Accuracy of self-reported cigarette smoking among pregnant women in the 1990s

Demographic characteristics, perinatal smoking patterns, and risk for neonatal health complications among pregnant smokers in the United States who begin using electronic cigarettes during pregnancy: A descriptive study using population-based surveillance data

INTRODUCTION

Health agencies have called for research evaluating e-cigarette (EC) use in supporting prenatal smoking cessation. This study aimed to describe (a) characteristics of smokers who begin using ECs during pregnancy, (b) how frequently smokers reduce or eliminate pre- and post-natal combustible cigarette (CC) use, and (c) risk for neonatal health complications among smokers who initiate ECs during pregnancy.

METHODS

Pregnant women using CCs exclusively pre-pregnancy, who participated in a U.S. surveillance study, were classified by their reported late-pregnancy smoking behavior as CC-exclusive users, EC initiators, or quitters. EC initiators were further subclassified as dual users (used both ECs and CCs) or EC replacers (used ECs exclusively).

RESULTS

Of 29,505 pregnant smokers, 1.5% reported using ECs during the last 3 pregnancy months. Among them, 29.7% became EC-exclusive users. EC initiators were disproportionately non-Hispanic White. Relative to quitters, EC initiators had lower income, were less likely to be married, have intended pregnancies, receive first-trimester prenatal care, and participate in a federal assistance program. Compared to CC-exclusive users, EC initiators overall, and dual users specifically, were more likely to reduce pre- and post-natal CC usage relative to pre-pregnancy levels. EC initiators' risk for neonatal health complications fell between quitters and CC-exclusive users, though differences were not statistically significant.

CONCLUSIONS

Although EC initiators reduced CC use more than CC-exclusive users, only 29.7% reported complete CC cessation, and there was insufficient evidence of reduction in neonatal health complications relative to CC-exclusive users. Currently, ECs should not be considered a viable gestational smoking cessation strategy.

IMPLICATIONS

Health agencies have identified a critical need for research evaluating the use of e-cigarettes in supporting prenatal smoking cessation. Using the US Pregnancy Risk Assessment Monitoring System surveillance study data, we provide real-world evidence that prenatal e-cigarette initiation as a smoking cessation tool is used infrequently among pregnant combustible cigarettes smokers. Most using e-cigarettes in the last three months of pregnancy also used combustible cigarettes.

Exploration of Differences between Women Who Do and Do Not Disclose Their Marijuana Use during Pregnancy

OBJECTIVE

This study aimed to explore demographic and health-related factors that may differentiate women who do and do not disclose their marijuana use during pregnancy.

STUDY DESIGN

The current study is a secondary analysis of data from a prospective cohort of pregnant women identified as using marijuana during pregnancy via a variety of assessment tools including self-report, urine screen, and obstetrics record abstraction. The cohort included a convenience sample of women recruited from several antenatal clinics at The Ohio State University Wexner Medical Center (OSUWMC). To be eligible, women needed to be within the first or second trimester of their pregnancy, 16 to 50 years of age, able to communicate in English, and intended to deliver at OSUWMC. Chi-square, independent samples t-tests, and logistic regression analyses were used to explore differences between those who did and did not disclose their use in relation to physical and mental health diagnoses, adverse experiences, use of other substances, and demographics.

RESULTS

Women who used marijuana during their pregnancy and had mental/physical health data available comprised the current sample (n = 109). Women who attended college were more likely to disclose their marijuana use compared with women who did not attend college (p < 0.001). Women who experienced homelessness (p < 0.01) or self-reported alcohol use during pregnancy (p < 0.001) were significantly more likely to disclose their marijuana use.

CONCLUSION

Findings, suggesting disclosure of other substance use and adverse experiences, such as homelessness, may increase the likelihood that pregnant women will voluntarily disclose their marijuana use to providers. Findings did not reflect racial differences nor significant differences in mental/physical health status among women based on their disclosure. Future research with larger datasets is needed to build on these findings by confirming results, as well as exploring additional factors, that may more effectively differentiate women who are unlikely to disclose their prenatal marijuana use from those who do disclose their use.

KEY POINTS

· Women with higher education were more likely to self-disclose their prenatal marijuana use.. · Women who experienced homelessness were more likely to self-disclose their prenatal marijuana use.. · Self-disclosure of prenatal alcohol use was related to self-disclosure of prenatal marijuana use.

Associations of pre- and postnatal exposures with optic nerve status in young adults

PURPOSE

We aimed to explore the effect of multiple pre- and postnatal exposures on optic nerve status in young adults due to this critical period for development.

METHODS

We analysed peripapillary retinal nerve fibre layer (RNFL) status and macular thickness at age 18 years in the Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000 ) cohort in relation to several exposures.

RESULTS

Of the 269 participants (median (IQR) age, 17.6 (0.6) years; 124 boys), 60 participants whose mothers had smoked during pregnancy had a thinner RNFL: adjusted mean difference -4.6 μm (95% CI -7.7; -1.5 μm, p = 0.004) compared with participants whose mothers had not smoked during pregnancy. A total of 30 participants who were exposed to tobacco smoke both during foetal life and childhood had thinner RNFL: -9.6 μm (-13.4; -5.8 μm, p < 0.001). Smoking during pregnancy was also associated with a macular thickness deficit: -4.7 μm (-9.0; -0.4 μm, p = 0.03). Higher indoor concentrations of particulate matter 2.5 (PM2.5) was associated with thinner RNFL: -3.6 μm (-5.6; -1.6 μm, p < 0.001) and a macular deficit: -2.7 μm (-5.3; -0.1 μm, p = 0.04) in the crude analyses, but not in the adjusted analyses. No difference was found among participants who smoked at age 18 years compared with non-smokers on RNFL or macular thickness.

CONCLUSIONS

We found that exposure to smoking during early life was associated with a thinner RNFL and macula at age 18 years. The absence of an association between active smoking at 18 years suggests that the vulnerability of the optic nerve is highest during prenatal life and early childhood.

Determinants of maternal and neonatal PFAS concentrations: a review

Per- and polyfluoroalkyl substances (PFAS) are used for their properties such as stain and water resistance. The substances have been associated with adverse health outcomes in both pregnant mothers and infants, including pre-eclampsia and low birthweight. A growing body of research suggests that PFAS are transferred from mother to fetus through the placenta, leading to in utero exposure. A systematic review was performed using the PubMed database to search for studies evaluating determinants of PFAS concentrations in blood matrices of pregnant mothers and neonates shortly after birth. Studies were included in this review if an observational study design was utilized, exposure to at least one PFAS analyte was measured, PFAS were measured in maternal or neonatal matrices, at least one determinant of PFAS concentrations was assessed, and results such as beta estimates were provided. We identified 35 studies for inclusion in the review and evaluated the PFAS and determinant relationships among the factors collected in these studies. Parity, breastfeeding history, maternal race and country of origin, and household income had the strongest and most consistent evidence to support their roles as determinants of certain PFAS concentrations in pregnant mothers. Reported study findings on smoking status, alcohol consumption, and pre-pregnancy body mass index (BMI) suggest that these factors are not important determinants of PFAS concentrations in pregnant mothers or neonates. Further study into informative factors such as consumer product use, detailed dietary information, and consumed water sources as potential determinants of maternal or neonatal PFAS concentrations is needed. Research on determinants of maternal or neonatal PFAS concentrations is critical to estimate past PFAS exposure, build improved exposure models, and further our understanding on dose-response relationships, which can influence epidemiological studies and risk assessment evaluations. Given the potential for adverse outcomes in pregnant mothers and neonates exposed to PFAS, it is important to identify and understand determinants of maternal and neonatal PFAS concentrations to better implement public health interventions in these populations.

Association between Prenatal Marijuana and Tobacco Smoke Exposures and Small for Gestational Age at Birth

OBJECTIVE

The aim of this study was to determine the association of prenatal marijuana exposure with and without tobacco smoke exposure and small for gestational age (SGA) at birth.

STUDY DESIGN

We conducted a secondary analysis of the prospective Lifestyle and Early Achievement in Families (LEAF) cohort enrolled from 2010 to 2015. We included singleton nonanomalous liveborn pregnancies. We assessed marijuana use inclusive of any pregnancy urine specimen with a Δ9-THC-COOH concentration of more than 15 ng/mL by mass spectrometry, self-report on questionnaire, and/or electronic health record; and self-reported maternal tobacco use. Because of the high co-frequency of marijuana with tobacco exposure in pregnancy and the known association between tobacco and fetal growth restriction, we modeled the exposure as: both marijuana and tobacco (hereafter "co-use"), only marijuana, only tobacco, and neither (reference). Incidence of SGA in each group was compared with the neither group. The primary outcome was SGA less than 10th percentile, and secondarily less than 5th percentile, using parity-specific definitions per 2017 US natality reference data.

RESULTS

Among 325 assessed mothers, 46% had neither exposure, 11% had only prenatal marijuana exposure, 20% only tobacco exposure, and 23% co-use exposure. A third (33%) of infants were SGA less than 10th percentile and 20% SGA less than 5th percentile. Marijuana exposure only was associated with an increased risk of SGA less than 10th percentile (43 vs. 26%; adjusted relative risk [aRR]: 1.66; 95% confidence interval [CI]: 1.02-2.69), and SGA less than5th percentile (30 vs. 13%; aRR: 2.26; 95% CI: 1.15-4.47). Tobacco was not associated with SGA less than 10th percentile, but was with SGA less than 5th percentile (26 vs. 13%; aRR: 2.01; 95% CI: 1.13, 3.56). Co-use was not associated with increased SGA risk in multivariate analysis, but was in sensitivity analysis when tobacco use was defined using a cotinine assay rather than self-report (SGA <10th percentile, aRR: 1.97; 95% CI: 1.24-3.15) and (SGA <5th percentile, aRR: 2.03; 95% CI: 1.09-3.78).

CONCLUSION

Prenatal marijuana exposure in addition to tobacco may increase the risk of SGA. Given the rising prevalence of marijuana use in pregnancy, further research is warranted to understand how in utero marijuana exposure may impact fetal growth and birth weight with and without tobacco exposure.

KEY POINTS

· Marijuana and tobacco are commonly used together in pregnancy.. · Prenatal marijuana and tobacco exposure may increase the risk of a small for gestational age infant.. · Further research is warranted to understand how in utero marijuana exposure impacts fetal growth..

Cigarette smoking during breastfeeding in Papua New Guinea: Prevalence and demographic and socio-economic predictors

BACKGROUND

Cigarette smoking during breastfeeding is reported to contribute to significant changes in the composition of breast milk not only by reducing its protective features but also affecting infants' response to breastfeeding and breast milk. However, studies on the prevalence of cigarette smoking and associated factors during breastfeeding are limited in Papua New Guinea (PNG). This study estimates the prevalence of cigarette smoking and its association with demographic and economic factors among breastfeeding women in PNG.

METHODS

We used weighted survey data from the 2016-2018 PNG Demographic and Health Survey (PNGDHS). A weighted sample of 3,822 women who were breastfeeding during the survey were included in the study. The outcome variable in the present study is current cigarette smoking. A multiple logistic regression analysis was used to estimate the association between current cigarette smoking status and socio-demographic and economic variables of breastfeeding women. The regression analysis results were reported using adjusted odds ratios (aOR) with their respective 95% confidence intervals (CIs).

RESULTS

From the weighted sample, the prevalence of cigarette smoking among breastfeeding women was 21.9%; of which 60.8% smoked daily. The mean number of cigarettes smoked in the last 24 hours preceding the survey was 6.05(SD = 5.99). Multiple logistic regression analysis revealed that breastfeeding women who were from the Momase (aOR: 2.337, CI: 1.786-3.058, p<0.001) and Highlands (AOR: 1.589, CI: 1.213-2.082, p = 0.001), had no religious affiliation (aOR: 3.665, CI: 1.235-10.877, p = 0.019), and households with daughters as household heads (aOR: 1.901, CI: 1.231-2.935, p = 0.004) and being in more than one union (aOR: 2.374, CI: 1.805-3.123, p<0.001) were significantly more likely to smoke cigarette compared to women from southern region, those affiliated to Anglican church, those with husband as household heads, and being in one union respectively.

CONCLUSION

Cigarette smoking among breastfeeding women in PNG is relatively high, and region of residence, religion, relationship to household head, and the number of unions remain independent predictors. Interventions should target the individual socio-economic and cultural contexts within which breastfeeding occurs.

Early factors associated with risk of developmental coordination disorder in very preterm children: A prospective area-based cohort study in Italy

BACKGROUND

Developmental coordination disorder (DCD) is a motor disorder of unknown aetiology that may have long-term consequences on daily activities, and psychological and physical health. Studies investigating risk factors for DCD have so far provided inconsistent results.

OBJECTIVES

To assess, using a parent-report screening tool, risk of DCD in school-age very preterm children born in Italy, and investigate the associated early biomedical and sociodemographic factors.

METHODS

A prospective area-based cohort (804 children, response rate 73.4%) was assessed at 8-11 years of age in three Italian regions. Perinatal data were abstracted from medical records. DCD risk was measured using the Italian-validated version of the Developmental Coordination Disorder Questionnaire (DCDQ-IT). For this study, children with cognitive deficit (i.e. intelligence quotient <70), cerebral palsy, severe vision and hearing disabilities, and other impairments affecting movement were excluded. A total of 629 children were analysed. We used inverse probability weighting to account for loss to follow-up, and multilevel, multivariable modified Poisson models to obtain adjusted risk ratio (aRR) and 95% confidence interval (CI). Missing values in the covariates were imputed.

RESULTS

195 children (weighted proportion 31.8%, 95% CI 28.2, 35.6) scored positive on the DCDQ-IT, corresponding to the 15th centile of the reference Movement-ABC test. Factors associated with overall DCD risk were male sex (aRR 1.35, 95% CI 1.05, 1.73), intrauterine growth restriction (aRR 1.45, 95% CI 1.14, 1.85), retinopathy of prematurity (aRR 1.62, 95% CI 1.07, 2.45), and older maternal age at delivery (aRR 1.39, 95% CI 1.09, 1.77). Complete maternal milk feeding at discharge from the neonatal unit and higher parental socio-economic status were associated with decreased risk.

CONCLUSIONS

Both biomedical and sociodemographic factors increase DCD risk. These findings can contribute to elucidating the origins of this disorder, and assist in the identification of children at risk for early referral and intervention.

Maternal Cigarette Smoking During Pregnancy and Genital Anomalies in Boys: A Register-Based Cohort and Sibling-Matched Design Study

Purpose

Cryptorchidism and hypospadias share several prenatal risk factors. However, in published studies, boys exposed to cigarette smoking during pregnancy have a higher risk of cryptorchidism and a lower risk of hypospadias. Using Danish register-based data, we revisited these findings with a cohort and sibling-matched design to investigate the potential effect of shared time-stable factors.

Patients and Methods

For the cohort study, we included 823,670 live-born, singleton boys born from 1991 to 2016. Crude and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox regression models for each genital anomaly according to maternal cigarette smoking during pregnancy. For the sibling-matched design, we included 399,258 brothers and used a stratified Cox regression model creating family-adjusted results.

Results

In the cohort study, we found a higher risk of cryptorchidism (aHR = 1.18, 95% CI: 1.12, 1.24) and a lower risk of hypospadias (aHR = 0.84, 95% CI: 0.76, 0.93) when comparing boys exposed to cigarette smoking with non-exposed, and for increasing numbers of cigarettes smoked. In comparison, the sibling-matched analyses suggested a slightly weaker association for cryptorchidism and an association of similar magnitude for hypospadias, both in the same direction as in the cohort study.

Conclusion

Shared, familial confounding does not seem to explain earlier findings of higher risk of cryptorchidism and lower risk of hypospadias.

Incidence of cilioretinal arteries in 11- to 12-year-old children and association with maternal smoking during pregnancy: the Copenhagen Child Cohort 2000 Eye Study

PURPOSE

To estimate the incidence of cilioretinal arteries in a Danish child cohort and associations with birth parameters.

METHODS

The population-based Copenhagen Child Cohort 2000 Eye Study examined 1406 children aged 11-12 years. Colour fundus images of both eyes were graded for cilioretinal arteries in the three categories large temporal (defined as supplying the central macula), small temporal and nasal. Data on maternal smoking during pregnancy, gestational ageand birth weight were obtained from the Danish Medical Birth Registry.

RESULTS

A total of 463/1338 (35%) children were found to have one or more cilioretinal arteries per child. Large temporal cilioretinal arteries were present in 280/1338 (21%) of children and were associated with tobacco smoking during pregnancy, being present in 70/246 (28%) of children with mothers who were smoking during pregnancy, but only in 191/990 (19%) of children whose mothers did not smoke during pregnancy (p = 0.0022). After adjustments for potential confounders, the odds ratio of having one or more large temporal cilioretinal arteries was 1.72 (CI95% 1.19-2.47; p = 0.0035) in the smoking versus none smoking category. No other associations with birth parameters were found.

CONCLUSION

Cilioretinal arteries were present in more than one third of 11- to 12-year-old Danish children. Large temporal cilioretinal arteries were found in one fifth of children and were associated with maternal smoking during pregnancy. This finding suggests that the intrauterine environment may have an impact on the development of retinal vessels during foetal life.

Behavioral and Cognitive Differences in Early Childhood related to Prenatal Marijuana Exposure

Prenatal marijuana exposure (PME) negatively impacts child development and behavior; however, few studies have examined these associations at early ages among children exposed to today's highly potent marijuana. Using a prospective prenatal cohort (Columbus, Ohio, USA), PME was determined from maternal self-report, medical chart abstraction, and urine toxicology from prenatal visits and delivery. At age 3.5 years, 63 offspring children completed tasks assessing executive function (EF), visual spatial ability, emotion regulation, and aggressive behavior. Caregivers reported on children's EF and problem behaviors. Logistic regressions and analyses of covariance controlling for key variables were used to examine associations between PME and child outcomes. Compared to non-exposed children, children with PME had more sleep-related problems, withdrawal symptoms, and externalizing problems, including aggressive behaviors and oppositional defiant behaviors. Children with and without PME did not differ in terms of executive functioning. Findings suggest behavioral problems associated with PME may manifest by age 3.5.

Marijuana Use during Pregnancy and Preterm Birth: A Prospective Cohort Study

OBJECTIVE

The aim of this study is to estimate the association between marijuana use during pregnancy and total, spontaneous and indicated preterm birth.

STUDY DESIGN

Prospective cohort study of women receiving antenatal care at The Ohio State University from 2010 to 2015. Marijuana use was assessed by questionnaire, record abstraction, and urine toxicology. Women were followed through the end of pregnancy. Relative risks were assessed with Poisson regression and time to delivery with proportional hazard models.

RESULTS

Of 363 eligible women, 119 (33%) used marijuana in pregnancy by at least one measure. In this high-risk cohort, preterm birth occurred to 36.0% of users and 34.6% of nonusers (p = 0.81). The unadjusted relative risk of all preterm birth was 1.06 (95% confidence interval [CI]: 0.76-1.47); the adjusted relative risk was similar 1.04 (95% CI: 0.72-1.50). Spontaneous preterm birth was nonsignificantly elevated among users before 1.32 (95% CI: 0.89-1.96), and after 1.21 (95% CI: 0.76-1.94) adjustment. Indicated preterm birth was nonsignificantly reduced before 0.52 (95% CI: 0.22-1.23) and after 0.75 (95% CI: 0.29-2.15) adjustment. The unadjusted hazard ratio (HR) for time to preterm birth was 1.26 (95% CI: 0.84-2.00); the adjusted HR was 1.32 (95% CI: 0.80-2.07). Both unadjusted 1.77 (95% CI: 1.06-2.93) and adjusted 2.16 (95% CI: 1.16-4.02) HRs for spontaneous preterm birth were significantly elevated, primarily due to an increased risk of spontaneous birth <28 weeks among users. The unadjusted and adjusted HRs for time to indicated preterm birth were 0.69 (95% CI: 0.33-1.43) and 0.58 (95% CI: 0.23-1.46).

CONCLUSION

Marijuana use was not associated with total preterm birth in this cohort, suggesting that among women already at high risk of preterm birth, marijuana does not increase risk further. However, there was a suggestion that pregnant women who use marijuana may deliver earlier, particularly from spontaneous preterm birth, than women who do not use marijuana.

KEY POINTS

· Marijuana was not associated with risk of all preterm birth.. · Marijuana was not associated with reduced time to delivery.. · However, users had reduced time to spontaneous preterm birth..

Prenatal tobacco smoke exposure and neurological impairment at 10 years of age among children born extremely preterm: a prospective cohort

OBJECTIVE

To determine the association between prenatal tobacco smoke exposure and neurological impairment at 10 years of age among children born extremely preterm (<28 weeks of gestation).

DESIGN

The Extremely Low Gestational Age Newborn (ELGAN) Study, a prospective cohort.

SETTING

Ten-year follow-up of extremely preterm infants born at 14 US hospitals between 2002 and 2004.

METHODS

Prenatal tobacco smoke exposure was defined as a mother's report at enrolment of active (i.e. maternal) and passive smoking during pregnancy. Poisson regression with generalized estimating equations was used. Models adjusted for mother's age, race/ethnicity, education, insurance, pre-pregnancy body mass index, US region, multiple gestation and infant's sex; and in sensitivity analysis, gestational age at delivery and clinical subtype of preterm birth, given their classification as intermediate and non-confounding variables.

MAIN OUTCOMES

Neurological impairment at 10 years, epilepsy, cerebral palsy and cognitive impairment.

RESULTS

Of 1200 ELGAN study survivors, 856 were assessed at 10 years of age with neurological outcomes, of whom 14% (118/856) had active tobacco exposure during pregnancy and 24% (207/852) had passive tobacco exposure. Compared with children who were not exposed prenatally to tobacco, children exposed to active tobacco use during pregnancy had a higher risk of epilepsy (14% versus 5%; adjusted relative risk: 1.68, 95% CI 1.45-1.92). This risk remained after adjustment for gestational age at delivery and clinical subtype of preterm birth. Prenatal tobacco smoke exposure was not associated with other assessed neurological outcomes, including cerebral palsy and multiple measures of cognitive impairment.

CONCLUSIONS

Among children born extremely preterm, prenatal active tobacco smoke exposure was associated with an increased risk of epilepsy at 10 years of life.

TWEETABLE ABSTRACT

Among infants born before 28 weeks of gestation, prenatal active tobacco smoke exposure was associated with an increased risk of epilepsy at 10 years of life.

Trends in Tobacco Smoking in Pregnant Women: Data From French National Perinatal Surveys

Objectives: To describe maternal smoking trends in France between 1972 and 2016, and identify whether maternal characteristics associated with smoking in the 3rd trimester of pregnancy evolved between 2010 and 2016. Methods: Using French National Perinatal Surveys, we estimated proportions of smokers and the number of cigarettes smoked both just before pregnancy and during the 3rd trimester from 1972 to 2016. We used a Poisson model with robust variance to estimate prevalence ratios for smoking during pregnancy. Results: Proportions of mothers quitting smoking were relatively stable (46.0% in 1972 and 45.8% in 2016). The number of cigarettes smoked just before pregnancy and in the 3rd trimester decreased from 1995 onward. However, proportions of smokers remained high before (30.1%) and during the 3rd trimester in 2016 (16.2%). Smoking in the 3rd trimester was associated with a lower education level and lower income in both 2010 and 2016, whereas the association with age, country of birth and parity varied according to the survey year. Conclusion: Early targeted interventions are needed for smokers who plan to have a child and must take smokers' characteristics during pregnancy into account.

Lifestyle and Early Achievement in Families (LEAF) study: Design of an ambidirectional cohort study of prenatal marijuana exposure and child development and behaviour

BACKGROUND

Marijuana is the most-used illicit substance during pregnancy in the USA, but only two cohort studies, begun over 30 years ago, were specifically established to assess the association of pregnancy use with childhood outcomes. They found use to be associated with specific deficits in executive function at 8+ years, but did not focus on these outcomes earlier in life when intervention may be more successful. Two general purpose cohorts found increased aggression in exposed female toddlers and increased behavioural problems and tic disorders in exposed school-age children.

OBJECTIVES

The Lifestyle and Early Achievement in Families (LEAF) study assesses the association of in utero marijuana exposure, documented prospectively by biomarker, self-report, and medical records, with executive function and aggression at age 3½-7 years.

METHODS

This ambidirectional cohort (historical cohort with continued follow-up) includes women enrolled in the Perinatal Research Repository during prenatal care at Ohio State University Wexner Medical Center and their children, recontacted 3½-7 years post-birth. Children complete 1-2 study visits including cognitive testing, behavioural observation, and maternal and teacher report of behaviour. Family and social environmental factors are assessed.

RESULTS

Child follow-up began in September 2016; visits continue through August 2020. There are 362 eligible children; 32% had mothers who used marijuana during pregnancy, 10% of mothers completed college, and 23% did not complete high school. Mean maternal age at study registration in pregnancy was 26.4 years, and 63% of mothers were African American. To date, 268 children have completed at least 1 study visit.

CONCLUSIONS

The LEAF Study will document the association of prenatal marijuana exposure with development and behaviour in the current era when marijuana is more potent than when previous cohorts were studied. The results may inform policy and interventions to counsel reproductive-aged women about the risks of use during pregnancy and guide prevention and treatment of adverse effects among children.

Parenthood and smoking

Parents' smoking is harmful to infants' health. While it is well established that the fraction of mothers smoking during pregnancy is non-negligible, it is an open question of how many parents actually quit smoking to account for the adverse health effects accruing to their offspring. It is also unknown for how long smoking is reduced after first childbirth. This paper investigates these questions in a longitudinal analysis. The analyzed time period covers smoking patterns several years before childbirth and up to twenty years afterwards. Women's smoking probability already drops several years before first childbirth and it remains reduced until the first child turns 18 years old. In the second and third trimester of pregnancy, the drop is largest by around 75 percent.

Smoking cessation in early-pregnancy, gestational weight gain and subsequent risks of pregnancy complications

OBJECTIVE

Smoking cessation is associated with weight gain. We first examined the associations of smoking cessation in early-pregnancy with gestational weight gain and subsequently evaluated the risks of pregnancy complications among women who quit smoking in early-pregnancy according to their gestational weight gain.

METHODS

In a population-based prospective cohort study among 7,389 women, we measured weight in each pregnancy period. Information on smoking and pregnancy complications was obtained from questionnaires and medical records.

RESULTS

As compared to continued smoking during pregnancy, smoking cessation in early-pregnancy was not associated with gestational weight gain. Smoking cessation in early-pregnancy was associated with decreased risks of delivering small-for-gestational-age infants (Odds Ratio (OR) 0.52 (95 % Confidence Interval (CI) 0.37, 0.75)), but with increased risks of pre-eclampsia (OR 2.07 (95 % CI 1.01, 4.27)) and delivering large-for-gestational-age infants (OR 2.11 (95 % CI 1.45, 3.09)). Among women who quit smoking in early-pregnancy with >12 kg weight gain, the risks of pre-eclampsia and delivering large-for-gestational-age infants were slightly increased.

CONCLUSION

As compared to continued smoking during pregnancy, smoking cessation in early-pregnancy is not associated with increased gestational weight gain. Among women who quit smoking in early-pregnancy, higher gestational weight gain does not strongly affect their risks of pregnancy complications.

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.

[Physiological and Psychological Data influencing Pregnant Women Smoking Behavior - CNGOF-SFT Expert Report and Guidelines for Smoking Management during Pregnancy]

Nicotine is the main addictive substance in tobacco and its addictive effects mainly involve dopamine. Nicotine is mainly metabolized (C-oxidation) in the liver to cotinine by the cytochrome P450 enzyme system. Nicotine half-life is short being about 2hours. Nicotine metabolism appears to be increased during pregnancy, mainly due to an increased cytochrome activity and maternal cardiac output. Thus, the smoking behavior of the pregnant woman is subsequently modified with an increase in withdrawal syndromes and an increased desire to smoke. These pharmacological elements should be taken into account when prescribing nicotine replacement therapy. Regarding the markers of tobacco intoxication, there is a good correlation between the importance of smoking and the measurement of expired air carbon monoxide. Although there is no evidence of decreased obstetrical complications related to its use, it is simple and non-invasive and therefore may be useful in routine practice. It gives an instantaneous value of tobacco intoxication, and represents a starting point for dialogue and management and can help to highlight the reality of withdrawal. Regarding the evaluation of tobacco addiction, the most commonly used questionnaires are the Fagerström tests (FTCD, HSI…), which are well correlated with cotinine concentration. However, there is insufficient evidence of their usefulness in reducing tobacco consumption during pregnancy to recommend them in current practice. DSM-V diagnostic criteria for addiction should be known as they can also be used to characterize the intensity of this addiction.

Prevalence and patterns of cigarette smoking before and during early and late pregnancy according to maternal characteristics: the first national data based on the 2003 birth certificate revision, United States, 2016

BACKGROUND

The objective of this study was to examine the prevalence of smoking by intensity status before pregnancy and during early (first and second trimester) and late (third trimester) pregnancy according to race/ethnicity, age, and educational attainment of women who gave birth in the United States in 2016.

METHODS

This cross-sectional study was based on the 2016 National Center for Health Statistics (NCHS) Natality File of 3,956,112 live births, the first year that it became 100% nationally representative. Self-reported smoking data were used to create new seven smoking intensity status categories to capture natural variability in smoking patterns during pregnancy and to identify maternal smokers by race/ethnicity, age, and educational attainment. The risk of smoking at low and high intensity in early pregnancy was estimated in multivariable logistic regression analyses.

RESULTS

Nearly 9.4% of women reported smoking before pregnancy and 7.1% during pregnancy, both at high and low intensity, and smoking rates were higher in the first trimester (7.1%) than in the second (6.1%) or the third (5.7%) trimester. Non-Hispanic White women, women 20-24 years old, and women with less than a high school education were the strongest predictors of smoking anytime during pregnancy. The odds of smoking in early pregnancy at high intensity were 88% lower (aOR 0.12, 95% CI: 0.11, 0.13) for Hispanic women, compared to non-Hispanic White women; 16% higher (aOR 1.16, 95% CI: 1.12, 1.21) for women 20-24 years old and 16% lower (aOR 0.84, 95% CI: 0.80, 0.89) for women ≥35 years old, compared to women 25-29 years old; as well as 13% higher (aOR 1.13, 95% CI: 1.09, 1.18) for women with less than a high school education and 92% lower (aOR 0.08, 95% CI: 0.08, 0.09) for women with a bachelor's degree or higher, compared to women with a high school diploma.

CONCLUSIONS

Despite the high prevalence of high intensity smoking before and during pregnancy, future intervention strategies need to focus on the proportion of low intensity quitters and reducers, who are ready to stop smoking. Continual monitoring of trends in smoking intensity patterns is necessary, including neonatal outcomes over time.

A gestational vulnerability window for smoking exposure and the increased risk of preterm birth: how timing and intensity of maternal smoking matter

BACKGROUND

Reducing the incidence of preterm birth is a national priority. Maternal cigarette smoking is strongly and consistently associated with preterm birth. The objective of this study was to examine prenatal exposure based on combined measures of timing (by trimester) and intensity level (the number of cigarettes smoked per day) of maternal smoking to identify a pregnancy period with the highest risk of preterm birth.

METHODS

A sample of 2,485,743 singleton births was drawn from the 2010 National Center of Health Statistics (NCHS) linked birth/infant death file of US residents in 33 states that implemented the revised 2003 birth certificate. Nine mutually exclusive smoking status categories were created to assess prenatal exposure across pregnancy in association with preterm birth. Gestational age was based on the obstetric estimate. Multiple logistic regression analyses were conducted to compare the odds of preterm birth among women who smoked at different intensity levels in the second or third trimester with those who smoked only in the first trimester.

RESULTS

Overall, 7.95% of women had a preterm birth; 8.90% of low intensity (less than a pack/day) smokers in the first trimester only, 12.99% of low and 15.38% of high intensity (pack a day or more) smokers in the first two trimesters, and 10.56% of low and 11.35% of high intensity smokers in all three trimesters delivered preterm. First and second trimester high (aOR 1.85, 95% CI: 1.66, 2.06) and low intensity smokers (aOR 1.51, 95% CI: 1.41, 1.61) had higher odds of preterm birth compared to those who smoked less than a pack a day only in the first trimester, but the odds did not increase for all three trimester smokers relative to the first and second trimester smokers. In sensitivity analysis, adjustment for exposure misclassification error corrected data and testing for effect modification by maternal race/ethnicity found no significant interaction.

CONCLUSIONS

This study documented a biologically plausible vulnerability window for smoking exposure and the increased risk of preterm birth. For women who do not modify their smoking behavior preconception, preterm birth risk of smoking remains low until late in the first trimester.

Effects of prenatal exposure to alcohol, tobacco and other drugs of abuse on retinal development

PURPOSE

To assess structural changes in the retina using optical coherence tomography (OCT) in children prenatally exposed to toxic substances.

METHODS

The study included a total of 49 infants, aged between 5 and 18years, exposed to toxic substances during pregnancy. Among the exposed children, 25 were exposed to tobacco, 20 were exposed to alcohol, and 4 children were exposed to other drugs of abuse. All children underwent a complete ophthalmology examination, including an OCT. The results were compared against a control group composed of 25 infants, age matched with controlled pregnancy, and not exposed to toxic substances.

RESULTS

Children prenatally exposed to toxic substances showed significantly thinner average retinal nerve fibre layer (RNFL) compared with control children (81.5 vs. 99.7μm; P<.005), as well as RNFL thinning in its four quadrants (superior RNFL: 97.5 vs. 127.5μm; P<.005; nasal RNFL: 61.5 vs. 72.3μm; P<.005; inferior RNFL: 99.8 vs. 128.6μm; P<.005, temporal RNFL: 58.3 vs. 68.2μm; P<.005). Exposed children also exhibited a thinner ganglion cell layer (72.9 vs. 85.9; P<.005). Greater RNFL thinning was observed in children exposed to drugs of abuse (RNFL thinner average=72), followed by children exposed to alcohol (RNFL thinner average=72.9), and finally the least affected were those children exposed to tobacco during pregnancy (RNFL=94.6).

CONCLUSION

Toxic substances during pregnancy interfere in retinal development. These results strengthen the evidence about the avoidance of any toxic substance during pregnancy.

Single Motherhood, Alcohol Dependence, and Smoking During Pregnancy: A Propensity Score Analysis

OBJECTIVE

Few studies linking single motherhood and maternal smoking during pregnancy consider correlated risk from problem substance use beyond history of smoking and concurrent use of alcohol. In the present study, we used propensity score methods to examine whether the risk of smoking during pregnancy associated with single motherhood is the result of potential confounders, including alcohol dependence.

METHOD

Data were drawn from mothers participating in a birth cohort study of their female like-sex twin offspring (n = 257 African ancestry; n = 1,711 European or other ancestry). We conducted standard logistic regression models predicting smoking during pregnancy from single motherhood at twins' birth, followed by propensity score analyses comparing single-mother and two-parent families stratified by predicted probability of single motherhood.

RESULTS

In standard models, single motherhood predicted increased risk of smoking during pregnancy in European ancestry but not African ancestry families. In propensity score analyses, rates of smoking during pregnancy were elevated in single-mother relative to two-parent European ancestry families across much of the spectrum a priori risk of single motherhood. Among African ancestry families, within-strata comparisons of smoking during pregnancy by single-mother status were nonsignificant.

CONCLUSIONS

These findings highlight single motherhood as a unique risk factor for smoking during pregnancy in European ancestry mothers, over and above alcohol dependence. Additional research is needed to identify risks, beyond single motherhood, associated with smoking during pregnancy in African ancestry mothers.

Prevalence, pattern and sociodemographic differentials in smokeless tobacco consumption in Bangladesh: evidence from a population-based cross-sectional study in Chakaria

BACKGROUND

The health hazards associated with the use of smokeless tobacco (SLT) are similar to those of smoking. However, unlike smoking, limited initiatives have been taken to control the use of SLT, despite its widespread use in South and Southeast Asian countries including Bangladesh. It is therefore important to examine the prevalence of SLT use and its social determinants for designing appropriate strategies and programmes to control its use.

OBJECTIVE

To investigate the use of SLT in terms of prevalence, pattern and sociodemographic differentials in a rural area of Bangladesh.

DESIGN

Population-based cross-sectional household survey.

SETTING AND PARTICIPANTS

A total of 6178 individuals aged ≥13 years from 1753 households under the Chakaria HDSS area were interviewed during October-November 2011.

METHODS

The current use of SLT, namely sadapatha (dried tobacco leaves) and zarda (industrially processed leaves), was used as the outcome variable. The crude and net associations between the sociodemographic characteristics of respondents and the outcome variables were examined using cross-tabular and multivariable logistic regression analysis, respectively.

RESULTS

23% of the total respondents (men: 27.0%, women: 19.3%) used any form of SLT. Of the respondents, 10.4% used only sadapatha,13.6% used only zarda and 2.2% used both. SLT use was significantly higher among men, older people, illiterate, ever married, day labourers and relatively poorer respondents. The odds of being a sadapatha user were 3.5-fold greater for women than for men and the odds of being a zarda user were 3.6-fold greater for men than for women.

CONCLUSIONS

The prevalence of SLT use was high in the study area and was higher among socioeconomically disadvantaged groups. The limitation of the existing regulatory measures for controlling the use of non-industrial SLT products should be understood and discussion for developing new strategies should be a priority.

Maternal Race/Ethnicity and Predictors of Pregnancy and Infant Outcomes

Objective. To examine predictors of pregnancy and infant outcomes, including maternal race/ethnicity. Design. Prospective and observational follow-up of high-risk pregnancies and births. Participants. Three hundred fifty-four mothers and their preterm and/or high-risk live-born neonates were closely followed in three tertiary care centers from the prenatal to postnatal periods for potential high-risk and/or preterm births that required neonatal resuscitations. Major Outcome Measures. Pregnancy complications, birth complications, and infant outcomes were examined in conjunction with maternal factors, including preexisting health problems, health behaviors (smoking, alcohol consumption, prenatal visits), and the birth setting (tertiary care centers or community hospitals). Results. About 22% of these infants were transferred into the tertiary care centers from the community hospitals right after birth; the rest were born in the centers. According to regression analyses, predictors of the birth setting were race (White vs. non-White), maternal health behaviors, pregnancy complications, fetal distress, and the presence of congenital defects for infants (p < .001). Predictors for fetal distress included race (Whites) and pregnancy-induced hypertension (p < .003). Predictors for lower birth weight included race (non-Whites), maternal cigarette smoking, pregnancy complications, fetal distress, and congenital defects (p < .001). Infant mortality rate was 3.9% for these high-risk infants, with the highest rate in infants born to Black mothers (8%). Conclusions. There are obvious health disparities among White and non-White women experiencing high-risk pregnancies and births. Future studies are needed to develop interventions targeted to different racial/ethnic groups during pregnancy to reduce preterm and high-risk births.

Prenatal vitamin C and E supplementation in smokers is associated with reduced placental abruption and preterm birth: a secondary analysis

OBJECTIVE

Smoking and pre-eclampsia (PE) are associated with increases in preterm birth, placental abruption and low birthweight. We evaluated the relationship between prenatal vitamin C and E (C/E) supplementation and perinatal outcomes by maternal self-reported smoking status focusing on outcomes known to be impacted by maternal smoking.

DESIGN/SETTING/POPULATION

A secondary analysis of a multi-centre trial of vitamin C/E supplementation starting at 9-16 weeks in low-risk nulliparous women with singleton gestations.

METHODS

We examined the effect of vitamin C/E by smoking status at randomisation using the Breslow-Day test for interaction.

MAIN OUTCOME MEASURES

The trial's primary outcomes were PE and a composite outcome of pregnancy-associated hypertension (PAH) with serious adverse outcomes. Perinatal outcomes included preterm birth and abruption.

RESULTS

There were no differences in baseline characteristics within subgroups (smokers versus nonsmokers) by vitamin supplementation status. The effect of prenatal vitamin C/E on the risk of PE (P = 0.66) or PAH composite outcome (P = 0.86) did not differ by smoking status. Vitamin C/E was protective for placental abruption in smokers (relative risk [RR] 0.09; 95% CI 0.00-0.87], but not in nonsmokers (RR 0.92; 95% CI 0.52-1.62) (P = 0.01), and for preterm birth in smokers (RR 0.76; 95% CI 0.58-0.99) but not in nonsmokers (RR 1.03; 95% CI 0.90-1.17) (P = 0.046).

CONCLUSION

In this cohort of women, smoking was not associated with a reduction in PE or the composite outcome of PAH. Vitamin C/E supplementation appears to be associated with a reduction in placental abruption and preterm birth among smokers.

Smoking among pregnant women in small towns in Poland

Objectives

The aim of the work was to assess among pregnant women from small towns and villages in Poland: the prevalence of smoking, credibility of smoking, and influence of socioeconomic factors on smoking status.

Methods

The data came from 4512 interviews with women in different trimesters of pregnancy. The interviews were collected in 2007 and 2008 year in towns up to 8000 citizens in 12 voivodeships.

Results

Prevalence of smoking in the beginning of pregnancy was confirmed by 34.6 % of women. During the pregnancy 14.7 % of women declared quitting smoking and 19.9 % continued smoking. Cigarette smoking was most frequent in those with a primary education, unemployed, very low incomes in household, and having both smoking parents. In multifactorial analysis, risk of smoking was highest (95 % CI 1.74–6.06) for women that were divorced or not living with a partner compared with married.

Conclusions

Rates of active smoking among a population of pregnant women living in small towns in Poland are very high. Since the correlates of smoking during pregnancy are a low education level and a low economic status of the pregnant woman, these socioeconomic groups should be first priority targets.

Does fetal smoke exposure affect childhood bone mass? The Generation R Study

We assessed the intrauterine influence of maternal smoking on childhood bone mass by comparing parental prenatal and postnatal smoking habits. We observed higher bone mass in children exposed to maternal smoking, explained by higher body weight. Maternal smoking or related lifestyle factors may affect childhood weight gain rather than skeletal growth.

INTRODUCTION

Maternal smoking during pregnancy may adversely affect bone health in later life. By comparing the associations of maternal and paternal smoking and of prenatal and postnatal exposure with childhood bone measures, we aimed to explore whether the suggested association could be explained by fetal programming or reflects confounding by familial factors.

METHODS

In 5565 mothers, fathers and children participating in a population-based prospective cohort study, parental smoking habits during pregnancy and current household smoking habits were assessed by postal questionnaires. Total body bone mineral content (BMC), bone area (BA) and bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry (DXA) at the median age of 6.0 years (IQR 0.37).

RESULTS

In confounder-adjusted models, maternal smoking during pregnancy was associated with a higher BMC of 11.6 g (95 % confidence interval (CI) 5.6, 17.5), a larger BA of 9.7 cm(2) (95 % CI 3.0, 16.4), a higher BMD of 6.7 g/cm(2) (95 % CI 2.4, 11.0) and a higher BMC of 5.4 g (95 % CI 1.3, 9.6) adjusted for BA of the child. Current weight turned out to mediate these associations. Among mothers who did not smoke, paternal smoking did not show evident associations with childhood bone measures. Also, household smoking practices during childhood were not associated with childhood bone measures.

CONCLUSIONS

Our results do not support the hypothesis of fetal smoke exposure affecting childhood bone mass via intrauterine mechanisms. Maternal smoking or related lifestyle factors may affect childhood weight gain rather than skeletal growth.

Prenatal vitamin C and E supplementation in smokers is associated with reduced placental abruption and preterm birth: a secondary analysis

OBJECTIVE

Smoking and pre-eclampsia (PE) are associated with increases in preterm birth, placental abruption and low birthweight. We evaluated the relationship between prenatal vitamin C and E (C/E) supplementation and perinatal outcomes by maternal self-reported smoking status focusing on outcomes known to be impacted by maternal smoking.

DESIGN/SETTING/POPULATION

A secondary analysis of a multi-centre trial of vitamin C/E supplementation starting at 9-16 weeks in low-risk nulliparous women with singleton gestations.

METHODS

We examined the effect of vitamin C/E by smoking status at randomisation using the Breslow-Day test for interaction.

MAIN OUTCOME MEASURES

The trial's primary outcomes were PE and a composite outcome of pregnancy-associated hypertension (PAH) with serious adverse outcomes. Perinatal outcomes included preterm birth and abruption.

RESULTS

There were no differences in baseline characteristics within subgroups (smokers versus nonsmokers) by vitamin supplementation status. The effect of prenatal vitamin C/E on the risk of PE (P = 0.66) or PAH composite outcome (P = 0.86) did not differ by smoking status. Vitamin C/E was protective for placental abruption in smokers (relative risk [RR] 0.09; 95% CI 0.00-0.87], but not in nonsmokers (RR 0.92; 95% CI 0.52-1.62) (P = 0.01), and for preterm birth in smokers (RR 0.76; 95% CI 0.58-0.99) but not in nonsmokers (RR 1.03; 95% CI 0.90-1.17) (P = 0.046).

CONCLUSION

In this cohort of women, smoking was not associated with a reduction in PE or the composite outcome of PAH. Vitamin C/E supplementation appears to be associated with a reduction in placental abruption and preterm birth among smokers.

Maternal cigarette smoking during pregnancy and reproductive health in children: a review of epidemiological studies

Maternal cigarette smoking may affect the intrauterine hormonal environment during pregnancy and this early fetal exposure may have detrimental effects on the future trajectory of reproductive health. In this review, we discuss the epidemiological literature on the association between prenatal exposure to maternal cigarette smoking and several aspects of reproductive health. The literature points towards an increased risk of the urogenital malformation cryptorchidism, but a potential protective effect on the risk of hypospadias in sons following prenatal cigarette smoking exposure. Studies on sexual maturation find a tendency towards accelerated pubertal development in exposed boys and girls. In adult life, prenatally exposed men have impaired semen quality compared with unexposed individuals, but an influence on fecundability, that is, the biological ability to reproduce, is less evident. We found no evidence to support an association between prenatal cigarette smoking exposure and testicular cancer. Among adult daughters, research is sparse and inconsistent, but exposure to cigarette smoking in utero may decrease fecundability. In conclusion, prenatal exposure to cigarette smoking may cause some long-term adverse effects on the reproductive health.

Reducing smoking among distracted individuals: a preliminary investigation

INTRODUCTION

According to the attentional myopia model, salient cues that serve to inhibit behavior can be especially effective under conditions of limited attention. A small field study tested the implications of this model for smoking reduction.

METHODS

Twenty-three undergraduate smokers were exposed to a prominent health warning for 2 5-day experimental phases, with phase order counterbalanced across participants. During one phase, participants simply viewed the warning at regular intervals. During the other phase, participants viewed the warning for the same duration but also simultaneously performed a distracting cognitive load task.

RESULTS

Participants in the phase that combined a health warning with cognitive load reported smoking significantly fewer cigarettes and taking significantly fewer puffs of smoke as compared to a baseline comparison phase-a reduction in smoking not observed in the absence of cognitive load.

CONCLUSIONS

Sources of attentional distraction may heighten the impact of salient smoking warnings, resulting in significant reductions in smoking.

Effect of maternal smoking cessation before and during early pregnancy on fetal and childhood growth

Background

Maternal smoking during pregnancy is a major cause of intrauterine growth restriction and childhood obesity, but only a few studies have examined the association of smoking cessation before and during pregnancy with fetal and childhood growth. We examined this association in a prospective cohort study in Japan.

Methods

Our study included children born between 1991 and 2006 and their mothers. Using a questionnaire, maternal smoking status was recorded at pregnancy. The anthropometric data of the children were collected during a medical check-up at age 3 years. Multiple linear and logistic regression models were used for data analysis stratified by sex.

Results

In total, 2663 mothers reported their smoking status during early pregnancy, and data were collected from 2230 (83.7%) children at age 3 years. Maternal smoking during pregnancy was associated with a significant reduction in birth weight (approximately 120–150 g). Body mass index at age 3 years was significantly higher among boys born to smoking mothers than among boys born to nonsmoking mothers. Maternal smoking during pregnancy was associated with overweight at age 3 years among boys (adjusted odds ratio, 2.4; 95% CI, 1.03–5.4). However, among women who stopped smoking in early pregnancy, there was no increase in the risks of a small for gestational age birth or childhood overweight at age 3 years.

Conclusions

Children born to mothers who stopped smoking before or during early pregnancy had appropriate fetal and childhood growth.

Exposure to parental smoking and child growth and development: a cohort study

Background

Studies on adverse childhood health and development outcomes associated with parental smoking have shown inconsistent results. Using a cohort of Belarusian children, we examined differences in cognition, behaviors, growth, adiposity, and blood pressure at 6.5 years according to prenatal and postnatal exposure to parental smoking.

Methods

Using cluster-adjusted multivariable regression, effects of exposure to prenatal smoking were examined by comparing (1) children whose mothers smoked during pregnancy with those of mothers who smoked neither during nor after pregnancy and (2) children whose mothers smoked during and after pregnancy with those whose mothers smoked after pregnancy only; effects of postnatal smoking were examined by comparing (1) children whose mothers smoked after pregnancy only with those of mothers who smoked neither during nor after pregnancy and (2) children whose fathers smoked with those whose fathers did not smoke among children of non-smoking mothers after adjusting for a wide range of socioeconomic and family characteristics.

Results

After adjusting for confounders, children exposed vs unexposed to prenatal maternal smoking had no differences in mean IQ, teacher-rated behavioral problems, adiposity, or blood pressure. Children exposed to maternal postnatal smoking had slightly increased behavioral problems [0.9, 95% CI: 0.6, 1.2 for total difficulties], higher body mass index [0.2, 95% CI: 0.1, 0.3], greater total skinfold thickness [0.4, 95% CI: 0.04, 0.71], and higher odds of overweight or obesity [1.4, 95% CI; 1.1, 1.7]. Similar magnitudes of association were observed with postnatal paternal smoking.

Conclusions

No adverse cognitive, behavioral and developmental outcomes were associated with exposure to maternal prenatal smoking. Observed associations with postnatal smoking of both parents may reflect residual confounding by genetic and family environmental factors.

The impact of tobacco use on preterm premature rupture of the membranes

OBJECTIVE

To determine if tobacco use increases the incidence of preterm premature rupture of the membranes (pPROM) or alters perinatal outcomes after pPROM.

STUDY DESIGN

This is a secondary analysis of the databases of three completed Eunice Kennedy Shriver National Institute of Child Health and Human Development-supported Maternal Fetal Medicine Units Network studies. Self-reported tobacco exposure data was obtained. Its relationship with the incidence of pPROM and associated neonatal outcome measures were assessed.

RESULTS

There was no difference in the incidence of pPROM when comparing nonsmokers to those using tobacco. Although a trend was seen between the incidence of pPROM and the amount smoked, this did not reach statistical significance. Among the patients with pPROM, the use of tobacco was not associated with an increase in perinatal morbidity.

CONCLUSION

Our data do not support a significant relationship between tobacco use and pPROM.

Accuracy of self-reported smoking status in first trimester aneuploidy screening

OBJECTIVES

To review the accuracy of self-reporting of smoking status in our first trimester screening population and to assess the levels of pregnancy-associated plasma protein-A (PAPP-A) and free-β human chorionic gonadotropin (free-hCGβ) in women who were classified for smoking status by serum cotinine concentrations and self-reporting.

METHODS

Cotinine concentration was determined in the stored serum 696 self-reported smokers and 442 self-reported non-smokers. PAPP-A and free-hCGβ multiples of the medians (MoMs) determined at screening were reverted to uncorrected for self-reported smoking status.

RESULTS

A total of 21.7% of those self-reporting as non-smokers had increased serum cotinine concentrations (using a cut-off of 13.7 ng/mL), indicating a positive smoking status. This under-reporting meant that serum PAPP-A and free-hCGβ MoMs were greater reduced in smokers classified by cotinine levels (17.2% and 9.7%) than in those classified by self-reporting (14.6% and 2.8%). Women who were classified as smokers at conception but had stopped at some time afterwards did not have significantly reduced marker MoMs to non-smokers.

CONCLUSIONS

Self-reporting results in under-representation of smoking in our population, resulting in a significant bias and inflated screen-positive rates.

Do socio-economic gradients in smoking emerge differently across time by gender? Implications for the tobacco epidemic from a pregnancy cohort in California, USA

Understanding current patterns of population smoking by socioeconomic position (SEP) can be substantially enhanced by research that follows birth cohorts over long periods of time, yet such data in the US are rare. Information from birth cohorts followed during critical time periods when the health consequences of smoking became widely known can inform the ways in which current smoking prevalence has been shaped by the historical processes that preceded it. The present study utilizes data from a substudy of the Child Health and Development Study pregnancy cohort (N = 1612). Women were queried about smoking status in 1959-1962, 1971-1972 and 1977-1980. Women were divided into three cohorts based on date of birth. Offspring represented another birth cohort assessed for smoking in 1977-1980. Results indicated that the overall prevalence of smoking exhibited cohort-specific patterns that persisted across time. Notably, the youngest maternal cohort (born 1937-1946) had high smoking prevalence throughout and showed no appreciable decrease (44.7%, 41.4%, 40.1% for 1959-1962, 1971-1972, and 1977-1980). Results also indicated that the relation of smoking to SEP exhibited cohort-specific patterns over time. Among the oldest birth cohort (born 1914-1930), no inverse relation of SEP to smoking was observed at any time; in contrast, an inverse relation emerged by 1959-1962 among the youngest cohort of mothers. Among the adolescent offspring, there was a strong SEP gradient (OR = 2.0, 95% CI = 1.4-3.0) that was stronger than in any maternal birth cohort at any assessment (β = 0.40, SE = 0.1, p<0.01). We conclude that SEP gradients in smoking emerge across birth cohorts rather than time alone, with increasingly strong gradients across time especially among younger cohorts.

Self-help booklets for preventing postpartum smoking relapse: a randomized trial

OBJECTIVES

We tested a series of self-help booklets designed to prevent postpartum smoking relapse.

METHODS

We recruited 700 women in months 4 through 8 of pregnancy, who quit smoking for their pregnancy. We randomized the women to receive either (1) 10 Forever Free for Baby and Me (FFB) relapse prevention booklets, mailed until 8 months postpartum, or (2) 2 existing smoking cessation materials, as a usual care control (UCC). Assessments were completed at baseline and at 1, 8, and 12 months postpartum.

RESULTS

We received baseline questionnaires from 504 women meeting inclusion criteria. We found a main effect for treatment at 8 months, with FFB yielding higher abstinence rates (69.6%) than UCC (58.5%). Treatment effect was moderated by annual household income and age. Among lower income women (< $30 000), treatment effects were found at 8 and 12 months postpartum, with respective abstinence rates of 72.2% and 72.1% for FFB and 53.6% and 50.5% for UCC. No effects were found for higher income women.

CONCLUSIONS

Self-help booklets appeared to be efficacious and offered a low-cost modality for providing relapse-prevention assistance to low-income pregnant and postpartum women.

Pregnancy, smoking and birth outcomes

This review summarizes the epidemiology and consequences of maternal smoking in pregnancy, with emphasis on the adverse effects on birth outcomes. In developed countries, approximately 15%, and in developing countries, approximately 8% of women smoke cigarettes, and adolescents and women from lower socioeconomic groups are more likely than other women to smoke while pregnant. Maternal smoking during pregnancy is the largest modifiable risk factor for intrauterine growth restriction. A meta-analysis of recent studies showed that the pooled estimate for reduction of mean birthweight was 174 g (95% confidence limits 132-220 g). Other studies confirm a weaker association between maternal smoking and preterm birth. The population attributable risk of low birthweight due to maternal smoking in the UK is estimated to be 29-39%. Tobacco smoke toxins damage the placenta and may lead to placental abruption, abortion or placenta praevia. Infants of mothers who smoke in pregnancy are at an increased risk of respiratory complications including asthma, obesity and, possibly, behavioral disorders. These effects may be dose-related, as there is good evidence that mean birthweight decrements are greater with increased numbers of cigarettes smoked during pregnancy. Cotinine is a useful indicator of tobacco smoke exposure in pregnant women and higher levels in body fluids have been related to lower birthweights. Maternal genetic polymorphisms of the cytochrome P (CYP)450 and glutathione-S-transferase (GST) subfamilies of metabolic genes influence the magnitude of the effect of nicotine exposure on birth outcomes through their influence on nicotine metabolism. Greatly increased risk of cigarette smoke-induced diseases, including low birthweight, has been found in individuals with susceptible genotypes. Interventions to control maternal smoking are also considered.

Maternal smoking during pregnancy and reproductive health of daughters: a follow-up study spanning two decades

STUDY QUESTION

Does in utero exposure to constituents of cigarette smoke have a programming effect on daughters' age of menarche and markers of long-term reproductive health?

SUMMARY ANSWER

In utero exposure to constituents of cigarette smoke was associated with earlier age of menarche and--to a lesser extent--changes in the testosterone profile of the young women.

WHAT IS KNOWN ALREADY

Studies observe potential effects of in utero exposure to constituents of cigarette smoke on the intrauterine formation of female gonads, but the consequences on long-term reproductive health in daughters remain unclear.

STUDY DESIGN, SIZE AND DURATION

A prospective cohort study was designed using data from 965 pregnant women enrolled prior to a routine 30th-week antenatal examination at a midwifery practice in Denmark from 1988 to 1989 and a follow-up of their 19-21-year-old daughters in 2008.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

The pregnant women provided information on lifestyle factors during pregnancy, including the exact number of cigarettes smoked per day during the first and the second trimesters. A total of 438 eligible daughters were asked to complete a web-based questionnaire on reproductive health and subsequently invited to participate in a clinical examination during 2008. Of the 367 daughters (84%) who answered the questionnaire, 267 (61%) agreed to further examination. Information on menstrual pattern was provided at examination, blood samples were drawn to be analyzed for serum levels of reproductive hormones [FSH, LH, estradiol (E(2)), sex hormone-binding globulin, anti-Müllerian hormone, dehydroepiandrosterone-sulphate (DHEAS), free testosterone and free E(2)] and number of follicles (2-9 mm) were examined by transvaginal ultrasound. The daughters were divided into three exposure groups according to the level of maternal smoking during first trimester [non-exposed (reference), low-exposed (mother smoking >0-9 cigarettes/day) and high-exposed (mother smoking ≥ 10 cigarettes/day)]. Data were analyzed by multiple regression analyses in which we adjusted for potential confounders. Both crude and adjusted test for trend were carried out using maternal smoking during the first trimester as a continuous variable.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed an inverse association between in utero exposure to constituents of cigarette smoke and age of menarche (P = 0.001). Daughters exposed to >0-9 cigarettes/day debuted with -2.7 [95% confidence interval (CI) -5.2 to -0.1] percentage earlier age of menarche, whereas daughters exposed to ≥ 10 cigarettes/day had -4.1 (95% CI: -6.6 to -1.5) percentage earlier age of menarche corresponding to 6.5 (95% CI: -10.7 to -2.2) months. There was a non-significant tendency towards lower levels of testosterone and DHEAS with increasing in utero exposure to constituents of cigarette smoke but no associations with follicle number, cycle length or serum levels of the other reproductive hormones were observed.

LIMITATIONS AND REASONS FOR CAUTION

We collected information on age of menarche retrospectively but the recall time was relatively short (2-10 years) and the reported values were within the normal range of Caucasians. Analyses of reproductive hormones are presented only for the group of daughters who were non-users of hormonal contraceptives because users were excluded, leaving only a low number of daughters available for the analyses (n = 75), as reflected in the wide CIs. The analyses of hormones were further adjusted for menstrual phase at time of clinical examination (follicular, ovulation and luteal phase) because blood samples were not collected on a specific day of the menstrual cycle.

WIDER IMPLICATIONS OF THE FINDINGS

This study supports the limited evidence of an inverse association between maternal smoking during pregnancy and age of menarche and further addresses to what extent reproductive capacity and hormones may be programmed by maternal smoking during pregnancy. A trend toward earlier maturation of females is suggested to have implications on long-term reproductive function.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by a scholarship from The Lundbeck Foundation (R93-A8476). No conflict of interest declared.

Self-reported smoking status and plasma cotinine concentrations among pregnant women in the Norwegian Mother and Child Cohort Study

INTRODUCTION

Underreporting of smoking in epidemiologic studies is common and may constitute a validity problem, leading to biased association measures. In this prospective study, we validated self-reported tobacco use against nicotine exposure assessed by plasma cotinine in the Norwegian Mother and Child Cohort Study (MoBa).

METHODS

The study was based on a subsample of 2,997 women in the MoBa study who delivered infants during the period 2002-2003. Self-reported tobacco use (test variable) and plasma cotinine concentrations (gold standard) were assessed at approximately gestational week 18.

RESULTS

Daily smoking was reported by 9% of the women, occasional smoking by 4%, and nonsmoking by 86% of the women. Sensitivity and specificity for self-reported smoking status were calculated using a cotinine cut-off estimated from the study population (30 nmol/l). Plasma cotinine concentrations ≥30 nmol/l were found in 94% of self-reported daily smokers, 66% of occasional smokers, and 2% of nonsmokers. After the numbers of self-reported nonsmokers with cotinine concentrations above the cut-off limit were added, the daily smoking prevalence increased from 9 to 11%. The sensitivity and specificity for self-reported daily smoking, using 30 nmol/l as the cut-off concentration, were 82 and 99%, respectively.

DISCUSSION

These findings suggest that self-reported tobacco use is a valid marker for tobacco exposure in the MoBa cohort.

A common genetic variant at 15q25 modifies the associations of maternal smoking during pregnancy with fetal growth: the generation R study

OBJECTIVE

Maternal smoking during pregnancy is associated with fetal growth retardation. We examined whether a common genetic variant at chromosome 15q25 (rs1051730), which is known to be involved in nicotine metabolism, modifies the associations of maternal smoking with fetal growth characteristics.

METHODS

This study was performed in 3,563 European mothers participating in a population-based prospective cohort study from early pregnancy onwards. Smoking was assessed by postal questionnaires and fetal growth characteristics were measured by ultrasound examinations in each trimester of pregnancy.

RESULTS

Among mothers who did not smoke during pregnancy (82.9%), maternal rs1051730 was not consistently associated with any fetal growth characteristic. Among mothers who continued smoking during pregnancy (17.1%), maternal rs1051730 was not associated with head circumference. The T-allele of maternal rs1051730 was associated with a smaller second and third trimester fetal femur length [differences -0.23 mm (95%CI -0.45 to -0.00) and -0.41 mm (95%CI -0.69 to -0.13), respectively] and a smaller birth length [difference -2.61 mm (95%CI -5.32 to 0.11)]. The maternal T-allele of rs1051730 was associated with a lower third trimester estimated fetal weight [difference -33 grams (95%CI -55 to -10)], and tended to be associated with birth weight [difference -38 grams (95%CI -89 to 13)]. This association persisted after adjustment for smoking quantity.

CONCLUSIONS

Our results suggest that maternal rs1051730 genotype modifies the associations of maternal smoking during pregnancy with impaired fetal growth in length and weight. These results should be considered as hypothesis generating and indicate the need for large-scale genome wide association studies focusing on gene--fetal smoke exposure interactions.

Is probabilistic bias analysis approximately Bayesian?

Case-control studies are particularly susceptible to differential exposure misclassification when exposure status is determined following incident case status. Probabilistic bias analysis methods have been developed as ways to adjust standard effect estimates based on the sensitivity and specificity of exposure misclassification. The iterative sampling method advocated in probabilistic bias analysis bears a distinct resemblance to a Bayesian adjustment; however, it is not identical. Furthermore, without a formal theoretical framework (Bayesian or frequentist), the results of a probabilistic bias analysis remain somewhat difficult to interpret. We describe, both theoretically and empirically, the extent to which probabilistic bias analysis can be viewed as approximately Bayesian. Although the differences between probabilistic bias analysis and Bayesian approaches to misclassification can be substantial, these situations often involve unrealistic prior specifications and are relatively easy to detect. Outside of these special cases, probabilistic bias analysis and Bayesian approaches to exposure misclassification in case-control studies appear to perform equally well.

A citywide smoking ban reduced maternal smoking and risk for preterm births: a Colorado natural experiment

BACKGROUND

Few reports exist on the association of a public smoking ban with fetal outcomes and maternal smoking in the United States. We sought to evaluate the effect of a citywide smoking ban in comparison to a like municipality with no such ban in Colorado on maternal smoking and subsequent fetal birth outcomes.

METHODS

A citywide smoking ban in Colorado provided a natural experiment. The experimental citywide smoking ban site was implemented in Pueblo, Colorado. A comparison community was chosen that had no smoking ban, El Paso County, with similar characteristics of population, size, and geography. The two sites served as their own controls, as each had a preban and postban retrospective observation period: preban was April 1, 2001, to July 1, 2003; postban was April 1, 2004, to July 1, 2006. Outcomes were maternal smoking (self-report), low birth weight (LBW) (defined as <2500 g or as <3000 g), and preterm births (<37 weeks gestation) in singleton births from mothers residing in these cities and reported to the State Department of Public Health. A difference-in-differences estimator was used to account for site and temporal trends in multivariate models.

RESULTS

Compared to El Paso County preban, the odds of maternal smoking and preterm births were, respectively, 38% (p<0.05) and 23% (p<0.05) lower in Pueblo. The odds for LBW births decreased by 8% for <3000 g and increased by 8.4% for <2500 g; however, neither was significant.

CONCLUSIONS

This is the first evidence in the United States that population-level intervention using a smoking ban improved maternal and fetal outcomes, measured as maternal smoking and preterm births.

Association of self-reported passive smoking in pregnant women with cotinine level of maternal urine and umbilical cord blood at delivery

Passive smoking during pregnancy leads to adverse effects on mother and infant. The present investigation was designed to evaluate the association between maternal reported passive smoking with the cotinine concentration of maternal urine and umbilical cord blood at delivery and to determine the accuracy of maternal reporting of exposure to cigarette smoke during pregnancy. This was a cross-sectional study. From the 108 non-smoker pregnant women who were referred for delivery, 54 were passive smokers. Urine samples were collected from the mothers in the delivery room and blood samples after birth were taken from the umbilical cord. Passive smoking was evaluated through questionnaire and cotinine level of urine and umbilical cord blood. The geometric mean cotinine concentration of the maternal urine and the umbilical cord serum were, respectively, 27.4 ± 29.96 ng/mL and 3.71 ± 1.22 ng/mL in the exposed group (P < 0.001) and 0.75 ± 2.29 and 0.40 ± 0.63 in the non-exposed group (P < 0.001). There was a statistically significant correlation between maternal urinary and umbilical cord serum level of cotinine (P < 0.001, r = 0.58). Significant associations were shown between maternal reports of exposure to cigarette smoking with cotinine level of urine (kappa = 96%) and umbilical cord (kappa = 98%) (P < 0.001). This study shows that the pregnant woman's report of passive smoking during pregnancy in Iran is accurate. The questionnaire is an appropriate method to evaluate smoke exposure and could replace cotinine measurement.

Folic acid supplements modify the adverse effects of maternal smoking on fetal growth and neonatal complications

Maternal smoking during pregnancy leads to increased risks of neonatal complications. The use of folic acid supplements might reduce the adverse effects of smoking. We examined whether folic acid supplement use modifies the associations of maternal smoking with first trimester plasma homocysteine concentrations, fetal growth characteristics, and risks of neonatal complications. The associations were studied in 6294 mothers participating in a prospective population-based cohort study in The Netherlands. Main outcomes measurements were first trimester plasma homocysteine concentrations, fetal growth characteristics, and neonatal complications, including preterm birth, low birth weight, and small-size-for-gestational-age. Continued maternal smoking was associated with higher first trimester plasma homocysteine concentrations [difference 0.52 μmol/L (95% range = 0.20, 2.14)], lower third trimester fetal weight (difference -44 g (95% CI = -57, -31)], and birth weight [difference -148 g (95% CI = -179, -118)]. There were significant interactions between maternal smoking and folic acid supplements on all outcome measures (all P-interaction < 0.040). Among mothers who continued smoking during pregnancy, those who did not use folic acid supplements had the highest risk of delivering a child with low birth weight [OR = 3.45 (95% CI = 1.25, 9.54)] compared to those who did use periconceptional folic acid supplements. No significant effects were observed for the risks of preterm birth and small-size-for-gestational-age at birth. Our results suggest that some adverse effects of maternal smoking on fetal growth and neonatal outcomes might be reduced by the use of folic acid supplements. The observed interaction seems to be mainly driven by smoking in the first trimester only.

Assessment of maternal smoking status during pregnancy and the associations with neonatal outcomes

INTRODUCTION

Single assessment of smoking during pregnancy may lead to misclassification due to underreporting or failure of smoking cessation. We examined the percentage of mothers who were misclassified in smoking status based on single assessment, as compared with repeated assessment, and whether this misclassification leads to altered effect estimates for the associations between maternal smoking and neonatal complications.

METHODS

This study was performed in 5,389 mothers participating in a prospective population-based cohort study in the Netherlands. Smoking status was assessed 3 times during pregnancy using questionnaires. Information on birth weight and neonatal complications was obtained from hospital records.

RESULTS

For categorizing mothers per smoking status, Cohen's Kappa coefficient was .86 (p < .001) between single and repeated assessments. Of all mothers who reported nonsmoking or first trimester-only smoking in early pregnancy, 1.7% (70 of 4,141) and 33.7% (217 of 643), respectively, were reclassified to continued smoking based on repeated assessment. Younger, shorter lower educated mothers who had non-European ethnicity experienced more stress, consumed more alcohol, and did not use folic acid supplements had higher risk of underreporting their smoking status or failure of smoking cessation. Marginal differences were found on the associations of maternal smoking with neonatal complications between single or repeated assessment.

CONCLUSIONS

Our results suggest that single assessment of smoking during pregnancy leads to underestimation of the continued smoking prevalence, especially among mothers who reported quitting smoking in first trimester. However, this underestimation does not materially change the effect estimates for the associations between maternal smoking and neonatal outcomes.

Maternal tobacco use is associated with increased markers of oxidative stress in the placenta

OBJECTIVE

We sought to extend our prior observations and histopathologically characterize key metabolic enzymes (CYP1A1) with markers of oxidative damage in the placental sections from smokers.

STUDY DESIGN

Placental specimens were collected from term singleton deliveries from smokers (n = 10) and nonsmokers (n = 10) and subjected to a detailed histopathological examination. To quantify the extent of oxidative damage, masked score-graded (0-6) histopathology against 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxydeoxyguanisine (8-OHdG) was performed. Minimal significance (P < .05) was determined with a Fisher's exact and a 2-tailed Student t test as appropriate.

RESULTS

We observed a significant increase in the presence of syncytial knots in placentas from smokers (70% vs 10%, P = .02). These gross observations were accompanied by a significant aberrant placental aromatic hydrocarbon metabolism (increased CYP1A1, 4.4 vs 2.1, P = .002) in addition to evidence of oxidative damage (4-HNE 3.4 vs 1.1, P = .00005; 8-OHdG 4.9 vs 3.1, P = .0038).

CONCLUSION

We observed a strong association between maternal tobacco use and aberrant placental metabolism, syncytial knot formation, and multiple markers of oxidative damage.