Recent trends in the prevalence of and factors associated with maternal smoking during pregnancy in Japan

Effects of active and/or passive smoking during pregnancy and the postpartum period

INTRODUCTION

Tobacco smoking may cause adverse effects during pregnancy and postpartum. The aim of this study was to evaluate several repercussions of active and/or passive smoking by the mother at home, during pregnancy, at delivery, as well as for the newborn baby and breastfeeding, including the effect of quitting smoking in the first trimester of pregnancy.

METHODS

A prospective longitudinal study was carried out with a sample of 800 pregnant women. Four evaluations were made: first and third trimester of pregnancy, and 2 and 6/8 months postpartum. Sociodemographic, obstetric, health and tobacco consumption details were collected, with biochemical tests being performed to confirm the self-reported abstinence.

RESULTS

Being an active and passive smoker predicted suffering complications in pregnancy (OR 2.50; 95% CI; 1.42-4.35) and delivery (OR 3.10; 95% CI; 1.75-5.51), and also tended not to breastfeed (OR 2.44; 95% CI; 1.35-4.42). Being an active smoker predicted complications at childbirth (OR 5.58; 95% CI; 2.64-7.77), for the baby (OR 3.77; 95% CI; 1.53-9.36) and not breastfeeding at 2 (OR 25.73; 95% CI; 11.95-55.40), and 6/8 months postpartum (OR 6.61; 95% CI; 3.21-13.58). Being a passive smoker reduces the intend to breastfeed (OR 1.81; 95% CI; 1.11-2.95), and the practice of breastfeeding at 2 months postpartum (OR 1.94; 95% CI; 1.11-3.37). Women who quit smoking are less likely to suffer complications in pregnancy and childbirth, and are more likely to attend antenatal and breastfeeding classes, and to have babies with higher birth weight.

CONCLUSIONS

Active and passive tobacco consumption has significant implications during pregnancy and postpartum period. Smoking cessation at the beginning of pregnancy reverses much of these effects.

Association between pregnancy intention and smoking or alcohol consumption in the preconception and pregnancy periods: A systematic review and meta-analysis

AIMS

To investigate the association between pregnancy intention and smoking or alcohol consumption in preconception and pregnancy periods.

BACKGROUND

Suboptimal lifestyle such as smoking and alcohol consumption can lead to devastating outcomes on the maternal and foetus. Pregnancy intention exerts a significant effect on promoting healthy lifestyle behaviours. However, no reliable evidences confirmed pregnancy intention was associated with smoking and alcohol consumption before and during pregnancy.

DESIGN

Systematic review and meta-analysis.

METHODS

We performed a comprehensive search from databases including PubMed, Cochrane, Web of Science, IEEE Xplore, MEDLINE, ProQuest and Scopus from the inception of these databases up to November, 2020. All eligible studies exploring the association between pregnancy intention and smoking or alcohol consumption were included. The fixed- or random effect pooled measure was used to estimate the odds ratio (OR) or risk ratio (RR) and 95% CI. In addition, the PRISMA checklist was used in this meta-analysis.

RESULTS

A total of 23 studies were included in this systematic review and meta-analysis. During pregnancy, the findings suggested that women with unplanned pregnancy were 68% more likely to consume cigarettes (OR = 1.68, 95% CI = 1.44-1.95) and 44% more likely to consume alcohol (OR = 1.44, 95% CI = 1.15-1.81) than those women with planned pregnancy. Meanwhile, during preconception, women with unplanned pregnancy were 30% more likely to consume cigarettes (OR = 1.30, 95% CI = 1.10-1.53) and 20% more likely to consume alcohol (OR = 1.20, 95% CI = 1.01-1.42) than those women with planned pregnancy.

CONCLUSION

The findings suggested that women with unplanned pregnancy were more likely to follow unhealthy behaviours such as smoking and alcohol consumption before and during pregnancy. Health professionals should consider the women's desire for pregnancy to decrease preconception and pregnancy smoking or alcohol consumption in future studies.

RELEVANCE OF CLINICAL PRACTICE

Pregnancy intention is the key determinant of smoking and alcohol consumption during preconception and pregnancy periods. Offering effective contraception in primary healthcare setting could prevent unplanned pregnancy. Meanwhile, popularising minimal alcohol consumption and comprehensive smoke-free legislation would be beneficial to improve reproductive outcomes.

[Effects of active and/or passive smoking during pregnancy and the postpartum period]

INTRODUCTION

Tobacco smoking may cause adverse effects during pregnancy and postpartum. The aim of this study was to evaluate several repercussions of active and/or passive smoking by the mother at home, during pregnancy, at delivery, as well as for the new born baby and breastfeeding, including the effect of quitting smoking in the first trimester of pregnancy.

METHODS

A prospective longitudinal study was carried out with a sample of 800 pregnant women. Four evaluations were made: first and third trimester of pregnancy, and 2 and 6/8 months postpartum. Sociodemographic, obstetric, health and tobacco consumption information was collected, with biochemical tests being performed to confirm the self-reported abstinence.

RESULTS

Being an active and passive smoker predicted suffering complications in pregnancy (OR 2.50; 95% CI; 1.42-4.35) and delivery (OR 3.10; 95% CI; 1.75-5.51), and also intend not to breastfeed (OR 2.44; 95% CI; 1.35-4.42). Being an active smoker predicted complications at childbirth (OR 5.58; 95% CI; 2.64-7.77), for the baby (OR 3.77; 95% CI; 1.53-9.36) and not breastfeeding at 2 (OR 25.73; 95% CI; 11.95-55.40), and 6/8 months postpartum (OR 6.61; 95% CI; 3.21-13.58). Being a passive smoker reduces the intention to breastfeed (OR 1.81; 95% CI; 1.11-2.95), and the practice of breastfeeding at 2 months postpartum (OR 1.94; 95% CI; 1.11-3.37). Women who quit smoking are less likely to suffer complications in pregnancy and childbirth, and are more likely to attend antenatal and breastfeeding classes, and to have babies with higher birth weight.

CONCLUSIONS

Active and passive tobacco consumption has significant implications during pregnancy and postpartum period. Smoking cessation at the beginning of pregnancy reverses much of these effects.

Description of Maternal Smoking Status Before and After Pregnancy: A Longitudinal, Community-Based Cohort Study

Background

Maternal smoking during pregnancy is a major risk for adverse perinatal outcomes, as well as children’s health status. Thus, it is important to describe maternal smoking status during pregnancy and child-rearing to devise better intervention strategies. However, there have been no longitudinal studies to describe the status. Thus, in this study, we aimed to describe maternal smoking status during pregnancy and child-rearing based on population-based maternal and child health information. Moreover, we explored the factors associated with maternal smoking relapse after delivery.

Methods

We performed a survey of 1,220 mothers in a Japanese rural area who responded to a questionnaire upon registration of their pregnancies. When their children received health checkups at 4, 18, and 36 months of age, maternal smoking status was also surveyed. We then performed multiple logistic regression analysis to explore factors associated with maternal smoking relapse after delivery.

Results

Ultimately, the total number of mothers with data available for longitudinal analysis was 727 (59.6%). At the time of pregnancy registration, there were 74 current smokers (10.2%) and 176 former smokers (24.2%). Among them, 59 (33.5%) relapsed after delivery. Under 28 years of maternal age at pregnancy registration (OR 2.6; 95% CI, 1.2–5.4) was associated with maternal smoking relapse after delivery.

Conclusions

Longitudinal analyses showed that about 60% of mothers who smoked before and after delivery failed smoking cessation. In addition, younger mothers were significantly likely to relapse smoking after delivery.

Association Between rs1051730 and Smoking During Pregnancy in Dutch Women

INTRODUCTION

The common genetic variant (rs1051730) in the 15q24 nicotinic acetylcholine receptor gene cluster CHRNA5-CHRNA3-CHRNB4 was associated with smoking quantity and has been reported to be associated also with reduced ability to quit smoking in pregnant women but results were inconsistent in nonpregnant women. The aim of this study was to explore the association between rs1051730 and smoking cessation during pregnancy in a sample of Dutch women.

METHODS

Data on smoking during pregnancy were available from 1337 women, who ever smoked, registered at the Netherlands Twin Register (NTR). Logistic regression was used to assess evidence for the association of rs1051730 genotype on smoking during pregnancy. In a subsample of 561 women, we investigated the influence of partner's smoking. Educational attainment and year of birth were used as covariates in both analyses.

RESULTS

There was evidence for a significant association between having one or more T alleles of the rs1051730 polymorphism and the likelihood of smoking during pregnancy (p = .03, odds ratio = 1.28, 95% CI = 1.02 to 1.61). However, this association attenuated when adjusting for birth cohort and educational attainment (p = .37, odds ratio = 1.12, 95% CI = 0.87 to 1.43). In the subsample, smoking spouse was highly associated with smoking during pregnancy, even when educational attainment and birth cohort were included in the model.

CONCLUSIONS

Our results did not support a strong association between this genetic variant and smoking during pregnancy. However, a strong association was observed with the smoking behavior of the partner, regardless of the genotype of the women.

IMPLICATIONS

The present study emphasizes the importance of social influences like spousal smoking on the smoking behavior of pregnant women. Further research is needed to address the role of rs1051730 genetic variant in influencing smoking cessation and the interaction with important environmental factors like the smoking behavior of the partner.

Continued tobacco consumption during pregnancy and women's depression and anxiety symptoms

OBJECTIVES

This study aimed to analyse depression and anxiety symptoms changes from the first to the third trimester of pregnancy in non-smokers versus quitters versus continuous smokers, and the contribution of depression and anxiety symptoms to continued tobacco consumption during pregnancy.

METHODS

The sample comprises 850 Spanish pregnant women (595 non-smokers, 123 quitters, and 132 continuous smokers), assessed at the first and the third trimester of pregnancy with a questionnaire concerning socio-demographic, obstetric, and tobacco consumption information, and measures of depression and anxiety.

RESULTS

Continuous smokers during pregnancy showed more depression and anxiety symptoms than both non-smokers and quitters and no changes from the first trimester to the third trimester of pregnancy, while both non-smokers and quitters revealed a decrease in depression and anxiety symptoms. More anxiety symptoms at the first trimester (OR 1.03) and depression symptoms at the third trimester (OR 1.14) were associated with continued smoking during pregnancy.

CONCLUSIONS

Anxiety and depression symptoms need to be considered to screening for women at risk of smoking during pregnancy. Future prenatal smoking cessation interventions must take into account these variables.

Association between Maternal Smoking during Pregnancy and Low Birthweight: Effects by Maternal Age

Background

Maternal smoking during pregnancy has been consistently related to low birthweight. However, older mothers, who are already at risk of giving birth to low birthweight infants, might be even more susceptible to the effects of maternal smoking. Therefore, this study aimed to examine the modified association between maternal smoking and low birthweight by maternal age.

Methods

Data were obtained from a questionnaire survey of all mothers of children born between 2004 and 2010 in Okinawa, Japan who underwent medical check-ups at age 3 months. Variables assessed were maternal smoking during pregnancy, maternal age, gestational age, parity, birth year, and complications during pregnancy. Stratified analyses were performed using a logistic regression model.

Results

In total, 92641 participants provided complete information on all variables. Over the 7 years studied, the proportion of mothers smoking during pregnancy decreased from 10.6% to 5.0%, while the prevalence of low birthweight did not change remarkably (around 10%). Maternal smoking was significantly associated with low birthweight in all age groups. The strength of the association increased with maternal age, both in crude and adjusted models.

Conclusions

Consistent with previous studies conducted in Western countries, this study demonstrates that maternal age has a modifying effect on the association between maternal smoking and birthweight. This finding suggests that specific education and health care programs for older smoking mothers are important to improve their foetal growth.

Smoking Prevalence and Associated Factors as well as Attitudes and Perceptions towards Tobacco Control in Northeast China

Objectives: The present study aimed to investigate the prevalence of smoking and environmental tobacco smoke (ETS), the associated factors of current smoking among adults, and their attitudes and perceptions towards tobacco control. Methods: A population-based cross-sectional survey was conducted in 2012 using a self-reported questionnaire. A representative sample of adults aged 18–79 years was collected in the Jilin Province of Northeast China by a multistage stratified random cluster sampling design. Descriptive data analysis was conducted, and 95% confidence intervals (CI) of prevalence/frequency were calculated to enable comparisons between the alleged differences and similarities. Multivariable logistic regressions were used to examine the risk factors associated with current smoking. Results: 21,435 adults responded to the survey (response rate: 84.9%). The overall prevalence of ever smoking, current smoking, and former smoking or smoking cessation was 39.1% (95% CI: 38.3–39.9), 31.8% (95% CI 31.1–32.6), and 7.3% (95% CI: 6.9–7.7), respectively. The proportion of ETS exposure among adult non-smokers in Jilin Province was 61.1% (95% CI: 60.1–62.1), and 23.1% (95% CI: 22.3–24.0) of the non-smokers reported daily ETS exposure. The proportion of ETS exposure at home was 33.4% (95% CI: 32.5–34.4), but the proportion of ETS exposure at restaurants was lower (6.5%) (95% CI: 6.0–7.1). More than 90% of the participants had positive attitudes and perceptions towards tobacco control, but 23.2% (95% CI: 22.5–24.0) of them did not agree with the perception of “smoking is fully quit in public places”, and almost half of the adults (49.5%) (95% CI: 48.7–50.3) did not agree with the perception of “hazards of low-tar cigarettes are equal to general cigarettes”. Conclusions: Smoking and exposure to ETS are prevalent among adults from the Jilin Province of Northeast China. Our findings suggest that tobacco control should be advocated in Northeast China. Anti-smoking campaigns and legislation should be built into the public health curriculum and government policy.

Longitudinal analyses of childhood growth: evidence from Project Koshu

Recently, it has been suggested that fetal and infant environments are associated with childhood and adulthood health status, specifically regarding presence of obesity and chronic diseases. This concept is known as the "Developmental Origins of Health and Disease (DOHaD) hypothesis." Thus, it is necessary to collect information about the fetal and infancy periods in order to examine the association between fetal and infancy exposures and later growth. Based on the DOHaD hypothesis, childhood growth trajectories, which were described by multilevel analysis, might be important in examining the effects of early-life environment on later-life health. The author and colleagues examined the association between maternal smoking during pregnancy and fetal/childhood growth, specifically risk of childhood obesity, by using the dataset from an ongoing prospective cohort study called "Project Koshu," which enrolled pregnant women and their children from a rural area of Japan. Children born to smoking mothers were likely to have lower birth weights and, thereafter, to show an increase in body mass index compared to children of non-smoking mothers. Differences in pubertal growth patterns by gender and childhood weight status were then examined. Growth rate and height gain trajectories were similar between genders, although pubertal growth spurts were observed earlier in girls than in boys. The overweight/obese children grew faster than did the non-overweight children in the early pubertal stages, and the non-overweight children caught up and showed greater height gains at older ages. Because Project Koshu is ongoing, further studies examining new research questions will be conducted with larger sample sizes.

Effects of maternal cigarette smoking during pregnancy on cognitive parameters of children and young adults: a literature review

The long term effects of maternal smoking during pregnancy on the cognitive development of the child are not well understood due to conflicting findings in past research. The aim of this paper was to provide an up to date, critical review of the literature to determine whether there is evidence of a relationship between tobacco smoke exposure in utero and cognitive functioning. We systematically reviewed observational studies (dated 2000-2011) that examined associations between tobacco smoke exposure in utero due to maternal smoking and performance on cognitive, intelligence, neurodevelopmental and academic tests. Eligible studies were identified through searches of Web of Knowledge, Medline, Science Direct, Google Scholar, CINAHL, EMBASE, Zetoc and Clinicaltrials.gov databases. The review found evidence of a relationship between tobacco smoke exposure in utero and reduced academic achievement and cognitive abilities independent of other variables. Maternal smoking during pregnancy may therefore be a modifiable risk factor for reduced cognitive abilities later in the life of the child. Giving up smoking during pregnancy should be initiated as early as possible to reduce the impact on the child's cognitive development.