 1997-1998 Medical Birth Register Database (N = 75,178) covering social-demographic factors, the obstetric anamnesis of previous pregnancies, as well as mothers health behaviour and pathology of the current pregnancy, delivery and obstetric aid. The multivariate analysis assessing odds ratios of risk factors for perinatal mortality using logistic regression has been carried out and related population attributable risk fractions were calculated.

RESULTS

A statistically significant (p < 0.01) model predicting perinatal mortality has been obtained in which 19 out of 76 analysed factors have been distinguished to be statistically significant. The septic state of the mother during the delivery (OR = 13.3; CI = 8.9-19.9) and haemorrhage due to a premature placental separation (OR = 11.6; CI = 7.9-16.9) were associated with substantial increased risks of the foetus. Factors from other groups (perinatal pathology during previous pregnancies and social, behavioural or environmental factors) had somewhat lower, though significant, risk on perinatal mortality. The highest population attributable risk fraction (PARF) was found for the breech birth and foetal growth retardation (PARF = 13 percent and PARF = 9.7 percent, respectively). It should be pointed out that the impact of marital status on perinatal mortality was very high (PARF = 6.4 percent), even higher than that of some clinical factors, though its odds ratio was among the lowest (OR = 1.5; CI = 1.2-1.7).

CONCLUSION

During 1997-1998, the highest risk for perinatal mortality in Lithuania was associated with obstetric aid during delivery and pathology of current pregnancy. These groups of risk factors had also the highest population attributable risk fraction.

Nicotine inhibits palatal fusion and modulates nicotinic receptors and the PI-3 kinase pathway in medial edge epithelia

OBJECTIVES

To analyze the effects of nicotine on palatal fusion inhibition in vitro and determine if nicotine modulated transforming growth factor beta3 or phosphatidylinositol-3 kinase signaling. A second objective was to determine the localization and regulation of nicotinic receptors in the medial edge epithelia (MEE) during palatal fusion.

DESIGN

Palatal shelves from embryonic day (E) 13.5 mice were cultured in serum free media and treated with 0, 0.06, 0.6, or 6 mM nicotine, nicotinic receptor antagonist alpha-bungarotoxin, or the combination of nicotine and alpha-bungarotoxin. Tissues harvested at 72 h were analyzed for epithelial-mesenchymal transformation (EMT) and fusion. MEE samples collected at 20 h were analyzed for phosphorylated Akt-Ser473, phosphorylated Smad2, and nicotinic receptors.

RESULTS

Nicotine inhibited palatal fusion in vitro in a dose dependent manner. Activated Akt-Ser473 was greater in control MEE than in nicotine treated tissues; while there was no difference in activated Smad2 between groups. The alpha7 subunit of nicotinic receptor was expressed in MEE during palate fusion and increased in nicotine treated tissues. Alpha-bungarotoxin did not rescue the nicotine treated palates.

CONCLUSION

Nicotine treatment had no effect on Smad2, but caused a down regulation of the PI-3 kinase pathway that may have contributed to inhibiting palatal fusion in vitro.

Is there an association between maternal hypotension and poor pregnancy outcome?: a review of contemporary literature

This literature review highlights that research about the effect of maternal hypotension in pregnancy has either concentrated on an acute hypotensive episode, or looked at the influence of persistent maternal hypotension on fetal growth and/or premature birth. Whilst there is some German literature no published English study has specifically examined the possible significance of chronic maternal hypotension on the risk of stillbirth. There is, therefore, a significant gap in the research in this area.

Folate levels in pregnant women who smoke: an important gene/environment interaction

OBJECTIVE

The objective of this study was to determine whether serum and red blood cell folate levels were decreased in pregnant women who smoke and whether total plasma homocysteine levels were elevated.

STUDY DESIGN

In this cross-sectional study, serum folate, red blood cell folate, and homocysteine were measured in pregnant first- and early second-trimester pregnant women who smoked (case subjects) and pregnant women who did not smoke (control subjects). In addition, vitamin B(12), albumin, creatinine, cotinine, and hematocrit levels and methylenetetrahydrofolate reductase status were determined and compared between groups.

RESULTS

Pregnant women who smoked had significantly lower concentrations of serum folate (22.7 vs 29.4 nmol/L; P =.001) and lower concentrations of red blood cell folate (766 vs 900 nmol/L; P =.038 [not significant]) than pregnant women who did not smoke. Dietary folate intake was not significantly different between pregnant women who smoked and pregnant women who did not smoke. Homocysteine levels were also not significantly different between the groups. For each genotype of methylenetetrahydrofolate reductase, lower levels of serum folate were observed in pregnant women who smoked, with the lowest folate levels seen in homozygous mutant methylenetetrahydrofolate reductase 677TT (18.6 nmol/L in pregnant women who smoked vs 24.2 nmol/L in pregnant women who did not smoke).

CONCLUSION

Both serum folate and red blood cell folate are lower in pregnant women who smoked than in pregnant women who did not smoke, although homocysteine levels are not significantly different. There is an important gene environment interaction between methylenetetrahydrofolate reductase gene activity and tobacco exposure on serum folate levels. Lower levels of serum folate may account for the higher rate of miscarriage, stillbirth, abruptio placentae, and fetal anomalies that are observed in pregnant women who smoke. Pregnant women who smoke may benefit from higher doses of folic acid periconceptionally.

Depression and smoking during pregnancy

This study examined the relationship between depression and smoking during a woman's pregnancy. It surveyed 487 pregnant women (aged 17-44) during routine ultrasound examinations at the 18th week of gestation. A multiple regression analysis showed that depression is a significant predictor of smoking during pregnancy, after controlling for other factors such as the desirability of the pregnancy and the presence of other smokers in the household. Both current smokers and former smokers were significantly more likely to report depressive symptoms (using Centers for Epidemiological Studies Depression Scale, CES-D) than never smokers; the rates are 12.9%, 25.1%, and 37.5% for never, former, and current smokers, respectively. Among current smokers, the depressed were significantly less confident about quitting than the nondepressed, although both felt the need to quit. These results suggest that interventions to help pregnant women quit smoking may need to take a more comprehensive approach to be effective.

The heavier the better? Birthweight and perinatal mortality in different ethnic groups

BACKGROUND

Mother's ethnicity is associated with her baby's birthweight and risk of perinatal mortality. Given the close relation between birthweight and perinatal mortality, we explored whether ethnic differences in birthweight explain ethnic differences in perinatal mortality.

METHODS

Data on all births to mothers born in Norway (808 658), Pakistan (6854), Vietnam (3283) and North Africa (1461) from 1980 to 1995 were obtained from the Medical Birth Registry of Norway. The associations between birthweight and perinatal mortality among ethnic groups were analysed using univariate and multivariate methods.

RESULTS

Mean birthweights were low for Vietnamese and Pakistani mothers (3202 g, 3244 g) and high for Norwegian and North African mothers (3530 g, 3559 g). Mean birthweights were largely unrelated to perinatal mortality, which was lowest for Vietnamese (8.2/1000, 95% CI: 5.1-11.3) and highest for Pakistanis (14.9/1000, 95% CI: 12.0-17.7). Intermediate perinatal mortality rates were found among Norwegians (9.5/1000, 95% CI: 9.3-9.7) and North Africans (9.6/1000, 95% CI: 4.6-14.6). Further comparison of weight-specific mortality rates between the two largest ethnic groups showed the low birthweight paradox, where among low-weight births, perinatal mortality was lower among Pakistani than among Norwegian babies. However, adjustment to a relative birthweight scale (units of standard deviations from population-specific mean value) revealed higher rates of weight-specific mortality among Pakistanis across the entire range of birthweights. Multivariate adjustment for relative birthweight and other factors did not change these results.

CONCLUSIONS

Differences in perinatal mortality between the ethnic groups were not explained by differences in mean birthweight. Paradoxical differences in birthweight-specific mortality rates could be resolved by adjustment to a relative scale.

Incidence, obstetric risk factors and pregnancy outcome of preterm placental abruption: a retrospective analysis

OBJECTIVE

To determine obstetric risk factors for the occurrence of preterm placental abruption and to investigate its subsequent perinatal outcome.

STUDY DESIGN

A retrospective comparison of all singleton preterm deliveries complicated with placental abruption, between the years 1990-1998, to all singleton preterm deliveries without placental abruption, in the Soroka University Medical Center.

RESULTS

Placental abruption complicated 300 (5.1%) of all preterm deliveries (n = 5934). A backstep multivariable analysis found the following factors to be independently correlated with the occurrence of preterm placental abruption: grandmultiparity (more than five deliveries), early gestational age, severe pregnancy-induced hypertension, previous second-trimester bleeding and non-vertex presentation. These pregnancies had a significantly lower rate of preterm premature rupture of membranes than preterm pregnancies without placental abruption. Pregnancies complicated with preterm placental abruption had significantly higher rates of cord prolapse, non-reassuring fetal heart rate patterns, congenital malformations, Cesarean deliveries, perinatal mortality, Apgar scores lower than 7 at 5 min, postpartum anemia and delayed discharge from the hospital than did preterm deliveries without placental abruption. In order to assess whether the increased risk for perinatal mortality was due to the placental abruption, or due to its significant association with other risk factors, a multivariable analysis was constructed with perinatal mortality as the outcome variable. Placental abruption (OR 3.0, 95% CI 2.1-4.1) as well as cord prolapse, previous perinatal death, low birth weight and congenital malformations were found to be independent risk factors for perinatal mortality.

CONCLUSION

Preterm placental abruption is an unpredictable severe complication associated with significant perinatal morbidity and mortality. Factors found to be independently associated with placental abruption were grandmultiparity, severe pregnancy-induced hypertension, malpresentation, earlier gestational age and a history of second-trimester vaginal bleeding.

Placental abruption and perinatal death

Studies of risk factors for abruptio placentae (AP) are partly conflicting and studies of risk factors for perinatal death in these pregnancies are scarce. Using the population-based Swedish Birth Registry from 1987 to 1993, we were able to study these risks in 795,459 singleton pregnancies. Logistic regression analysis was used to estimate odds ratios (OR) for risk of AP and risk of perinatal death in pregnancies with and without AP. Risk factors for AP were: age, primiparity, high parity, not cohabiting with infant's father, low education, smoking, infertility, pregestational diabetes, essential hypertension, pregnancy-induced hypertensive diseases, preterm premature rupture of membranes, preterm birth and small-for-gestational-age (SGA) births. Risk factors for perinatal death in pregnancies with placental abruption were smoking (1--9 and > or =10 cigarettes/day; OR 1.4 and 1.7 respectively), severe pre-eclampsia (OR 2.0) and SGA (OR 1.9), whereas in pregnancies without abruption, risks were also increased in maternal age > or =35 years, primiparity, infertility, essential hypertension and pregestational diabetes. These findings support the theory that, in cases of AP, a general impairment of the placenta and/or a defect placentation may be fatal.

Risk of stillbirth in offspring of men exposed to ionising radiation

Radiation genetic risk models are employed to predict the frequency of radiation-related stillbirths to partners of occupationally exposed male workers, using the incidence data recently reported by Parker et al from an epidemiological study of Cumbrian births. Expanding on previously developed conservative risk estimates suggests that, of the 130 observed stillbirths to partners of male radiation workers, 0.3 cases would be attributable to paternal preconceptional irradiation, in contrast to the 17.5 (95% confidence interval: 3.1 to 31.9) cases predicted by Parker et al from their preferred dose-response model. The incompatibility of the results reported by Parker et al with those from other investigations, both epidemiological and experimental, and the inability of the study to consider a number of factors which might affect stillbirth rates, particularly those relating to the mother, make it difficult to accept that paternal irradiation received occupationally could have contributed to a detectable increase in stillbirths.

Perinatal complications associated with maternal tobacco use

The use of tobacco products by pregnant women is associated with placenta previa, abruptio placentae, premature rupture of the membranes, preterm birth, intrauterine growth restriction and sudden infant death syndrome. Approximately 15-20% of women smoke during pregnancy. It has been suggested that smoking is responsible for 15% of all preterm births, 20-30% of all infants of low birthweight, and a 150% increase in overall perinatal mortality. Cigarette smoking is one of the most important and modifiable risk factors associated with adverse perinatal outcomes.