Contribution of smoking during pregnancy to inequalities in stillbirth and infant death in Scotland 1994-2003: retrospective population based study using hospital maternity records

The Effectiveness of Text Support for Stopping Smoking in Pregnancy (MiQuit): Multi-Trial Pooled Analysis Investigating Effect Moderators and Mechanisms of Action

INTRODUCTION

Digital cessation support appeals to pregnant smokers. In two pooled RCTs, MiQuit, a pregnancy-specific tailored text messaging intervention, did not show effectiveness for validated prolonged abstinence. However, secondary outcomes and potential moderators and mediators have not been investigated. We aimed to determine, using pooled RCT data: (1) MiQuit effectiveness on a range of smoking outcomes; (2) whether baseline tobacco dependence or quit motivation moderate effectiveness; (3) whether hypothesized mechanisms of action (quitting determination, self-efficacy, baby harm beliefs, lapse prevention strategies) mediate effectiveness.

METHODS

Pooled data analysis from two procedurally identical RCTs comparing MiQuit (N = 704) to usual care (N = 705). Participants were smokers, <25 weeks pregnant, recruited from 40 English antenatal clinics. Outcomes included self-reported 7-day abstinence at 4 weeks post-baseline and late pregnancy, and prolonged abstinence. Late pregnancy outcomes were also biochemically validated. We used hierarchical regression and structural equation modeling.

RESULTS

MiQuit increased self-reported, 7-day abstinence at 4 weeks (OR = 1.73 [95% CI 1.10-2.74]) and was borderline significant at late pregnancy (OR = 1.34 [0.99-1.82]) but not for prolonged or validated outcomes. Effectiveness was not moderated by baseline dependence (heaviness of smoking "low" vs. "moderate-high") or motivation (planning to quit ≤30 days [high] vs. >30 days [low]), but effects on self-reported outcomes were larger for the high motivation sub-group. MiQuit had a small effect on mean lapse prevention strategies (MiQuit 8.6 [SE 0.17], UC 8.1 [SE 0.17]; P = .030) but not other mechanisms.

CONCLUSIONS

MiQuit increased short-term but not prolonged or validated abstinence and may be most effective for those motivated to quit sooner.

IMPLICATIONS

Digital cessation support appeals to pregnant smokers. MiQuit, a tailored, theory-guided text messaging program for quitting smoking in pregnancy, has not shown effectiveness for validated prolonged abstinence in two previous RCTs but its impact on other smoking outcomes and potential mechanisms of action are unknown. When pooling trial data, MiQuit increased self-reported short-term abstinence, including making a quit attempt and abstinence at 4-week follow-up, but not late pregnancy, sustained, or validated abstinence. MiQuit appeared effective at late pregnancy for participants with high quitting motivation, but its mechanisms of action remain uncertain. Additional support components are likely required to enhance effectiveness.

Development of "Baby, Me, & NRT": A Behavioral Intervention to Improve the Effectiveness of Nicotine Replacement Therapy in Pregnancy

BACKGROUND

The effectiveness of Nicotine Replacement Therapy (NRT) for smoking cessation in pregnancy is limited by inconsistent and incorrect use. This paper describes the development process for "Baby, Me, & NRT", a novel pregnancy-specific intervention aimed at enhancing adherence to NRT.

METHODS

An integrated approach to intervention development was used, combining evidence, theory, stakeholders' feedback, and tailoring principles. The process involved six iterative steps: (1) synthesizing relevant published evidence and guidance, (2) collecting primary qualitative data on barriers and facilitators to NRT adherence along with potential intervention design features, (3) identifying relevant behavioral theories and mapping the evidence against these, (4) prioritizing behavioral determinants identified in steps 1 and 2, generating intervention objectives, and identifying behavior change techniques which target the prioritized determinants, (5) consulting with stakeholders on intervention components, key content and tailoring features, and (6) producing a prototype intervention along with implementation guidance.

RESULTS

The prototype intervention comprises of a multi-component, 1-month cessation programme, which includes six enhanced behavioral support sessions delivered by a trained advisor, tailored text messages, a website, and an illustrated booklet. It promotes the uptake of high-dose and combination NRT, emphasizes the importance of adherence, addresses motivation to use NRT, proactively helps problem solve NRT use issues, and provides guidance on preventing and managing smoking lapses.

CONCLUSION

The development process generated an evidence- and theory-guided intervention, designed with stakeholder input, aimed at improving NRT effectiveness for smoking cessation in pregnancy. The prototype intervention has since been optimized and is being evaluated in a randomized controlled trial.

Helping pregnant smokers quit: a multi-centre randomised controlled trial of electronic cigarettes versus nicotine replacement therapy

Background

Some pregnant smokers try e-cigarettes, but effectiveness and safety of such use are unknown.

Objectives

To compare effectiveness and safety of nicotine patches and e-cigarettes in pregnancy.

Design

A pragmatic multi-centre randomised controlled trial.

Setting

Twenty-three hospitals across England, and a Stop Smoking Service in Scotland.

Participants

One thousand one hundred and forty pregnant daily smokers (12-24 weeks' gestation) motivated to stop smoking, with no strong preference for using nicotine patches or e-cigarettes.

Interventions

Participants in the e-cigarette arm were posted a refillable e-cigarette device with two 10 ml bottles of tobacco-flavoured e-liquid (18 mg nicotine). Participants in the nicotine patches arm were posted a 2-week supply of 15 mg/16-hour nicotine patches. Supplies were provided for up to 8 weeks. Participants sourced further supplies themselves as needed. Participants in both arms received support calls prior to their target quit date, on the quit date, and weekly for the next 4 weeks.

Outcome measures

The primary outcome was validated prolonged abstinence at the end of pregnancy. Participants lost to follow-up or not providing biochemical validation were included as non-abstainers. Secondary outcomes included self-reported abstinence at different time points, treatment adherence and safety outcomes.

Results

Only 55% of self-reported abstainers mailed back useable saliva samples. Due to this, validated sustained abstinence rates were low (6.8% vs. 4.4% in the e-cigarettes and nicotine patches arms, respectively, risk ratio = 1.55, 95% confidence interval 0.95 to 2.53; Bayes factor = 2.7). In a pre-specified sensitivity analysis that excluded abstainers using non-allocated products, the difference became significant (6.8% vs. 3.6%, risk ratio = 1.93, 95% confidence interval 1.14 to 3.26; Bayes factor = 10). Almost a third of the sample did not set a target quit date and the uptake of support calls was low, as was the initial product use. At end of pregnancy, 33.8% versus 5.6% of participants were using their allocated product in the e-cigarettes versus nicotine patches arm (risk ratio = 6.01, 95% confidence interval 4.21 to 8.58). Regular use of e-cigarettes in the nicotine patches arm was more common than use of nicotine replacement products in the e-cigarette arm (17.8% vs. 2.8%). Rates of adverse events and adverse birth outcomes were similar in the two study arms, apart from participants in the e-cigarette arm having fewer infants with low birthweight (<2500 g) (9.6% vs. 14.8%, risk ratio = 0.65, 95% confidence interval 0.47 to 0.90; Bayes factor = 10.3).

Limitations

Low rates of validation reduced the study power. A substantial proportion of participants did not use the support on offer sufficiently to test its benefits. Sample size may have been too small to detect differences in less frequent adverse effects.

Conclusions

E-cigarettes were not significantly more effective than nicotine patches in the primary analysis, but when e-cigarettes use in the nicotine patches arm was accounted for, e-cigarettes were almost twice as effective as patches in all abstinence outcomes. In pregnant smokers seeking help, compared to nicotine patches, e-cigarettes are probably more effective, do not pose more risks to birth outcomes assessed in this study and may reduce the incidence of low birthweight.

Future work

Routine monitoring of smoking cessation and birth outcomes in pregnant women using nicotine patches and e-cigarettes and further studies are needed to confirm these results.

Trial registration

This trial is registered as ISRCTN62025374 and Eudract 2017-001237-65.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 13. See the NIHR Journals Library website for further project information.

Associations between intimate partner violence and adverse birth outcomes during pregnancy: a systematic review and meta-analysis

Background

Intimate partner violence (IPV) has been associated with an elevated risk of multiple adverse birth outcomes, yet little is known about how specific IPV influences adverse birth outcomes. The aim of this study was to examine the association between IPV during pregnancy and adverse birth outcomes (i.e., preterm birth, low birth weight, and stillbirth).

Methods

Systematic searches were conducted using four databases: EMBASE, Web of Science, PubMed, and CINAHL for observational studies published from 1 January 2011 to 31 August 2021. Two reviewers independently carried out the literature search, study selection, data extraction, assessment of the study, and risk of bias assessment; disagreements were resolved by a third reviewer. A random-effect model was used to calculate the odds ratio (OR) with a 95% confidence interval (CI) for preterm birth, low birth weight, and stillbirth. I² statistic accompanied by chi-square p-value was used to assess heterogeneity, and funnel plot and Peter's test were used to assess publication bias.

Results

In total, 23 studies met the inclusion criterion. IPV was associated with preterm birth (OR = 1.84; 95% CI: 1.37-2.49; I² = 88%), low birth weight (OR = 2.73; 95% CI: 1.66-4.48; I² = 95%), and stillbirth (OR = 1.74; 95% CI: 0.86-3.54; I² = 64%). We attained comparable results among all specific IPV including physical, sexual, emotional, and mixed.

Conclusion

Intimate partner violence and specific IPV during pregnancy were significantly associated with adverse birth outcomes, especially for physical IPV. An urgent need for greater action to prevent or intervene in IPV during pregnancy is warranted.

Systematic review registration

CRD42021282936, https://www.crd.york.ac.uk/prospero/.

Dose-response association between maternal smoking during pregnancy and the risk of infant death: a nationwide, population-based, retrospective cohort study

Background

Association of timing and intensity of maternal smoking during pregnancy with all-cause and cause-specific infant death remains inconclusive. We aimed to examine the dose-response association of maternal smoking during each of the three trimesters of pregnancy with all-cause and cause-specific infant death.

Methods

In this nationwide, population-based, retrospective cohort study, data were extracted from the U.S. National Vital Statistics System, 2015-2019. We included mother-infant pairs after excluding twin or multiple births, newborns with gestation age <37 weeks and those with low birthweight, mothers aged <18 years or ≥50 years, mothers with pre-existing hypertension or diabetes, and those with missing values for variables of interest. Poisson regression models were used to examine the association of different intensities and doses of maternal smoking during each of the three trimesters of pregnancy with all-cause and cause-specific infant death attributed to congenital anomalies, preterm birth, other perinatal conditions, sudden unexpected infant death, and infection.

Findings

A total of 13,524,204 mother-infant pairs were included in our analyses. Maternal smoking during the entire pregnancy was associated with infant all-cause death (relative risk [RR] 1.88, 95% confidence interval [95% CI] 1.79-1.97), cause-specific death due to preterm birth (1.57, 1.25-1.98), perinatal conditions excluding preterm birth (1.35, 1.10-1.65), sudden unexpected infant death (2.56, 2.40-2.73), and infection (1.51, 1.20-1.88). The risk of infant all-cause death (RR values from 1.80 to 2.15) and cause-specific infant death by preterm birth (RR values from 1.42 to 1.74), perinatal conditions excluding preterm birth (RR values from 1.46 to 1.53), sudden unexpected infant death (RR values from 2.37 to 3.04), and infection (RR values from 1.48 to 2.69) increased with the intensity of maternal cigarette use during the entire pregnancy from 1-5 to ≥11 cigarettes. Compared with mothers who smoked during their entire pregnancy, those who smoked in the first trimester and then quit smoking in the second or third trimesters of pregnancy had a reduced risk of infant all-cause death (0.71, 0.65-0.78) and sudden unexpected infant death (0.64, 0.57-0.72).

Interpretation

There was a dose-response association of maternal cigarette use during each of the three trimesters of pregnancy with all-cause and cause-specific infant death. In addition, mothers who are smokers in the first trimester and then quit smoking in the subsequent two trimesters are at decreased risk of infant all-cause mortality and sudden unexpected infant death compared with those who smoked during the entire pregnancy. These findings suggest that there is no safe level of maternal smoking in any trimester of pregnancy and maternal smokers should stop smoking during pregnancy to improve the survival of infants.

Funding

Youth Team of Humanistic and Social Science and the Innovation Team of the "Climbing" Program of Shandong University (20820IFYT1902).

European progress in working towards a tobacco-free generation

Children have the right to grow up free from the hazards associated with tobacco smoking. Tobacco smoke exposure can have detrimental effects on children's health and development, from before birth and beyond. As a result of effective tobacco control policies, European smoking rates are steadily decreasing among adults, as is the proportion of adolescents taking up smoking. Substantial variation however exists between countries, both in terms of smoking rates and regarding implementation, comprehensiveness and enforcement of policies to address smoking and second-hand smoke exposure. This is important because comprehensive tobacco control policies such as smoke-free legislation and tobacco taxation have extensively been shown to carry clear health benefits for both adults and children. Additional policies such as increasing the legal age to buy tobacco, reducing the number of outlets selling tobacco, banning tobacco display and advertising at the point-of-sale, and introducing plain packaging for tobacco products can help reduce smoking initiation by youth. At societal level, health professionals can play an important role in advocating for stronger policy measures, whereas they also clearly have a duty to address smoking and tobacco smoke exposure at the patient level. This includes providing cessation advise and referring to effective cessation services.Conclusion: Framing of tobacco exposure as a child right's issue and of comprehensive tobacco control as a tool to work towards the ultimate goal of reaching a tobacco-free generation can help accelerate European progress to curb the tobacco epidemic. What is Known: • Tobacco exposure is associated with a range of adverse health effects among babies and children. • Comprehensive tobacco control policies helped bring down smoking rates in Europe and benefit child health. What is New: • Protecting the rights and health of children provides a strong starting point for tobacco control advocacy. • The tobacco-free generation concept helps policy-makers set clear goals for protecting future generations from tobacco-associated harms.

Association Between Income and Perinatal Mortality in the Netherlands Across Gestational Age

Importance

The association between household income and perinatal health outcomes has been understudied. Examining disparities in perinatal mortality within strata of gestational age and before and after adjusting for birth weight centile can reveal how the income gradient is associated with gestational age, birth weight, and perinatal mortality.

Objectives

To investigate the association between household income and perinatal mortality, separately by gestational age strata and time of death, and the potential role of birth weight centile in mediating this association.

Design, Setting, and Participants

This cross-sectional study used individually linked data of all registered births in the Netherlands with household-level income tax records. Singletons born between January 1, 2004, and December 31, 2016, at 24 weeks to 41 weeks 6 days of gestation with complete information on birth outcomes and maternal characteristics were studied. Data analysis was performed from March 1, 2018, to August 30, 2021.

Exposures

Household income rank (adjusted for household size).

Main Outcomes and Measures

Perinatal mortality, stillbirth (at ≥24 weeks of gestation), and early neonatal mortality (at ≤7 days after birth). Disparities were expressed as bottom-to-top ratios of projected mortality among newborns with the poorest 1% of households vs those with the richest 1% of households. Generalized additive models stratified by gestational age categories, adjusted for potential confounding by maternal age at birth, maternal ethnicity, parity, sex, and year of birth, were used. Birth weight centile was included as a potential mediator.

Results

Among 2 036 431 singletons in this study (1 043 999 [51.3%] males; 1 496 579 [73.5%] with mother of Dutch ethnicity), 121 010 (5.9%) were born before 37 weeks of gestation, and 8720 (4.3 deaths per 1000) died during the perinatal period. Higher household income was positively associated with higher rates of perinatal survival, with an unadjusted bottom-to-top ratio of 2.18 (95% CI, 1.87-2.56). The bottom-to-top ratio decreased to 1.30 (95% CI, 1.22-1.39) after adjustment for potential confounding factors and inclusion of birth weight centile as a possible mediator. The fully adjusted ratios were lower for stillbirths (1.27; 95% CI, 1.20-1.36) than for early neonatal deaths (1.35; 95% CI, 1.14-1.66). Inequalities in perinatal mortality were found for newborns at greater than 26 weeks of gestation but not between 24 and 26 weeks of gestation (fully adjusted bottom-to-top ratio, 0.89; 95% CI, 0.77-1.04).

Conclusions and Relevance

The results of this large nationally representative cross-sectional study suggest that a large part of the increased risk of perinatal mortality among low-income women is mediated via a lower birth weight centile. The absence of disparities at very low gestational ages suggests that income-related risk factors for perinatal mortality are less prominent at very low gestational ages. Further research should aim to understand which factors associated with preterm birth and lower birth weight can reduce inequalities in perinatal mortality.

Vaping in Pregnancy: A Systematic Review

INTRODUCTION

Smoking in pregnancy increases the risk of negative health outcomes. Vaping can be effective for smoking cessation in nonpregnant populations. We conducted a systematic review of vaping in pregnancy, covering prevalence, patterns of use, reasons for use, smoking cessation, and health effects.

METHODS

Five academic databases were searched on 17 February 2020. Studies reporting prevalence, patterns, reasons, cessation, or health effects of vaping in pregnancy were included; animal and in vitro studies were excluded. A narrative review was used, with risk of bias assessed using Hoy and colleague's tool, the Newcastle-Ottawa scale, and the Consolidated Criteria for reporting Qualitative Research.

RESULTS

Twenty-three studies were identified: 11 survey, 7 qualitative, 3 cohort, and 2 secondary analyses of randomized clinical trials. Prevalence of vaping in pregnancy (four studies) was between 1.2% and 7.0% overall, and <1% among nonsmokers. Twelve studies reported patterns of use, but findings were inconsistent. Twelve of 14 studies asking why pregnant women vaped reported that most vaped to reduce or quit smoking. Mixed findings were reported from six studies on smoking cessation. Of three studies with health-related outcomes, two were underpowered and one reported similar birthweights for babies born to nonsmokers and women who vaped, with both higher (p < .0001) than the birthweight of babies born to smokers.

CONCLUSIONS

There were insufficient data to draw conclusions about prevalence, patterns, and effects of vaping in pregnancy on smoking cessation. The limited literature suggests that vaping in pregnancy has little or no effect on birthweight.

IMPLICATIONS

Smoking causes many negative health outcomes for pregnant women and to babies born to people who smoke. There remains a paucity of research on the effects of vaping in pregnancy. There is, however, the potential for vaping products to reduce the negative health outcomes associated with smoking. More research is needed to develop an evidence base in this area.

Social Determinants of Cigarette Smoking among American Women during Pregnancy

Educational attainment is among the most substantial protective factors against cigarette smoking, including during pregnancy. Although Minorities’ Diminished Returns (MDRs) of educational attainment, defined as weaker protective effect of education for racial and ethnic minority groups compared to Non-Hispanic Whites, has been demonstrated in previous studies; such MDRs are not tested for cigarette smoking during pregnancy. To better understand the relevance of MDRs to tobacco use during pregnancy, this study had three aims: firstly, to investigate the association between educational attainment and cigarette smoking in pregnant women; secondly, to compare racial and ethnic groups for the association between educational attainment and cigarette smoking; and thirdly, to explore the mediating effect of poverty status on such MDRs, among American adults during pregnancy. This cross-sectional study explored a nationally representative sample of pregnant American women (n = 338), which was taken from the Population Assessment of Tobacco and Health (PATH; 2013). Current smoking was the outcome. Educational attainment was the independent variable. Region and age were the covariates. Poverty status was the mediator. Race and ethnicity were the effect modifiers. Overall, a higher level of educational attainment (OR = 0.54, p < 0.05) was associated with lower odds of current smoking among pregnant women. Race (OR = 2.04, p < 0.05) and ethnicity (OR = 2.12, p < 0.05) both showed significant interactions with educational attainment on smoking, suggesting that the protective effect of educational attainment against smoking during pregnancy is smaller for Blacks and Hispanics than Non-Hispanic Whites. Poverty status fully mediated the above interactions. In the United States, highly educated pregnant Black and Hispanic women remain at higher risk of smoking cigarettes, possibly because they are more likely to live in poverty, compared to their White counterparts. The results suggest the role that labor market discrimination has in explaining lower returns of educational attainment in terms of less cigarette smoking by racial and ethnic minority pregnant women.

Fetal safety of nicotine replacement therapy in pregnancy: systematic review and meta-analysis

BACKGROUND AND AIMS

Smoking in pregnancy causes substantial avoidable harm to mothers and offspring; nicotine replacement therapy (NRT) may prevent this, and is used to help women to quit. A recently updated Cochrane Review of randomized controlled trials (RCTs) investigating impacts of NRT in pregnancy focuses primarily on efficacy data, but also reports adverse impacts from NRT. Here we identify and summarize NRT impacts on adverse pregnancy outcomes reported in non-randomized controlled trials (non-RCTs).

METHODS

Systematic reviews and meta-analyses of RCTs and non-RCT studies of NRT in pregnancy, with design-specific risk of bias assessment and grading of recommendations, assessment, development and evaluations (GRADE) criteria applied to selected outcomes.

FINDINGS

Relevant Cochrane Review findings are reported alongside those from this new review. Seven RCTs were included; n = 2340. Nine meta-analyses were performed; non-statistically significant estimates indicated potentially reduced risk from NRT compared with smoking for mean birth weight, low birth weight, preterm birth, intensive care admissions, neonatal death, congenital anomalies and caesarean section and potentially increased risks for miscarriage and stillbirth. GRADE assessment for mean birth weight and miscarriage outcomes indicated 'low' confidence in findings. Twenty-three non-RCTs were included; n = 931 163. Eleven large studies from five routine health-care cohorts reported clinical outcomes; 12 small studies investigated mainly physiological outcomes within in-patient women given NRT. Findings from meta-analyses for congenital anomalies, stillbirth and preterm birth were underpowered and not in a consistent direction; GRADE assessment of confidence in findings was 'very low'. Routine health-care studies were of higher quality, but implications of reported findings were unclear as there was inadequate measurement and reporting of women's smoking.

CONCLUSIONS

Available evidence from randomized controlled trials and non-randomized comparative studies does not currently provide clear evidence as to whether maternal use of nicotine replacement therapy during pregnancy is harmful to the fetus.

Associations between maternal age and socioeconomic status with smoking during the second and third trimesters of pregnancy: a register-based study of 932 671 women in Finland from 2000 to 2015

OBJECTIVES

This study aimed to explore the association between maternal age and smoking during the second and third trimesters of pregnancy across socioeconomic groups and to evaluate the interacting effect of maternal age and socioeconomic status on smoking with a view to informing public health interventions.

DESIGN

This is a register-based study.

SETTINGS

Data from the Finnish Medical Birth Register were cross-linked with background data from Statistics Finland.

PARTICIPANTS

The information of 932 671 pregnant women who gave birth in Finland from 2000 to 2015.

MAIN OUTCOME MEASURES

Maternal smoking during the second and third trimesters of pregnancy by occupation and maternal age.

RESULTS

The proportion of women who smoked during the second and third trimesters of pregnancy was 10.5%. Using women 30-34 years as the reference group, adjusted ORs (aOR) and 95% CIs for smoking were 6.02 (5.81 to 6.24) in women below 20 years and 2.77 (2.71 to 2.84) in women 20 to 24 years. The prevalence of smoking across socioeconomic groups compared with upper-level employees increased, peaking for women in manual occupations (aOR 3.39, 95% CI 3.25 to 3.52) and unemployed women (aOR 4.49, 95% CI 4.30 to 4.68). Significant interactions on the additive scale with the relative excess risk due to interaction >2 were found for unemployed women aged 25-29 years and for teenage mothers and mothers aged 20-24 years across all socioeconomic groups, but not for self-employed women.

CONCLUSIONS

Smoking during the second and third trimesters of pregnancy was most common among teenage mothers across all socioeconomic groups. The association between maternal age and smoking differed by socioeconomic status for young mothers. Interventions should address a wider range of maternal risk factors among young mothers with low socioeconomic status and simultaneously target a broader number of women who smoke during the pregnancy.

Maternal smoking during pregnancy affects adult onset of asthma in offspring: a follow up from birth to age 46 years

RATIONALE

Environmental tobacco smoke (ETS) exposure increases asthma risk in children. There is limited knowledge of prenatal ETS for adult-onset asthma.

OBJECTIVES

To determine the association between prenatal ETS and adult onset asthma.

MEASUREMENTS AND MAIN RESULTS

The questionnaire and clinical data of 5200 people, free of physician-diagnosed asthma by 31 years of age, who were included in the Northern Finland Birth Cohort 1966 Study was used. The association of maternal smoking during the last 3 months of pregnancy with onset of physician-diagnosed asthma and with lung function in adult offspring was studied using adjusted multivariate regression analyses. The cumulative incidence of physician-diagnosed asthma between the ages of 31 and 46 years was 5.1% among men and 8.8% among women. Gestational smoke exposure was associated with adult-onset asthma among offspring (adjusted OR 1.54, 95% CI 1.04-2.29), namely among offspring who reported either past non-diagnosed asthma (OR 9.63, 95% CI 2.28-40.67) or past cough with wheeze (3.21, 95% CI 1.71-6.05). A significant association was detected between gestational smoke exposure and the offspring's forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio at 31 years of age. In offspring with the haplotype rs11702779-AA of RUNX1, gestational smoke exposure was associated with adult-onset asthma (5.53, 95% CI 2.11-14.52, adjusted p-value for interaction 0.10).

CONCLUSION

Maternal smoking during pregnancy is associated with the cumulative incidence of asthma in offspring between the ages of 31 and 46 years. The association was accentuated in offspring who at age 31, reported having past respiratory problems and/or who had haplotype rs11702779-AA. A reduction in FEV₁/FVC ratio was also observed at age 31 years in offspring with gestational smoke exposure. These results could reflect the early vulnerability of offspring's airways to ETS and its putative long-term effects.

Persisting inequalities in birth outcomes related to neighbourhood deprivation

INTRODUCTION

Health inequalities can be observed in early life as unfavourable birth outcomes. Evidence indicates that neighbourhood socioeconomic circumstances influence health. However, studies looking into temporal trends in inequalities in birth outcomes including neighbourhood socioeconomic conditions are scarce. The aim of this work was to study how inequalities in three different key birth outcomes have changed over time across different strata of neighbourhood deprivation.

METHODS

Nationwide time trends ecological study with area-level deprivation in quintiles as exposure. The study population consisted of registered singleton births in the Netherlands 2003-2017 between 24 and 41 weeks of gestation. Outcomes used were perinatal mortality, premature birth and small for gestational age (SGA). Absolute rates for all birth outcomes were calculated per deprivation quintile. Time trends in birth outcomes were examined using logistic regression models. To investigate relative inequalities, rate ratios for all outcomes were calculated per deprivation quintile.

RESULTS

The prevalence of all unfavourable birth outcomes decreased over time: from 7.2 to 4.1 per 1000 births for perinatal mortality, from 61.8 to 55.6 for premature birth, and from 121.9 to 109.2 for SGA. Inequalities in all birth outcomes have decreased in absolute terms, and the decline was largest in the most deprived quintile. Time trend analyses confirmed the overall decreasing time trends for all outcomes, which were significantly steeper for the most deprived quintile. In relative terms however, inequalities remained fairly constant.

CONCLUSION

In absolute terms, inequalities in birth outcomes by neighbourhood deprivation in the Netherlands decreased between 2003 and 2017. However, relative inequalities remained persistent.

Inequalities and stillbirth in the UK: a meta-narrative review

OBJECTIVE

To review what is known about the relationship between stillbirth and inequalities from different disciplinary perspectives to inform stillbirth prevention strategies.

DESIGN

Systematic review using the meta-narrative method.

SETTING

Studies undertaken in the UK.

DATA SOURCES

Scoping phase: experts in field, exploratory electronic searches and handsearching. Systematic searches phase: Nine databases with no geographical or date restrictions. Non-English language studies were excluded.

STUDY SELECTION

Any investigation of stillbirth and inequalities with a UK component.

DATA EXTRACTION AND SYNTHESIS

Three authors extracted data and assessed study quality. Data were summarised, tabulated and presented graphically before synthesis of the unfolding storyline by research tradition; and then of the commonalities, differences and interplays between narratives into resultant summary meta-themes.

RESULTS

Fifty-four sources from nine distinctive research traditions were included. The evidence of associations between social inequalities and stillbirth spanned 70 years. Across research traditions, there was recurrent evidence of the social gradient remaining constant or increasing, fuelling repeated calls for action (meta-theme 1: something must be done). There was less evidence of an effective response to these calls. Data pertaining to socioeconomic, area and ethnic disparities were routinely collected, but not consistently recorded, monitored or reported in relation to stillbirth (meta-theme 2: problems of precision). Many studies stressed the interplay of socioeconomic status, deprivation or ethnicity with aggregated factors including heritable, structural, environmental and lifestyle factors (meta-theme 3: moving from associations towards intersectionality and intervention(s)). No intervention studies were identified.

CONCLUSION

Research investigating inequalities and stillbirth in the UK is underdeveloped. This is despite repeated evidence of an association between stillbirth risk and poverty, and stillbirth risk, poverty and ethnicity. A specific research forum is required to lead the development of research and policy in this area, which can harness the multiple relevant research perspectives and address the intersections between different policy areas.

PROSPERO REGISTRATION NUMBER

CRD42017079228.

Comparison of nicotine exposure during pregnancy when smoking and abstinent with nicotine replacement therapy: systematic review and meta-analysis

BACKGROUND AND AIMS

Smoking during pregnancy is strongly associated with negative pregnancy and perinatal outcomes. Some guidelines recommend nicotine replacement therapy (NRT) for smoking cessation during pregnancy, but adherence with NRT is generally poor and could be partially explained by nicotine-related safety concerns. We compared pregnant women's cotinine and nicotine exposures from smoking with those when they were abstinent from smoking and using NRT.

DESIGN

Systematic review with meta-analysis and narrative reporting. Twelve studies were included: in most, only one type of NRT was used. Seven were quality-assessed and judge of variable quality.

SETTING

Studies from any setting that reported nicotine or cotinine levels when smoking and later when abstinent and using NRT.

PARTICIPANTS

Pregnant women who smoked and became abstinent but used NRT either in a cessation study or in a study investigating other impacts of NRT.

MEASUREMENTS

We quality-assessed longitudinal cohort studies using a modified version of the Newcastle-Ottawa scale. For meta-analysis, we used mean within-person differences in cotinine or nicotine levels when smoking and at later follow-up when abstinent and using NRT. Where such data were not available, we calculated differences in group mean levels and reported these narratively, indicating where data were not completely longitudinal.

FINDINGS

Of the 12 included studies, four cotinine-measuring studies (n = 83) were combined in a random effects meta-analysis; the pooled estimate for the mean difference (95% confidence intervals) in cotinine levels between when women were smoking and abstinent but using NRT was 75.3 (57.1 to 93.4) ng/ml (I2  = 42.1%, P = 0.11). Of eight narratively-described studies, six reported lower cotinine and/or nicotine levels when abstinent and using NRT; two had mixed findings, with higher levels when abstinent but using NRT reported from at least one assay time-point.

CONCLUSIONS

Pregnant women who use nicotine replacement therapy instead of smoking reduce their nicotine exposure.

Adverse neonatal outcomes and house prices in London

Objective To explore whether the average price of houses per postcode sector [sector house average prices (SHAP)] is related to perinatal outcomes and whether gestational age would be lower and mortality higher in the least expensive areas compared to the most expensive. Methods All neonatal unit admissions at King's College Hospital from 1/1/2012 to 31/12/2016 were reviewed. The SHAP was retrieved from the Land Registry and the population was divided in equal quintiles with quintiles 1 and 5 representing the most and least expensive areas, respectively. Gestational age and birth weight z-score were collected. Mortality was defined as death before discharge from neonatal care. Results Three thousand three hundred and sixty infants were included and divided in quintiles consisting of 672 infants. Gestational age was lower in quintile 5 compared to all other quintiles (adjusted P<0.001). Birthweight z-score was not significantly different between the quintiles. The SHAP was lower in the infants who died before discharge (n=92) compared to the SHAP of the infants who were alive at discharge (n=3268) (P<0.001). Infants of quintile 5 had 6 times higher risk of death before discharge from neonatal care compared to infants of quintile 1. Conclusion Low SHAPs were associated with poorer perinatal outcomes suggesting SHAP could potentially be used in perinatal populations to determine socio-economic status and associated outcomes.

Effect of tobacco control policies on perinatal and child health: a systematic review and meta-analysis

BACKGROUND

Tobacco smoking and smoke exposure during pregnancy and childhood cause considerable childhood morbidity and mortality. We did a systematic review and meta-analysis to investigate whether implementation of WHO's recommended tobacco control policies (MPOWER) was of benefit to perinatal and child health.

METHODS

We searched 19 electronic databases, hand-searched references and citations, and consulted experts to identify studies assessing the association between implementation of MPOWER policies and child health. We did not apply any language restrictions, and searched the full time period available for each database, up to June 22, 2017. Our primary outcomes of interest were perinatal mortality, preterm birth, hospital attendance for asthma exacerbations, and hospital attendance for respiratory tract infections. Where possible and appropriate, we combined data from different studies in random-effects meta-analyses. This study is registered with PROSPERO, number CRD42015023448.

FINDINGS

We identified 41 eligible studies (24 from North America, 16 from Europe, and one from China) that assessed combinations of the following MPOWER policies: smoke-free legislation (n=35), tobacco taxation (n=11), and smoking cessation services (n=3). Risk of bias was low in 23 studies, moderate in 16, and high in two. Implementation of smoke-free legislation was associated with reductions in rates of preterm birth (-3·77% [95% CI -6·37 to -1·16]; ten studies, 27 530 183 individuals), rates of hospital attendance for asthma exacerbations (-9·83% [-16·62 to -3·04]; five studies, 684 826 events), and rates of hospital attendance for all respiratory tract infections (-3·45% [-4·64 to -2·25]; two studies, 1 681 020 events) and for lower respiratory tract infections (-18·48% [-32·79 to -4·17]; three studies, 887 414 events). Associations appeared to be stronger when comprehensive smoke-free laws were implemented than when partial smoke-free laws were implemented. Among two studies assessing the association between smoke-free legislation and perinatal mortality, one showed significant reductions in stillbirth and neonatal mortality but did not report the overall effect on perinatal mortality, while the other showed no change in perinatal mortality. Meta-analysis of studies on other MPOWER policies was not possible; all four studies on increasing tobacco taxation and one of two on offering disadvantaged pregnant women help to quit smoking that reported on our primary outcomes had positive findings. Assessment of publication bias was only possible for studies assessing the association between smoke-free legislation and preterm birth, showing some degree of bias.

INTERPRETATION

Smoke-free legislation is associated with substantial benefits to child health. The majority of studies on other MPOWER policies also indicated a positive effect. These findings provide strong support for implementation of such policies comprehensively across the world.

FUNDING

Chief Scientist Office Scotland, Farr Institute, Netherlands Lung Foundation, Erasmus MC.

Going to sleep in the supine position is a modifiable risk factor for late pregnancy stillbirth; Findings from the New Zealand multicentre stillbirth case-control study

Objective

Our objective was to test the primary hypothesis that maternal non-left, in particular supine going-to-sleep position, would be a risk factor for late stillbirth (≥28 weeks of gestation).

Methods

A multicentre case-control study was conducted in seven New Zealand health regions, between February 2012 and December 2015.

Cases (n = 164) were women with singleton pregnancies and late stillbirth, without congenital abnormality. Controls (n = 569) were women with on-going singleton pregnancies, randomly selected and frequency matched for health region and gestation.

The primary outcome was adjusted odds of late stillbirth associated with self-reported going-to-sleep position, on the last night. The last night was the night before the late stillbirth was thought to have occurred or the night before interview for controls. Going-to-sleep position on the last night was categorised as: supine, left-side, right-side, propped or restless. Multivariable logistic regression adjusted for known confounders.

Results

Supine going-to-sleep position on the last night was associated with increased late stillbirth risk (adjusted odds ratios (aOR) 3.67, 95% confidence interval (CI) 1.74 to 7.78) with a population attributable risk of 9.4%. Other independent risk factors for late stillbirth (aOR, 95% CI) were: BMI (1.04, 1.01 to 1.08) per unit, maternal age ≥40 (2.88, 1.31 to 6.32), birthweight <10^th customised centile (2.76, 1.59 to 4.80), and <6 hours sleep on the last night (1.81, 1.14 to 2.88). The risk associated with supine-going-to-sleep position was greater for term (aOR 10.26, 3.00 to 35.04) than preterm stillbirths (aOR 3.12, 0.97 to 10.05).

Conclusions

Supine going-to-sleep position is associated with a 3.7 fold increase in overall late stillbirth risk, independent of other common risk factors. A public health campaign encouraging women not to go-to-sleep supine in the third trimester has potential to reduce late stillbirth by approximately 9%.

The Stillbirth Classification System for the Safe Passage Study

Objective Describe the classification system for assigning the cause of stillbirth in the Safe Passage Study, an international, multi-institutional, prospective analysis conducted by the NIAAA/NICHD-funded Prenatal Alcohol in SIDS and Stillbirth (PASS) Research Network. The study mission is to determine the role of prenatal alcohol and/or cigarette smoke exposure in adverse pregnancy outcomes, including stillbirth, in a high-risk cohort of 12,000 maternal/fetal dyads. Methods The PASS Network classification system is based upon 5 "sites of origin" for cause of stillbirth, further subdivided into mechanism subcategories; both are employed to assign an ultimate cause of death. Each PASS stillbirth was assigned a cause of death and status of sporadic versus recurrent. Adjudication involved review of maternal and obstetrical records; fetal autopsy and placental findings; and required complete consensus in each case. Two published classification systems, ie, INCODE and ReCoDe, were used for comparison. Results Causes of stillbirth classified were fetal (26%), placental (53%), external (5%), and undetermined (16%). Nine cases (47%) had placental causes of death due to maternal disorders that carry recurrence risks. There was full agreement for cause of death across the 3 classification systems in 26% of cases and partial agreement among them in 42% of cases. Conclusions The proposed PASS schema employs a user-friendly classification that provides comparable information to previously published systems. Advantages include its simplicity, mechanistic formulations, tight clinicopathologic integration, provision for an undetermined category, and its wide applicability to perinatal mortality review boards with access to information routinely collected during clinicopathologic evaluations.

Quantifying the Spatial Inequality and Temporal Trends in Maternal Smoking Rates in Glasgow

Maternal smoking is well known to adversely affect birth outcomes, and there is considerable spatial variation in the rates of maternal smoking in the city of Glasgow, Scotland. This spatial variation is a partial driver of health inequalities between rich and poor communities, and it is of interest to determine the extent to which these inequalities have changed over time. Therefore in this paper we develop a Bayesian hierarchical model for estimating the spatio-temporal pattern in smoking incidence across Glasgow between 2000 and 2013, which can identify the changing geographical extent of clusters of areas exhibiting elevated maternal smoking incidences that partially drive health inequalities. Additionally, we provide freely available software via the R package CARBayesST to allow others to implement the model we have developed. The study period includes the introduction of a ban on smoking in public places in 2006, and the results show an average decline of around 11% in maternal smoking rates over the study period.

Use of geographic indicators of healthcare, environment and socioeconomic factors to characterize environmental health disparities

BACKGROUND

An environmental health inequality is a major public health concern in Europe. However just few studies take into account a large set of characteristics to analyze this problematic. The aim of this study was to identify and describe how socioeconomic, health accessibility and exposure factors accumulate and interact in small areas in a French urban context, to assess environmental health inequalities related to infant and neonatal mortality.

METHODS

Environmental indicators on deprivation index, proximity to high-traffic roads, green space, and healthcare accessibility were created using the Geographical Information System. Cases were collected from death certificates in the city hall of each municipality in the Nice metropolitan area. Using the parental addresses, cases were geocoded to their census block of residence. A classification using a Multiple Component Analysis following by a Hierarchical Clustering allow us to characterize the census blocks in terms of level of socioeconomic, environmental and accessibility to healthcare, which are very diverse definition by nature. Relation between infant and neonatal mortality rate and the three environmental patterns which categorize the census blocks after the classification was performed using a standard Poisson regression model for count data after checking the assumption of dispersion.

RESULTS

Based on geographic indicators, three environmental patterns were identified. We found environmental inequalities and social health inequalities in Nice metropolitan area. Moreover these inequalities are counterbalance by the close proximity of deprived census blocks to healthcare facilities related to mother and newborn. So therefore we demonstrate no environmental health inequalities related to infant and neonatal mortality.

CONCLUSION

Examination of patterns of social, environmental and in relation with healthcare access is useful to identify census blocks with needs and their effects on health. Similar analyzes could be implemented and considered in other cities or related to other birth outcomes.

Women's Longitudinal Patterns of Smoking during the Pre-Conception, Pregnancy and Postnatal Period: Evidence from the UK Infant Feeding Survey

BACKGROUND

An understanding of women's longitudinal patterns of smoking during the pre-conception, pregnancy and postnatal period and the factors associated with these patterns could help better inform smoking cessation services and interventions.

METHODS

Latent class analysis (LCA) was used to empirically identify women's smoking patterns in a sample of 10,768 mothers from the 2010 UK Infant Feeding Survey. Multinomial logistic regression was used to identify characteristics associated with these patterns.

RESULTS

LCA identified five distinct smoking patterns during the pre-conception, pregnancy and postnatal period: "non-smokers" (74.1% of women); "pregnancy-inspired quitters" (10.2%); "persistent smokers" (10.1%); "temporary quitters" (4.4%); and postnatal quitters (1.1%). Smoking patterns varied markedly according to socio-demographic variables and parity. After adjusting for these variables, mothers who lived during pregnancy with a partner who smoked were more likely to be temporary quitters (aOR 2.64, 95% CI 1.74-3.99) or persistent smokers (aOR 3.32, 95% CI 2.34-4.72) than pregnancy-inspired quitters. Mothers who lived during pregnancy with someone else other than a partner who smoked were more likely to be persistent smokers (aOR 2.34, 95% CI 1.38-3.97) or postnatal quitters (aOR 2.97, 95% CI 1.07-8.24) than pregnancy-inspired quitters. Mothers given information on how their partner could stop smoking if they lived during pregnancy with a smoking partner were less likely to be persistent smokers (aOR 0.42, 95% CI 0.27-0.65) than pregnancy-inspired quitters.

CONCLUSION

Health professionals should ask about smoking at every opportunity, and refer women who self-report as current smokers to an evidence based smoking cessation service.

Deconstructing the smoking-preeclampsia paradox through a counterfactual framework

Although smoking during pregnancy may lead to many adverse outcomes, numerous studies have reported a paradoxical inverse association between maternal cigarette smoking during pregnancy and preeclampsia. Using a counterfactual framework we aimed to explore the structure of this paradox as being a consequence of selection bias. Using a case-control study nested in the Icelandic Birth Registry (1309 women), we show how this selection bias can be explored and corrected for. Cases were defined as any case of pregnancy induced hypertension or preeclampsia occurring after 20 weeks' gestation and controls as normotensive mothers who gave birth in the same year. First, we used directed acyclic graphs to illustrate the common bias structure. Second, we used classical logistic regression and mediation analytic methods for dichotomous outcomes to explore the structure of the bias. Lastly, we performed both deterministic and probabilistic sensitivity analysis to estimate the amount of bias due to an uncontrolled confounder and corrected for it. The biased effect of smoking was estimated to reduce the odds of preeclampsia by 28 % (OR 0.72, 95 %CI 0.52, 0.99) and after stratification by gestational age at delivery (<37 vs. ≥37 gestation weeks) by 75 % (OR 0.25, 95 %CI 0.10, 0.68). In a mediation analysis, the natural indirect effect showed and OR > 1, revealing the structure of the paradox. The bias-adjusted estimation of the smoking effect on preeclampsia showed an OR of 1.22 (95 %CI 0.41, 6.53). The smoking-preeclampsia paradox appears to be an example of (1) selection bias most likely caused by studying cases prevalent at birth rather than all incident cases from conception in a pregnancy cohort, (2) omitting important confounders associated with both smoking and preeclampsia (preventing the outcome to develop) and (3) controlling for a collider (gestation weeks at delivery). Future studies need to consider these aspects when studying and interpreting the association between smoking and pregnancy outcomes.

Understanding Inequalities of Maternal Smoking--Bridging the Gap with Adapted Intervention Strategies

Women who are generally part of socially disadvantaged and economically marginalized groups are especially susceptible to smoking during pregnancy but smoking rates are underreported in both research and interventions. While there is evidence to support the short-term efficacy of nicotine replacement therapy (NRT) use in pregnancy, long-term abstinence rates are modest. Current health strategies and interventions designed to diminish smoking in pregnancy have adopted a simplified approach to maternal smoking-one that suggests that they have a similar degree of choice to non-pregnant smokers regarding the avoidance of risk factors, and overlooks individual predictors of non-adherence. As a result, interventions have been ineffective among this high-risk group. For this reason, this paper addresses the multiple and interacting determinants that must be considered when developing and implementing effective strategies that lead to successful smoking cessation: socioeconomic status (SES), nicotine dependence, social support, culture, mental health, and health services. Based on our review of the literature, we conclude that tailoring cessation programs for pregnant smokers may ultimately optimize NRT efficacy and reduce the prevalence of maternal smoking.

Towards reducing variations in infant mortality and morbidity: a population-based approach

Background

Our aims were (1) to improve understanding of regional variation in early-life mortality rates and the UK’s poor performance in international comparisons; and (2) to identify the extent to which late and moderately preterm (LMPT) birth contributes to early childhood mortality and morbidity.

Objective

To undertake a programme of linked population-based research studies to work towards reducing variations in infant mortality and morbidity rates.

Design

Two interlinked streams: (1) a detailed analysis of national and regional data sets and (2) establishment of cohorts of LMPT babies and term-born control babies.

Setting

Cohorts were drawn from the geographically defined areas of Leicestershire and Nottinghamshire, and analyses were carried out at the University of Leicester.

Data sources

For stream 1, national data were obtained from four sources: the Office for National Statistics, NHS Numbers for Babies, Centre for Maternal and Child Enquiries and East Midlands and South Yorkshire Congenital Anomalies Register. For stream 2, prospective data were collected for 1130 LMPT babies and 1255 term-born control babies.

Main outcome measures

Detailed analysis of stillbirth and early childhood mortality rates with a particular focus on factors leading to biased or unfair comparison; review of clinical, health economic and developmental outcomes over the first 2 years of life for LMPT and term-born babies.

Results

The deprivation gap in neonatal mortality has widened over time, despite government efforts to reduce it. Stillbirth rates are twice as high in the most deprived as in the least deprived decile. Approximately 70% of all infant deaths are the result of either preterm birth or a major congenital abnormality, and these are heavily influenced by mothers’ exposure to deprivation. Births at < 24 weeks’ gestation constitute only 1% of all births, but account for 20% of infant mortality. Classification of birth status for these babies varies widely across England. Risk of LMPT birth is greatest in the most deprived groups within society. Compared with term-born peers, LMPT babies are at an increased risk of neonatal morbidity, neonatal unit admission and poorer long-term health and developmental outcomes. Cognitive and socioemotional development problems confer the greatest long-term burden, with the risk being amplified by socioeconomic factors. During the first 24 months of life each child born LMPT generates approximately £3500 of additional health and societal costs.

Conclusions

Health professionals should be cautious in reviewing unadjusted early-life mortality rates, particularly when these relate to individual trusts. When more sophisticated analysis is not possible, babies of < 24 weeks’ gestation should be excluded. Neonatal services should review the care they offer to babies born LMPT to ensure that it is appropriate to their needs. The risk of adverse outcome is low in LMPT children. However, the risk appears higher for some types of antenatal problems and when the mother is from a deprived background.

Future work

Future work could include studies to improve our understanding of how deprivation increases the risk of mortality and morbidity in early life and investigation of longer-term outcomes and interventions in at-risk LMPT infants to improve future attainment.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Tobacco control policies and perinatal and child health: a systematic review and meta-analysis protocol

INTRODUCTION

Children experience considerable morbidity and mortality due to tobacco smoke exposure. Tobacco control policies may benefit child health by reducing this exposure. We aim to comprehensively assess the effects of the range of tobacco control policies advocated by the WHO on perinatal and child health.

METHODS AND ANALYSIS

We will systematically search 19 electronic literature databases (from inception) for published studies, and the WHO International Clinical Trials Registry Platform for unpublished studies. Additional work will be identified via handsearching references and citations, and through consulting an international panel of experts. No language restrictions will apply. Following Cochrane Effective Practice and Organisation of Care (EPOC) guidelines, randomised and clinical controlled trials, controlled before-and-after studies, and interrupted time series designs, are eligible. Studies of interest will assess the impact of any of the WHO-advocated tobacco control policies contained in the MPOWER acronym (except 'Monitoring tobacco use') on at least one outcome of interest among children aged 0-12 years. The primary outcomes are: perinatal mortality, preterm birth, asthma exacerbations requiring hospital attendance and respiratory infections requiring hospital attendance. Data will be extracted using customised forms and authors will be contacted to obtain missing information. Risk of bias will be assessed using EPOC criteria. Findings will be reported in narrative and tabular form. Between-study heterogeneity will be assessed clinically and statistically using I(2). If appropriate and possible, random-effects meta-analysis will be conducted for each unique combination of intervention and outcome. Subgroup analyses will be performed to assess the influence of the comprehensiveness of each policy, and to explore the impact of each policy according to socioeconomic status.

ETHICS AND DISSEMINATION

No ethical assessment is necessary as we will summarise existing studies. We will publish our findings in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

PROSPERO; CRD42015023448.

Impact of smoke-free legislation on perinatal and infant mortality: a national quasi-experimental study

Smoke-free legislation is associated with improved early-life outcomes; however its impact on perinatal survival is unclear. We linked individual-level data with death certificates for all registered singletons births in England (1995–2011). We used interrupted time series logistic regression analysis to study changes in key adverse perinatal events following the July 2007 national, comprehensive smoke-free legislation. We studied 52,163 stillbirths and 10,238,950 live-births. Smoke-free legislation was associated with an immediate 7.8% (95%CI 3.5–11.8; p < 0.001) reduction in stillbirth, a 3.9% (95%CI 2.6–5.1; p < 0.001) reduction in low birth weight, and a 7.6% (95%CI 3.4–11.7; p = 0.001) reduction in neonatal mortality. No significant impact on SIDS was observed. Using a counterfactual scenario, we estimated that in the first four years following smoke-free legislation, 991 stillbirths, 5,470 cases of low birth weight, and 430 neonatal deaths were prevented. In conclusion, smoke-free legislation in England was associated with clinically important reductions in severe adverse perinatal outcomes.

Adverse Perinatal Outcomes among Immigrant Women from Ethiopia in Israel

BACKGROUND

Immigration from Ethiopia to Israel started about 30 years ago. We aimed to compare birth outcomes between Israeli women of Ethiopian origin and Israeli-born, non-Ethiopian women. We hypothesized a higher frequency of adverse birth outcomes among Ethiopian women and a trend of improvement among those who were raised in Israel since early childhood.

METHODS

This is a descriptive study, comparing birth outcomes of Ethiopian (n = 1,319) and non-Ethiopian women (n = 27,307) who gave birth in a medical center in Central Israel in 2002 to 2009. Ethiopian women were further categorized by age at immigration. Logistic regressions were constructed to compare the incidence of adverse birth outcomes between Ethiopian and non-Ethiopian women, controlling for potential confounders.

RESULTS

Ethiopian women had about twice the incidence of very and extremely preterm births, compared with non-Ethiopians. Ethiopian women had twice the odds for neonates who were either small for gestational age or had low 5-minute Apgar scores. Ethiopian women had about threefold increased risk of stillbirths (OR 2.9 [95% CI 1.87-4.49]). No trend of improvement was noted for women who were raised in Israel from early childhood.

CONCLUSION

Ethiopian women are at increased risk of adverse birth outcomes. Future research is needed to investigate the underlying causes for the increased risks and lack of improvement among those who were raised in Israel that will lead to effective interventions.

Disparities in prevalence of smoking and smoking cessation during pregnancy: a population-based study

Objective. To examine time trends in prevalence of smoking and smoking cessation during pregnancy by family income, maternal level of education, skin color, and age. Methods. We conducted three population-based surveys in 2007, 2010, and 2013 with newly delivered mothers living in the municipality of Rio Grande, Southern Brazil. Data were collected using questionnaires administered after delivery in all (two) maternity units in the city, at Dr. Miguel Riet Corrêa Júnior Hospital and at Santa Casa de Misericórdia. Time trends were analyzed using chi-square test for linear trend. Results. Data of 7,572 women showed that the prevalence of smoking before pregnancy decreased from 28% (26.2–29.7) in 2007 to 22% (20.8–24.0) in 2013 (P < 0.001). Prevalence of smoking during pregnancy decreased from 22% (20.4–23.7) in 2007 to 18% (16.6–19.5) in 2013 (P < 0.001). This reduction varied across income ranging from 17% (poorest) to 35% (richest) (P < 0.001). The lower the income, the higher the smoking prevalence during pregnancy. Smoking cessation was more prevalent among women of higher level of education and income. Conclusions. Smoking before and during pregnancy is still highly prevalent and the prevalence of cessation is low pointing to a need to strengthen actions targeting low-income, less educated, black pregnant women.

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

Background

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

Methods

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

Results

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

Conclusion

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

Electronic supplementary material

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

An ecological study to identify census blocks supporting a higher burden of disease: infant mortality in the lille metropolitan area, france

In France, reducing social health inequalities has become an explicit goal of health policies over the past few years, one of its objectives is specifically the reduction of the perinatal mortality rate. This study investigates the association between infant mortality and social deprivation categories at a small area level in the Lille metropolitan area, in the north of France, to identify census blocks where public authorities should prioritize appropriate preventive actions. We used census data to establish a neighbourhood deprivation index whose multiple dimensions encompass socioeconomic characteristics. Infant mortality data were obtained from the Lille metropolitan area municipalities to estimate a death rate at the census tract level. We used Bayesian hierarchical models in order to reduce the extra variability when computing relative risks (RR) and to assess the associations between infant mortality and deprivation. Between 2000 and 2009, 668 cases of infant death occurred in the Lille metropolitan area (4.2 per 1,000 live births). The socioeconomic status is associated with infant mortality, with a clear gradient of risk from the most privileged census blocks to the most deprived ones (RR = 2.62, 95 % confidence interval [1.87; 3.70]). The latter have 24.6 % of families who were single parents and 29.9 % of unemployed people in the labor force versus 8.5 % and 7.7 % in the former. Our study reveals socio-spatial disparities in infant mortality in the Lille metropolitan area and highlights the census blocks most affected by the inequalities. Fine spatial analysis may help inform the design of preventive policies tailored to the characteristics of the local communities.

Ethnicity and first birth: age, smoking, delivery, gestation, weight and feeding: Scottish Health and Ethnicity Linkage Study

BACKGROUND

We linked census and health service data sets to address the shortage of information comparing maternal characteristics and pregnancy outcomes by ethnic group in Scotland.

METHODS

Retrospective cohort study linking the 2001 National Census for Scotland and hospital obstetric data (2001-08), comparing maternal age, smoking status, gestational age, caesarean section rates, birthweight, preterm birth and breastfeeding rates by ethnic group.

RESULTS

In all, 144 344 women were identified as having had a first birth between 1 May 2001 and 30 April 2008. White Scottish mothers were younger [mean age 27.3 years; 95% confidence interval (CI): 27.3, 27.4] than other white groups and most non-white groups. They had the highest smoking rates (25.8%; CI: 25.5, 26.0) and the lowest rates of breastfeeding at 6-8 weeks (23.4%; CI: 23.1, 23.6), with most of the other groups being around 40%. Women from non-white minority ethnic groups in Scotland tended to have babies of lower birthweight (e.g. Pakistani mean birthweight-3105 g, white Scottish-3356 g), even after adjustment for gestational age, maternal age, education, smoking and housing tenure. This effect was more noticeable for women born in the UK. White English, Irish and other white babies tended to have higher birthweights. There was little variation between groups in caesarean section rates.

CONCLUSIONS

Pregnant women from ethnic minority populations in Scotland have more favourable health behaviour than the white Scottish, although the non-white groups tend to have lower birthweight. Further exploration of the reasons for these differences has potential to benefit women from the majority population.

A cross-sectional pilot study of the Scottish early development instrument: a tool for addressing inequality

BACKGROUND

Early childhood is recognised as a key developmental phase with implications for social, academic, health and wellbeing outcomes in later childhood and indeed throughout the adult lifespan. Community level data on inequalities in early child development are therefore required to establish the impact of government early years' policies and programmes on children's strengths and vulnerabilities at local and national level. This would allow local leaders to target tailored interventions according to community needs to improve children's readiness for the transition to school. The challenge is collecting valid data on sufficient samples of children entering school to derive robust inferences about each local birth cohort's developmental status. This information needs to be presented in a way that allows community stakeholders to understand the results, expediting the improvement of preschool programming to improve future cohorts' development in the early years. The aim of the study was to carry out a pilot to test the feasibility and ease of use in Scotland of the 104-item teacher-administered Early Development Instrument, an internationally validated measure of children's global development at school entry developed in Canada.

METHODS

Phase 1 was piloted in an education district with 14 Primary 1 teachers assessing a cohort of 154 children, following which the instrument was adapted for the Scottish context (Scottish Early Development Instrument: SEDI). Phase 2 was then carried out using the SEDI. Data were analysed from a larger sample of 1090 participants, comprising all Primary 1 children within this school district, evaluated by 68 teachers.

RESULTS

The SEDI displayed adequate psychometric and discriminatory properties and is appropriate for use across Scotland without any further modifications. Children in the lowest socioeconomic status quintiles were 2-3 times more likely than children in the most affluent quintile to score low in at least one developmental domain. Even in the most affluent quintile though, 17% of children were 'developmentally vulnerable', suggesting that those in need cannot be identified by socioeconomic status alone.

CONCLUSIONS

The SEDI offers a feasible means of providing communities with a holistic overview of school readiness for targeting early years' interventions.

Population-based study of smoking behaviour throughout pregnancy and adverse perinatal outcomes

There has been limited research addressing whether behavioural change in relation to smoking is maintained throughout pregnancy and the effect on perinatal outcomes. A cohort study addressed lifestyle behaviours of 907 women who booked for antenatal care and delivered in a large urban teaching hospital in 2010-2011. Adverse perinatal outcomes were compared for "non-smokers", "ex-smokers" and "current smokers". Of the 907 women, 270 (30%) reported smoking in the six months prior to pregnancy, and of those 160 (59%) had stopped smoking and 110 (41%) continued to smoke at the time of the first antenatal visit. There was virtually no change in smoking behaviour between the first antenatal visit and the third trimester of pregnancy. Factors associated with continuing to smoke included unplanned pregnancy (OR 1.9; 95% CI 1.3, 2.9), alcohol use (OR 3.4; 95% CI 2.1, 6.0) and previous illicit drug use (OR 3.6; 95% CI 2.1, 6.0). Ex-smokers had similar perinatal outcomes to non-smokers. Current smoking was associated with an average reduction in birth weight of 191 g (95% CI -294, -88) and an increased incidence of intrauterine growth restriction (24% versus 13%, adjusted OR 1.39 (95% CI 1.06, 1.84). Public Health campaigns emphasise the health benefits of quitting smoking in pregnancy. The greatest success appears to be pre-pregnancy and during the first trimester where women are largely self-motivated to quit.

Association of Smoking Habits of Mother during Pregnancy with Pregnancy Outcome

BACKGROUND

The objectives of this work were to study the association of maternal smoking habits with stillbirths, abortions, neonatal deaths, birth weights, placental weights and the outcomes on the 28(th) day of life.

METHODS

A questionnaire was developed and completed with the hospitals' recorded data collected over a period of 5 years from 47,000 babies born in several hospitals in Ontario, Canada. The mothers were classified into four categories: non-smokers, light smokers (less than 10 cigarettes per day), moderate smokers (between 10 and 19 cigarettes per day) and heavy smokers (20 or more cigarettes per day). The population surveyed was of mixed ethnicity from both rural and urban areas. Statistical analysis was performed using the SPSS statistical package.

RESULTS

Even the light smoking habit has an effect on the birth weight and the placental weight but for other characteristics, stillbirth, abortion, and the outcomes on the 28(th) day of life, no significant difference observed between light smokers and non-smokers.

CONCLUSION

While quit smoking must be the ultimate goal for any smoker, the present study concludes that moderate and heavy smokers, if they will not be able to quit, they should reduce their number of cigarettes per day to at least the level of light smokers to achieve the same results for non-smokers. All characteristics show significant difference between non-smokers and moderate and heavy smokers.

Audio computer-assisted survey instrument versus face-to-face interviews: optimal method for detecting high-risk behaviour in pregnant women and their sexual partners in the south of Brazil

Audio computer-assisted survey instrument (ACASI) has been shown to decrease under-reporting of socially undesirable behaviours, but has not been evaluated in pregnant women at risk of HIV acquisition in Brazil. We assigned HIV-negative pregnant women receiving routine antenatal care at in Porto Alegre, Brazil and their partners to receive a survey regarding high-risk sexual behaviours and drug use via ACASI (n = 372) or face-to-face (FTF) (n = 283) interviews. Logistic regression showed that compared with FTF, pregnant women interviewed via ACASI were significantly more likely to self-report themselves as single (14% versus 6%), having >5 sexual partners (35% versus 29%), having oral sex (42% versus 35%), using intravenous drugs (5% versus 0), smoking cigarettes (23% versus 16%), drinking alcohol (13% versus 8%) and using condoms during pregnancy (32% versus 17%). Therefore, ACASI may be a useful method in assessing risk behaviours in pregnant women, especially in relation to drug and alcohol use.

Financial incentives for smoking cessation in pregnancy: protocol for a single arm intervention study

BACKGROUND

Smoking during pregnancy and in the postnatal period is a major cause of low birth weight and a range of adverse infant health outcomes. Stop smoking services can double quit rates, but only 17% of pregnant women smoking at the time they book for antenatal care use these services. In a recent Cochrane review on the effectiveness of smoking cessation interventions in pregnancy, financial incentives were found to be the single most effective intervention. We describe a single arm intervention study offering participation in a financial incentive scheme for smoking cessation to all pregnant smokers receiving antenatal care in one area in England. The aim of the study is to assess the potential effectiveness of using financial incentives to achieve smoking cessation in pregnant women who smoke, to inform the use of financial incentive schemes in routine clinical practice as well as the interpretation of existing trials and the design of future studies.

METHOD/DESIGN

500 consecutive pregnant smokers are offered participation in the scheme, which involves attending for up to 32 assessments until six months post-partum, to verify smoking cessation by self report and a negative exhaled carbon monoxide measurement. At each visit when cessation is verified, participants receive a shopping voucher starting at a value of £8 and increasing by £1 at each consecutive successful visit. Assessments decline in frequency, occurring most frequently during the first two weeks after quitting and the first two weeks after delivery. The maximum cumulative total that can be earned through the scheme is £752.

DISCUSSION

The results of this study will inform the use of financial incentive schemes in routine clinical practice as well as the interpretation of existing trials and the design of future studies. The main results are (a) an estimate of the proportion of pregnant smokers who enrol in the scheme; (b) estimates of the proportion of pregnant smokers who participate in the scheme and who achieve prolonged abstinence at: i. delivery and ii. six months postpartum; (c) predictors of i. participation in the scheme, and ii. smoking cessation; and (d) estimates of the adverse effects of using incentives to achieve quitting as indexed by: i. the delay in quitting smoking to enrol in an incentive scheme and, ii. false reporting of smoking status, either to gain entry into the scheme or to gain an incentive.

Educational inequality in stillbirth: temporal trends in Québec from 1981 to 2009

OBJECTIVE

Educational inequality in stillbirth has been documented in high-income countries and the province of Québec, Canada, but temporal trends are poorly understood. Our objective was to determine time trends in inequality related to maternal education for all-cause and cause-specific stillbirth over the past three decades in Québec.

METHODS

We included 2,397,971 live births and 9,983 stillbirths from 1981 through 2009 using Québec vital statistics. For each decade, we computed measures of inequality capturing relative (relative index of inequality, RII) and absolute (slope index of inequality, SII) differences between the least- and most-educated mothers for all-cause and cause-specific stillbirth, adjusting for maternal characteristics.

RESULTS

Stillbirth rates decreased over time for all education levels. Absolute educational inequality (SII 2.5 per 1000 births, 95% CI 2.1-2.8; all periods combined) was stable over time, whereas relative inequality increased (RII(1981-1989) 1.8 vs. RII(2000-2009) 2.3). Absolute inequality decreased for stillbirths caused by placental abruption (SII(1981-1989) 0.6 vs. SII(2000-2009) 0.3), but increased for unspecified causes (SII(1981-1989) 0.2 vs. SII(2000-2009) 0.7).

CONCLUSIONS

Absolute educational inequality in stillbirth persisted and relative inequality increased over the past three decades, despite an overall decrease in stillbirth rates. The decrease in absolute inequality for placental abruption was countered by an increase for unspecified causes. A better understanding of the underlying components of unspecified causes is needed to further address educational inequality in stillbirth.

The cessation in pregnancy incentives trial (CPIT): study protocol for a randomized controlled trial

Background

Seventy percent of women in Scotland have at least one baby, making pregnancy an opportunity to help most young women quit smoking before their own health is irreparably compromised. By quitting during pregnancy their infants will be protected from miscarriage and still birth as well as low birth weight, asthma, attention deficit disorder and adult cardiovascular disease. In the UK, the NICE guidelines: ‘How to stop smoking in pregnancy and following childbirth’ (June 2010) highlighted that little evidence exists in the literature to confirm the efficacy of financial incentives to help pregnant smokers to quit. Its first research recommendation was to determine: Within a UK context, are incentives an acceptable, effective and cost-effective way to help pregnant women who smoke to quit?

Design and methods

This study is a phase II exploratory individually randomized controlled trial comparing standard care for pregnant smokers with standard care plus the additional offer of financial voucher incentives to engage with specialist cessation services and/or to quit smoking during pregnancy.

Participants (n = 600) will be pregnant smokers identified at maternity booking who, when contacted by specialist cessation services, agree to having their details passed to the NHS Smokefree Pregnancy Study Helpline to discuss the trial. The NHS Smokefree Pregnancy Study Helpline will be responsible for telephone consent and follow-up in late pregnancy. The primary outcome will be self reported smoking in late pregnancy verified by cotinine measurement. An economic evaluation will refine cost data collection and assess potential cost-effectiveness while qualitative research interviews with clients and health professionals will assess the level of acceptance of this form of incentive payment. The research questions are: What is the likely therapeutic efficacy? Are incentives potentially cost-effective? Is individual randomization an efficient trial design without introducing outcome bias? Can incentives be introduced in a way that is feasible and acceptable?

Discussion

This phase II trial will establish a workable design to reduce the risks associated with a future definitive phase III multicenter randomized controlled trial and establish a framework to assess the costs and benefits of financial incentives to help pregnant smokers to quit.

Trial registration

Current Controlled Trials ISRCTN87508788

Socioeconomic inequalities in the rate of stillbirths by cause: a population-based study

OBJECTIVE

To assess time trends in socioeconomic inequalities in overall and cause-specific stillbirth rates in England.

DESIGN

Population-based retrospective study.

SETTING

England.

PARTICIPANTS

Stillbirths occurring among singleton infants born between 1 January 2000 and 31 December 2007.

MAIN OUTCOME MEASURE

Cause-specific stillbirth rate per 10 000 births by deprivation tenth and year of birth. Deprivation measured using the UK index of multiple deprivation at Super Output Area level.

METHODS

Poisson regression models were used to estimate the relative deprivation gap (comparing the most and least deprived tenths) in rates of stillbirths (overall and cause-specific). Excess mortality was calculated by applying the rates seen in the least deprived tenth to the entire population at risk. Discussions with our local NHS multicentre ethics committee deemed that this analysis of national non-identifiable data did not require separate ethics approval.

RESULTS

There were 44 stillbirths per 10 000 births, with no evidence of a change in rates over time. Rates were twice as high in the most deprived tenth compared with the least (rate ratio (RR) 2.1, 95% CI 2.0 to 2.2) with no evidence of a change over time. There was a significant deprivation gap for all specific causes except mechanical events (RR 1.2, 95% CI 0.9 to 1.5). The widest gap was seen for stillbirths due to antepartum haemorrhages (RR 3.1, 95% CI 2.8 to 3.5). No evidence of a change in the rate of stillbirth or deprivation gap over time was seen for any specific cause.

CONCLUSION

A wide deprivation gap exists in stillbirth rates for most causes and is not diminishing. Unexplained antepartum stillbirths accounted for 50% of the deprivation gap, and a better understanding of these stillbirths is necessary to reduce socioeconomic inequalities.

Social inequality and infant health in the UK: systematic review and meta-analyses

OBJECTIVES

To determine the association between area and individual measures of social disadvantage and infant health in the UK.

DESIGN

Systematic review and meta-analyses.

DATA SOURCES

26 databases and websites, reference lists, experts in the field and hand-searching.

STUDY SELECTION

36 prospective and retrospective observational studies with socioeconomic data and health outcomes for infants in the UK, published from 1994 to May 2011.

DATA EXTRACTION AND SYNTHESIS

2 independent reviewers assessed the methodological quality of the studies and abstracted data. Where possible, study outcomes were reported as ORs for the highest versus the lowest deprivation quintile.

RESULTS

In relation to the highest versus lowest area deprivation quintiles, the odds of adverse birth outcomes were 1.81 (95% CI 1.71 to 1.92) for low birth weight, 1.67 (95% CI 1.42 to 1.96) for premature birth and 1.54 (95% CI 1.39 to 1.72) for stillbirth. For infant mortality rates, the ORs were 1.72 (95% CI 1.37 to 2.15) overall, 1.61 (95% CI 1.08 to 2.39) for neonatal and 2.31 (95% CI 2.03 to 2.64) for post-neonatal mortality. For lowest versus highest social class, the odds were 1.79 (95% CI 1.43 to 2.24) for low birth weight, 1.52 (95% CI 1.44 to 1.61) for overall infant mortality, 1.42 (95% CI 1.33 to1.51) for neonatal and 1.69 (95% CI 1.53 to 1.87) for post-neonatal mortality. There are similar patterns for other infant health outcomes with the possible exception of failure to thrive, where there is no clear association.

CONCLUSIONS

This review quantifies the influence of social disadvantage on infant outcomes in the UK. The magnitude of effect is similar across a range of area and individual deprivation measures and birth and mortality outcomes. Further research should explore the factors that are more proximal to mothers and infants, to help throw light on the most appropriate times to provide support and the form(s) that this support should take.

Social and ethnic inequalities in infant mortality: a perspective from the United kingdom

Social inequalities in infant mortality can be clearly demonstrated in the countries of the United Kingdom with a social gradient between different groups. Marked variations in infant mortality between ethnic groups are also evident in England and Wales, with the highest rates seen in Pakistani and Caribbean infants and the lowest rates in the white and Bangladeshi groups. Although individual risk factors for infant mortality are well understood, the reasons why certain social and ethnic groups have higher rates remain to be fully elucidated. Policies and interventions to tackle these inequalities are likely to be most effective if they have both universal and targeted components to "level-up" rates to the rate of the most advantaged in society.

Racial and ethnic disparities in United States: stillbirth rates: trends, risk factors, and research needs

As with most adverse health outcomes, there has been long standing and persistent racial and ethnic disparity for stillbirth in the United States. In 2005, the stillbirth rate (fetal deaths ≥ 20 weeks' gestation per 1000 fetal deaths and live births) for non-Hispanic blacks was 11.13 compared with 4.79 for non-Hispanic whites. Rates were intermediate for American Indian or Alaska Natives (6.17) and Hispanics (5.44). There is racial disparity for both early (< 28 weeks' gestation) and late stillbirths. We review available data regarding risk factors for stillbirth with a focus on those factors that are more prevalent in certain racial/ethnic groups and those factors that appear to have a more profound effect in certain racial/ethnic groups. Although many factors, including genetics, environment, stress, social issues, access to and quality of medical care and behavior, contribute to racial disparity in stillbirth, the reasons for the disparity remain unclear. Knowledge gaps and recommendations for further research and interventions intended to reduce racial disparity in stillbirth are highlighted.

Association between maternal sleep practices and risk of late stillbirth: a case-control study

OBJECTIVES

To determine whether snoring, sleep position, and other sleep practices in pregnant women are associated with risk of late stillbirth.

DESIGN

Prospective population based case-control study.

SETTING

Auckland, New Zealand

CASES

155 women with a singleton late stillbirth (≥ 28 weeks' gestation) without congenital abnormality born between July 2006 and June 2009 and booked to deliver in Auckland.

CONTROLS

310 women with single ongoing pregnancies and gestation matched to that at which the stillbirth occurred. Multivariable logistic regression adjusted for known confounding factors.

MAIN OUTCOME MEASURE

Maternal snoring, daytime sleepiness (measured with the Epworth sleepiness scale), and sleep position at the time of going to sleep and on waking (left side, right side, back, and other).

RESULTS

The prevalence of late stillbirth in this study was 3.09/1000 births. No relation was found between snoring or daytime sleepiness and risk of late stillbirth. However, women who slept on their back or on their right side on the previous night (before stillbirth or interview) were more likely to experience a late stillbirth compared with women who slept on their left side (adjusted odds ratio for back sleeping 2.54 (95% CI 1.04 to 6.18), and for right side sleeping 1.74 (0.98 to 3.01)). The absolute risk of late stillbirth for women who went to sleep on their left was 1.96/1000 and was 3.93/1000 for women who did not go to sleep on their left. Women who got up to go to the toilet once or less on the last night were more likely to experience a late stillbirth compared with women who got up more frequently (adjusted odds ratio 2.28 (1.40 to 3.71)). Women who regularly slept during the day in the previous month were also more likely to experience a late stillbirth than those who did not (2.04 (1.26 to 3.27)).

CONCLUSIONS

This is the first study to report maternal sleep related practices as risk factors for stillbirth, and these findings require urgent confirmation in further studies.

Efficacy and safety of nicotine replacement therapy for smoking cessation in pregnancy: systematic review and meta-analysis

AIMS

To determine the efficacy and safety of nicotine replacement therapy (NRT) with or without behavioural support when used to support smoking cessation in pregnancy.

DESIGN, SETTING AND PARTICIPANTS

A systematic review of randomized controlled trials (RCTs) in which NRT was used with or without behavioural support to promote smoking cessation; trials providing unequal behavioural support to different trial groups were excluded.

EFFICACY

self-reported smoking cessation in later pregnancy, validated where possible by biochemical measures with appropriate cut-points; infants' safety: mean and low birth weights (LBW), preterm birth, fetal demise and neonatal intensive care unit (NICU) admissions.

FINDINGS

Five trials, enrolling 695 pregnant, regular smokers were included in the review. The pooled risk ratio (RR) and 95% confidence Interval (CI) for smoking cessation in later pregnancy after using NRT was 1.63 (0.85, 3.14). Subgroup analysis comparing studies at lower risk of bias (placebo-RCTs) with those at higher risk of bias (non-placebo-RCTs) found that efficacy estimates varied with trial design [RR (95% CI) for cessation in placebo-RCTs 1.17 (0.83, 1.65) versus 7.81 (1.51, 40.35) for non-placebo-RCTs]. Five of the seven safety outcomes were more positive among infants born to women who had used NRT, but none of the observed differences between trial groups reached statistical significance.

CONCLUSIONS

There is currently insufficient evidence to determine whether or not nicotine replacement therapy is effective or safe when used in pregnancy for smoking cessation; further research and, in particular, placebo-randomized controlled trials are required.