Epidemiology of prenatal smoking and perinatal outcomes

Smoked, smokeless, and poly-tobacco use during pregnancy in relation to infant mortality in Cambodia: Findings from a nationwide sample

INTRODUCTION

Maternal cigarette smoking during pregnancy is an established risk factor for adverse maternal, fetal, and infant outcomes. In contrast, maternal smokeless tobacco use (i.e. e-cigarettes, snus, betel quid, iqmik) during pregnancy has a more complex risk profile due to its potential use as a smoking cessation aid or to reduce the harm from smoking tobacco. The overall aim of this study was to investigate the association between smoked, smokeless, and poly-tobacco (smoked + smokeless) use during pregnancy and infant mortality, in a national sample of women in Cambodia.

METHODS

The study used data from the National Adult Tobacco Survey of Cambodia (NATSC) that employed sampling methods and tobacco survey items from the CDC Global Adult Tobacco Survey but also included a supplement on reproductive health and birthing history. We selected 5342 women of the NATSC who reported complete data on at least one pregnancy, and our unit of analysis was the 15998 pregnancies from these women. We conducted a multivariable logistic regression to relate tobacco use to infant mortality. Taylor linearized variance estimators were used to account for clustering by sampling unit and mother.

RESULTS

We found that smokeless tobacco in the form of a betel quid was the most common form of tobacco used during pregnancy. In multivariable logistic regression, we found increased odds of infant death for all tobacco use categories (smoked, smokeless), but that the strongest effects were seen for habits that included smokeless tobacco (relative to never use of tobacco in any form): exclusive use of smokeless tobacco (adjusted odds ratio, AOR=2.08; 95% CI: 1.15-3.76), and poly-tobacco use (AOR=5.68; 95% CI: 1.03-31.46). In more detailed analyses that considered the composition of the betel quid (tobacco, areca nut/leaf, slaked lime), we found that even chewing of tobacco leaves with no processing or additives was associated with a three-fold increase in odds of infant death relative to a never user (AOR=3.05; 95% CI: 1.45-6.45).

CONCLUSIONS

We found that even among those pregnant women who limited their nicotine habit to chewing tobacco leaves with no processing or additives, there remained higher odds of fetal or infant death from that pregnancy.

Prenatal and postnatal factors associated with sudden infant death syndrome: an umbrella review of meta-analyses

BACKGROUND

Comprehensive quantitative evidence on the risk and protective factors for sudden infant death syndrome (SIDS) effects is lacking. We investigated the risk and protective factors related to SIDS.

METHODS

We conducted an umbrella review of meta-analyses of observational and interventional studies assessing SIDS-related factors. PubMed/MEDLINE, Embase, EBSCO, and Google Scholar were searched from inception until January 18, 2023. Data extraction, quality assessment, and certainty of evidence were assessed by using A Measurement Tool Assessment Systematic Reviews 2 following PRISMA guidelines. According to observational evidence, credibility was graded and classified by class and quality of evidence (CE; convincing, highly suggestive, suggestive, weak, or not significant). Our study protocol was registered with PROSPERO (CRD42023458696). The risk and protective factors related to SIDS are presented as equivalent odds ratios (eORs).

RESULTS

We identified eight original meta-analyses, including 152 original articles, covering 12 unique risk and protective factors for SIDS across 21 countries/regions and five continents. Several risk factors, including prenatal drug exposure [eOR = 7.84 (95% CI = 4.81-12.79), CE = highly suggestive], prenatal opioid exposure [9.55 (95% CI = 4.87-18.72), CE = suggestive], prenatal methadone exposure [9.52 (95% CI = 3.34-27.10), CE = weak], prenatal cocaine exposure [4.38 (95% CI = 1.95-9.86), CE = weak], prenatal maternal smoking [2.25 (95% CI = 1.95-2.60), CE = highly suggestive], postnatal maternal smoking [1.97 (95% CI = 1.75-2.22), CE = weak], bed sharing [2.89 (95% CI = 1.81-4.60), CE = weak], and infants found with heads covered by bedclothes after last sleep [11.01 (95% CI = 5.40-22.45), CE = suggestive], were identified. On the other hand, three protective factors, namely, breastfeeding [0.57 (95% CI = 0.39-0.83), CE = non-significant], supine sleeping position [0.48 (95% CI = 0.37-0.63), CE = suggestive], and pacifier use [0.44 (95% CI = 0.30-0.65), CE = weak], were also identified.

CONCLUSIONS

Based on the evidence, we propose several risk and protective factors for SIDS. This study suggests the need for further studies on SIDS-related factors supported by weak credibility, no association, or a lack of adequate research.

Why Female Smokers Have Poorer Long-Term Health Outcomes than Male Smokers: The Role of Cigarette Smoking During Pregnancy

Objectives: Women's health status is better than men but the opposite is true for female smokers who usually have poorer long-health outcomes than male smokers. The objectives of this study were to thoroughly reviewed and analyzed relevant literature and to propose a hypothesis that may explain this paradox phenomenon. Methods: We conducted a search of literature from three English databases (EMBASE, MEDLINE, and Google Scholar) from inception to 13 November 2023. A combination of key words and/or subject headings in English was applied, including relevant terms for cigarette smoking, sex/gender, pregnancy, and health indicators. We then performed analysis of the searched literature. Results: Based on this review/analysis of literature, we proposed a hypothesis that may explain this paradox phenomenon: female smokers have worse long-term health outcomes than male smokers because some of them smoke during pregnancy, and the adverse effects of cigarette smoking during pregnancy is much stronger than cigarette smoking during non-pregnancy periods. Conclusion: Approval of our pregnancy-amplification theory could provide additional evidence on the adverse effect on women's long-term health outcomes for cigarette smoking during pregnancy.

Pilot study of attentional retraining for postpartum smoking relapse

Introduction

Tobacco smoking is a leading cause of preventable death worldwide. The perinatal period provides a unique opportunity for intervention, as many smokers quit smoking during pregnancy but relapse postpartum. Novel relapse prevention interventions that reduce the burden of treatment attendance in this population are needed. Attentional retraining (AR) has been shown to reduce attentional biases toward smoking-related stimuli, a cognitive process implicated in smoking, AR has not been applied to perinatal smokers, and the effect of AR on craving and smoking is not clear. The goal of this study was to evaluate the delivery of AR for smoking cues in perinatal smokers utilizing a mobile intervention.

Methods

This pilot study utilized Ecological Momentary Assessment (EMA) methodology delivered on a mobile device to examine the relapse process and evaluate the utility of AR in former smokers attempting to remain abstinent postpartum. AR (or Control Training) was administered to abstinent smokers (N = 17) for up to 2 weeks both before and after delivery.

Results

All 17 participants completed the study. There was evidence that AR reduced attentional bias in the AR group (vs. Controls). There was no evidence that AR reduced craving. An exploratory analysis revealed that there was no evidence that AR reduced smoking during the study period.

Discussion

AR using EMA methodology via a mobile device is feasible in perinatal smokers. Further research using larger samples is required to evaluate the utility of mobile AR in reducing craving and smoking.

Explaining the Link Between Paternal Socioeconomic Position and Small for Gestational Age Birth: The Effect of Maternal Unhealthy Behaviors

OBJECTIVE

To determine the proportion of small for gestational age (weight < 10th percentile, SGA) births among fathers with lifelong low (compared to high) socioeconomic position (SEP) attributable to white and African-American women's unhealthy pregnancy-related behaviors.

METHODS

Oaxaca-Blinder decomposition methods were conducted on the Illinois transgenerational dataset of infants (1989-1991) and their Chicago-born parents (1956-1976) with appended US census income data. The neighborhood income of father's residence at the time of his birth and at the time of his infant's birth were used to estimate his lifetime SEP. Maternal unhealthy pregnancy-related behaviors were defined as cigarette smoking, inadequate prenatal care, and/or low weight gain during pregnancy.

RESULTS

Among African-American women, births (n = 4426) to fathers with lifetime low SEP had an SGA rate of 14.8% compared to 12.1% for those (n = 365) born to fathers with lifetime high SEP (p < 0.0001). Among white women, births (n = 1430) to fathers with lifetime low SEP had an SGA rate of 9.8% compared to 6.2% for those (n = 9141) born to fathers with lifetime high SEP (p < 0.0001). Adjusting for maternal age, marital status, education, and parity, African-American and white women's unhealthy pregnancy behaviors accounted for 25% and 33%, respectively, of the disparity in SGA rates among infants of lifetime low (compared to high) SEP fathers.

CONCLUSION

A significant proportion of the disparity in SGA rates between fathers with lifelong low (compared to high) SEP is explained in both races by maternal unhealthy pregnancy behaviors.

Intrauterine exposure to nicotine through maternal vaping disrupts embryonic lung and skeletal development via the Kcnj2 potassium channel

Smoking cigarettes during pregnancy is associated with adverse effects on infants including low birth weight, defective lung development, and skeletal abnormalities. Pregnant women are increasingly turning to vaping [use of electronic (e)-cigarettes] as a perceived safer alternative to cigarettes. However, nicotine disrupts fetal development, suggesting that like cigarette smoking, nicotine vaping may be detrimental to the fetus. To test the impact of maternal vaping on fetal lung and skeletal development in mice, pregnant dams were exposed to e-cigarette vapor throughout gestation. At embryonic day (E)18.5, vape exposed litter sizes were reduced, and some embryos exhibited growth restriction compared to air exposed controls. Fetal lungs were collected for histology and whole transcriptome sequencing. Maternally nicotine vaped embryos exhibited histological and transcriptional changes consistent with impaired distal lung development. Embryonic lung gene expression changes mimicked transcriptional changes observed in adult mouse lungs exposed to cigarette smoke, suggesting that the developmental defects may be due to direct nicotine exposure. Fetal skeletons were analyzed for craniofacial and long bone lengths. Nicotine directly binds and inhibits the Kcnj2 potassium channel which is important for bone development. The length of the maxilla, palatal shelves, humerus, and femur were reduced in vaped embryos, which was further exacerbated by loss of one copy of the Kcnj2 gene. Nicotine vapor exposed Kcnj2KO/+ embryos also had significantly lower birth weights than unexposed animals of either genotype. Kcnj2 mutants had severely defective lungs with and without vape exposure, suggesting that potassium channels may be broadly involved in mediating the detrimental developmental effects of nicotine vaping. These data indicate that intrauterine nicotine exposure disrupts fetal lung and skeletal development likely through inhibition of Kcnj2.

Prenatal nicotine exposure during pregnancy results in adverse neurodevelopmental alterations and neurobehavioral deficits

Maternal tobacco use and nicotine exposure during pregnancy have been associated with adverse birth outcomes in infants and can lead to preventable pregnancy complications. Exposure to nicotine and other compounds in tobacco and electronic cigarettes (e-cigarettes) has been shown to increases the risk of miscarriage, prematurity, stillbirth, low birth weight, perinatal morbidity, and sudden infant death syndrome (SIDS). Additionally, recent data provided by clinical and pre-clinical research demonstrates that nicotine exposure during pregnancy may heighten the risk for adverse neurodevelopmental disorders such as Attention-Deficit Hyperactivity (ADHD), anxiety, and depression along with altering the infants underlying brain circuitry, response to neurotransmitters, and brain volume. In the United States, one in 14 women (7.2%) reported to have smoked cigarettes during their pregnancy with the global prevalence of smoking during pregnancy estimated to be 1.7%. Approximately 1.1% of women in the United States also reported to have used e-cigarettes during the last 3 months of pregnancy. Due to the large percentage of women utilizing nicotine products during pregnancy in the United States and globally, this review seeks to centralize pre-clinical and clinical studies focused on the neurobehavioral and neurodevelopmental complications associated with prenatal nicotine exposure (PNE) such as alterations to the hypothalamic-pituitary-adrenal (HPA) axis and brain regions such as the prefrontal cortex (PFC), ventral tegmental area (VTA), nucleus accumbens (NA), hippocampus, and caudate as well as changes to nAChR and cholinergic receptor signaling, long-term drug seeking behavior following PNE, and other related developmental disorders. Current literature analyzing the association between PNE and the risk for offspring developing schizophrenia, attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), anxiety, and obesity will also be discussed.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

A mixed methods evaluation of Quit for new life, a smoking cessation initiative for women having an Aboriginal baby

BACKGROUND

Quit for new life (QFNL) is a smoking cessation initiative developed to support mothers of Aboriginal babies to quit smoking during pregnancy. The state-wide initiative provides support for pregnant women and their households including free nicotine replacement therapy (NRT) and follow up cessation advice. Services are also supported to implement systems-level changes and integrate QFNL into routine care. This study aimed to evaluate: (1) models of implementation of QFNL; (2) the uptake of QFNL; (3) the impact of QFNL on smoking behaviours; and (4) stakeholder perceptions of the initiative.

METHODS

A mixed methods study was conducted comprising semi-structured interviews and analysis of routinely collected data. Interviews were conducted with 6 clients and 35 stakeholders involved in program implementation. Data were analysed using inductive content analysis. Aboriginal Maternal and Infant Health Service Data Collection (AMDC) records for the period July 2012-June 2015 were investigated to examine how many eligible women attended a service implementing QFNL and how many women took up a QFNL support. Smoking cessation rates were compared in women attending a service offering QFNL with women attending the same service prior to the implementation of QFNL to determine program impact.

RESULTS

QFNL was implemented in 70 services located in 13 LHDs across New South Wales. Over 430 staff attended QFNL training, including 101 staff in Aboriginal-identified roles. In the period July 2012-June 2015 27% (n = 1549) of eligible women attended a service implementing QFNL and 21% (n = 320) of these were recorded as taking up a QFNL support. While stakeholders shared stories of success, no statistically significant impact of QFNL on smoking cessation rates was identified (N = 3502; Odds ratio (OR) = 1.28; 95% Confidence Interval (CI) = 0.96-1.70; p-value = 0.0905). QFNL was acceptable to both clients and stakeholders, increased awareness about smoking cessation, and gave staff resources to support clients.

CONCLUSION

QFNL was perceived as acceptable by stakeholders and clients and provided care providers with knowledge and tangible support to offer women who presented at antenatal care as smokers, however, no statistically significant impact on rates of smoking cessation were found using the measures available.

Perinatal Health Outcomes Across Rural and Nonrural Counties Within a Single Health System Catchment

Background

Perinatal health outcomes are influenced by a variety of socioeconomic, behavioral, and economic factors that reduce access to health services. Despite these observations, rural communities continue to face barriers, including a lack of resources and the fragmentation of health services.

Objective

To evaluate patterns in health outcomes, health behaviors, socioeconomic vulnerability, and sociodemographic characteristics across rural and nonrural counties within a single health system catchment area.

Methods

Socioeconomic vulnerability metrics, health care access as determined by licensed provider metrics, and behavioral data were obtained from FlHealthCHARTS.gov and the County Health Rankings. County-level birth and health data were obtained from the Florida Department of Health. The University of Florida Health Perinatal Catchment Area (UFHPCA) was defined as all Florida counties where ≥5% of all infants were delivered at Shands Hospital between June 2011 and April 2017.

Results

The UFHPCA included 3 nonrural and 10 rural counties that represented more than 64,000 deliveries. Nearly 1 in 3 infants resided in a rural county, and 7 out of 13 counties did not have a licensed obstetrician gynecologist. Maternal smoking rates (range 6.8%-24.8%) were above the statewide rate (6.2%). Except for Alachua County, breastfeeding initiation rates (range 54.9%-81.4%) and access to household computing devices (range 72.8%-86.4%) were below the statewide rate (82.9% and 87.9%, respectively). Finally, we found that childhood poverty rates (range 16.3%-36.9%) were above the statewide rate (18.5%). Furthermore, risk ratios suggested negative health outcomes for residents of counties within the UFHPCA for each measure, except for infant mortality and maternal deaths, which lacked sample sizes to adequately test.

Conclusions

The health burden of the UFHPCA is characterized by rural counties with increased maternal death, neonatal death, and preterm birth, as well as adverse health behaviors that included increased smoking during pregnancy and lower levels of breastfeeding relative to nonrural counties. Understanding perinatal health outcomes across a single health system has potential to not only estimate community needs but also facilitate planning of health care initiatives and interventions in rural and low-resource communities.

Impact of BMI and smoking in adolescence and at the start of pregnancy on birth weight

BACKGROUND

Birth weight is an indicator of intra-uterine conditions but also a determinant for future health. The importance of preconception health for a healthy birth weight has been emphasized, but evidence is lacking on how modifiable factors in adolescence, such as body mass index (BMI) and smoking, affect future pregnancy outcome. We evaluated associations between BMI and smoking in adolescence and at the start of pregnancy and birth weight of the first-born child.

METHODS

This longitudinal study included 1256 mothers, born 1962-1992, and their first-born children, born between 1982-2016. Self-reported questionnaire information on weight, height and smoking at age 19 was cross-linked with national register data obtained at the start of pregnancy and with the birth weights of the children. Univariable and multivariable linear regressions were performed to determine the impact of maternal factors at 19 years of age and at the start of the pregnancy respectively, and the importance of BMI status at these points of time for the birth weight of the first child.

RESULTS

BMI and smoking at the start of the pregnancy displayed strong associations with birth weight in a multivariable analysis, BMI with a positive association of 14.9 g per BMI unit (95% CI 6.0; 23.8 p = 0.001) and smoking with a negative association of 180.5 g (95% CI -275.7; -85.4) p = 0.0002). Smoking and BMI at 19 years of age did not show this association. Maternal birth weight showed significant associations in models at both time-points. Becoming overweight between age 19 and the start of the pregnancy was associated with a significantly higher birth weight (144.6 (95% CI 70.7;218.5) p = 0.0002) compared to mothers with normal weight at both time points.

CONCLUSIONS

Our findings indicate that the time period between adolescence and first pregnancy could be a window of opportunity for targeted health promotion to prevent intergenerational transmission of obesity.

Prevalence and Factors Associated With Low Birth Weight in the Solomon Islands: Evidence From the 2015 Solomon Islands Demographic and Health Survey data

Low birth weight (LBW) has contributed to more than 80% of under-5 deaths worldwide, most occurring in low- and middle-income countries. We used the 2015 Solomon Islands Demographic and Health Survey data to identify the prevalence and risks associated with LBW in the Solomon Islands. Low birth weight prevalence estimated was 10%. After adjustment for potential confounders, we found the risk of LBW for women with a history of marijuana and kava use was 2.6 times, adjusted relative risk (aRR) 2.64 at a 95% confidence interval [0.64, 10.95] and 2.5 times [aRR: 2.50 (0.63, 9.88)] than among unexposed women, respectively. Polygamous relationship, no antenatal care, decision-making by another person were 84% [aRR: 1.84 (1.15, 2.93)], 73% [aRR: 1.73 (0.96, 3.13)], and 73% [aRR: 1.73 (0.96, 3.13)] than among unexposed women, respectively. We also found that 10% and 4% of LBW cases in the Solomon Islands were attributable to a household of more than 5 members and tobacco and cigarette use history. We concluded that LBW in the Solomon Islands relied more on behavioral risk factors, including substance use and health and social risk factors. We recommended further study on kava use and its impact on pregnancy and LBW.

Is WIC effective in improving pregnancy-related outcomes? An empirical reassessment

This study provides new evidence on how prenatal WIC participation influences pregnancy-related outcomes, using a large dataset of Medicaid mothers with two or more singleton births. Our analysis suggests there is negative selection by maternal unobserved factors even with a relatively homogenous sample and a rich set of observed characteristics. The conservative estimates from multiple regression which doesn't address maternal unobserved heterogeneity already demonstrate beneficial effects on a range of outcomes. The concern of mis-specification or extrapolation in the linear model is also ruled out. Controlling for the mother fixed effects, we find more statistically significant estimates which are usually larger in size. The within-mother estimates are robust in a series of sensitivity checks especially multiple inference adjustments. Overall, we find WIC does work to improve infant health and maternal health behaviors as well as reduce usage of costly maternity care.

Using mixed methods to establish tobacco treatment acceptability from the perspective of clients and clinicians of antenatal substance use services

Background

Up to 95% of pregnant women with alcohol and other drug (AOD) problems also smoke tobacco. Challenging psychosocial circumstances and a lack of targeted tobacco interventions contribute to low rates of prenatal abstinence and more effective treatment strategies are required. This study explores smoking in pregnant clients of AOD treatment services from a consumer and healthcare provider perspective to examine characteristics of behaviour change and the acceptability of evidence-based tobacco treatment strategies. Outcomes will support the design and implementation of a comprehensive tobacco intervention.

Methods

A mixed methods triangulated design was used. Thirteen women who smoked and attended antenatal AOD services in New South Wales, Australia, were interviewed and 28 clinicians from the same services were surveyed. Domains including experiences of tobacco smoking in pregnancy, motivators and barriers to cessation and evidence-based strategies to assist cessation during pregnancy were explored. Interviews were analysed using Iterative Categorization, with interpretation guided by Qualitative Description. Online surveys were analysed descriptively. A convergent-parallel mixed methods analysis was performed.

Results

Women and clinicians agreed that improving baby’s health outcomes was the primary motivation to stop smoking. Negative experiences with nicotine replacement therapy (NRT), financial constraints and maternal contraindications restricted its uptake and effectiveness during pregnancy. Both groups agreed that other AOD use, stopping multiple substances concurrently, difficulty coping with stress and the influence of partners who smoke had the biggest impacts on cessation efforts. Clinicians favoured harm-reduction rather than abstinence-based tobacco interventions and women appeared satisfied with reduction efforts. Both views may influence the attainment of prenatal abstinence-based goals. Although previous evidence suggested the contrary, clinicians were willing to encourage simultaneous cessation of tobacco and other substances. Non-judgmental treatment approaches that provide extra support, education and motivation were important for women. Women and clinicians supported use of NRT despite concerns. Financial incentives, counselling, partner support and offering tobacco treatment with antenatal AOD care were considered acceptable treatment options.

Conclusions

NRT, incentives, counselling and partner support could be utilized in a tobacco intervention for pregnant women with substance use concerns. Non-judgmental education, motivation, and provision of NRT including instruction for correct use are important considerations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13722-022-00337-y.

Oral cleaning habits and the copy number of periodontal bacteria in pregnant women and its correlation with birth outcomes: an epidemiological study in Mibilizi, Rwanda

BACKGROUND

Since 1996, many studies have reported that periodontal disease during pregnancy may be a risk factor for preterm birth and low birth weight; however, in Africa, periodontal disease is considered a non-high-priority disease. In addition, there are few dental facilities in rural Rwanda; thus, the oral condition of pregnant women has not been investigated. The objective of this study was to assess the tooth brushing habits of pregnant women in rural Rwanda and evaluate whether periodontal bacteria in the oral cavity of pregnant women are related to birth outcomes or oral cleaning habits.

METHODS

A questionnaire survey and saliva collection were conducted for pregnant women in the catchment area population of Mibilizi Hospital located in the western part of Rwanda. Real-time PCR was performed to quantitatively detect total bacteria and 4 species of periodontal bacteria. The relationship of the copy number of each bacterium and birth outcomes or oral cleaning habits was statistically analyzed.

RESULTS

Among the participants, high copy numbers of total bacteria, Tannerella forsythia, and Treponema denticola were correlated with lower birth weight (p = 0.0032, 0.0212, 0.0288, respectively). The sex ratio at birth was higher in women who had high copy numbers of Porphyromonas gingivalis and T. denticola during pregnancy (p = 0.0268, 0.0043). Furthermore, regarding the correlation between oral cleaning habits and the amount of bacteria, the more frequently teeth were brushed, the lower the level of P. gingivalis (p = 0.0061); the more frequently the brush was replaced, the lower the levels of P. gingivalis and T. forsythia (p = 0.0153, 0.0029).

CONCLUSIONS

This study suggested that improving tooth brushing habits may reduce the risk of periodontal disease among pregnant women in rural Rwanda. It also indicated that the amount of bacteria is associated with various birth outcomes according to the bacterial species. Both access to dental clinics and the oral cleaning habits of pregnant women should be important considerations in efforts to alleviate reproductive-related outcomes in rural Africa.

Embryonic exposure to benzo[a]pyrene causes age-dependent behavioral alterations and long-term metabolic dysfunction in zebrafish

Polycyclic aromatic hydrocarbons (PAH) are products of incomplete combustion which are ubiquitous pollutants and constituents of harmful mixtures such as tobacco smoke, petroleum and creosote. Animal studies have shown that these compounds exert developmental toxicity in multiple organ systems, including the nervous system. The relative persistence of or recovery from these effects across the lifespan remain poorly characterized. These studies tested for persistence of neurobehavioral effects in AB* zebrafish exposed 5-120 h post-fertilization to a typical PAH, benzo[a]pyrene (BAP). Study 1 evaluated the neurobehavioral effects of a wide concentration range of BAP (0.02-10 μM) exposures from 5 to 120 hpf during larval (6 days) and adult (6 months) stages of development, while study 2 evaluated neurobehavioral effects of BAP (0.3-3 μM) from 5 to 120 hpf across four stages of development: larval (6 days), adolescence (2.5 months), adulthood (8 months) and late adulthood (14 months). Embryonic BAP exposure caused minimal effects on larval motility, but did cause neurobehavioral changes at later points in life. Embryonic BAP exposure led to nonmonotonic effects on adolescent activity (0.3 μM hyperactive, Study 2), which attenuated with age, as well as startle responses (0.2 μM enhanced, Study 1) at 6 months of age. Similar startle changes were also detected in Study 2 (1.0 μM), though it was observed that the phenotype shifted from reduced pretap activity to enhanced posttap activity from 8 to 14 months of age. Changes in the avoidance (0.02-10 μM, Study 1) and approach (reduced, 0.3 μM, Study 2) of aversive/social cues were also detected, with the latter attenuating from 8 to 14 months of age. Fish from study 2 were maintained into aging (18 months) and evaluated for overall and tissue-specific oxygen consumption to determine whether metabolic processes in the brain and other target organs show altered function in late life based on embryonic PAH toxicity. BAP reduced whole animal oxygen consumption, and overall reductions in total basal, mitochondrial basal, and mitochondrial maximum respiration in target organs, including the brain, liver and heart. The present data show that embryonic BAP exposure can lead to neurobehavioral impairment across the life-span, but that these long-term risks differentially emerge or attenuate as development progresses.

Quitting Smoking before and after Pregnancy: Study Methods and Baseline Data from a Prospective Cohort Study

Smoking during pregnancy and postpartum remains an important public health problem. No known prior study has prospectively examined mutual changes in risk factors and women's smoking trajectory across pregnancy and postpartum. The objective of this study was to report methods used to implement a prospective cohort (Msgs4Moms), present participant baseline characteristics, and compare our sample characteristics to pregnant women from national birth record data. The cohort study was designed to investigate smoking patterns, variables related to tobacco use and abstinence, and tobacco treatment quality across pregnancy through 1-year postpartum. Current smokers or recent quitters were recruited from obstetrics clinics. Analyses included Chi-square and independent sample t-tests using Cohen's d. A total of 62 participants (41 smokers and 21 quitters) were enrolled. Participants were Black (45.2%), White (35.5%), and multiracial (19.3%); 46.8% had post-secondary education; and most were Medicaid-insured (64.5%). Compared with quitters, fewer smokers were employed (65.9 vs 90.5%, Cohen's d = 0.88) and more reported financial strain (61.1% vs 28.6%; Cohen's d = 0.75). Women who continue to smoke during pregnancy cope with multiple social determinants of health. Longitudinal data from this cohort provide intensive data to identify treatment gaps, critical time points, and potential psychosocial variables warranting intervention.

Licit and illicit drug use across trimesters in pregnant women endorsing past-year substance use: Results from National Survey on Drug Use and Health (2009-2019)

PURPOSE

Given the health consequences, perinatal substance use is a significant public health concern, especially as substance use rates increase among women; ongoing data regarding the rates of substance use across trimesters of pregnancy is needed.

METHODS

The present study utilized cross-sectional population-based data from the National Survey of Drug Use and Health (NSDUH) between 2009 and 2019. We aimed to explore both licit and illicit substance use assessed within each trimester among women endorsing past-year substance use. The NSDUH sample included 8,530 pregnant women.

RESULTS

Perinatal substance use was less prevalent among women in later trimesters; however, past-month substance use was observed for all substances across trimesters. The prevalence of past-month licit substance use among pregnant women ranged from 5.77 to 22.50% and past-month illicit substance use ranged from 4.67 to 14.81%. In the second trimester, lower odds of past-month substance use were observed across tobacco, alcohol, and marijuana (odds ratios [ORs] ranging from 0.29 to 0.47), when compared to the first trimester. A similar lower rate of past-month substance use was observed in the third trimester compared to the first trimester, across tobacco, alcohol, and marijuana use, as well as cocaine, prescription pain medication, and tranquilizer use (ORs ranging from 0.02 to 0.42). The likelihood of polysubstance use was lower among women in the second and third trimesters compared to the first trimester (ORs ranging from 0.09 to 0.46).

CONCLUSION

Findings indicate that a minority of women continue to use substances across all trimesters. This is especially true among women using licit substances and marijuana. These results highlight the need for improved interventions and improved access to treatment for these women.

A Virtual Exercise Program throughout Pregnancy during the COVID-19 Pandemic Modifies Maternal Weight Gain, Smoking Habits and Birth Weight—Randomized Clinical Trial

The intrauterine environment is key to health from a short- and long-term perspective. Birth weight is an important indicator that may influence the fetal environment due to epigenetics. Considering physical inactivity, in parallel with higher levels of stress, affecting smoking patterns and the physical and emotional health of the pregnant population, maintaining the health of future generations is crucial. A randomized clinical trial (NCT04563065) was conducted. One-hundred and ninety-two healthy pregnant individuals were assigned to the intervention (IG) or control (CG) group. Overall, significant differences were found between groups when stratified by birth weight (χ2 (1) = 6.610; p = 0.037) with low birth weight and macrosomia found more often in the CG (4% vs. 14% and 3% vs. 9%, respectively) and higher admissions to the neonatal intensive care unit (χ2 (1) = 5.075; p = 0.024) in the CG (20/28.6%) compared to the IG (9/13.0). Smoking during pregnancy was also found more often in the CG (12/17.1%) compared to the IG (3/4.4%) (p = 0.016). A virtual program of supervised exercise throughout pregnancy during the ongoing pandemic could help to maintain adequate birth weights, modify maternal smoking habits, and lower admissions to the neonatal intensive care unit.

Promoting smoking cessation during pregnancy: A feasibility and pilot trial of a digital storytelling intervention delivered via text-messaging

OBJECTIVE

Smoking during pregnancy causes risks to mother and infant health. We investigated the feasibility and likely success of SKIP-IT, a narrative and picture-based smoking cessation intervention delivered via text messages.

METHODS

A feasibility and pilot trial. We aimed to recruit 70 pregnant women who smoked, randomised to usual care alone, or usual care and the SKIP-IT intervention, between 12 weeks of pregnancy and 6 weeks post due-date. Outcomes assessed were recruitment, retention, acceptability of, and engagement with the intervention, smoking behaviour, intentions, perceived risk, and self-efficacy.

RESULTS

Of 312 women initially approached by smoking cessation services only 54 (17%) agreed to be contacted by the research team. Twenty were then either ineligible or uncontactable and 28 (82%) participated. Most women reported texts to be entertaining and helpful. The proportion of women not smoking at follow-up was lower in the intervention group, but numbers were too small to draw conclusions about effectiveness.

CONCLUSION

The intervention was acceptable, but difficulty in making initial and follow-up contacts meant our methods were unfeasible for a larger trial.

PRACTICE IMPLICATIONS

Digital Storytelling interventions could help women quit smoking, but further research is required to identify alternative methods for studies with pregnant women who smoke.

Home Cardiorespiratory Monitoring in Infants at Risk for Sudden Infant Death Syndrome (SIDS), Apparent Life-Threatening Event (ALTE) or Brief Resolved Unexplained Event (BRUE)

Sudden infant death syndrome (SIDS) is defined as the sudden death of an infant younger than one year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history. About 90% of SIDS occur before six months of age, the peak incidence is between two and four months, and the median age for death is elven weeks. The clinical, social, and economic relevance of SIDS, together with the evidence that prevention of this syndrome was possible, has significantly stimulated research into risk factors for the development of SIDS in the hope of being able to introduce new effective preventive measures. This narrative review discusses the potential relationships between apparent life-threatening events (ALTE) or brief resolved unexplained events (BRUE) and SIDS development, and when a home cardiorespiratory monitor is useful for prevention of these conditions. A literature analysis showed that home cardiorespiratory monitoring has been considered a potential method to identify not only ALTE and BRUE but SIDS also. ALTE and BRUE are generally due to underlying conditions that are not detectable in SIDS infants. A true relationship between these conditions has never been demonstrated. Use of home cardiorespiratory monitor is not recommended for SIDS, whereas it could be suggested for children with previous ALTE or severe BRUE or who are at risk of the development of these conditions. However, use of home cardiorespiratory monitors assumes that family members know the advantages and limitations of these devices after adequate education and instruction in their use.

Pregnancy Outcomes Associated With Use of Tobacco and Marijuana

Tobacco and marijuana are the most common drugs of abuse among pregnant women. Cigarettes have been extensively studied and increase the risk of miscarriage, preterm birth, premature rupture of membranes, placental dysfunction, low birth rate, stillbirth, and infant mortality. There are sparse data on the specific effects of electronic cigarettes and smokeless tobacco in pregnancy. Literature on marijuana in pregnancy is limited by confounding, bias, and the retrospective nature of studies that do not capture contemporary trends in use. However, several studies suggest an association between marijuana and fetal growth restriction, low birth weight, and neurodevelopmental differences in offspring.

Polycyclic aromatic hydrocarbons (PAHs) may explain the paradoxical effects of cigarette use on preeclampsia (PE)

Tobacco smoking and use of snus (smokeless tobacco) are associated with adverse effects on pregnancy and neonatal outcomes. Nicotine is considered a key toxicant involved in effects caused by both smoking and snus, while pyrolysis products including polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke represents the constituents most unequally divided between these two groups of tobacco products. The aim of this review was: i) to compare the impact, in terms of relative effect estimates, of cigarette smoking and use of Swedish snus on pregnancy outcomes using similar non-tobacco user controls, and ii) to examine whether exposure to PAHs from smoking could explain possible differences in impact on pregnancy outcomes. We systematically searched MEDLINE, Embase, PsycInfo, Web of Science and the Cochrane Database of Systematic Reviews up to October 2021 and identified studies reporting risks for adverse pregnancy and neonatal outcomes associated with snus use and with smoking relative to pregnant women with no use of tobacco. Both snus use and smoking were associated with increased risk of stillbirth, preterm birth, and oral cleft malformation, with comparable point estimates. These effects were likely due to comparable nicotine exposure. We also found striking differences. While both smoking and snus increased the risk of having small for gestational age (SGA) infants, risk from maternal smoking was markedly higher as was the reduction in birthweight. In contrast, the risk of preeclampsia (PE) was markedly lower in smokers than in controls, while snus use was associated with a slightly increased risk. We suggest that PAHs acting via AhR may explain the stronger effects of tobacco smoking on SGA and also to the apparent protective effect of cigarette smoking on PE. Possible mechanisms involved include: i) disrupted endocrine control of fetal development as well as placental development and function, and ii) stress adaption and immune suppression in placenta and mother.

Electronic cigarettes versus nicotine patches for smoking cessation in pregnancy: a randomized controlled trial

Nicotine replacement therapy, in the form of nicotine patches, is commonly offered to pregnant women who smoke to help them to stop smoking, but this approach has limited efficacy in this population. Electronic cigarettes (e-cigarettes) are also used by pregnant women who smoke but their safety and efficacy in pregnancy are unknown. Here, we report the results of a randomized controlled trial in 1,140 participants comparing refillable e-cigarettes with nicotine patches. Pregnant women who smoked were randomized to e-cigarettes (n = 569) or nicotine patches (n = 571). In the unadjusted analysis of the primary outcome, validated prolonged quit rates at the end of pregnancy in the two study arms were not significantly different (6.8% versus 4.4% in the e-cigarette and patch arms, respectively; relative risk (RR) = 1.55, 95%CI: 0.95-2.53, P = 0.08). However, some participants in the nicotine patch group also used e-cigarettes during the study. In a pre-specified sensitivity analysis excluding abstinent participants who used non-allocated products, e-cigarettes were more effective than patches (6.8% versus 3.6%; RR = 1.93, 95%CI: 1.14-3.26, P = 0.02). Safety outcomes included adverse events and maternal and birth outcomes. The safety profile was found to be similar for both study products, however, low birthweight (<2,500 g) was less frequent in the e-cigarette arm (14.8% versus 9.6%; RR = 0.65, 95%CI: 0.47-0.90, P = 0.01). Other adverse events and birth outcomes were similar in the two study arms. E-cigarettes might help women who are pregnant to stop smoking, and their safety for use in pregnancy is similar to that of nicotine patches. ISRCTN62025374.

Impact of prenatal tobacco smoking on infant telomere length trajectory and ADHD symptoms at 18 months: a longitudinal cohort study

BACKGROUND

Prenatal maternal tobacco smoking is a predictor of child attention-deficit/hyperactivity disorder (ADHD) and is associated with offspring telomere length (TL). In this study, we examine the relationship between maternal prenatal smoking, infant TL, and maternal report of early childhood symptoms of ADHD.

METHODS

One-hundred and eighty-one mother-infant dyads were followed prospectively for the infant's first 18 months of life. Prenatal smoking was assessed from maternal report and medical records. TL was measured from infant buccal swab DNA obtained across the first 18 months of life. ADHD symptoms were obtained from maternal report on the Child Behavior Check List. Multiple regression models tested the relation between prenatal smoking and both ADHD symptoms and infant TL. Additional analyses tested whether the change in infant TL influenced the relation between prenatal smoking and ADHD symptoms.

RESULTS

Sixteen percent of mothers reported prenatal smoking. Infant TL at 4, 12, and 18 months of age were correlated. Consistent with previous cross-sectional studies linking shorter offspring TL to maternal prenatal smoking, maternal prenatal smoking predicted greater telomere shortening from four to 18 months of infant age (β = - 5.797, 95% CI [-10.207, -1.386]; p = 0.010). Maternal depression was positively associated with both prenatal smoking (odds ratio (OR): 4.614, 95% CI [1.733, 12.282]; p = 0.002) and child ADHD symptoms (β = 4.713, 95% CI [2.073, 7.354]; p = 0.0006). To prevent confounding, analyses examined the relation between TL, ADHD symptoms, and prenatal smoking only in non-depressed mothers. In non-depressed mothers, infant TL attrition across the first 18 months moderated the relation between smoking and child ADHD.

CONCLUSIONS

The findings extend previous studies linking prenatal smoking to shorter infant TL by providing data demonstrating the effect on TL trajectory. The relation between prenatal smoking and early infant ADHD symptoms was moderated by the change in TL. The findings provide novel initial evidence suggesting that TL dynamics are one mechanistic pathway influencing the relation between maternal prenatal smoking and ADHD.

Comparison of saliva cotinine and exhaled carbon monoxide concentrations when smoking and after being offered dual nicotine replacement therapy in pregnancy

BACKGROUND AND AIMS

Although English Stop Smoking Services routinely offer dual nicotine replacement therapy (NRT) to help pregnant women to quit smoking, little is known about how nicotine and tobacco smoke exposures following this compare with that from smoking. We compared, in pregnant women when smoking and after being offered dual NRT, saliva cotinine and exhaled carbon monoxide (CO) concentrations and numbers of daily cigarettes smoked.

DESIGN AND SETTING

Secondary analysis of data from three sequential, observational, mixed-methods cohort studies conducted as part of the Nicotine Replacement Effectiveness and Delivery in Pregnancy programme. Participants were recruited on-line or in Nottingham University Hospitals (UK) antenatal clinics between June 2019 and September 2020.

PARTICIPANTS

Forty pregnant women, who agreed to try stopping smoking.

INTERVENTION

Participants were offered dual NRT, agreed a smoking quit date and received an intervention to improve adherence to NRT.

MEASUREMENTS

Saliva cotinine and exhaled CO concentrations and reported number of cigarettes smoked per day.

FINDINGS

There were no differences in saliva cotinine concentrations at baseline and day 7 post quit date [n = 20, mean difference = -32.31 ng/ml, 95% confidence interval (CI) = -68.11 to 3.5 ng/ml; P = 0.074, Bayes factor = 0.04]. There were reductions in the reported number of cigarettes smoked per day (n = 26, mean difference = -7 cigarettes, 95% CI = -8.35 to -5.42 cigarettes, P < 0.001) and concurrently in exhaled CO concentrations (n = 17, ratio of geometric means = 0.30 p.p.m., 95% CI = 0.17-0.52 p.p.m.; P < 0.001).

CONCLUSION

Pregnant women who smoke and are offered dual nicotine replacement therapy (NRT) appear to show no change in their exposure to cotinine compared with their pre-NRT exposure levels but they report smoking fewer cigarettes, as validated by reductions in exhaled carbon monoxide concentrations.

Sleep quality and health among pregnant smokers

STUDY OBJECTIVES

We aimed to examine 1) sleep quality trends of pregnant smokers and 2) their associations with health outcomes.

METHODS

A secondary analysis of 88 participants from the University at Buffalo Pregnancy and Smoking Cessation Study (non-randomized clinical study) was performed. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI) (higher scores, worse quality) and sleep duration was self-reported repeatedly during pregnancy at pre-intervention, post-intervention, and end-of-pregnancy visits. Participants were divided into 3 groups (until pre-intervention, until post-intervention, until end-of-pregnancy). Maternal outcomes included gestational weight gain (GWG) and smoking cessation. Infant outcomes included birth weight, gestational age, and APGAR score.

RESULTS

There was a significant increase (P= 0.046) in PSQI score from post-intervention (mean, 5.5 [SD, 2.6]) to end-of-pregnancy (6.6 [SD, 2.8]). Mean GWG was significantly lower for participants with poor sleep quality than those with good sleep quality (19.0 kg [SD, 21.3] vs. 36.1 kg [SD, 22.8]; P=0.008). Newborns with poor maternal sleep quality had a significantly lower mean 5-minute APGAR score (8.1 [SD, 1.3] vs. 9.0 [SD, 0.0]; P=0.021) than newborns with good maternal sleep quality. Pre-intervention sleep quality was not associated with smoking cessation, birth weight, or gestational age. Smoking cessation was almost half as prevalent in participants with insufficient sleep (<7 hours/night) vs. sufficient sleep duration (47.4% vs. 92.3%, P=0.011).

CONCLUSIONS

Sleep quality worsened towards the end-of-pregnancy among smokers. Poor sleep might negatively influence GWG and APGAR score. Insufficient pre-intervention sleep might negatively influence smoking cessation.

High-resolution metabolomics of exposure to tobacco smoke during pregnancy and adverse birth outcomes in the Atlanta African American maternal-child cohort

Exposure to tobacco smoke during pregnancy has been associated with a series of adverse reproductive outcomes; however, the underlying molecular mechanisms are not well-established. We conducted an untargeted metabolome-wide association study to identify the metabolic perturbations and molecular mechanisms underlying the association between cotinine, a widely used biomarker of tobacco exposure, and adverse birth outcomes. We collected early and late pregnancy urine samples for cotinine measurement and serum samples for high-resolution metabolomics (HRM) profiling from 105 pregnant women from the Atlanta African American Maternal-Child cohort (2014-2016). Maternal metabolome perturbations mediating prenatal tobacco smoke exposure and adverse birth outcomes were assessed by an untargeted HRM workflow using generalized linear models, followed by pathway enrichment analysis and chemical annotation, with a meet-in-the-middle approach. The median maternal urinary cotinine concentrations were 5.93 μg/g creatinine and 3.69 μg/g creatinine in early and late pregnancy, respectively. In total, 16,481 and 13,043 metabolic features were identified in serum samples at each visit from positive and negative electrospray ionization modes, respectively. Twelve metabolic pathways were found to be associated with both cotinine concentrations and adverse birth outcomes during early and late pregnancy, including tryptophan, histidine, urea cycle, arginine, and proline metabolism. We confirmed 47 metabolites associated with cotinine levels, preterm birth, and shorter gestational age, including glutamate, serine, choline, and taurine, which are closely involved in endogenous inflammation, vascular reactivity, and lipid peroxidation processes. The metabolic perturbations associated with cotinine levels were related to inflammation, oxidative stress, placental vascularization, and insulin action, which could contribute to shorter gestations. The findings will support the further understanding of potential internal responses in association with tobacco smoke exposures, especially among African American women who are disproportionately exposed to high tobacco smoke and experience higher rates of adverse birth outcomes.

Tobacco consumption from the 1st trimester of pregnancy to 7 months postpartum: Effects of previous tobacco consumption, and depression and anxiety symptoms

OBJECTIVE

Previous tobacco consumption, and depression and anxiety symptoms are major predictors of women's tobacco consumption during pregnancy and the postpartum period. However, the joint effect of these predictors is still unexplored. This study aimed to analyse the effects of previous tobacco consumption, and depression and anxiety symptoms on women's tobacco consumption status and quantity from the 1st trimester of pregnancy to 7 months postpartum.

METHOD

A sample of 803 Spanish women was assessed at the 1st and the 3rd trimester of pregnancy, and at 2 and 7 months postpartum. Previous tobacco consumption, and depression and anxiety symptoms were self-reported. Pregnancy and postpartum tobacco consumption were confirmed with biochemical tests.

RESULTS

Women with more previous tobacco consumption or more anxiety symptoms presented a steeper decrease in the number of cigarettes smoked per week from the 1st trimester of pregnancy to the childbirth, although smoking more cigarettes than women with less previous tobacco consumption or less anxiety symptoms. Women with more depression symptoms showed a higher tendency to relapse smoking during the first 2 months postpartum.

CONCLUSIONS

Previous tobacco consumption and anxiety symptoms were associated with higher smoking quantity during pregnancy, while depression symptoms were associated with consumption relapse during postpartum period.

Residential proximity to pesticide applications in Argentine Patagonia: impact on pregnancy and newborn parameters

Among residents living close to agricultural fields who are potentially exposed to pesticides, pregnant women and their fetuses are of particular concern for their vulnerability to environmental chemicals. In this collaborative multicenter study, we covered a wide distribution of participants in the most important fruit production zone of north Patagonia (Argentina) to investigate whether maternal residential proximity to fruit croplands with intense pesticide applications (rural group -RG-) is associated with pregnancy complications and alterations in their newborn parameters compared to the urban population (urban group -UG-). A total of 776 pregnant women met the inclusion criteria. The percentage of threatened miscarriage was significantly higher in the RG than in the UG. The percentage of miscarriage, threat of premature labor, intrauterine fetal death, preterm premature rupture of membranes, and intrauterine growth retardation were similar in both groups. Newborn anthropometric parameters were corrected by sex and gestational age prior to statistical analysis. Length at birth and head circumference were lower in the RG than in the UG. Birth weight was similar in both groups. The percentage of head circumference less than the 5th percentile and the ponderal index were greater in the RG than in the UG. Our results suggest that proximity to pesticide applications may increase the risk of pregnancy complications and altered newborn parameters.

Remote Patient Monitoring and Incentives to Support Smoking Cessation Among Pregnant and Postpartum Medicaid Members: Three Randomized Controlled Pilot Studies

BACKGROUND

Smoking rates among low-income individuals, including those eligible for Medicaid, have not shown the same decrease that is observed among high-income individuals. The rate of smoking among pregnant women enrolled in Medicaid is almost twice that among privately insured women, which leads to significant disparities in birth outcomes and a disproportionate cost burden placed on Medicaid. Several states have identified maternal smoking as a key target for improving birth outcomes and reducing health care expenditures; however, efficacious, cost-effective, and feasible cessation programs have been elusive.

OBJECTIVE

This study aims to examine the feasibility, acceptability, and effectiveness of a smartwatch-enabled, incentive-based smoking cessation program for Medicaid-eligible pregnant smokers.

METHODS

Pilot 1 included a randomized pilot study of smartwatch-enabled remote monitoring versus no remote monitoring for 12 weeks. Those in the intervention group also received the SmokeBeat program. Pilot 2 included a randomized pilot study of pay-to-wear versus pay-to-quit for 4 weeks. Those in a pay-to-wear program could earn daily incentives for wearing the smartwatch, whereas those in pay-to-quit program could earn daily incentives if they wore the smartwatch and abstained from smoking. Pilot 3, similar to pilot 2, had higher incentives and a duration of 3 weeks.

RESULTS

For pilot 1 (N=27), self-reported cigarettes per week among the intervention group declined by 15.1 (SD 27) cigarettes over the study; a similar reduction was observed in the control group with a decrease of 17.2 (SD 19) cigarettes. For pilot 2 (N=8), self-reported cigarettes per week among the pay-to-wear group decreased by 43 cigarettes (SD 12.6); a similar reduction was seen in the pay-to-quit group, with an average of 31 (SD 45.6) fewer cigarettes smoked per week. For pilot 3 (N=4), one participant in the pay-to-quit group abstained from smoking for the full study duration and received full incentives.

CONCLUSIONS

Decreases in smoking were observed in both the control and intervention groups during all pilots. The use of the SmokeBeat program did not significantly improve cessation. The SmokeBeat program, remote cotinine testing, and remote delivery of financial incentives were considered feasible and acceptable. Implementation challenges remain for providing evidence-based cessation incentives to low-income pregnant smokers. The feasibility and acceptability of the SmokeBeat program were moderately high. Moreover, the feasibility and acceptability of remote cotinine testing and the remotely delivered contingent financial incentives were successful.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03209557; https://clinicaltrials.gov/ct2/show/NCT03209557.

Protective Mechanism of Luteinizing Hormone and Follicle-Stimulating Hormone Against Nicotine-Induced Damage of Mouse Early Folliculogenesis

Previous studies have shown that nicotine could impair the germ cell cyst breakdown and the primordial follicle assembly by autophagy. In this paper, we discovered that luteinizing hormone (LH) and follicle-stimulating hormone (FSH) could counteract the damage caused by nicotine of mouse germ cell cyst breakdown. The neonatal mice were separately intraperitoneally injected with nicotine, nicotine plus LH, nicotine plus FSH, and saline (control) for 4 days. Compared with the nicotine group, the quality of oocytes and the number of follicles were remarkably increased in the nicotine plus LH group or nicotine plus FSH group. LH and FSH could alleviate nicotine-induced oocyte autophagy by different pathways. LH reduced the nicotine-induced autophagy by restoring the phosphorylation level of adenosine 5′-monophosphate-activated protein kinase α-1, while FSH by downregulating the phosphorylation level of Forkhead box class O 1. In addition, in a subsequent study of 6-week mice in different treated groups, we found that LH and FSH supplementation significantly improved normal maturation rates, fertilization rates, and embryo’s developmental potential of oocytes in oocytes exposed to nicotine. Taken together, these results suggested that LH and FSH could counteract the damage caused by nicotine and finally ensure normal germ cell cyst breakdown and early embryo development.

DNA methylome perturbations: an epigenetic basis for the emergingly heritable neurodevelopmental abnormalities associated with maternal smoking and maternal nicotine exposure†

Maternal smoking during pregnancy is associated with an ensemble of neurodevelopmental consequences in children and therefore constitutes a pressing public health concern. Adding to this burden, contemporary epidemiological and especially animal model research suggests that grandmaternal smoking is similarly associated with neurodevelopmental abnormalities in grandchildren, indicative of intergenerational transmission of the neurodevelopmental impacts of maternal smoking. Probing the mechanistic bases of neurodevelopmental anomalies in the children of maternal smokers and the intergenerational transmission thereof, emerging research intimates that epigenetic changes, namely DNA methylome perturbations, are key factors. Altogether, these findings warrant future research to fully elucidate the etiology of neurodevelopmental impairments in the children and grandchildren of maternal smokers and underscore the clear potential thereof to benefit public health by informing the development and implementation of preventative measures, prophylactics, and treatments. To this end, the present review aims to encapsulate the burgeoning evidence linking maternal smoking to intergenerational epigenetic inheritance of neurodevelopmental abnormalities, to identify the strengths and weaknesses thereof, and to highlight areas of emphasis for future human and animal model research therein.

Birth outcomes following unexpected job loss: a matched-sibling design

BACKGROUND

Research documents social and economic antecedents of adverse birth outcomes, which may include involuntary job loss. Previous work on job loss and adverse birth outcomes, however, lacks high-quality individual data on, and variation in, plausibly exogenous job loss during pregnancy and therefore cannot rule out strong confounding.

METHODS

We analysed unique linked registries in Denmark, from 1980 to 2017, to examine whether a father's involuntary job loss during his spouse's pregnancy increases the risk of a low-weight (i.e. <2500 grams) and/or preterm (i.e. <37 weeks of gestational age) birth. We applied a matched-sibling design to 743 574 sibling pairs.

RESULTS

Results indicate an increased risk of a low-weight birth among infants exposed in utero to fathers' unexpected job loss [odds ratio (OR) = 1.37, 95% confidence interval (CI): 1.07, 1.75]. Sex-specific analyses show that this result holds for males (OR = 1.70, 95% CI: 1.14, 2.53) but not females (OR = 1.24, 95% CI: 0.80, 1.91). We find no relation with preterm birth.

CONCLUSIONS

Findings support the inference that a father's unexpected job loss adversely affects the course of pregnancy, especially among males exposed in utero.

Smoking for two- effects of tobacco consumption on placenta

Tobacco smoking is an important public health issue recognized by the world health organization as one of the most serious, preventable risk factors for developing a series of pregnancy pathologies. Maternal smoking is positively associated with intrauterine growth restriction (IUGR) and gestational diabetes (GDM), but negatively associated with preeclampsia (PE). In this review, we examine epidemiological, clinical and laboratory studies of smoking effects on immunoregulation during pregnancy, trophoblast function, and placental vasculature development and metabolism. We aim to identify effects of tobacco smoke components on specific placental compartments or cells, which may contribute to the understanding of the influences of maternal smoking on placenta function in normal and pathological pregnancies. Data corroborates that in any trimester, smoking is unsafe for pregnancy and that its detrimental effects outweigh questionable benefits. The effects of maternal smoking on the maternal immune regulation throughout pregnancy and the impact of different tobacco products on fetal growth have not yet been fully understood. Smoking cessation rather than treatment with replacement therapies is recommended for future mothers because also single components of tobacco and its smoke may have detrimental effects on placental function.

Racial and ethnic disparities in birth Outcomes: A decomposition analysis of contributing factors

This study seeks to quantify and rank the contribution of selected factors to the observed racial/ethnic disparities in low-birth-weight births (LBWBs) and preterm births (PTBs). Based on vital statistics data on births to primiparous women and characteristics of mothers in the State of Nebraska during the period of 2005 to 2014 (n = 93,375), unadjusted and adjusted odds ratios were estimated to examine the association between selected variables and the odds of having LBWBs or PTBs. Fairlie decomposition analysis was performed to quantify the contribution of each selected factor to racial/ethnic differences in LBWB and PTB rates. The prevalence of PTBs was 9.1% among non-Hispanic White (NHW) women, as compared to 12.8% among non-Hispanic Black (NHB) women and 10.6% among Hispanic women. The corresponding prevalence of LBWBs in the three groups were 5.9%, 11.9%, and 7.2%, respectively. The higher educational attainment among NHW women, relative to NHB women accounted for 10% of the observed difference in LBWB rate between the two groups. Health insurance coverage was the second most important factor accounting for the observed disparities in birth outcomes. Addressing socioeconomic disadvantages in NHB and Hispanic women would be important for them to narrow their gaps with NHW women in LBWB and PTB prevalence. More research is needed to identify key factors leading to the disparities in birth outcomes between NHW and NHB women.

The Intergenerational Transmission of Developmental Nicotine Exposure-Induced Neurodevelopmental Disorder-Like Phenotypes is Modulated by the Chrna5 D397N Polymorphism in Adolescent Mice

Maternal tobacco smoking during pregnancy constitutes developmental nicotine exposure (DNE) and is associated with nicotine dependence and neurodevelopmental disorders in both children and grandchildren as well as animal models thereof. Genetic variants such as the CHRNA5 single nucleotide polymorphism (SNP) rs16969968, which leads to an aspartic acid to asparagine substitution at amino acid position 398 (D398N) in the alpha-5 nicotinic acetylcholine receptor subunit, can also confer risk for nicotine dependence and neurodevelopmental disorders in the absence of DNE. However, the degrees to which, the consequences of maternal smoking on offspring outcomes are influenced by genetic variants and interactions therewith are not well understood. Addressing this void in the literature, the present study utilizes a DNE mouse model engineered to possess the equivalent of the human D398N SNP in CHRNA5 (D397N SNP in mice) to assess how the N397 risk allele impacts the induction and intergenerational transmission of a range of neurodevelopmental disorder-related behavioral phenotypes in first- and second-generation DNE offspring. Results reveal that offspring possessing the N397 variant in the absence of DNE as well as DNE offspring and grand offspring possessing theD397 variant exhibit analogous neurodevelopmental disorder-like phenotypes including hyperactivity, risk-taking behaviors, aberrant rhythmicity of activity, and enhanced nicotine consumption. DNE amplified these behavioral anomalies in first-generation N397 progeny, but the severity of DNE-evoked behavioral perturbations did not significantly differ between first-generation D397 and N397 DNE mice for any measure. Remarkably, the behavioral profiles of second-generation N397 DNE progeny closely resembled DNE-naive D397 mice, suggesting that the N397 variant may protect against the intergenerational transmission of DNE-induced neurodevelopmental disorder-like behaviors.

Maternal Nicotine Exposure Alters Hippocampal Microglia Polarization and Promotes Anti-inflammatory Signaling in Juvenile Offspring in Mice

Accumulating evidence reveal that maternal smoking or perinatal nicotine replacement therapy impairs hippocampal neurogenesis, neural development, and cognitive behaviors in the offspring. Microglia is a source of non-neural regulation of neuronal development and postnatal neurogenesis. In this study, we explored the impact of nicotine on the microglia during the development of hippocampus. Developmental nicotine exposure in a mouse model was conducted by supplementing nicotine in the drinking water to mother mice during gestation and lactation period. We found that juvenile offspring with maternal nicotine exposure presented physical and neurobehavioral development delay and an increase in anxiety-like behavior in the open field test on postnatal day (PND) 20. To further detect possible developmental neurotoxic effects of nicotine in offspring and underlying mechanism, whole genome microarray analysis of the expression profile of the hippocampus was performed on postnatal day 20. Significant alterations in the expression of genes related to inflammatory, neurotransmitter, and synapsis were observed in the hippocampus after maternal nicotine exposure, as compared to the vehicle control. Concurrently, an increase in microglial markers and the presence of M2 polarity state in the hippocampus of the nicotine offspring were observed by histological analysis and confocal z-stacking scanning. The M2 microglial polarization state was further confirmed with in vitro primary microglia culture by cytokine array, and double-positive expression of BDNF/Iba1 in microglia by immunohistochemical staining in the juvenile offspring hippocampus was visualized. We also found that nicotine offspring showed an increase of neurite length in the molecular layer and CA1 by Tuj1 staining, as well as an increase in the expression of synapse associated protein, PSD95, but the expression of NeuroD1 in CA1 and CA3 reduced. In summary, maternal nicotine exposure dysregulates immune-related genes expression by skewing the polarity of M2 microglia in the hippocampus, which may cause abnormal cognitive and behavioral performance in the offspring.

Agreement and Disparities between Women and Stop-Smoking Specialists about How to Promote Adherence to Nicotine Replacement Therapy in Pregnancy

Evidence for the effectiveness of nicotine replacement therapy (NRT) for smoking-cessation in pregnancy is weak. This has been attributed to insufficient dosing and low adherence. This study investigated the acceptability of key messages and delivery modes for a behavioral intervention to increase NRT adherence in pregnancy. Semi-structured telephone interviews were carried out with pregnant or postpartum women aged ≥16 from across England, who had been offered NRT during pregnancy as part of a quit attempt and who struggled to quit (n = 10), and a focus group with stop-smoking specialists from across England (n = 6). The two data sources were coded separately using a thematic approach and then integrated to compare perspectives. Women and specialists agreed on message tone and delivery modes. However, views diverged on the most influential sources for certain messages and whether some information should be given proactively or reactively. There was also disagreement over which messages were novel and which were routinely delivered. This study demonstrates the value of capturing and integrating different perspectives and informational requirements when developing behavior-change interventions. The findings provide useful insights for designing a pregnancy-specific NRT adherence intervention that is acceptable to both those who will deliver and receive it.

The Intricate Interactions between Maternal Smoking and Drinking During Pregnancy and Birthweight Z-Scores of Preterm Births

BACKGROUND

The extent to which smoking and drinking in a local community is associated with nutrition and Z-scores of infants from spontaneous preterm deliveries, is uncertain.

AIM

To investigate associations of different levels of maternal smoking and drinking in spontaneous preterm birth with infant birthweight Z-scores.

METHODS

Information, including gestational age (determined by earliest ultrasound), maternal arm circumference (measured at enrolment), smoking-drinking data (obtained up to 4 occasions), birthweight data (obtained from medical records) and birthweight Z-scores (calculated from INTERGROWTH- 21st study), collected over a period of nine years was used to compare 407 spontaneous preterm births with 3 493 spontaneous term births Analyses of variance, correlations and multiple regression were performed in STATISTICA.

RESULTS

Women with spontaneous preterm birth, had significantly lower gravidity and smaller arm circumference when compared to women with spontaneous birth at term. Women with spontaneous preterm birth drank more and heavier during pregnancy, and more smoked. Gestational age at birth was significantly longer in heavy-smokers-heavy-drinkers compared to heavy-smokers-no-drinkers (7.1 days) and in no-smokers-heavy-drinkers when compared to no-smokers-no-drinkers (11.2 days). Birthweight was significantly lower in low-smokers-heavy-drinkers when compared to low-smokers-no-drinkers (240g) and in heavy-smokers-low-drinkers when compared to no-smokers-low-drinkers (273g). Birthweight Z-scores were significantly lower in low-smokers-heavy-drinkers when compared to low-smokers-low-drinkers and low-smokers-no-drinkers; and, also significantly lower in heavy-smokers-low-drinkers when compared to low-smokers-low-drinkers and no-smokers-low-drinkers.

CONCLUSION

Alcohol aggravates the detrimental effect of smoking on birthweight and birthweight Z-scores but seems to counteract the negative association of smoking with gestational age.

Health outcomes of smoking during pregnancy and the postpartum period: an umbrella review

BACKGROUND

Smoking during pregnancy (SDP) and the postpartum period has serious health outcomes for the mother and infant. Although some systematic reviews have shown the impact of maternal SDP on particular conditions, a systematic review examining the overall health outcomes has not been published. Hence, this paper aimed to conduct an umbrella review on this issue.

METHODS

A systematic review of systematic reviews (umbrella review) was conducted according to a protocol submitted to PROSPERO ( CRD42018086350 ). CINAHL, EMBASE, MEDLINE, PsycINFO, Web of Science, CRD Database and HMIC databases were searched to include all studies published in English by 31 December 2017, except those focusing exclusively on low-income countries. Two researchers conducted the study selection and quality assessment independently.

RESULTS

The review included 64 studies analysing the relationship between maternal SDP and 46 health conditions. The highest increase in risks was found for sudden infant death syndrome, asthma, stillbirth, low birth weight and obesity amongst infants. The impact of SDP was associated with the number of cigarettes consumed. According to the causal link analysis, five mother-related and ten infant-related conditions had a causal link with SDP. In addition, some studies reported protective impacts of SDP on pre-eclampsia, hyperemesis gravidarum and skin defects on infants. The review identified important gaps in the literature regarding the dose-response association, exposure window, postnatal smoking.

CONCLUSIONS

The review shows that maternal SDP is not only associated with short-term health conditions (e.g. preterm birth, oral clefts) but also some which can have life-long detrimental impacts (e.g. obesity, intellectual impairment).

IMPLICATIONS

This umbrella review provides a comprehensive analysis of the overall health impacts of SDP. The study findings indicate that while estimating health and cost outcomes of SDP, long-term health impacts should be considered as well as short-term effects since studies not including the long-term outcomes would underestimate the magnitude of the issue. Also, interventions for pregnant women who smoke should consider the impact of reducing smoking due to health benefits on mothers and infants, and not solely cessation.

Maternal smoking during pregnancy: Trends and determinants in the conception to community study

BACKGROUND

Despite earlier declines, maternal smoking during pregnancy continues to be a public health problem. We examined trends and factors associated with maternal smoking during and between pregnancy over six years.

METHODS

Participants were 27 532 pregnant women in Tasmanian public hospitals whose smoking status was gathered by midwives during perinatal care between July 2008 and June 2014. Generalized linear modeling was used to examine the trends in prevalence of maternal smoking over time and factors associated with change in smoking status both within and between pregnancies.

RESULTS

Smoking during pregnancy decreased from 25.9% in 2008 to 16.4% in 2014 (57.9% decline). Multivariable regression analysis suggested that maternal alcohol consumption during pregnancy, living in a highly socioeconomically disadvantaged area, and being an Aboriginal or Torres Strait Islander significantly increased the risk of maternal smoking during pregnancy. Being older, married, or in a de facto relationship, and intending to breastfeed were associated with reduced risk of smoking during pregnancy. Between index (first birth recorded in data set) and last pregnancy, 35.1% of smokers quit, but 5.1% of nonsmokers started smoking. Only 8.1% of mothers who smoked during the first half of pregnancy quit by the second half.

CONCLUSIONS

Maternal smoking during pregnancy is decreasing. To sustain the decline, preventive efforts must address the role of social determinants of health (eg, mothers who drink alcohol, live in highly disadvantaged areas, are younger and single) among women who smoke during pregnancy.

Preterm Birth and Antiretroviral Exposure in Infants HIV-exposed Uninfected

BACKGROUND

Infants HIV-exposed and uninfected (IHEU) who are born to women living with HIV are at an increased risk of preterm birth (PTB). Antenatal exposure to certain maternal antiretroviral therapy (ART) regimens has been associated with PTB, although existing studies in this domain are limited and report discordant findings. We determined odds of PTB among IHEU by antenatal ART regimens and timing of exposure, adjusting for maternal risk factors.

METHODS

We retrospectively studied IHEU born in British Columbia (BC), Canada between 1990 and 2012 utilizing provincial health administrative databases. We included data from a control group of infants HIV-unexposed and uninfected (IHUU) matched ~3:1 for each IHEU on age, sex and geocode.

RESULTS

A total of 411 IHEU and 1224 IHUU were included in univariable analysis. PTB was more frequent among IHEU (20%) compared with IHUU (7%). IHEU were more often antenatally exposed to alcohol, tobacco, as well as prescription, nonprescription, and illicit drugs (IHEU: 36%, 8% and 35%; vs. IHUU: 3%, 1% and 9%, respectively). After adjusting for maternal substance use and smoking exposure, IHEU remained at increased odds of PTB [adjusted odds ratio (aOR) (95% CI): 2.66; (1.73, 4.08)] compared with matched IHUU controls. ART-exposed IHEU (excluding those with NRTIs only ART) had lower adjusted odds of PTB compared with IHEU with no maternal ART exposure, regardless of regimen [aOR range: 0.16-0.29 (0.02-0.95)]. Odds of PTB between IHEU exposed to ART from conception compared with IHEU exposed to ART postconception did not differ [aOR: 0.91 (0.47, 1.76)]; however, both groups experienced lower odds of PTB compared with IHEU with no maternal ART [preconception: aOR: 0.28 (0.08, 0.89); postconception: aOR 0.30 (0.11, 0.83)].

CONCLUSIONS

BC IHEU were over twice as likely to be born preterm compared with demographically matched controls. Maternal substance use in pregnancy modulated this risk; however, we found no adverse associations of PTB with exposure to antenatal ART.

A Qualitative Study of Factors Influencing Adherence among Pregnant Women Taking Part in a Trial of E-Cigarettes for Smoking Cessation

Use of e-cigarettes (vaping) has potential to help pregnant women stop smoking. This study explored factors influencing adherence among participants in the vaping arm of the first trial of vaping for smoking cessation in pregnancy. We conducted semi-structured telephone interviews (n = 28) with women at three-months postpartum. Interviews were analysed using thematic analysis, informed by the Theoretical-Domains Framework, Necessity-Concerns Framework and Perceptions and Practicalities Approach. Interviewees generally reported high levels of vaping. We found that: (1) intervention adherence was driven by four necessity beliefs-stopping smoking for the baby, and vaping for harm reduction, smoking cessation or as a last resort; (2) necessity beliefs outweighed vaping concerns, such as dependence and safety; (3) adherence was linked to four practicalities themes, acting as barriers and facilitators to vaping-device and e-liquid perceptions, resources and support, whether vaping became habitual, and social and environmental factors; and (4) intentional non-adherence was rare; unintentional non-adherence was due to device failures, forgetting to vape, and personal circumstances and stress. Pregnant smokers provided with e-cigarettes, and with generally high levels of vaping, had positive beliefs about the necessity of vaping for smoking cessation which outweighed concerns about vaping. Non-adherence was mainly due to unintentional factors.

Proposing a new approach to measuring birth size asymmetry

BACKGROUND

Existing methods of measuring birth size asymmetry based on ratios of growth parameters are clinically useful but simplistic, and as such may have limited usefulness in studies of aetiology.

OBJECTIVES

We aimed to develop a novel method of measuring asymmetric fetal growth at birth and demonstrate its utility in characterising the perturbed growth associated with a number of prenatal exposures and neonatal outcomes.

METHODS

Data were drawn from the Queensland (QLD) Perinatal Data Collection, which included all livebirths in the Australian state of QLD between July 2010 and December 2015, with analyses restricted to babies born between 32 and 42 weeks of gestation (n = 280 084). Novel measures of asymmetric birthweight, length, and head circumference were developed using a weighted average, representing "how far" an individual's given birth size measure deviated from the sample average and their other birth size measures. Associations among prenatal exposures and neonatal outcomes with the new asymmetry measures and traditional ratio measures (ie ponderal index, brain-to-body weight ratio, and birth length divided by head circumference) were then compared using log-binomial and multinomial regressions.

RESULTS

The new asymmetry measures clearly indicated that prenatal smoking was linked to a disproportionate decrease in all birth size measures and that low birthweight asymmetry and low birth head circumference asymmetry were specifically associated with neonatal respiratory distress and chromosomal abnormalities, respectively. When these same associations were tested using the traditional ratios, the estimates were weak, imprecise, and non-specific.

CONCLUSIONS

We developed a new approach to measuring fetal growth asymmetry which provides complimentary insights against the existing ratios approach. Associations with the new asymmetry measures were more precise and easier to interpret than the associations obtained using the ratios, and may better reflect the underlying pathological processes, providing an advantage when investigating the aetiologies of perturbed fetal growth.

Antenatal interventions for preventing stillbirth, fetal loss and perinatal death: an overview of Cochrane systematic reviews

BACKGROUND

Stillbirth is generally defined as a death prior to birth at or after 22 weeks' gestation. It remains a major public health concern globally. Antenatal interventions may reduce stillbirths and improve maternal and neonatal outcomes in settings with high rates of stillbirth. There are several key antenatal strategies that aim to prevent stillbirth including nutrition, and prevention and management of infections.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on the effects of antenatal interventions for preventing stillbirth for low risk or unselected populations of women.

METHODS

We collaborated with Cochrane Pregnancy and Childbirth's Information Specialist to identify all their published reviews that specified or reported stillbirth; and we searched the Cochrane Database of Systematic Reviews (search date: 29 Feburary 2020) to identify reviews published within other Cochrane groups. The primary outcome measure was stillbirth but in the absence of stillbirth data, we used perinatal mortality (both stillbirth and death in the first week of life), fetal loss or fetal death as outcomes. Two review authors independently evaluated reviews for inclusion, extracted data and assessed quality of evidence using AMSTAR (A Measurement Tool to Assess Reviews) and GRADE tools. We assigned interventions to categories with graphic icons to classify the effectiveness of interventions as: clear evidence of benefit or harm; clear evidence of no effect or equivalence; possible benefit or harm; or unknown benefit or harm or no effect or equivalence.

MAIN RESULTS

We identified 43 Cochrane Reviews that included interventions in pregnant women with the potential for preventing stillbirth; all of the included reviews reported our primary outcome 'stillbirth' or in the absence of stillbirth, 'perinatal death' or 'fetal loss/fetal death'. AMSTAR quality was high in 40 reviews with scores ranging from 8 to 11 and moderate in three reviews with a score of 7. Nutrition interventions Clear evidence of benefit: balanced energy/protein supplementation versus no supplementation suggests a probable reduction in stillbirth (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.39 to 0.94, 5 randomised controlled trials (RCTs), 3408 women; moderate-certainty evidence). Clear evidence of no effect or equivalence for stillbirth or perinatal death: vitamin A alone versus placebo or no treatment; and multiple micronutrients with iron and folic acid versus iron with or without folic acid. Unknown benefit or harm or no effect or equivalence: for all other nutrition interventions examined the effects were uncertain. Prevention and management of infections Possible benefit for fetal loss or death: insecticide-treated anti-malarial nets versus no nets (RR 0.67, 95% CI 0.47 to 0.97, 4 RCTs; low-certainty). Unknown evidence of no effect or equivalence: drugs for preventing malaria (stillbirth RR 1.02, 95% CI 0.76 to 1.36, 5 RCTs, 7130 women, moderate certainty in women of all parity; perinatal death RR 1.24, 95% CI 0.94 to 1.63, 4 RCTs, 5216 women, moderate-certainty in women of all parity). Prevention, detection and management of other morbidities Clear evidence of benefit: the following interventions suggest a reduction: midwife-led models of care in settings where the midwife is the primary healthcare provider particularly for low-risk pregnant women (overall fetal loss/neonatal death reduction RR 0.84, 95% CI 0.71 to 0.99, 13 RCTs, 17,561 women; high-certainty), training versus not training traditional birth attendants in rural populations of low- and middle-income countries (stillbirth reduction odds ratio (OR) 0.69, 95% CI 0.57 to 0.83, 1 RCT, 18,699 women, moderate-certainty; perinatal death reduction OR 0.70, 95% CI 0.59 to 0.83, 1 RCT, 18,699 women, moderate-certainty). Clear evidence of harm: a reduced number of antenatal care visits probably results in an increase in perinatal death (RR 1.14 95% CI 1.00 to 1.31, 5 RCTs, 56,431 women; moderate-certainty evidence). Clear evidence of no effect or equivalence: there was evidence of no effect in the risk of stillbirth/fetal loss or perinatal death for the following interventions and comparisons: psychosocial interventions; and providing case notes to women. Possible benefit: community-based intervention packages (including community support groups/women's groups, community mobilisation and home visitation, or training traditional birth attendants who made home visits) may result in a reduction of stillbirth (RR 0.81, 95% CI 0.73 to 0.91, 15 RCTs, 201,181 women; low-certainty) and perinatal death (RR 0.78, 95% CI 0.70 to 0.86, 17 RCTs, 282,327 women; low-certainty). Unknown benefit or harm or no effect or equivalence: the effects were uncertain for other interventions examined. Screening and management of fetal growth and well-being Clear evidence of benefit: computerised antenatal cardiotocography for assessing infant's well-being in utero compared with traditional antenatal cardiotocography (perinatal mortality reduction RR 0.20, 95% CI 0.04 to 0.88, 2 RCTs, 469 women; moderate-certainty). Unknown benefit or harm or no effect or equivalence: the effects were uncertain for other interventions examined.

AUTHORS' CONCLUSIONS

While most interventions were unable to demonstrate a clear effect in reducing stillbirth or perinatal death, several interventions suggested a clear benefit, such as balanced energy/protein supplements, midwife-led models of care, training versus not training traditional birth attendants, and antenatal cardiotocography. Possible benefits were also observed for insecticide-treated anti-malarial nets and community-based intervention packages, whereas a reduced number of antenatal care visits were shown to be harmful. However, there was variation in the effectiveness of interventions across different settings, indicating the need to carefully understand the context in which these interventions were tested. Further high-quality RCTs are needed to evaluate the effects of antenatal preventive interventions and which approaches are most effective to reduce the risk of stillbirth. Stillbirth (or fetal death), perinatal and neonatal death need to be reported separately in future RCTs of antenatal interventions to allow assessment of different interventions on these rare but important outcomes and they need to clearly define the target populations of women where the intervention is most likely to be of benefit. As the high burden of stillbirths occurs in low- and middle-income countries, further high-quality trials need to be conducted in these settings as a priority.

Sex-specific alterations in GABA receptor-mediated responses in laterodorsal tegmentum are associated with prenatal exposure to nicotine

Smoking during pregnancy is associated with deleterious physiological and cognitive effects on the offspring, which are likely due to nicotine-induced alteration in the development of neurotransmitter systems. Prenatal nicotine exposure (PNE) in rodents is associated with changes in behaviors controlled in part by the pontine laterodorsal tegmentum (LDT), and LDT excitatory signaling is altered in a sex and age-dependent manner by PNE. As effects on GABAergic LDT signaling are unknown, we used calcium imaging to evaluate GABA_A receptor- (GABA_A R as well as GABA_A -_ρ R) and GABA_B receptor (GABA_B R)-mediated calcium responses in LDT brain slices from female and male PNE mice in two different age groups. Overall, in older PNE females, changes in calcium induced by stimulation of GABA_A R and GABA_B R, including GABA_A -_ρ R were shifted toward calcium rises. In both young and old males, PNE was associated with alterations in calcium mediated by all three receptors; however, the GABA_A R was the most affected. These results show for the first time that PNE is associated with alterations in GABAergic transmission in the LDT in a sex- and age-dependent manner, and these data are the first to show PNE-associated alterations in functionality of GABA receptors in any nucleus. PNE-associated alterations in LDT GABAergic transmission within the LDT would be expected to alter output to target regions and could play a role in LDT-implicated, negative behavioral outcomes following gestational exposure to smoking. Accordingly, our data provide further supportive evidence of the importance of eliminating the consumption of nicotine during pregnancy.