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

Associations of maternal and personal smoking with all-cause and cause-specific mortality risk and life expectancy: a prospective cohort study

OBJECTIVES

The aim of this study was to evaluate the individual and combined effects of maternal smoking during pregnancy (MSDP) and personal smoking on mortality and life expectancy.

STUDY DESIGN

A prospective cohort study based on the UK Biobank, with a median follow-up of 12.47 years.

METHODS

This study employed multivariate Cox regression to determine the relative risks of mortality from all causes and specific diseases according to maternal and/or personal smoking status and pack-years of smoking (0, 1-20, 21-30, >30). Additionally, this study estimated the additive interaction between the two exposures. Life table analyses were performed using the estimated age-specific mortality rates to forecast life expectancy.

RESULTS

Results indicated that MSDP elevated the risk of all-cause mortality (HR = 1.12, 95% CI: 1.09-1.15) and mortality due to neoplasms (HR = 1.10, 95% CI: 1.06-1.12), circulatory (HR = 1.13, 95% CI: 1.06-1.19), respiratory (HR = 1.27, 95% CI: 1.16-1.40) and digestive system diseases (HR = 1.22, 95% CI: 1.08-1.38). Notably, both multiplicative and additive interactions were observed between maternal and personal smoking, with Relative Excess Risk due to Interaction (RERI) values for mortality from all causes, neoplasms, circulatory, and respiratory diseases being 0.21, 0.22, 0.16, and 0.76, respectively. This study also found a trend towards shorter gained life expectancy when maternal smoking and increasing pack-years of personal smoking were combined.

CONCLUSIONS

In this cohort study of UK Biobank, MSDP was associated with an increased risk of all-cause mortality and reduced life expectancy, suggesting that quitting smoking during pregnancy might have health and longevity benefits for both generations.

A single-center, prospective, observational study on maternal smoking during pregnancy in Greece: The HELENA study

INTRODUCTION

The unequivocal association between exposure to smoke and numerous complications of pregnancy, demonstrated in the last decades, has led to a significant decrease of smoking rates in pregnancy. The aim of the present study was to determine the prevalence of maternal smoking and to elucidate factors predisposing to it among pregnant women in Athens, Greece.

METHODS

A population of 1700 pregnant women (mean age: 31.2±5.5 years) who visited consecutively the Cardiology Department of Helena Venizelou Maternity Hospital in Athens, Greece, between September 2016 and August 2017, was prospectively analyzed. Data regarding changes in the future mother’s smoking habit as well as different sociodemographic factors potentially related to these changes were recorded.

RESULTS

Of the 1700 participants, 704 (41.4%) were smokers, and of those 52.4% quit smoking after knowledge of their pregnancy status. The overall prevalence of smoking in pregnancy was 19.7%. Prevalence was higher in women who were aged <20 years (p=0.038), were multipara (p=0.032), had ≤12 years of education (p=0.044) and had a partner who was a smoker (p=0.047). Women aged ≤20 years were more likely to be persistent smokers at the beginning of pregnancy and demonstrated a higher prevalence of smoking during pregnancy (42.2% vs 19.7% in the overall study population).

CONCLUSIONS

Our data demonstrate that maternal smoking during pregnancy still remains a major public health issue in Greece with a prevalence higher than most other industrialized countries.

Early life exposures and risk of adult respiratory disease during 50 years of follow-up

Adult health is influenced by factors during fetal life affecting organ development and birth weight. We aimed to study such factors in relation to adult respiratory disease (ARD) risk. The Helsingborg Birth Cohort, Sweden, contributed baseline data collected by medical staff through clinical examination and questionnaires on maternal and birth characteristics 1964-1967. Register linkages were performed with completions of data on ARD by ICD 8-10 classifications (1969-2016), and/or ARD-related drug usage (2005-2016) enabling a 50-year follow-up time. Cox proportional hazard regression analyses were made to adjust for potential confounders, adjusted hazard ratio (aHR). A total of 3675 mothers and their offspring were included. Female offspring showed higher frequency of ARD than males, aHR 1.5 (95% CI 1.3-1.8). Maternal use of sedatives during second trimester, aHR 2.2 (95% CI 1.4-3.4), and maternal smoking during most of pregnancy, aHR 1.2 (95% CI 1.0-1.4), were associated with offspring ARD. Stratified by sex, large-for-gestational-age, aHR 1.4 (95% CI 1.0-1.9), was significantly associated with ARD in female offspring along with maternal sedative use during second trimester and maternal smoking during most of pregnancy. Maternal sedative use during second trimester or all trimesters were the only significant risk factors for male offspring. In conclusion, maternal sedative use in second trimester was independently associated with subsequent respiratory disease in adult offspring irrespective of sex.

Changes in Smoking Rates Among Pregnant Women and the General Female Population in Australia, Finland, Norway, and Sweden

Introduction:

Smoking rates have dropped substantially in most developed countries in recent decades. This general trend has, however, not always been evident among women—particularly younger women. Smoking habits do, however, often change in connection with pregnancy and the aim of this study is to determine whether smoking during pregnancy follows general trends in smoking rates in the general female population in four countries with active anti-tobacco policies and decreasing population smoking rates.

Methods:

Changes in rates of persistent smoking, that is, smoking in late pregnancy or daily smoking among all women of childbearing age were described according to age groups. Data were retrieved from the Australian Household Drug Surveys during 2000–2013 and from registries and surveys in Finland, Norway, and Sweden between 1995 and 2014.

Results:

In general, persistent smoking has decreased and late-pregnancy smoking rates are lower than daily smoking rates among all women. However, younger women are more likely to be persistent smokers regardless of pregnancy status. In Norway and Finland, persistent smoking was most common among young pregnant women and in Sweden there was an increased polarization between age groups. In Australia, a steady decrease in smoking rates appears to have stalled in younger pregnant women.

Conclusion:

Although smoking has declined substantially in recent decades, there are groups lagging behind this general trend. Young pregnant women are of particular concern in this respect. The possibility that these findings reflect the changing characteristics of younger pregnant women is discussed.

Implications:

This study puts recent trends in maternal smoking into a broader context by relating developments to changes in smoking rates among women in general. By using similar data from four countries we were able to follow changes in smoking rates “within” groups of women within the four countries without being limited by methodological problems related to cross-country or inter-group comparisons. We were above all able to show that aggregate data disclose the strong age gradient in maternal smoking habits.

Patterns of polydrug use among pregnant substance abusers

Aim

Studies of drug use during pregnancy have generally focused on individual substances or specific combinations of drugs. The aim of this article is to increase our knowledge about polydrug use and pregnancy in a Nordic context by describing the sociodemographic characteristics of a clinical population of pregnant women with severe substance use, examining the scope and type of polydrug use and analysing factors associated with concurrent use of many, as opposed to a few, drugs.

Method

A cross-sectional study of pregnant women on admission to compulsory care for substance abuse in Sweden between 2000 and 2009 (n = 119 women, representing 128 pregnancies). Data were retrieved from administrative registers and client records. Univariate links between demographic, social, obstetrical, treatment history variables and polydrug use were examined. Binary logistic regression was used to analyse the association between explanatory variables and polydrug use.

Results

The average number of drugs being used concurrently was 2.65, and injection drug use was recorded in 73% of the pregnancies. Opiates and amphetamines were the most common primary drugs, followed by alcohol. The likelihood of polydrug use increased with first trimester pregnancy, planned (as opposed to emergency) committals, as well as the combination of partner substance abuse and injection drug use.

Conclusions

Polydrug use was widespread among pregnant substance abusers. Policies, interventions and research often focus on individual drugs separately, but for clinical populations in particular there is a need to address drug use broadly, including a systematic recording of smoking habits. This also entails awarding more attention to those not eligible for established interventions, such as opiate maintenance treatment, and giving more consideration to a variety of life circumstances, such as partner drug use.

Protocol for study of financial incentives for smoking cessation in pregnancy (FISCP): randomised, multicentre study

INTRODUCTION

Maternal smoking during pregnancy is associated with adverse perinatal and postnatal health outcomes. The efficacy of nicotine replacement therapies in helping pregnant smokers to quit is not clearly demonstrated; therefore new interventions should be proposed and assessed. Financial incentives rewarding abstinence from tobacco smoking is one of the promising options.

OBJECTIVE

To assess the efficacy of financial incentives on smoking abstinence among French pregnant smokers.

PARTICIPANTS

pregnant smokers aged ≥18 years, smoking at least five manufactured or three roll-your-own cigarettes per day, and pregnant for <18 weeks of amenorrhoea (WA).

SETTING

participants will be recruited, included and followed-up at monthly face-to-face visits in 16 maternity wards in France.

INTERVENTIONS

participants will be randomised to a control or an intervention group. After a predefined quit date, participants in the control group will receive €20 vouchers at the completion of each visit but no financial incentive for smoking abstinence. Participants in the intervention group will be rewarded for their abstinence by vouchers on top of the €20 show-up fee. The amount of reward for abstinence will increase as a function of duration of abstinence to stimulate longer periods of abstinence.

MAIN OUTCOME MEASURE

complete abstinence from quit date to the last predelivery visit.

SECONDARY OUTCOME MEASURES

point prevalence abstinence, time to relapse to smoking, birth weight, fetal growth restriction, preterm birth. Main data analysis: outcomes will be analysed on an intention-to-treat (ITT) basis. The ITT population is defined as all randomised smoking pregnant women.

ETHICS AND DISSEMINATION

The research protocol was approved by the ethics committee (Comité de Protection des Personnes, CPP) of the Pitié-Salpêtrière Hospital on 15 May 2015, and Amendment No 1 was approved on 13 July 2015. Results will be presented at scientific meetings and published.

TRIAL REGISTRATION NUMBER

NCT02606227; Pre-results.

Exposure to maternal smoking during pregnancy and risk of childhood cancer: a study using the Danish national registers

PURPOSE

The relation between maternal smoking during pregnancy and childhood cancer in the offspring remains uncertain. This paper uses Danish national registers, which have collected data prospectively on smoking and cancer, to investigate the association.

METHODS

Smoking during pregnancy was ascertained from maternal self-reported data in the Danish National Patient Register. Index children were followed up from birth until the first of the following events: cancer diagnosis, death, emigration, day before 15th birthday, or end of follow-up. Smoking during pregnancy was considered as a binary variable (no smoking in pregnancy and smoking in pregnancy) and by amounts smoked (no smoking, cessation during pregnancy, ≤5, 6-10, or ≥11 cigarettes/day).

RESULTS

Of the 801,867 children included in the study, 20 % were exposed to maternal smoking during pregnancy. Overall, the hazard ratio (HR) for childhood cancer for the exposed compared to the non-exposed was 0.91 [95 % confidence interval (CI) 0.78, 1.07]. Stratification by number of cigarettes also gave statistically nonsignificant inverse associations. There was a statistically significant increased risk of childhood cancer among children whose mothers reported smoking cessation in pregnancy (HR 1.46; 95 % CI 1.01, 2.10). Regarding specific cancer sites, maternal smoking in pregnancy was positively associated with the risk of eye cancers in childhood.

CONCLUSIONS

Our results do not provide evidence for an association between maternal smoking in pregnancy and childhood cancer overall. An increased risk of childhood cancer was seen for children whose mothers reported smoking cessation in pregnancy. Future research could employ biomarkers, such as cotinine, to validate maternal smoking status recorded in registers as, even if collected prospectively, this self-reported variable may be subject to reporting bias.

A Comparison of the Fagerström Test for Cigarette Dependence and Cigarette Dependence Scale in a Treatment-Seeking Sample of Pregnant Smokers

INTRODUCTION

Valid and reliable brief measures of cigarette dependence are essential for research purposes and effective clinical care. Two widely-used brief measures of cigarette dependence are the six-item Fagerström Test for Cigarette Dependence (FTCD) and five-item Cigarette Dependence Scale (CDS-5). Their respective metric characteristics among pregnant smokers have not yet been studied.

METHODS

This was a secondary analysis of data of pregnant smokers (N = 476) enrolled in a smoking cessation study. We assessed internal consistency, reliability, and examined correlations between the instruments and smoking-related behaviors for construct validity. We evaluated predictive validity by testing how well the measures predict abstinence 2 weeks after quit date.

RESULTS

Cronbach's alpha coefficient for the CDS-5 was 0.62 and for the FTCD 0.55. Measures were strongly correlated with each other, although FTCD, but not CDS-5, was associated with saliva cotinine concentration. The FTCD, CDS-5, craving to smoke, and withdrawal symptoms failed to predict smoking status 2 weeks following the quit date.

CONCLUSIONS

Suboptimal reliability estimates and failure to predict short-term smoking call into question the value of including either of the brief measures in studies that aim to explain the obstacles to smoking cessation during pregnancy.

[Environmental tobacco smoke exposure in children and its relationship with the severity of asthma]

INTRODUCTION

Environmental tobacco smoke (ETS) exposure produces serious respiratory problems in childhood. The aim of the study was to evaluate if environmental tobacco smoke affects the severity of asthma in asthmatic children.

MATERIAL AND METHODS

A prospective, multicentre study was conducted on asthmatic children and their parents in 2007-2008, using an exposure questionnaire, pulmonary function, level of cotinine in urine, and evaluation of the severity of asthma according to GEMA guide. The characteristics of the sample are summarised using the appropriate statistical tools, and the comparisons were made using the Pearson chi2 test, Mann-Whitney U test or Studentĭs t, according to the variable and number of groups compared.

RESULTS

Four hundred and eighty four households in 7 Autonomous Communities were included. The population included, 61% male children with asthma, 56% with a smoking caregiver in their home, 34% fathers, 31% mothers and 17% both. Home exposure was 37%, with 11% daily and 94% passive smokers since birth. There was 20% with exposure during whole period of pregnancy of 5±1 cigarettes/day. Children exposed to 6±1 cigarettes/day, 27%, up to 10 cigarettes/day, and 10% to more than 10. Severity of asthma during the survey was worse among those exposed (episodic-occasional 47%, episodic-frequent 35% and persistent-moderate 18% versus 59%, 25% and 16%, respectively, P=.040). Severity of asthma in the last year was worse in those exposed (episodic - occasional 22%, episodic - frequent 37% and persistent - moderate 50% versus 38%, 28% and 25% respectively, P=.037). The spirometry was abnormal in 64% of the exposed against to 36% in the non-exposed for FEV(1) (P=.003, 63% vs 38% for FVC (P=.038), and 54% vs 46% for the PEF (P=.050). The cotinine was higher in exposed: 51 (0-524) ng/ml vs 27 (0-116) ng/ml (P=.032). A relationship was observed between cotinine and level of exposure: 120 (0-590) ng/ml for >10 cigarettes/day as opposed to 44 (0-103) ng/ml ≤10 cigarettes/day (P=.035), which corroborates the consistency of the data collected.

CONCLUSIONS

The exposure of children with asthma to environmental tobacco smoke has a highly negative effect on the severity of their asthma.

Birthweight and mortality in adulthood: a systematic review and meta-analysis

BACKGROUND

Small birth size may be associated with increased risk of cardiovascular diseases (CVD), whereas large birth size may predict increased risk of obesity and some cancers. The net effect of birth size on long-term mortality has only been assessed in individual studies, with conflicting results.

METHODS

The Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines for conducting and reporting meta-analysis of observational studies were followed. We retrieved 22 studies that assessed the association between birthweight and adult mortality from all causes, CVD or cancer. The studies were systematically reviewed and those reporting hazard ratios (HRs) and 95% confidence intervals (95% CIs) per kilogram (kg) increase in birthweight were included in generic inverse variance meta-analyses.

RESULTS

For all-cause mortality, 36,834 deaths were included and the results showed a 6% lower risk (adjusted HR = 0.94, 95% CI: 0.92-0.97) per kg higher birthweight for men and women combined. For cardiovascular mortality, the corresponding inverse association was stronger (HR = 0.88, 95% CI: 0.85-0.91). For cancer mortality, HR per kg higher birthweight was 1.13 (95% CI: 1.07-1.19) for men and 1.04 (95% CI: 0.98-1.10) for women (P(interaction) = 0.03). Residual confounding could not be eliminated, but is unlikely to account for the main findings.

CONCLUSION

These results show an inverse but moderate association of birthweight with adult mortality from all-causes and a stronger inverse association with cardiovascular mortality. For men, higher birthweight was strongly associated with increased risk of cancer deaths. The findings suggest that birthweight can be a useful indicator of processes that influence long-term health.

Smoking and diabetes--the double health hazard!

Smoking is a predictor of the transition from normoglycaemia to impaired fasting glucose and increases the risk of type 2 diabetes, independent from possible confounders. In patients with diabetes as in non-diabetics, smoking is a significant and independent risk factor for all-cause mortality and for mortality from cardiovascular disease and corononary heart disease, as well as for aggregates of fatal and non-fatal cardiovascular events. There is little doubt that smoking is a risk factor for coronary heart disease, but this risk appears to be stronger than the risk for stroke in diabetics. Pathophysiological mechanisms by which smoking causes glucose intolerance and worsens clinical outcomes in established diabetes include greater insulin resistance, impaired beta-cell function and insulin secretion, chronic low-grade inflammation, endothelial dysfunction, as well as interacting indirectly with other factors known to aggravate diabetes and lifestyle factors. Smoking cessation programs are of great importance for primary care specialists dealing with diabetes.

Maternal cardiovascular disease risk in relation to the number of offspring born small for gestational age: national, multi-generational study of 2.7 million births

AIM

To investigate the risk of small for gestational age (SGA) births in relation to maternal history of cardiovascular disease (CVD) across two generations and additionally to analyse maternal CVD risk based on number of SGA offspring.

METHODS

We used register data from 1.4 million women and 2.7 million offspring. The outcome measures were risk of being SGA in relation to maternal total CVD (n = 10 436) across two generations, as well as risk of CVD in mothers in relation to the number of their SGA offspring, stratified by educational level.

RESULTS

Compared to no family history of CVD (reference) the hazard ratio (HR) for being SGA in female offspring was 1.11 (95% confidence interval (CI) 1.09-1.13) for a positive maternal history of CVD. The highest risk was shown in daughters when both the mother and the grandmother had a history of CVD (HR 1.32, 95% CI 1.24-1.39). There was a stepwise increased risk of CVD events in mothers in relation to the number of their SGA offspring (HR 1.41-1.86) when 'no SGA offspring' was used as reference. The risk of CVD in relation to SGA status was increased in the least educated group (HR 2.7-5.0) compared to the group with the highest level of education with no SGA offspring.

CONCLUSION

The risk of SGA offspring and the risk of maternal CVD are mutually interdependent and both conditions increased in women with a low level of education.

Alcohol use, injuries, and prenatal visits during three successive pregnancies among American Indian women on the Northern Plains who have children with fetal alcohol syndrome or incomplete fetal alcohol syndrome

INTRODUCTION

The purpose of the study was to compare three sequential pregnancies of American Indian women who have children with FAS or children with incomplete FAS with women who did not have children with FAS.

METHODS

Two retrospective case-control studies were conducted of Northern Plains American Indian children with fetal alcohol syndrome (FAS) (Study 1) or incomplete FAS (Study 2) in 1981-1993. Three successive pregnancies ending in live births of 43 case mothers who had children with FAS, and 35 case mothers who had children with incomplete FAS were compared to the pregnancies of 86 and 70 control mothers who did not have children with FAS, respectively, in the two studies. Prenatal records were abstracted for the index child (child with FAS or incomplete FAS) and siblings born just before and just after the index child, and comparable prenatal records for the controls.

RESULTS

Compared to the controls, significantly more case mothers used alcohol before and after all three pregnancies and during pregnancy with the before sibling and the index child. Mothers who had children with FAS reduced their alcohol use during the pregnancy following the birth of the index child. All Study 1 case mothers (100%) and 60% of Study 2 case mothers used alcohol during the pregnancy with the index child compared to 20 and 9% of respective control mothers. More study 1 case mothers experienced unintentional injuries (OR 9.50) and intentional injuries during the index pregnancy (OR 9.33) than the control mothers. Most case mothers began prenatal care in the second trimester.

CONCLUSIONS

Alcohol use was documented before, during and after each of the three pregnancies. Women of child-bearing age should be screened for alcohol use whenever they present for medical services. Mothers who had a child with FAS decreased their alcohol consumption with the next pregnancy, a finding that supports the importance of prenatal screening throughout pregnancy. Women who receive medical care for injuries should be screened for alcohol use and referred for appropriate treatment. Protective custody, case management and treatment services need to be readily available for women who use alcohol.

Maternal smoking during pregnancy specifically reduces human fetal desert hedgehog gene expression during testis development

CONTEXT

Maternal cigarette smoking during gestation increases cryptorchidism and hypospadias and reduces testis size and fertility in sons by unknown mechanisms.

OBJECTIVE

The objective of the study was to determine whether maternal smoking is linked with changes in male human fetal endocrinology, testis gene expression, and liver concentrations of cigarette smoke chemicals.

DESIGN

This was an observational study of the male fetus, comparing pregnancies during which the mothers either did or did not smoke.

SETTING

The study was conducted at the universities of Aberdeen, Glasgow, and Nottingham and Macaulay Institute (Aberdeen).

PATIENTS/PARTICIPANTS

Testes, blood, and livers were collected from 69 morphologically normal human male fetuses of women undergoing elective termination of normal second-trimester pregnancies.

MAIN OUTCOME MEASURES

Testosterone, human chorionic gonadotropin, LH, and cotinine; expression of 30 reproductive/developmental genes; liver concentrations of 16 polycyclic aromatic hydrocarbons; and Leydig, Sertoli. and germ cell numbers were determined.

RESULTS

There were no significant differences in fetal size, testis weight, cell numbers, seminiferous tubule diameter, or circulating LH and testosterone. Fetuses from smoking mothers had smoking range cotinine levels and liver concentrations of polycyclic aromatic hydrocarbons that were significant predictors of maternal smoking (P < 0.001). Only the Sertoli cell-specific gene, desert hedgehog (DHH), was significantly altered by maternal smoking (reduced 1.8-fold, P = 0.013).

CONCLUSIONS

The consequences of reduced DHH signaling in men and mice are consistent with epidemiology for effects of gestational maternal smoking on sons. Given the absence of other observed effects of maternal smoking, we concluded that reduced DHH is part of a mechanism linking maternal gestational smoking with impaired reproductive development in male offspring.