Prevalence of health behaviours in pregnancy at service entry in a Queensland health service district

Objective: Limited prevalence data for unhealthy pregnancy health behaviours make it difficult to prioritise primary prevention efforts for maternal and infant health. This study's objective was to establish the prevalence of cigarette smoking, sufficient fruit and vegetable intake and sufficient physical activity among women accessing antenatal clinics in a Queensland (Australia) health service district.
Method: Cross-sectional self-reported smoking status, daily fruit and vegetable intake, weekly physical activity and a range of socio-demographic variables were obtained from women recruited at their initial antenatal clinic visit, over a three-month recruitment phase during 2007.
Results: Analyses were based on 262 pregnant women. The study sample was broadly representative of women giving birth in the district and state, with higher representation of women with low levels of education and high income. More than one quarter of women were smoking. Few women met the guidelines for sufficient fruit (9.2%), vegetables (2.7%) or physical activity (32.8%) during pregnancy.
Conclusions: There were low levels of adherence to health behaviour recommendations for pregnancy in this sample.
Implications: There is a clear need to develop and evaluate effective pregnancy behaviour interventions to improve primary prevention in maternal and infant health. Brief minimal contact interventions that can be delivered through primary care to create a greater primary prevention focus for maternal and infant health would be worth exploring.     

Does maternal smoking during pregnancy have a direct effect on future offspring obesity? Evidence from a prospective birth cohort study

The authors used a population-based birth cohort of 3,253 children (52% males) born in Brisbane, Australia, between 1981 and 1984 to prospectively examine whether maternal smoking during pregnancy was associated with offspring overweight and obesity. The authors compared mean body mass indexes (weight (kg)/height (m)2) and levels of overweight and obesity at age 14 years among offspring by patterns of maternal smoking (never smoked, smoked before and/or after pregnancy but not during pregnancy, or smoked during pregnancy). Adolescent body mass index and prevalences of overweight and obesity were greater in offspring whose mothers had smoked during pregnancy than in those whose mothers had never smoked. Body mass index and levels of overweight and obesity among adolescent offspring whose mothers stopped smoking during pregnancy but smoked at other times in the child's life were similar to those among offspring whose mothers had never smoked. These results were independent of a range of potentially confounding factors and suggest a direct effect of maternal smoking during pregnancy on adolescent overweight and obesity. They provide yet another incentive for pregnant women to be persuaded not to smoke and for young women to be encouraged to never take up smoking.     

Smoking in pregnancy in relation to gender and adult mortality risk in offspring: the Helsingborg Birth Cohort Study

BACKGROUND: Smoking in pregnancy is a well-documented risk factor for fetal growth impairment and poor perinatal outcomes. Less is known about the long-term effects of maternal smoking on offspring mortality. METHODS: A follow-up study in national registers on total mortality and cancer based on a birth cohort from Helsingborg, Sweden, including data on 2,010 sons and 1,982 daughters born to mothers for whom the smoking habits during pregnancy (50% smokers) have been recorded. RESULTS: A total of 92 offspring deaths were recorded (54 men, 38 women) during follow-up. Of these deaths, 43 deaths were related to trauma, 6 to circulatory disease, and 2 to endocrine disorders. In men, an elevated mortality risk was associated with increasing maternal smoking habits (p for trend 0.011), but in women with low birth weight (p for trend 0.006). A total of 47 incident offspring cancers were registered (18 in men and 29 in women). No significant relation was noted for maternal smoking habits and cancer in the offspring. CONCLUSIONS: Maternal smoking during pregnancy is associated with an increased mortality risk in early adult life for male offspring but not for female offspring. This could represent the possible consequence of an increased susceptibility in male fetuses.     

Aboriginal mothers, breastfeeding and smoking

Objective : To document the smoking practices of Aboriginal mothers living in Perth during pregnancy and during the subsequent year while feeding their infants.
Method : A cohort of mothers was followed from the time of delivery for 12 months to obtain details of infant feeding practices. A total of 455 mothers delivered between May 2000 and July 2001 and 425 completed the baseline questionnaire.
Results : Prior to and during pregnancy, 67% of the mothers smoked regularly. While the rate appeared to decline slightly with the length of breastfeeding, the trend was not significant. The rate of smoking of Aboriginal mothers was significantly greater than for an earlier study of non-Aboriginal mothers in Perth, where the rate was 28.4%. Among Aboriginal women there was no difference in the percentage of smokers and non-smokers who initiated breastfeeding. While fewer women who smoked were still breastfeeding at 24 weeks postpartum, compared with non-smokers (58% vs. 64%), this difference was not significant.
Conclusions : The percentage of women smoking in this study is consistent with rates reported in the 2001 National Drug Strategy Household Survey. In other studies, smoking is associated with lower rates of breastfeeding initiation and duration, but this was not the case in the Aboriginal mothers.
Implications : Although the high prevalence of smoking identified in this study did not appear to adversely affect breastfeeding, smoking during and after pregnancy does contribute to increased rates of low birth weight and other health problems in early childhood. Targeted antenatal smoking cessation programs are needed for Aboriginal mothers.     

Maternal smoking during pregnancy and offspring IQ

BACKGROUND: Maternal smoking in pregnancy lowers birthweight. It is unclear, however, whether smoking during pregnancy lowers offspring IQ, and, if it does, whether it is through the smoking effect on fetal growth. METHOD: Representative samples of low birthweight (<2500 g) and normal birthweight children born in 1983-85 from inner-city and suburban communities in southeast Michigan, USA were assessed at ages 6, 11, and 17, using Wechsler intelligence tests. Smoking during pregnancy was ascertained from mothers at the first assessment; and smoking at any time was ascertained at the first and second assessment. Generalized estimating equation models were used, with children's IQ at all three assessments as outcomes (n = 798). RESULTS: Without adjustment, offspring of mothers who smoked during pregnancy scored 6.8 IQ points lower than offspring of mothers who never smoked, on average. Low birthweight children scored 5.4 IQ points lower than normal birthweight children, on average. The statistical association of maternal smoking with offspring IQ was confounded by maternal characteristics, chiefly, maternal cognitive ability as measured by IQ and education; adjustment for these factors eliminated the association. By contrast, adjustment for maternal IQ and education as well as smoking during pregnancy had a negligible effect on the low birthweight-related IQ deficit. Low birthweight did not mediate the association of smoking and lowered IQ in offspring. CONCLUSION: Maternal smoking during pregnancy is a proxy for a matrix of vulnerabilities for adverse child cognitive development and has no direct causal effect on child's IQ. The relationship of low birthweight and IQ is independent of maternal smoking and maternal cognitive abilities.     

Fetal environment and subsequent obesity: a study of maternal smoking

BACKGROUND: The intrauterine environment may influence the development of obesity, but as yet, the long-term effect of growth in utero is unclear. We studied maternal smoking during pregnancy to gain insight on how an insult affecting fetal growth might subsequently influence obesity risk through childhood to age 33. METHODS: Data from the 1958 British birth cohort (all births in England, Wales and Scotland, 3-9 March 1958), including body mass index (BMI), maternal smoking during pregnancy and several potential confounding factors. We assessed obesity risk at ages 7, 11, 16, 23 and 33 associated with maternal smoking. Adjusted odds ratios (OR) for obesity at age 33 were estimated for 2918 men and 2921 women with complete data. RESULTS: Infants of mothers who smoked in pregnancy were lighter at birth than infants of non-smokers, but from adolescence (age 11 for females, 16 for males) they had an increased risk of being in the fattest decile of BMI. The OR for obesity associated with maternal smoking increased with age, suggesting strengthening of the relationship over time. At age 33 the OR was 1.56 (95% CI : 1.22-2.00) for men and 1.41 (95% CI : 1.12-1.79) for women. This was robust to adjustment for factors in early life, childhood and adulthood. CONCLUSIONS: An elevated risk of obesity among the offspring of smokers was not accounted for by other known influences. Findings are consistent with a long-term effect of intrauterine environment on adiposity, possibly through fetal nutrition, although other mechanisms should be investigated in future studies of obesity.     

A dose-response relationship between maternal smoking during late pregnancy and adult intelligence in male offspring

An association between maternal smoking during pregnancy and cognitive and behavioural development has been observed in several studies, but potential effects of maternal smoking on offspring adult intelligence have not been investigated. The objective of the present study was to investigate a potential association between maternal smoking during pregnancy and offspring intelligence in young adulthood. Adult intelligence was assessed at the mean age of 18.7 years by a military draft board intelligence test (Borge Priens Prove) for 3044 singleton males from the Copenhagen Perinatal Cohort with information regarding maternal smoking during the third trimester coded into five categories (about 50% of the mothers were smokers). The following potential confounders were included as covariates in multivariable analyses: parental social status and education, single mother status, mother's height and age, number of pregnancies, and gestational age. In separate analyses, birthweight and length were also included as covariates. Maternal cigarette smoking during the third trimester, adjusted for the seven covariates, showed a negative association with offspring adult intelligence (P=0.0001). The mean difference between the no-smoking and the heaviest smoking category amounted to 0.41 standard deviation, corresponding to an IQ difference of 6.2 points [95% confidence interval 0.14, 0.68]. The association remained significant when further adjusted for birthweight and length (P=0.007). Both unadjusted and adjusted means suggested a dose-response relationship between maternal smoking during pregnancy and offspring adult intelligence. When subjects with missing data were excluded, essentially the same results were obtained in the reduced sample (n=1829). These results suggest that smoking during pregnancy may have long-term negative consequences on offspring adult intelligence.     

妇女怀孕前后被动吸烟与神经管畸形关系的病例对照研究

目的 探讨母亲怀孕前后被动吸烟与子代发生神经管畸形(NTD)危险性的关系.方法 资料来源于北京大学生育健康研究所在山西省平定、昔阳、太谷和泽州4个县开展的以人群为基础的出生缺陷病例对照研究.病例为2003年1月到2007年6月监测到的515例NTD病例(其中无脑儿236例,脊柱裂237例,脑膨出42例),对照组为同期在同地区调查的682例无体表出生缺陷的婴儿.研究人员在妇女分娩一周内问卷调查妇女怀孕前后的被动吸烟及其他信息.用非条件logistic回归模型调整混杂因素.结果 与无被动吸烟的妇女相比,怀孕前后有被动吸烟的妇女生育NTD的危险性(OR值)为1.84(95%CI:1.39～2.44).妇女被动吸烟频度与子代发生NTD危险性之间存在显著的剂量反应关系.与无被动吸烟的妇女相比,偶尔有被动吸烟的妇女和每天有被动吸烟的妇女生育NTD的OR值分别为1.51和2.44(趋势x2=24.9,P＜0.001).结论 妇女怀孕前后被动吸烟增加生育NTD患儿的危险性.     

母亲孕期铁营养与子代先天性心脏病关系的病例对照研究

  目的  探讨母亲孕期铁营养与子代先天性心脏病(congenital heart disease,CHD)的关系。  方法  数据来源于陕西省2014年1月―2016年12月开展的CHD病例对照研究,对纳入孕妇进行膳食营养问卷调查。采用条件logistic回归分析模型分析母亲孕期铁营养与子代CHD及其各亚型的关系,并进行亚组分析探索其稳定性。  结果  在调整了混杂因素后,母亲孕期增补铁剂降低了子代CHD的发生风险(< 30 d:OR=0.54, 95% CI: 0.37~0.79;≥30 d:OR=0.25, 95% CI: 0.16~0.38),孕期膳食铁摄入量较高(≥29 mg/d)降低了子代CHD的发生风险(OR=0.69, 95% CI: 0.54~0.88),亚组分析结果显示,母亲孕期铁营养和子代CHD的关系稳定。此外,母亲孕期增补铁剂≥30 d子代在室间隔缺损(ventricular septal defect, VSD)、房间隔缺损(atrial septal defect, ASD)、动脉导管未闭(patent ductus arteriosus, PDA)、法洛四联症(tetralogy of fallot, TOF)上发生风险均降低,增补铁剂 < 30 d子代在ASD发生风险降低,孕期膳食铁摄入量较高(≥29 mg/d)子代在VSD、PDA发生风险均降低。  结论  母亲孕期铁营养水平升高降低了子代CHD的发生风险,孕妇孕期应注意机体铁营养的摄入和补充,促进母婴健康。     

Maternal smoking during pregnancy and smoking by adolescent daughters.

OBJECTIVES. Since cigarette smoking in adolescence represents a crucial entry point in the progression to illicit drugs, risk factors for adolescent smoking have public health implications. The influence of mothers on children's smoking appears to be greater than that of fathers. To explain the selective influence of mothers, we examined the consequences of maternal smoking during pregnancy in two longitudinal samples. METHODS. Analyses were conducted on follow-up interview data from two dyadic samples of mothers and firstborn adolescents for whom data on maternal smoking during and after pregnancy were available (192 mother-child pairs originating from New York State and 797 dyads from a national sample). RESULTS. In both samples, maternal smoking during pregnancy, when postnatal smoking was controlled, selectively increased the probability that female children would smoke and would persist in smoking (adjusted odds ratios of about 4). CONCLUSIONS. The findings suggest that nicotine or other substances released by maternal smoking can affect the fetus, perhaps through the nicotinic input to the dopaminergic motivational system, so as to predispose the brain in a critical period of its development to the subsequent addictive influence of nicotine consumed more than a decade later in life.     

Maternal and paternal smoking during pregnancy and risk of ADHD symptoms in offspring: testing for intrauterine effects

Maternal smoking during pregnancy is associated with attention deficit hyperactivity disorder (ADHD) in offspring. It is assumed by many that this association is causal. Others suggest that observed associations are due to unmeasured genetic factors or other confounding factors. The authors compared risks of maternal smoking during pregnancy with those of paternal smoking during pregnancy. With a causal intrauterine effect, no independent association should be observed between paternal smoking and offspring ADHD. If the association is due to confounding factors, risks of offspring ADHD should be of similar magnitudes regardless of which parent smokes. This hypothesis was tested in 8,324 children from a well-characterized United Kingdom prospective cohort study, the Avon Longitudinal Study of Parents and Children (data from 1991-2000). Associations between offspring ADHD and maternal and paternal smoking during pregnancy were compared using regression analyses. Offspring ADHD symptoms were associated with exposure to both maternal and paternal smoking during pregnancy (mothers: β = 0.25, 95% confidence interval: 0.18, 0.32; fathers: β = 0.21, 95% confidence interval: 0.15, 0.27). When paternal smoking was examined in the absence of maternal smoking, associations remained and did not appear to be due to passive smoking exposure in utero. These findings suggest that associations between maternal smoking during pregnancy and child ADHD may be due to genetic or household-level confounding rather than to causal intrauterine effects.     

Maternal use of nicotine replacement therapy during pregnancy and offspring birthweight: a study within the Danish National Birth Cohort

Lassen TH, Madsen M, Skovgaard LT, Strandberg‐Larsen K, Olsen J, Andersen A‐MN. Maternal use of nicotine replacement therapy during pregnancy and offspring birthweight: a study within the Danish National Birth Cohort. Paediatric and Perinatal Epidemiology 2010; 24: 272–281. Smoking is a well‐established risk factor for fetal growth restriction and other adverse pregnancy outcomes, and nicotine may be one of the chemical compounds that drive these associations. Nicotine replacement therapy (NRT) is a smoking cessation aid, which can facilitate smoking cessation. It is, however, unknown whether NRT used during pregnancy impairs fetal growth. The aim of this study was to estimate the association between the use of NRT during pregnancy and offspring birthweight. The study population consisted of 72 761 women enrolled in the Danish National Birth Cohort between 1996 and 2002. Information on NRT and potential confounders was obtained from two computer‐assisted telephone interviews conducted in the second and third trimesters, respectively. Multiple linear regression in a multilevel model was used to estimate the association between NRT use and birthweight adjusted for gestational age and potential confounders. The adjusted analyses showed no significant association between the duration of NRT use and birthweight (b = 0.25 g per week of NRT use [95% CI ?2.31, 2.81]) and neither was the type of NRT product (patch, gum, inhaler) associated with reduced birthweight. However, simultaneous use of more than one NRT product was associated with reduced birthweight (b = ?10.73 g per week of NRT use [95% CI ?26.51, 5.05]), although the association was not statistically significant. The results of this study suggest that maternal use of NRT in pregnancy does not seriously affect birthweight, but there could be a negative effect on birthweight associated with simultaneous use of more than one type of NRT product.     

Lower Prevalence of Cigarette and Waterpipe Smoking,But a Higher Risk of Waterpipe Dependence in Lebanese Adult Women Than in Men

The objective of this study was to evaluate whether nicotine dependence was higher in Lebanese women smokers compared with men smokers. Data were taken from a national cross-sectional study. Lebanese residents aged ≥ 40 years were enrolled between October 2009 and September 2010. After informed consent, participants answered a standardized questionnaire about smoking behaviors and dependence (measured by the Fagerström-Test-Nicotine-Dependence for cigarettes and the Lebanon-Waterpipe-Dependence-Scale 11 for waterpipes): 1,066 males and 1,134 females were interviewed. 58.7% versus 42.9% of them, respectively, ever smoked cigarettes, while 6.9% versus 6.7% ever smoked a waterpipe (p < 0.001). Moreover, 57.5% in male versus 49.1% in female cigarette smokers (p = 0.041), 35.9% versus 51.6% in waterpipe smokers (p = 0.076), and 67.9% versus 43.6% in mixed smokers were tobacco dependent. A dose-effect relationship was observed with increased rates of women versus men with waterpipe dependence) and an increased odds of dependence among women in multivariable analysis (ORa = 2.28). Positive (smoking waterpipe for pleasure and conviviality) and negative (smoking waterpipe to relax nerves and improve morale) reinforcements were significantly more frequent in women, while no significant sex difference was observed for nicotine dependence or psychological craving. In exclusive waterpipe smokers, significantly higher respiratory diseases and symptoms prevalences were found in females compared with males. Women who smoke waterpipes should receive attention during tobacco health education and smoking cessation.     

Nicotine concentration in the hair of nonsmoking mothers and size of offspring.

OBJECTIVES: The purpose of this study was to estimate the risk of small-for-gestational-age birth by levels of nicotine in the hair of mothers and offspring. METHODS: In a sample of 58 case subjects and 105 control subjects, hair nicotine concentrations were measured by gas chromatography and mass spectrometry. RESULTS: With women whose hair nicotine concentrations were in the lowest quartile as the reference group, the odds ratio (OR) for small-for-gestational-age birth was increased among women with concentrations in the upper and two middle quartiles (OR=4.2, 95% confidence interval [CI]=1.5, 11.5, and OR = 3.2, 95% CI=1.3, 8.0). When smoking mothers were excluded from the analysis, the corresponding odds ratios were 2.1 (95% CI=0.4, 10.1) and 3.4 (95 % CI= 1.3, 8.6). CONCLUSIONS: The results suggest that passive maternal smoking increases the risk of small-for-gestational-age births.     

Early intrauterine exposure to tobacco-inhaled products and obesity

An association between maternal smoking during pregnancy and offspring obesity has been reported. This study assessed the impact of maternal smoking during the first trimester. Data on 4,974 German children aged 5-6 years were obtained at school entry health examinations in 2001-2002 in Bavaria. Obesity was defined by body mass index using International Obesity Task Force cutpoints. Prevalence of obesity was 1.9% (95% confidence interval (CI): 1.5, 2.4) in offspring of never smokers, 4.5% (95% CI: 2.9, 6.7) for maternal smoking during the first trimester only, and 5.9% (95% CI: 3.8, 8.7) for maternal smoking throughout pregnancy. Unadjusted odds ratios were higher for maternal smoking throughout pregnancy (odds ratio = 3.23, 95% CI: 2.00, 5.21) compared with the first trimester only (odds ratio = 2.41, 95% CI: 1.49, 3.91). Adjusted odds ratios were similar: 1.70 (95% CI: 1.02, 2.87) for maternal smoking throughout pregnancy and 2.22 (95% CI: 1.33, 3.69) for maternal smoking in the first trimester only. When modeled together, no statistically significant difference in obesity risk was found between maternal smoking in the first trimester compared with throughout pregnancy. The effect of intrauterine tobacco exposure on childhood obesity may depend largely on cigarette smoking during the first trimester, whereas the additional impact of smoking throughout pregnancy might be due to confounding by sociodemographics. Women should be encouraged to quit smoking prior to conception.     

Life-long programming implications of exposure to tobacco smoking and nicotine before and soon after birth: evidence for altered lung development

Tobacco smoking during pregnancy remains common, especially in indigenous communities, and likely contributes to respiratory illness in exposed offspring. It is now well established that components of tobacco smoke, notably nicotine, can affect multiple organs in the fetus and newborn, potentially with life-long consequences. Recent studies have shown that nicotine can permanently affect the developing lung such that its final structure and function are adversely affected; these changes can increase the risk of respiratory illness and accelerate the decline in lung function with age. In this review we discuss the impact of maternal smoking on the lungs and consider the evidence that smoking can have life-long, programming consequences for exposed offspring. Exposure to maternal tobacco smoking and nicotine intake during pregnancy and lactation changes the genetic program that controls the development and aging of the lungs of the offspring. Changes in the conducting airways and alveoli reduce lung function in exposed offspring, rendering the lungs more susceptible to obstructive lung disease and accelerating lung aging. Although it is generally accepted that prevention of maternal smoking during pregnancy and lactation is essential, current knowledge of the effects of nicotine on lung development does not support the use of nicotine replacement therapy in this group.     

Maternal smoking and birth weight: interaction with parity and mother's own in utero exposure to smoking

BACKGROUND: Few studies have reported interactions between maternal smoking and other maternal characteristics and exposures. We examined maternal smoking in a cohort study for which data from 3 generations were available to examine maternal characteristics and exposures from a life-course perspective. METHODS: We had data from 3 generations: women enrolled in the U.S. Collaborative Perinatal Project (CPP) between 1959 and 1965 at the Baltimore site (G1); daughters (G2) of those G1 mothers who were followed to ages 27-33 years in the Pathways to Adulthood study; and children (G3) born to the G2 women who provided pregnancy and birth information during the Pathways study. These data allowed examination of exposures that occurred to the mother during her childhood and in utero. RESULTS: We found evidence of a 3-way interaction effect on birth weight for maternal smoking in pregnancy, maternal exposure to smoking in utero (grandmaternal smoking), and maternal parity. Maternal smoking reduced birth weight in 3 of the subgroups, with the size of the effect on birth weight moderated by parity and the mother's own in utero exposure to smoking. CONCLUSIONS: A mother's prenatal exposure to smoke may affect the birth weight of her offspring. This effect would be consistent with both the accumulation-of-risk and the fetal-programming hypotheses.     

N-3 fatty acids and pregnancy outcomes

PURPOSE OF REVIEW: To discuss new data from the literature on the relationship between the supply of n-3 polyunsaturated fatty acids during pregnancy and pregnancy outcomes, evaluated as the fatty acid composition of blood and breast milk, fetal and infantile development and maternal health. RECENT FINDINGS: Supplementation of alpha-linolenic acid in high doses or docosahexaenoic acid in low doses did not result in a significant enhancement of the blood docosahexaenoic acid status of the offspring. In contrast, supplementation of docosahexaenoic acid in relatively high doses led to significant increases in infantile docosahexaenoic acid values and to a significant enhancement of breast milk docosahexaenoic acid content. Electroretinogram data obtained during the first week of life and pattern-reversal visual evoked potentials investigated at 50 and 66 weeks postconception were significantly associated with the docosahexaenoic acid status of the infant at birth. Children whose mothers received docosahexaenoic acid supplementation during pregnancy and lactation scored better in mental processing tests carried out at 4 years than children whose mothers received placebo. SUMMARY: Beneficial health outcomes are more likely to result from supplementation with docosahexaenoic acid itself, rather than its precursor alpha-linolenic acid. Trials have shown that a higher maternal docosahexaenoic acid intake during pregnancy may be favourable for the visual and cognitive development of the offspring. The significant positive association between maternal docosahexaenoic acid intake during pregnancy and the children's mental processing scores at 4 years suggest that optimization of the docosahexaenoic acid status of expectant women may offer long-term developmental benefits to their children.     

Trends in smoking before,during, and after pregnancy in ten states

BACKGROUND: While trends in smoking prevalence during pregnancy are known, little is known about trends in quitting during pregnancy and resuming smoking after pregnancy. OBJECTIVES: This study examined the trends in and correlates of quitting during pregnancy and resuming smoking after pregnancy. METHODS: We used population-based random surveys of recent mothers in ten U.S. states (total of 115,000 women) conducted between 1993 and 1999. RESULTS: Although the prevalence of smoking 3 months before pregnancy was stable at around 26%, quitting during pregnancy rose from 37% to 46% between 1993 and 1999. Adjusted for maternal and state characteristics, the odds of quitting during pregnancy increased 51% between 1993 and 1999 (odds ratio [OR]=1.51; 95% confidence interval [CI]=1.08-2.12). Approximately half of the women who quit smoking during pregnancy resumed smoking within 6 months postpartum. Primiparous, privately insured, college-educated women are more likely to quit and least likely to resume smoking after delivery, compared to multiparous, Medicaid-insured, and high school-educated women. Teenaged women are more likely to quit, but also more likely to resume smoking than older women. CONCLUSIONS: The increase in quit rates during pregnancy is encouraging, but the lack of any change in smoking before pregnancy or in postpartum relapse rates suggests that permanent changes in maternal smoking will require additional focus.     

In-utero exposure to maternal smoking is not linked to tobacco use in adulthood after controlling for genetic and family influences: a Swedish sibling study

Previous studies have linked maternal smoking during pregnancy with regular tobacco use in offspring, but findings are not consistent and confounding from genetic and environmental factors have not fully been taken into account. A comparison between siblings discordant for prenatal smoking exposure adjusts for confounding by shared familial (i.e., genetic and environmental) factors. We investigated the association between prenatal exposure to maternal smoking during pregnancy and the risk of regular smoking or snus (Swedish moist smokeless tobacco) use in young adult offspring, using a population based matched cohort study. The cohort consisted of 1,538 randomly sampled same-sex sibling pairs, discordant for maternal smoking during pregnancy, 19–27 years old, participating in a survey conducted in Sweden 2010–2011. Lifetime and current history of tobacco use was self-reported in the survey, and information about maternal smoking during pregnancy was retrieved from the Medical Birth Register. Conditional logistic regression and stratified Cox proportional hazards regression were used to calculate odds ratios, hazard ratios, and corresponding 95 % confidence intervals. Analyses of exposure-discordant siblings did not reveal significant associations between prenatal exposure to maternal smoking and lifetime or current daily tobacco use, intensity of use, or time to onset of daily tobacco use. These findings suggest that the previously reported higher risks of tobacco use in offspring of mothers who smoked during pregnancy, compared with offspring of non-smoking mothers, were likely due to confounding from genetic or environmental factors.