Tobacco and pregnancy: Overview of exposures and effects

Risk Factors for Thyroid Dysfunction in Pregnancy: An Individual Participant Data Meta-Analysis

Background: International guidelines recommend targeted screening to identify gestational thyroid dysfunction. However, currently used risk factors have questionable discriminative ability. We quantified the risk for thyroid function test abnormalities for a subset of risk factors currently used in international guidelines. Methods: We included prospective cohort studies with data on gestational maternal thyroid function and potential risk factors (maternal age, body mass index [BMI], parity, smoking status, pregnancy through in vitro fertilization, twin pregnancy, gestational age, maternal education, and thyroid peroxidase antibody [TPOAb] or thyroglobulin antibody [TgAb] positivity). Exclusion criteria were pre-existing thyroid disease and use of thyroid interfering medication. We analyzed individual participant data using mixed-effects regression models. Primary outcomes were overt and subclinical hypothyroidism and a treatment indication (defined as overt hypothyroidism, subclinical hypothyroidism with thyrotropin >10 mU/L, or subclinical hypothyroidism with TPOAb positivity). Results: The study population comprised 65,559 participants in 25 cohorts. The screening rate in cohorts using risk factors currently recommended (age >30 years, parity ≥2, BMI ≥40) was 58%, with a detection rate for overt and subclinical hypothyroidism of 59%. The absolute risk for overt or subclinical hypothyroidism varied <2% over the full range of age and BMI and for any parity. Receiver operating characteristic curves, fitted using maternal age, BMI, smoking status, parity, and gestational age at blood sampling as explanatory variables, yielded areas under the curve ranging from 0.58 to 0.63 for the primary outcomes. TPOAbs/TgAbs positivity was associated with overt hypothyroidism (approximate risk for antibody negativity 0.1%, isolated TgAb positivity 2.4%, isolated TPOAb positivity 3.8%, combined antibody positivity 7.0%; p < 0.001), subclinical hypothyroidism (risk for antibody negativity 2.2%, isolated TgAb positivity 8.1%, isolated TPOAb positivity 14.2%, combined antibody positivity 20.0%; p < 0.001) and a treatment indication (risk for antibody negativity 0.2%, isolated TgAb positivity 2.2%, isolated TPOAb positivity 3.0%, and combined antibody positivity 5.1%; p < 0.001). Twin pregnancy was associated with a higher risk of overt hyperthyroidism (5.6% vs. 0.7%; p < 0.001). Conclusions: The risk factors assessed in this study had poor predictive ability for detecting thyroid function test abnormalities, questioning their clinical usability for targeted screening. As expected, TPOAb positivity (used as a benchmark) was a relevant risk factor for (subclinical) hypothyroidism. These results provide insights into different risk factors for gestational thyroid dysfunction.

Direct adsorption sampling and ambient mass spectrometry analysis of tobacco smoke with porous paper strips

Chemical analysis of atmospheric aerosols by conventional analytical methods is usually required to perform complicated and time-consuming sample preparation processes. In recent decades, ambient ionization mass spectrometry (AI-MS) methods have been proven to be simple, rapid, and effective analytical tools for direct analysis of various complex samples. In this work, we applied porous paper filters for direct adsorptive sampling of tobacco smoke, and then the sampled paper filters were performed the emitters of the paper spray ionization (PSI) device. An auto-sampling device was made to control the generation and collection of tobacco smoke. Nicotine, the typical compound of tobacco smoke, was used to optimize the key conditions of auto-sampling. Moreover, different types of tobacco smoke were also compared with multivariate variable analysis, and the makers of tobacco smoke from different sources of tobacco smoke were investigated. By using this method, direct sampling and analysis of a single tobacco sample can be completed within minutes. Overall, our results show that PSI-MS is a powerful tool that integrates collection, extraction, ionization, and identification analytes in smoke.

Association between prenatal cadmium exposure and child development: The Japan Environment and Children's study

Cadmium is a heavy metal that can be found in soil, air, food, and water. Cadmium has toxic effects on the kidneys, bones, and respiratory system. Prenatal exposure to cadmium has been found to affect the mental development of children, but inconsistent results have been found in different studies. Therefore, it is unknown that prenatal cadmium exposure associated with child development after birth. To elucidate whether cadmium affect the child development or not, we analyzed nation-wide cohort study data, the Japan Environment and Children's Study. Prenatal cadmium concentrations in blood from mothers in the second or third trimester were determined by inductively coupled plasma mass spectrometry. Child development was evaluated using "Ages and Stages" questionnaires. The association between cadmium and child development were investigated by performing logistic regression analyses, multinomial logistic regression analyses and generalized linear mixed model using the child development parameters as dependent variables and the cadmium concentrations in maternal blood as the independent variable. There were significant associations between the cadmium concentration and child development at 6 months, 1 year, and 1.5 years after birth. However, the effect had disappeared at 2 years after birth or later. The number of developmental delays was positively associated with the cadmium concentration after adjusting individual difference. The results indicate that prenatal exposure affects child development, but the effect decreases with age.

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.

Harmful Effect of Intrauterine Smoke Exposure on Neuronal Control of "Fetal Breathing System" in Stillbirths

This article is aimed to contribute to the current knowledge on the role of toxic substances such as nicotine on sudden intrauterine unexplained deaths’ (SIUDS’) pathogenetic mechanisms. The in-depth histopathological examination of the autonomic nervous system in wide groups of victims of SIUDS (47 cases) and controls (20 cases), with both smoking and no-smoking mothers, highlighted the frequent presence of the hypodevelopment of brainstem structures checking the vital functions. In particular, the hypoplasia of the pontine parafacial nucleus together with hypoplastic lungs for gestational age were observed in SIUDS cases with mothers who smoked cigarettes, including electronic ones. The results allow us to assume that the products of cigarette smoke during pregnancy can easily cross the placental barrier, thus entering the fetal circulation and damaging the most sensitive organs, such as lungs and brain. In a non-negligible percentage of SIUDS, the mothers did not smoke. Furthermore, based on previous and ongoing studies conducted through analytical procedures and the use of scanning electron microscopy, the authors envisage the involvement of toxic nanoparticles (such as agricultural pesticides and nanomaterials increasingly used in biomedicine, bioscience and biotechnology) in the death pathogenesis, with similar mechanisms to those of nicotine.

The relation of number of childbirths with age at natural menopause: a population study of 310 147 women in Norway

STUDY QUESTION

Does age at natural menopause increase with increasing of number of childbirths?

SUMMARY ANSWER

Age at menopause increased with increasing number of childbirths up to three childbirths; however, we found no further increase in age at menopause beyond three childbirths.

WHAT IS KNOWN ALREADY

Pregnancies interrupt ovulation, and a high number of pregnancies have therefore been assumed to delay menopause. Previous studies have had insufficient statistical power to study women with a high number of childbirths. Thus, the shape of the association of number of childbirths with age at menopause remains unknown.

STUDY DESIGN, SIZE, DURATION

A retrospective population study of 310 147 women in Norway who were 50–69 years old at data collection.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The data were obtained by two self-administered questionnaires completed by women attending BreastScreen Norway, a population-based screening program for breast cancer. The associations of number of childbirths with age at menopause were estimated as hazard ratios by applying Cox proportional hazard models, adjusting for the woman’s year of birth, cigarette smoking, educational level, country of birth, oral contraceptive use and body mass index.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with three childbirths had the highest mean age at menopause (51.36 years; 95% CI: 51.33–51.40 years), and women with no childbirths had the lowest (50.55 years; 95% CI: 50.48–50.62 years). Thus, women with no childbirths had higher hazard ratio of reaching menopause compared to women with three childbirths (reference group) (adjusted hazard ratio, 1.24; 95% CI: 1.22–1.27). Beyond three childbirths, we estimated no further increase in age at menopause. These findings were confirmed in sub-analyses among (i) women who had never used hormonal intrauterine device and/or systemic menopausal hormonal therapy; (ii) women who were born before 1950 and (iii) women who were born in 1950 or after.

LIMITATIONS, REASONS FOR CAUTION

Information about age at menopause was based on self-reports.

WIDER IMPLICATIONS OF THE FINDINGS

If pregnancies truly delay menopause, one would expect that women with the highest number of childbirths had the highest age at menopause. Our results question the assumption that interrupted ovulation during pregnancy delays menopause.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the South-Eastern Norway Regional Health Authority [2016112 to M.S.G.] and by the Norwegian Cancer Society [6863294-2015 to E.K.B.]. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Declining trends in smokeless tobacco use among Indian women: findings from global adult tobacco survey I and II

BACKGROUND

Smokeless Tobacco (SLT) use is culturally rooted and more acceptable among women in India. SLT is a significant risk for oral cancers and has other adverse health outcomes on women's general as well as reproductive health. This study aimed to estimate and compare the prevalence and correlates of SLT among adult females in India using Global Adult Tobacco Survey (GATS), 2009-2010 (GATS 1) and 2016-2017 (GATS 2).

METHODS

Data from a nationally representative cross-sectional study GATS 1 (n = 35,529) and GATS 2 (n = 40,265) were analysed for adult female smokeless tobacco users. Correlates of SLT exposure were assessed separately using binary logistic regression. Multivariable logistic regression analysis was done for the variables which computed p < 0.1. The association was expressed as Adjusted Odds ratio with 95% confidence intervals.

RESULTS

There was a reduction in prevalence of SLT use among women in India between GATS 1 (18.4%) and GATS 2 (12.8%). SLT use was highest among the North-Eastern women in both rounds [AOR: 4.567 (3.942-5.292) during GATS-1 and 9.149 (7.722-10.839) during GATS-2]. Odisha had highest prevalence of 56.53% while Himachal Pradesh had lowest 0.14% during the recent GATS 2 survey. 33.3% vs. 34.80% of the participants were willing to quit tobacco in Central region across both rounds of survey.

CONCLUSIONS

Although, smokeless tobacco prevalence among females has reduced between 2009 and 2016 in India, yet tobacco control strategies need further pace. Hence, more focused gender-based tobacco control programs and policies are the need of time.

Impact of Heavy Metals on Human Male Fertility-An Overview

Heavy metals are endocrine disruptors which interfere with processes mediated by endogenous hormones of the organism, negatively affecting endocrine functions. Some studies have correlated heavy metal exposure with male infertility. However, the number of studies conducted on humans are limited. Therefore, the aim of this study is to summarize the current knowledge on how heavy metals influence human male fertility. Hence, three distinct databases were consulted—PubMed, Scopus and Web of Science—using single keywords and combinations of them. The total number of identified articles was 636. Nevertheless, by using the inclusion and exclusion criteria, 144 articles were finally included in this work. Results display that the development of adequate instruments for heavy metal assessment may play an important function in human male fertility diagnosis and treatment. Furthermore, clinical trials could be useful to confirm the role of heavy metals in human male fertility diagnosis. Overall, further research is required to fully understand the molecular and cellular basis of the influence of environmental and occupational exposure to heavy metals on human male infertility and reproductive outcomes.

Prenatal Exposure to Cigarette Smoke and Anogenital Distance at 4 Years in the INMA-Asturias Cohort

Smoking by women is associated with adverse pregnancy outcomes such as spontaneous abortion, preterm delivery, low birth weight, infertility, and prolonged time to pregnancy. Anogenital distance (AGD) is a sensitive biomarker of prenatal androgen and antiandrogen exposure. We investigated the effect of smoking and passive smoke exposure during pregnancy on anogenital distance in offspring at 4 years in the INMA-Asturias cohort (Spain). Women were interviewed during pregnancy to collect information on tobacco consumption, and anogenital distance was measured in 381 children: Anoscrotal distance in boys and anofourchetal distance in girls. We also measured maternal urinary cotinine levels at 32 weeks of pregnancy. We constructed linear regression models to analyze the association between prenatal smoke exposure and anogenital distance and adjusted the models by relevant covariates. Reported prenatal smoke exposure was associated with statistically significant increased anogenital index (AGI), both at week 12 of pregnancy (β = 0.31, 95% confidence interval: 0.00, 0.63) and at week 32 of pregnancy (β = 0.31, 95% confidence interval: 0.00, 0.63) in male children, suggesting altered androgenic signaling.

White paper on smokeless tobacco & women's health in India

Smokeless tobacco (SLT) use is widespread across many nations and populations, and India shares more than three-quarters of the global burden of SLT consumption. Tobacco use in India has been largely viewed as a male-dominant behaviour. However, evidence from medical, social and behavioural sciences show significant SLT use among women and young girls. This paper highlights key dimensions of SLT use among women in India including prevalence and determinants, the health effects arising from SLT use and cessation behaviours. The paper concludes by providing recommendations with the aim of setting research priorities and policy agenda to achieve a tobacco-free society. The focus on women and girls is essential to achieve the national targets for tobacco control under the National Health Policy, 2017, and Sustainable Development Goals 3 of ensuring healthy lives and promote well-being for all.

Increased Risk for Cerebral Hypoxia During Immediate Neonatal Transition After Birth in Term Neonates Delivered by Caesarean Section With Prenatal Tobacco Exposure

Introduction: Maternal tobacco smoking during pregnancy is a global health problem leading to an increased risk for fetal and neonatal morbidities. So far, there are no data of the potential impact of maternal smoking during pregnancy on the most vulnerable period after birth - the immediate postnatal transition. The aim of the present study was therefore, to compare cerebral oxygenation during immediate postnatal transition in term neonates with and without prenatal tobacco exposure. Methods: Included in this post-hoc analysis were healthy term neonates, with measurements of cerebral oxygenation (INVOS 5100C) during the first 15 min after birth, and for whom information on maternal smoking behavior during pregnancy was available. Neonates with prenatal tobacco exposure (smoking group) were matched 1:1 according to gestational age (±1 week), birth weight (±100 grams) and hematocrit (±5 %) to neonates without (non-smoking group). Cerebral regional tissue oxygen saturation (crSO₂), cerebral fractional tissue oxygen extraction (cFTOE), arterial oxygen saturation (SpO₂) and heart rate (HR) within the first 15 min after birth were compared between the two groups. Results: Twelve neonates in the smoking group with a median (IQR) gestational age of 39.1 (38.8-39.3) weeks and a birth weight of 3,155 (2,970-3,472) grams were compared to 12 neonates in the non-smoking group with 39.1 (38.7-39.2) weeks and 3,134 (2,963-3,465) grams. In the smoking group, crSO₂ was significantly lower and cFTOE significantly higher until min 5 after birth. HR was significantly higher in the smoking group in min 3 after birth. Beyond this period, there were no significant differences between the two groups. Conclusion: Cerebral oxygenation within the first 5 min after birth was compromised in neonates with prenatal tobacco exposure. This observation suggests a higher risk for cerebral hypoxia immediately after birth due to fetal tobacco exposure.

Fetal and Postnatal Nicotine Exposure Modifies Maturation of Gonocytes to Spermatogonia in Mice

Studies in laboratory animals have shown that male offspring from dams, exposed to nicotine during pregnancy and postnatal periods, show alterations in fertility, although the origin of this is still uncertain. In this study, we examined in a mouse model if the process of gonocyte maturation to spermatogonia was affected in male offspring from dams with nicotine administration during pregnancy and postnatal periods. BALB/C mice, with and without nicotine administrations in pregnancy and postnatal periods, were studied. The animals were euthanized at 3, 7, 10, 16, and 35 days postpartum (dpp). Testicular tissue samples were processed for histological, ultrastructural, and immunohistochemical studies; and testicular lipoperoxidation was determined. It was observed that in the nicotine-exposed animals, there was increased apoptosis and a reduction in the number of gonocytes that matured to spermatogonia. This gonocyte-spermatogonia maturation reduction was associated with a greater immunoreactivity to nicotinic acetylcholine receptors in the germ cells. Lipoperoxidation was similar in both groups until 16 dpp, with significant reduction at 35 dpp. Our findings suggest that nicotine intake during pregnancy and postnatal periods can affect the process of maturation of gonocytes to spermatogonia and the pool of available spermatogonia for spermatogenesis.

Chronic effects of maternal tobacco-smoke exposure and/or α-lipoic acid treatment on reproductive parameters in female rat offspring

Prenatal tobacco-smoke exposure negatively affects the reproductive functions of female offspring and oxidative stress plays a major role at this point. Alpha-lipoic acid (ALA), well known as a biological antioxidant, has been used as a nutritional supplement and as a therapeutic agent in the treatment of certain complications during pregnancy. We aimed to investigate the effects of maternal tobacco-smoke exposure and/or ALA administration on puberty onset, sexual behavior, gonadotrophin levels, apoptosis-related genes, apoptotic cell numbers and oxidative stress markers in the adult female rat offspring. Sprague-Dawley rats were divided into four groups; control, tobacco smoke (TS), TS+ALA and ALA groups. Animals were exposed to TS and/or ALA for 8 weeks before pregnancy and throughout pregnancy. All treatments ended with birth and later newborn female rats were selected for each experimental group. The experiment ended at postnatal day 74-77. Maternal tobacco smoke advanced the onset of puberty in the female offspring of the TS group (p < 0.05). In all treatment groups; the mean number of anogenital investigations and lordosis quality scores showed a decline, serum luteinizing hormone levels significantly increased (p < 0.05) and several histopathological changes in ovaries were observed compared to the control group. In addition, an increase in apoptotic marker levels and apoptotic cell numbers was detected in the ovaries of all treatment groups. Decreased TAS and increased TOS levels were detected in all treatment groups compared to control. These findings suggested that maternal tobacco smoke and/or ALA administration may be leading to the impaired reproductive health of female offspring. Abbreviations: ALA: alpha-lipoic acid; LH: luteinizing hormone; FSH: follicle-stimulating hormone; TAS: total antioxidant status; TOS: total oxidant status; Apaf1: apoptotic protease-activating factor 1; Casp3: caspase 3; Casp9: caspase 9; CF: cyst follicles; 4-HNE: 4-Hidroxynonenal; 8-OHdG: 8-hydroxydeoxyguanosine; TUNEL: terminal deoxynucleotidyl transferase-mediated deoxyuridine-biotin nick end labeling; ROS: reactive oxygen species; GnRHR: gonadotropin-releasing hormone receptor; HPG: hypothalamic-pituitary-gonadal; AMPK: AMP-activated protein kinase; ELISA: enzyme-linked immunosorbent assay; cDNA: complementary DNA; qPCR: quantitative real-time PCR; FC: follicular cysts; PF: primary follicle; SF: secondary follicle; GF: graafian follicle; CL: corpus luteum; DF: degenerated follicle; AF: atretic follicle.

In vivo assessment of the toxicity of electronic cigarettes to zebrafish (Danio rerio) embryos, following gestational exposure, in terms of mortality, developmental toxicity, and hair cell damage: Toxicity of E-cigs to zebrafish embryos

With the ban of conventional cigarettes from public spaces, electronic cigarette (E-cig) liquids have emerged as a nicotine replacement treatment for smoking cessation. However, consumers possess little knowledge of the ingredients and health effects of E-cig liquids following exposure. This study evaluated hair cell damage and developmental toxicities following gestational exposure to E-cig liquids. Zebrafish embryos were exposed to E-cig liquids at different concentrations (0.1%, 0.2%, and 0.4%). Embryonic developmental toxicity and hair cell damage was evaluated at 6 and 7 d, respectively, after fertilization. The average number of hair cells in the anterior lateral line (ALL) and posterior lateral line (PLL) following E-cig exposure was compared to that of the control. Morphological abnormalities and heart rate were evaluated. E-cig liquids significantly damaged the hair cells in the ALL, compared to the control (control; 52.85 ± 5.29 cells, 0.1% E-cig; 49.43 ± 7.70 cells, 0.2% E-cig; 40.68 ± 12.00 cells, 0.4% E-cig; 32.14 ± 20.75%; n = 29-40; p < 0.01). At high concentrations, E-cig liquids significantly damaged the hair cells in the PLL (control; 36.88 ± 5.43 cells, 0.1% E-cig; 33.06 ± 5.21 cells, 0.2% E-cig; 30.95 ± 8.03 cells, 0.4% E-cig; 23.72 ± 15.53%, n = 29-40; p < 0.01). No morphological abnormalities in body shape, somites, notochord, tail, and pectoral fin were observed; however, abnormalities were observed in the dorsal fin and heart rate at high concentrations. Thus, gestational exposure to E-cigs significantly damaged hair cells in a concentration-dependent manner and induced developmental toxicities to the dorsal fin and heart rate at high concentrations.

General practitioner and obstetrician views on system changes to improve smoking cessation care in pregnancy in Australia: a cross-sectional survey

Introduction

Systemic barriers impacting smoking cessation in pregnant women may include nicotine replacement therapy (NRT) access and training.

Aim

Assess general practitioner (GP) and obstetrician's agreement with system-based changes to improve the management of smoking in pregnancy; compare group responses.

Methods

National cross-sectional survey with two samples: (1) online survey emailed to a random sample of 500 GPs from Royal Australian College of General Practitioners (RACGP); (2) paper survey posted to 5571 GPs and obstetricians from Royal Australia and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). Percentages agreeing that specified changes would improve the management of smoking in pregnancy were calculated. Pairwise comparisons used Kruskal–Wallis tests (RACGP/RANZCOG GPs/obstetricians).

Results

N = 378 participated. Response rates 8.4% (N = 42; online survey) and 6% (N = 335; paper survey), respectively. Total percentages agreeing with system-based changes: 79% training, 64% oral NRT subsidy, 62% Medicare item for smoking cessation, 54% improved access to NRT patches. Within RANZCOG, more GPs (73.1%) agreed that oral NRT should be subsidised (P = 0.001) than obstetricians (53.7%).

Conclusion

GPs and obstetricians agreed that system changes would improve their management of smoking in pregnancy. Oral NRT subsidy was the only pairwise group difference. Subsequently, oral NRT has been subsidised; in time, this may influence prescribing and quit rates.

Effects of cigarette smoke components on myocardial differentiation of mouse embryonic stem cells

The heart is the first organ formed in the developing fetus, and abnormal development of the heart is a major cause of fetal death. The adverse effects of cigarette smoke on the heart have been well established, but it is not well understood how cigarette smoke components regulate signaling molecules and cardiac specific functions during the early differentiation stage of the embryonic heart. In this study, we identified changes in the size of mouse embryoid bodies (mEBs) in response to treatment with cigarette smoke extract (CSE) via regulation of HDAC2, p53, p21, and cyclin D1 protein expression, which are cardiac differentiation and cell-cycle markers, respectively. In addition, exposure of mouse embryonic stem cells (mESCs) to cigarette smoke components inhibited myocardial differentiation and development through the expression of HDAC1, HDAC2, GATA4, NKX2-5, TBX5, HAND1, and Troponin I. Long-term exposure studies showed that CSE and nicotine may delay the development of mouse cardiomyocytes from mESCs and inhibit the contractibility, which is a fundamental function of the heart. Taken together, these findings suggest that cigarette smoke components, including nicotine, may affect abnormal myocardial differentiation and development.

The brain-placental axis: Therapeutic and pharmacological relevancy to pregnancy

The placenta plays a critical role in mammalian reproduction. Although it is a transient organ, its function is indispensable to communication between the mother and fetus, and supply of nutrients and oxygen to the growing fetus. During pregnancy, the placenta is vulnerable to various intrinsic and extrinsic conditions which can result in increased risk of fetal neurodevelopmental disorders as well as fetal death. The placenta controls the neuroendocrine secretion in the brain as a means of adaptive processes to safeguard the fetus from adverse programs, to optimize fetal development and other physiological changes necessary for reproductive success. Although a wealth of information is available on neuroendocrine functions in pregnancy, they are largely limited to the regulation of hypothalamus-pituitary-adrenal/gonad (HPA/ HPG) axis, particularly the oxytocin and prolactin system. There is a major gap in knowledge on systems-level functional interaction between the brain and placenta. In this review, we aim to outline the current state of knowledge about the brain-placental axis with description of the functional interactions between the placenta and the maternal and fetal brain. While describing the brain-placental interactions, a special emphasis has been given on the therapeutics and pharmacology of the placental receptors to neuroligands expressed in the brain during gestation. As a key feature of this review, we outline the prospects of integrated pharmacogenomics, single-cell sequencing and organ-on-chip systems to foster priority areas in this field of research. Finally, we remark on the application of precision genomics approaches to study the brain-placental axis in order to accelerate personalized medicine and therapeutics to treat placental and fetal brain disorders.

Smoking and pregnancy: Epigenetics and developmental origins of the metabolic syndrome

Maternal smoking causes lower birth weight, birth defects, and other adverse pregnancy outcomes. Epidemiological evidence over the past four decades has grown stronger and the adverse outcomes attributed to maternal smoking and secondhand smoke exposure have expanded. This review presents findings of latent and persistent metabolic effects in offspring of smoking mothers like those observed in studies of maternal undernutrition during pregnancy. The phenotype of offspring of smoking mothers is like that associated with maternal undernutrition. Born smaller than offspring of nonsmokers, these children have increased risk of being overweight or obese later. Plausible mechanisms include in utero hypoxia, nicotine-induced reductions in uteroplacental blood flow, placental toxicity, or toxic growth restriction from the many toxicants in tobacco smoke. Studies have reported increased risk of insulin resistance, type 2 diabetes and hypertension although the evidence here is weaker than for overweight/obesity. Altered DNA methylation has been consistently documented in smoking mothers' offspring, and these epigenetic alterations are extensive and postnatally durable. A causal link between altered DNA methylation and the phenotypic changes observed in offspring remains to be firmly established, yet the association is strong, and mediation analyses suggest a causal link. Studies examining expression patterns of affected genes during childhood development and associated health outcomes should be instructive in this regard. The adverse effects of exposure to tobacco smoke during pregnancy now clearly include permanent metabolic derangements in offspring that can adversely affect life-long health.

Prenatal toxicity of the environmental pollutants on neuronal and cardiac development derived from embryonic stem cells

Pesticides, antibiotics, and industrial excipients are widely used in agriculture, medicine, and chemical industry, respectively. They often end up in the environment, not only being not easily decomposed but also being accumulated. Moreover, they may cause serious toxic problems such as reproductive and developmental defects, immunological toxicity, and carcinogenesis. Hence, they are called environmental pollutants. It is known that the environmental pollutants easily enter the body through various channels such as respiration, ingestion of food, and skin contact etc. in everyday life. If they enter the mother through the placenta, they can cause the disturbance in embryo development as well as malfunction of organs after birth because early prenatal developmental process is highly sensitive to toxic chemicals and stress. Embryonic stem cells (ESCs) that consist of inner cell mass of blastocyst differentiate into distinct cell lineages via three germ layers such as the ectoderm, mesoderm, and endoderm due to their pluripotency. The differentiation process initiated from ESCs reflects dynamic nature of embryonic development. Therefore, ESCs have been used as a useful tool to investigate early developmental toxicities of a variety of stress. Based on relatively recent scientific results, this review would address toxicity of a few chemical substances that have been widely used as pesticide, antibiotics, and industrial excipient on ESCs based-prenatal developmental process. This review further suggests how they act on the viability of ESCs and/or early stages of cardiac and neuronal development derived from ESCs as well as on expression of pluripotency and/or differentiation markers through diverse mechanisms.

Developmental toxicity of e-cigarette aerosols

Maternal smoking during pregnancy represents a major public health concern increasing the risk for low birth weight, congenital anomalies, preterm birth, fetal mortality, and morbidity. In an effort to diminish adverse developmental effects of exposure to cigarette smoking, pregnant women, and women of reproductive age, are increasingly turning to electronic nicotine delivery systems (ENDS), such as e-cigarettes, as an alternative. Given that health risks associated with ENDS use during pregnancy are largely unknown, there is an acute need to determine risks vs. benefits of e-cigarette use by pregnant women. While the most recent Surgeon General's Report on the "Health Consequences of Smoking" states that "the evidence is sufficient to infer that nicotine adversely affects maternal and fetal health during pregnancy, contributing to multiple adverse outcomes," it remains unclear whether use of ENDS represents a "safer alternative" to tobacco smoking during pregnancy. This is due, in part, to the lack of sufficient and conclusive evidence concerning whether or not maternal e-cigarette use adversely affects embryonic/fetal development. While several recent developmental studies have challenged the safety of nicotine inhalation via ENDS, the true risks of smoking e-cigarettes during the first trimester of pregnancy-the period of organogenesis-are largely unknown. Moreover, evidence is emerging that even nicotine-free e-cigarette aerosols may harm the developing conceptus, suggesting that components of e-cigarette liquid, including flavorings, may be developmentally toxicity. Focused human epidemiological analyses, and carefully designed animal studies are critically needed to address the question of the safety of ENDS use during pregnancy.

Secondhand smoke exposure during pregnancy: a cross-sectional analysis of data from Demographic and Health Survey from 30 low-income and middle-income countries

BACKGROUND

Secondhand smoke (SHS) exposure during pregnancy increases the risk of infant stillbirth, congenital malformations, low birth weight and respiratory illnesses. However, little is known about the extent of SHS exposure during pregnancy. We assessed the prevalence of SHS exposure in pregnant women in low-income and middle-income countries (LMICs).

METHODS

We used Demographic and Health Survey data collected between 2008 and 2013 from 30 LMICs. We estimated weighted country-specific prevalence of SHS exposure among 37 427 pregnant women. We accounted for sampling weights, clustering and stratification in the sampling methods. We also explored associations between sociodemographic variables and SHS exposure in pregnant women using pairwise multinomial regression model.

FINDINGS

The prevalence of daily SHS exposure during pregnancy ranged from 6% (95% CI 5% to 7%) (Nigeria) to 73% (95% CI 62% to 81%) (Armenia) and was greater than active tobacco use in pregnancy across all countries studied. Being wealthier, maternal employment, higher education and urban households were associated with lower SHS exposure in full regression models. SHS exposure in pregnant women closely mirrors WHO Global Adult Tobacco Survey male active smoking patterns. Daily SHS exposure accounted for a greater population attributable fraction of stillbirths than active smoking, ranging from 1% of stillbirths (Nigeria) to 14% (Indonesia).

INTERPRETATION

We have demonstrated that SHS exposure during pregnancy is far more common than active smoking in LMICs, accounting for more stillbirths than active smoking. Protecting pregnant women from SHS exposure should be a key strategy to improve maternal and child health.

Associations between metal concentrations in whole blood and placenta previa and placenta accreta: the Japan Environment and Children's Study (JECS)

Background

Placenta previa and placenta accreta associate with high morbidity and mortality for both mothers and fetus. Metal exposure may have relationships with placenta previa and placenta accreta. This study analyzed the associations between maternal metal (cadmium [Cd], lead [Pb], mercury [Hg], selenium [Se], and manganese [Mn]) concentrations and placenta previa and placenta accreta.

Methods

We recruited 17,414 women with singleton pregnancies. Data from a self-administered questionnaire regarding the first trimester and medical records after delivery were analyzed. Maternal blood samples were collected to measure metal concentrations. The subjects were classified into four quartiles (Q1, Q2, Q3, and Q4) according to metal concentrations.

Results

The odds ratio for placenta previa was significantly higher among subjects with Q4 Cd than those with Q1 Cd. The odds ratio for placenta previa was significantly higher for subjects with Q2 Pb than those with Q1 Pb.

Conclusion

Participants with placenta previa had higher Cd concentrations. However, this study was cross-sectional and lacked important information related to Cd concentration, such as detailed smoking habits and sources of Cd intake. In addition, the subjects in this study comprised ordinary pregnant Japanese women, and it was impossible to observe the relationship between a wide range of Cd exposure and placenta previa. Therefore, epidemiological and experimental studies are warranted to verify the relationship between Cd exposure and pregnancy abnormalities.

Electronic supplementary material

The online version of this article (10.1186/s12199-019-0795-7) contains supplementary material, which is available to authorized users.

Manganese levels in newborns' hair by maternal sociodemographic, dietary and environmental factors

Exposure to manganese (Mn) has been associated with neurodevelopmental problems in children. Mn exposure begins in utero, and maternal sociodemographic, dietary and environmental factors may affect Mn levels in newborns' hair. This study aimed to characterize in utero Mn exposure using Mn levels in newborns' hair as a biomarker of prenatal exposure, and to analyze its relationship with sociodemographic, dietary and environmental factors in the Spanish INMA-Gipuzkoa cohort. Overall, 638 pregnant women were recruited in the first trimester of pregnancy and a hair sample was obtained from 473 newborns. Sociodemographic, dietary and environmental data were recorded through two questionnaires administered in the first and third trimesters of pregnancy. The median Mn concentration in newborns´ hair was 0.31 µg/g (P5 = 0.02; P95 = 1.23). Mn levels in newborns´ hair were associated with smoking during pregnancy (β = 0.222; 95% CI = 0.065-0.379) and with maternal PM_2.5 exposure (β = 0.025; 95% CI = 0.004; 0.047), as well as with cereal and pasta intake in the first trimester of pregnancy (β = 0.002; 95% CI = 0.0004; 0.003). In conclusion, fetal exposure to Mn was associated with smoking and exposure to atmospheric pollution during pregnancy.

Toxic Effect of Cigarette Smoke on Brainstem Nicotinic Receptor Expression: Primary Cause of Sudden Unexplained Perinatal Death

Among the neurotoxicants contained in tobacco smoke, if absorbed during pregnancy, nicotine significantly affects α7-nicotinic acetylcholine receptors, which play essential roles in the development of the brainstem regions receiving cholinergic projections in perinatal life. Immunohistochemical procedures for analysing formalin-fixed and paraffin-embedded brainstem samples from 68 fetuses and early newborns, with smoking and non-smoking mothers, who died of known and unknown causes, were carried out in order to determine if nicotine had activated the α7-nicotinic acetylcholine receptors. High α7-nicotinic acetylcholine receptor expression levels were only observed in the victims with smoking mothers. Frequently, these findings were associated with the hypoplasia of the brainstem structures controlling vital functions. The results of this study indicate that the exposition to nicotine in pregnancy exerts a strong direct effect on α7-nicotinic acetylcholine receptor activity especially in perinatal life and may be one of the primary risk factors leading to the sudden unexplained death of fetuses and newborns.

Maternal smoking and low family income during pregnancy as predictors of the relationship between depression and adiposity in young adults

There is an increasing incidence of overweight/obesity and mental health disorders in young adults and the two conditions often coexist. We aimed to investigate the influence of antenatal and postnatal factors that may underlie this association with a focus on maternal prenatal smoking, socio-economic status and gender. Data from the Western Australian Pregnancy Cohort (Raine) Study (women enrolled 1989-1991) including 1056 offspring aged 20 years (cohort recalled 2010-2012) were analyzed (2015-2016) using multivariable models for associations between offspring depression scores (DASS-21 Depression-scale) and body mass index (BMI), adjusting for pregnancy and early life factors and offspring behaviours. There was a significant positive relationship between offspring depression-score and BMI independent of gender and other psychosocial covariates. There was a significant interaction between maternal prenatal smoking and depression-score (interaction coefficient=0.096; 95% CI: 0.006, 0.19, P=0.037), indicating the relationship between depression-score and BMI differed according to maternal prenatal smoking status. In offspring of maternal prenatal smokers, a positive association between BMI and depression-score (coefficient=0.133; 95% CI: 0.05, 0.21, P=0.001) equated to 1.1 kg/m2 increase in BMI for every 1standard deviation (8 units) increase in depression-score. Substituting low family income during pregnancy for maternal prenatal smoking in the interaction (interaction coefficient=0.091; 95% CI: 0.01, 0.17, P=0.027) showed a positive association between BMI and depression score only among offspring of mothers with a low family income during pregnancy (coefficient=0.118; 95% CI: 0.06, 0.18, P<0.001). There were no significant effects of gender on these associations. Whilst further studies are needed to determine whether these associations are supported in other populations, they suggest potentially important maternal behavioural and socio-economic factors that identify individuals vulnerable to the coexistence of obesity and depression in early adulthood.

Examining characteristics associated with quitting smoking during pregnancy and relapse postpartum

INTRODUCTION

Smoking during pregnancy is a significant public health concern that can cause adverse health outcomes for both the mother and fetus. Studies have shown only 40% of women quit smoking during pregnancy, with more than half relapsing within 6months, and up to 90% relapsing within one year. This study investigates differences in demographics and smoking-related symptomatology between pregnant smokers and pregnant quitters, as well as factors associated with postpartum relapse.

METHODS

Data on pregnant smokers and pregnant quitters were obtained from two separate parent studies. Data on smoking demographics and smoking-related symptomatology were collected at screening visits.

RESULTS

Compared to pregnant smokers, pregnant quitters had more favorable smoking characteristics (e.g., smoked fewer cigarettes per day, reported higher motivation for abstinence and less dependency). They also had more favorable relationship characteristics (e.g., were more likely to be married, less likely to have a significant other who smokes) and had less reproductive liability (e.g., fewer pregnancies, fewer children). In terms of symptomatology, pregnant quitters reported more positive affect, negative affect, physical symptoms and withdrawal but less craving. Predictors of postpartum relapse included increased maternal age, having a significant other who smokes and an increased likelihood of returning to smoking after pregnancy (self-reported prior to delivery).

CONCLUSIONS

Several demographics and smoking-related symptomatology were significantly different between pregnant quitters and pregnant smokers. In addition, multiple factors predicting postpartum relapse were identified. This information can inform personalized interventions for high risk pregnant smokers and pregnant quitters at risk for postpartum relapse.

Barriers to and facilitators of smoking cessation in pregnancy and following childbirth: literature review and qualitative study

BACKGROUND

Although many women stop smoking in pregnancy, others continue, causing harm to maternal and child health. Smoking behaviour is influenced by many factors, including the role of women's significant others (SOs) and support from health-care professionals (HPs).

OBJECTIVES

To enhance understanding of the barriers to, and facilitators of, smoking cessation and the feasibility and acceptability of interventions to reach and support pregnant women to stop smoking.

DESIGN

Four parts: (1) a description of interventions in the UK for smoking cessation in pregnancy; (2) three systematic reviews (syntheses) of qualitative research of women's, SOs' and HPs' views of smoking in pregnancy using meta-ethnography (interpretative approach for combining findings); (3) semistructured interviews with pregnant women, SOs and HPs, guided by the social-ecological framework (conceptualises behaviour as an outcome of individuals' interactions with environment); and (4) identification of new/improved interventions for future testing.

SETTING

Studies in reviews conducted in high-income countries. Qualitative research was conducted from October 2013 to December 2014 in two mixed urban/rural study sites: area A (Scotland) and area B (England).

PARTICIPANTS

Thirty-eight studies (1100 pregnant women) in 42 papers, nine studies (150 partners) in 14 papers and eight studies described in nine papers (190 HPs) included in reviews. Forty-one interviews with pregnant women, 32 interviews with pregnant women's SOs and 28 individual/group interviews with 48 HPs were conducted.

MAIN OUTCOME MEASURES

The perceived barriers to, and facilitators of, smoking cessation in pregnancy and the identification of potential new/modified interventions.

RESULTS

Syntheses identified smoking-related perceptions and experiences for pregnant women and SOs that were fluid and context dependent with the capacity to help or hinder smoking cessation. Themes were analysed in accordance with the social-ecological framework levels. From the analysis of the interviews, the themes that were central to cessation in pregnancy at an individual level, and that reflected the findings from the reviews, were perception of risk to baby, self-efficacy, influence of close relationships and smoking as a way of coping with stress. Overall, pregnant smokers were faced with more barriers than facilitators. At an interpersonal level, partners' emotional and practical support, willingness to change smoking behaviour and role of smoking within relationships were important. Across the review and interviews of HPs, education to enhance knowledge and confidence in delivering information about smoking in pregnancy and the centrality of the client relationship, protection of which could be a factor in downplaying risks, were important. HPs acknowledged that they could best assist by providing support and understanding, and access to effective interventions, including an opt-out referral pathway to Stop Smoking Services, routine carbon monoxide screening, behavioural support and access to pharmacotherapy. Additional themes at community, organisational and societal levels were also identified.

LIMITATIONS

Limitations include a design grounded in qualitative studies, difficulties recruiting SOs, and local service configurations and recruitment processes that potentially skewed the sample.

CONCLUSIONS

Perceptions and experiences of barriers to and facilitators of smoking cessation in pregnancy are fluid and context dependent. Effective interventions for smoking cessation in pregnancy should take account of the interplay between the individual, interpersonal and environmental aspects of women's lives.

FUTURE WORK

Research focus: removing barriers to support, improving HPs' capacity to offer accurate advice, and exploration of weight concerns and relapse prevention. Interventions focus: financial incentives, self-help and social network interventions.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013004170.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Cumulative exposure to environmental pollutants during early pregnancy and reduced fetal growth: the Project Viva cohort

BACKGROUND

Reduced fetal growth is associated with perinatal and later morbidity. Prenatal exposure to environmental pollutants is linked to reduced fetal growth at birth, but the impact of concomitant exposure to multiple pollutants is unclear. The purpose of this study was to examine interactions between early pregnancy exposure to cigarette smoke, traffic pollution, and select perfluoroalkyl substances (PFASs) on birth weight-for-gestational age (BW/GA).

METHODS

Among 1597 Project Viva mother-infant pairs, we assessed maternal cigarette smoking by questionnaire, traffic pollution at residential address by black carbon land use regression model, and plasma concentration of select PFASs in early pregnancy. We calculated sex-specific BW/GA z-scores, an index of fetal growth, from national reference data. We fit covariate-adjusted multi-pollutant linear regression models and examined interactions between exposures, using a likelihood-ratio test to identify a best-fit model.

RESULTS

Two hundred six (13%) mothers smoked during pregnancy. Mean [standard deviation (SD)] for black carbon was 0.8 (0.3) μg/m³, perfluorooctane sulfonate (PFOS) was 29.1 (16.5) ng/mL, and BW/GA z-score was 0.19 (0.96). In the best-fit model, BW/GA z-score was lower in infants of mothers exposed to greater black carbon [- 0.08 (95% CI: -0.15, - 0.01) per interquartile range (IQR)]. BW/GA z-score (95% CI) was also lower in infants of mothers who smoked [- 0.09 (- 0.23, 0.06)] or were exposed to greater PFOS [- 0.03 (- 0.07, 0.02) per IQR], although confidence intervals crossed the null. There were no interactions between exposures. In secondary analyses, instead of PFOS, we examined perfluorononanoate (PFNA) [mean (SD): 0.7 (0.4) ng/mL], a PFAS more closely linked to lower BW/GA in our cohort. The best-fit multi-pollutant model included positive two-way interactions between PFNA and both black carbon and smoking (p-interactions = 0.03).

CONCLUSIONS

Concurrent prenatal exposures to maternal smoking, black carbon, and PFOS are additively associated with lower fetal growth, whereas PFNA may attenuate associations of smoking and black carbon with lower fetal growth. It is important to examine interactions between multiple exposures in relation to health outcomes, as effects may not always be additive and may shed light on biological pathways.

Improving Behavioral Support for Smoking Cessation in Pregnancy: What Are the Barriers to Stopping and Which Behavior Change Techniques Can Influence These? Application of Theoretical Domains Framework

Behavioral support interventions are used to help pregnant smokers stop; however, of those tested, few are proven effective. Systematic research developing effective pregnancy-specific behavior change techniques (BCTs) is ongoing. This paper reports contributory work identifying potentially-effective BCTs relative to known important barriers and facilitators (B&Fs) to smoking cessation in pregnancy; to detect priority areas for BCTs development. A Nominal Group Technique with cessation experts (n = 12) elicited an expert consensus on B&Fs most influencing women's smoking cessation and those most modifiable through behavioral support. Effective cessation interventions in randomized trials from a recent Cochrane review were coded into component BCTs using existing taxonomies. B&Fs were categorized using Theoretical Domains Framework (TDF) domains. Matrices, mapping BCT taxonomies against TDF domains, were consulted to investigate the extent to which BCTs in existing interventions target key B&Fs. Experts ranked "smoking a social norm" and "quitting not a priority" as most important barriers and "desire to protect baby" an important facilitator to quitting. From 14 trials, 23 potentially-effective BCTs were identified (e.g., information about consequences). Most B&Fs fell into "Social Influences", "Knowledge", "Emotions" and "Intentions" TDF domains; few potentially-effective BCTs mapped onto every TDF domain. B&Fs identified by experts as important to cessation, are not sufficiently targeted by BCT's currently within interventions for smoking cessation in pregnancy.

Gene-gene-environment interactions of prenatal exposed to environmental tobacco smoke, CYP1A1 and GSTs polymorphisms on full-term low birth weight: relationship of maternal passive smoking, gene polymorphisms, and FT-LBW

OBJECTIVE

To examine the interaction effects of prenatal exposed to environmental tobacco smoke (ETS) and genotypes of cytochrome P4501A1 (CYP1A1), glutathione S-transferases (GSTs) on the risk of full-term low birth weight (FT-LBW).

STUDY DESIGN

We conducted a case-control study among pregnant women at two Women and Children's Hospitals in Guangdong, China (n = 910). Information was collected through interview, medical records review, and blood lab tests. Maternal selfreport and serum cotinine concentration were combined to define prenatal exposed to ETS. Logistic regression approach was applied for statistical analysis.

RESULTS

Our results showed that regardless of genotypes, prenatal exposed to ETS significantly increased the risk of FT-LBW. Then, two-way interactions showed increased prevalence of FT-LBW in prenatal exposed to ETS mothers with the CYP1A1 variant genotype (MspI "CC"), or with GSTT1-null genotype. Furthermore, three-way interactions showed that women with CYP1A1 variant (MspI "TC" or BsrDI "AG") genotypes and GSTT1 "null" genotype had higher risk to give birth of FT-LBW. Additionally, among nonexposed ETS mothers, genotype did not independently confer adverse effects on FT-LBW.

CONCLUSIONS

Our results revealed that prenatal exposed to ETS is independently associated with FT-LBW while gene polymorphisms of CYP1A1 and GSTs merely play modified roles in this process. This study extends understanding of three-way interaction, and stresses the need to tobacco control toward pregnant women for better pregnant outcomes.

Maternal Active Smoking During Pregnancy and Low Birth Weight in the Americas: A Systematic Review and Meta-analysis

Introduction

Smoking during pregnancy may negatively impact newborn birth weight. This study investigates the relationship between maternal active smoking during pregnancy and low birth weight in the Americas through systematic review and meta-analysis.

Methods

A literature search was conducted through indexed databases and the grey literature. Case-control and cohort studies published between 1984 and 2016 conducted within the Americas were included without restriction regarding publication language. The article selection process and data extraction were performed by two independent investigators. A meta-analysis of random effects was conducted, and possible causes of between-study heterogeneity were evaluated by meta-regressions and subgroup analyses. Publication bias was assessed by visual inspection of Begg's funnel plot and by Egger's regression test.

Results

The literature search yielded 848 articles from which 34 studies were selected for systematic review and 30 for meta-analysis. Active maternal smoking was associated with low birth weight, OR = 2.00 (95% CI: 1.77-2.26; I2 = 66.3%). The funnel plot and Egger's test (p = .14) indicated no publication bias. Meta-regression revealed that sample size, study quality, and the number of confounders in the original studies did not account for the between-study heterogeneity. Subgroup analysis indicated no significant differences when studies were compared by design, sample size, and regions of the Americas.

Conclusion

Low birth weight is associated with maternal active smoking during pregnancy regardless of the region in the Americas or the studies' methodological aspects.

Implications

A previous search of the major electronic databases revealed that no studies appear to have been conducted to summarize the association between maternal active smoking during pregnancy and low birth weight within the Americas. Therefore, this systematic review may help to fill the information gap. The region of the Americas contains some of the most populous countries in the world; therefore, this study may provide useful data from this massive segment of the world's population.

Nicotinic Receptor Abnormalities in the Cerebellar Cortex of Sudden Unexplained Fetal and Infant Death Victims-Possible Correlation With Maternal Smoking

Nicotinic acetylcholine receptors (nAChRs) are cationic channels of the neuronal cell membrane, differentially expressed in the central nervous system which, when activated by endogenous acetylcholine or exogenous nicotine, are able to enhance cholinergic transmission. The aim of this study was to investigate in human perinatal age the immunohistochemical expression of the α7-nAChR subtype, given its involvement in neuronal differentiation and its significant vulnerability to the toxic effects of nicotine. Thirty fetuses (with a gestational age between 25 and 40 weeks) and 35 infants (1-6 months old), suddenly died of known (controls) and unknown causes (unexplained deaths), with smoking and nonsmoking mothers, were included in this study. A negative or low immunoexpression of α7-nAChRs, indicative of their inactivation, was observed in the granular layers of the cerebellar cortex in 66% of the sudden unexplained perinatal deaths and 11% of the controls. A high correlation was also observed between these findings and maternal smoking. Apart from the well-known adverse effects of nicotine exposure during pregnancy, it may also cause significant alterations in cerebellar cholinergic transmission in areas of the brain involved in vital functions. These events may give us insights into the pathogenetic mechanisms leading to sudden unexplained fetal and infant death.

Mediating role of maternal serum interleukin-1beta and tumor necrosis factor-alpha in the association between environmental tobacco smoke exposure in pregnancy and low birth weight at term

OBJECTIVES

To explore the mediation effects of maternal serum interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) on the association between environmental tobacco smoke (ETS) exposure during pregnancy and low birth weight (LBW) at term.

METHODS

ETS exposure, birth weight, blood sample and covariates were collected from 195 pregnant women delivered term LBW infants and 195 controls delivered normal birth weight infants in two Maternity and Child Hospitals in Guangdong, China. Maternal serum IL-1β and TNF-α were measured by flow cytometry. Logistic regression models and path analyses explored the mediation effects of maternal IL-1β and TNF-α on the association between ETS exposure and LBW.

RESULTS

LBW was significantly associated with maternal ETS exposure (OR = 2.14 (95% CI =1.06-4.32)). TNF-α and IL-1β were significantly associated with both LBW (OR = 1.87 (1.41-2.47) and OR = 1.53 (1.14-2.05)) and ETS (β = 0.32 (0.04-0.60) and β = 0.27 (0.05-0.49)). Traditional mediation analyses indicated the separate mediation effect of TNF-α and IL-1β was 32.2% and 24.6%, respectively. Path analysis revealed the combined mediation effects of TNF-α and IL-1β as 29.4% in the pathway from ETS exposure to LBW.

CONCLUSIONS

Maternal serum IL-1β and TNF-α may play a mediating role in the association between maternal ETS exposure during pregnancy and term LBW.

Timing of Maternal Exposure and Foetal Sex Determine the Effects of Low-level Chemical Mixture Exposure on the Foetal Neuroendocrine System in Sheep

We have shown that continuous maternal exposure to the complex mixture of environmental chemicals (ECs) found in human biosolids (sewage sludge), disrupts mRNA expression of genes crucial for development and long-term regulation of hypothalamic-pituitary gonadal (HPG) function in sheep. The present study investigated whether exposure to ECs only during preconceptional period or only during pregnancy perturbed key regulatory genes within the hypothalamus and pituitary gland and whether these effects were different from chronic (life-long) exposure to biosolid ECs. The findings demonstrate that the timing and duration of maternal EC exposure influences the subsequent effects on the foetal neuroendocrine system in a sex-specific manner. Maternal exposure prior to conception, or during pregnancy only, altered the expression of key foetal neuroendocrine regulatory systems such as gonadotrophin-releasing hormone and kisspeptin to a greater extent than when maternal exposure was 'life-long'. Furthermore, hypothalamic gene expression was affected to a greater extent in males than in females and, following EC exposure, male foetuses expressed more 'female-like' mRNA levels for some key neuroendocrine genes. This is the first study to show that 'real-life' maternal exposure to low levels of a complex cocktail of chemicals prior to conception can subsequently affect the developing foetal neuroendocrine system. These findings demonstrate that the developing neuroendocrine system is sensitive to EC mixtures in a sex-dimorphic manner likely to predispose to reproductive dysfunction in later life.

An interview study of pregnant women who were provided with indoor air quality measurements of second hand smoke to help them quit smoking

Background

Maternal smoking can cause health complications in pregnancy. Particulate matter (PM_2.5) metrics applied to second hand smoke (SHS) concentrations provide indoor air quality (IAQ) measurements and have been used to promote smoking behaviour change among parents of young children. Here, we present the qualitative results from a study designed to use IAQ measurements to help pregnant women who smoke to quit smoking.

Methods

We used IAQ measurements in two centres (Aberdeen and Coventry) using two interventions: 1. In Aberdeen, women made IAQ measurements in their homes following routine ultrasound scan; 2. In Coventry, IAQ measurements were added to a home-based Stop Smoking in Pregnancy Service. All women were invited to give a qualitative interview to explore acceptability and feasibility of IAQ measurements to help with smoking cessation. A case study approach using grounded theory was applied to develop a typology of pregnant women who smoke.

Results

There were 39 women recruited (18 in Aberdeen and 21 in Coventry) and qualitative interviews were undertaken with nine of those women. Diverse accounts of smoking behaviours and experiences of participation were given. Many women reported changes to their smoking behaviours during pregnancy. Most women wanted to make further changes to their own behaviour, but could not commit or felt constrained by living with a partner or family members who smoked. Others could not envisage quitting. Using themes emerging from the interviews, we constructed a typology where women were classified as follows: ‘champions for change’; ‘keen, but not committed’; and ‘can’t quit, won’t quit’. Three women reported quitting smoking alongside participation in our study.

Conclusions

Pregnant women who smoke remain hard to engage,. Although providing IAQ measurements does not obviously improve quit rates, it can support changes in smoking behaviour in/around the home for some individuals. Our typology might offer a useful assessment tool for midwives.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1062-1) contains supplementary material, which is available to authorized users.

Common congenital anomalies: Environmental causes and prevention with folic acid containing multivitamins

Congenital anomalies, congenital defects, or birth defects are significant causes of death in infants. The most common congenital defects are congenital heart defects (CHDs) and neural tube defects (NTDs). Defects induced by genetic mutations, environmental exposure to toxins, or a combination of these effects can result in congenital malformations, leading to infant death or long-term disabilities. These defects produce significant mortality and morbidity in the affected individuals, and families are affected emotional and financially. Also, society is impacted on many levels. Congenital anomalies may be reduced by dietary supplements of folic acid and other vitamins. Here, we review the evidence for specific roles of toxins (alcohol, cigarette smoke) in causing common severe congenital anomalies like CHDs, NTDs, and ocular defects. We also review the evidence for beneficial effects for dietary supplementation, and highlight gaps in our knowledge, where research may contribute to additional benefits of intervention that can reduce birth defects. Extensive discussion of common severe congenital anomalies (CHDs, NTDs, and ocular defects) illustrates the effects of diet on the frequency and severity of these defects. Birth Defects Research (Part C) 108:274-286, 2016. © 2016 Wiley Periodicals, Inc.

N-acetylcysteine attenuates nicotine-induced kindling in female periadolescent rats

Kindling is a form of behavioral sensitization that is related to the progression of several neuropsychiatric disorders such as bipolar disorder. We recently demonstrated that female periadolescent rats are more vulnerable to nicotine (NIC)-induced kindling than their male counterparts. Furthermore, we evidenced that decreases in brain antioxidative defenses may contribute to this gender difference. Here we aimed to determine the preventive effects of the antioxidant N-acetyl cysteine (NAC) against NIC-kindling in female periadolescent rats. To do this female Wistar rats at postnatal day 30 received repeated injections of NIC 2mg/kg, i.p. every weekday for up to 19 days. NAC90, 180 or 270 mg/kg, i.p. was administered 30 min before NIC. The levels of glutathione (GSH), superoxide dismutase (SOD) activity, lipid peroxidation (LP) and nitrite were determined in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST). The development of kindling occurred at a median time of 16.5 days with 87.5% of NIC animals presenting stage 5 seizures in the last day of drug administration. NAC270 prevented the occurrence of kindling. NIC-kindled animals presented decreased levels of GSH and increased LP in the PFC, HC and ST, while SOD activity was decreased in the ST. NAC180 or 270 prevented the alterations in GSH induced by NIC, but only NAC270 prevented the alterations in LP. Nitrite levels increased in the ST of NAC270 pretreated NIC-kindled animals. Taken together we demonstrated that NAC presents anti-kindling effects in female animals partially through the restoration of oxidative alterations.

'Opt-out' referrals after identifying pregnant smokers using exhaled air carbon monoxide: impact on engagement with smoking cessation support

Background

In the UK, free smoking cessation support is available to pregnant women; only a minority accesses this. ‘Opt-out’ referrals to stop smoking services (SSS) are recommended by UK guidelines. These involve identifying pregnant smokers using exhaled carbon monoxide (CO) and referring them for support unless they object.

Methods

To assess the impact of ‘opt-out’ referrals for pregnant smokers on SSS uptake and effectiveness, we conducted a ‘before–after’ service development evaluation. In the 6-month ‘before’ period, there was a routine ‘opt-in’ referral system for self-reported smokers at antenatal ‘booking’ appointments. In the 6-month ‘after’ period, additional ‘opt-out’ referrals were introduced at the 12-week ultrasound appointments; women with CO≥4 ppm were referred to, and outcome data were collected from, local SSS.

Results

Approximately 2300 women attended antenatal care in each period. Before the implementation, 536 (23.4%) women reported smoking at ‘booking’ and 290 (12.7%) were referred to SSS. After the implementation, 524 (22.9%) women reported smoking at ‘booking’, an additional 156 smokers (6.8%) were identified via the ‘opt-out’ referrals and, in total, 421 (18.4%) were referred to SSS. Over twice as many women set a quit date with the SSS after ‘opt-out’ referrals were implemented (121 (5.3%, 95% CI 4.4% to 6.3%) compared to 57 (2.5%, 95% CI 1.9% to 3.2%) before implementation) and reported being abstinent 4 weeks later (93 (4.1%, 95% CI 3.3% to 4.9%) compared to 46 (2.0%, 1.5% to 2.7%) before implementation).

Conclusions

In a hospital with an ‘opt-in’ referral system, adding CO screening with ‘opt-out’ referrals as women attended ultrasound examinations doubled the numbers of pregnant smokers setting quit dates and reporting smoking cessation.

Benefits of Incentives for Breastfeeding and Smoking cessation in pregnancy (BIBS): a mixed-methods study to inform trial design

BACKGROUND

Smoking in pregnancy and/or not breastfeeding have considerable negative health outcomes for mother and baby.

AIM

To understand incentive mechanisms of action for smoking cessation in pregnancy and breastfeeding, develop a taxonomy and identify promising, acceptable and feasible interventions to inform trial design.

DESIGN

Evidence syntheses, primary qualitative survey, and discrete choice experiment (DCE) research using multidisciplinary, mixed methods. Two mother-and-baby groups in disadvantaged areas collaborated throughout.

SETTING

UK.

PARTICIPANTS

The qualitative study included 88 pregnant women/recent mothers/partners, 53 service providers, 24 experts/decision-makers and 63 conference attendees. The surveys included 1144 members of the general public and 497 health professionals. The DCE study included 320 women with a history of smoking.

METHODS

(1) Evidence syntheses: incentive effectiveness (including meta-analysis and effect size estimates), delivery processes, barriers to and facilitators of smoking cessation in pregnancy and/or breastfeeding, scoping review of incentives for lifestyle behaviours; (2) qualitative research: grounded theory to understand incentive mechanisms of action and a framework approach for trial design; (3) survey: multivariable ordered logit models; (4) DCE: conditional logit regression and the log-likelihood ratio test.

RESULTS

Out of 1469 smoking cessation and 5408 breastfeeding multicomponent studies identified, 23 smoking cessation and 19 breastfeeding studies were included in the review. Vouchers contingent on biochemically proven smoking cessation in pregnancy were effective, with a relative risk of 2.58 (95% confidence interval 1.63 to 4.07) compared with non-contingent incentives for participation (four studies, 344 participants). Effects continued until 3 months post partum. Inconclusive effects were found for breastfeeding incentives compared with no/smaller incentives (13 studies) but provider commitment contracts for breastfeeding show promise. Intervention intensity is a possible confounder. The acceptability of seven promising incentives was mixed. Women (for vouchers) and those with a lower level of education (except for breastfeeding incentives) were more likely to disagree. Those aged ≤ 44 years and ethnic minority groups were more likely to agree. Agreement was greatest for a free breast pump and least for vouchers for breastfeeding. Universal incentives were preferred to those targeting low-income women. Initial daily text/telephone support, a quitting pal, vouchers for > £20.00 per month and values up to £80.00 increase the likelihood of smoking cessation. Doctors disagreed with provider incentives. A 'ladder' logic model emerged through data synthesis and had face validity with service users. It combined an incentive typology and behaviour change taxonomy. Autonomy and well-being matter. Personal difficulties, emotions, socialising and attitudes of others are challenges to climbing a metaphorical 'ladder' towards smoking cessation and breastfeeding. Incentive interventions provide opportunity 'rungs' to help, including regular skilled flexible support, a pal, setting goals, monitoring and outcome verification. Individually tailored and non-judgemental continuity of care can bolster women's capabilities to succeed. Rigid, prescriptive interventions placing the onus on women to behave 'healthily' risk them feeling pressurised and failing. To avoid 'losing face', women may disengage.

LIMITATIONS

Included studies were heterogeneous and of variable quality, limiting the assessment of incentive effectiveness. No cost-effectiveness data were reported. In surveys, selection bias and confounding are possible. The validity and utility of the ladder logic model requires evaluation with more diverse samples of the target population.

CONCLUSIONS

Incentives provided with other tailored components show promise but reach is a concern. Formal evaluation is recommended. Collaborative service-user involvement is important.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012001980.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Prenatal nicotine exposure induces poor articular cartilage quality in female adult offspring fed a high-fat diet and the intrauterine programming mechanisms

Prenatal nicotine exposure (PNE) induces skeletal growth retardation and dyslipidemia in offspring displaying intrauterine growth retardation (IUGR). Cholesterol accumulation resulting from cholesterol efflux dysfunction may reduce the quality of articular cartilage through fetal programming. This study evaluated the quality of articular cartilage of female adult offspring fed a high-fat diet and explored the mechanisms using a rat IUGR model established by the administration of 2.0mg/kg/d of subcutaneous nicotine from gestational days 11-20. The results demonstrated an increased OARSI (Osteoarthritis Research Society International) score and total cholesterol content, decreased serum corticosterone, and increased IGF1 and dyslipidemia with catch-up growth in PNE adult offspring. Cartilage matrix, IGF1 and cholesterol efflux pathway expression were reduced in PNE fetuses and adult offspring. Therefore, PNE induced poor articular cartilage quality in female adult offspring fed a high-fat diet via a dual programming mechanism.

Maternal Smoking and Metabolic Health Biomarkers in Newborns

Background

Maternal smoking has been associated with elevated risk of type 2 diabetes among the offspring in adulthood. The mechanisms underlying this fetal “programming” effect remain unclear. The present study sought to explore whether maternal smoking affects metabolic health biomarkers in fetuses/newborns.

Methods

In a prospective singleton pregnancy cohort (n = 248), we compared metabolic health biomarkers in the newborns of smoking and non-smoking mothers. Outcomes included cord plasma insulin, proinsulin, insulin-like growth factor I (IGF-I), IGF-II, leptin and adiponectin concentrations, glucose-to-insulin ratio (an indicator of insulin sensitivity) and proinsulin-to-insulin ratio (an indicator of β-cell function).

Results

Independent of maternal (glucose tolerance, age, ethnicity, parity, education, body mass index, alcohol use) and infant (sex, gestational age, birth weight z score, mode of delivery, cord blood glucose concentration) characteristics, the newborns of smoking mothers had lower IGF-I concentrations (mean: 6.7 vs. 8.4 nmol/L, adjusted p = 0.006), and marginally higher proinsulin-to-insulin ratios (0.94 vs. 0.72, adjusted p = 0.06) than the newborns of non-smoking mothers. Cord plasma insulin, proinsulin, IGF-II, leptin and adiponectin concentrations and glucose-to-insulin ratios were similar in the newborns of smoking and non-smoking mothers.

Conclusions

Maternal smoking was associated with decreased fetal IGF-I levels, and borderline lower fetal β-cell function. Larger cohort studies are required to confirm the latter finding. The preliminary findings prompt the hypothesis that these early life metabolic changes may be involved in the impact of maternal smoking on future risk of metabolic syndrome related disorders in the offspring.

Intrauterine low-functional programming of IGF1 by prenatal nicotine exposure mediates the susceptibility to osteoarthritis in female adult rat offspring

This study aimed to evaluate whether female adult offspring born with intrauterine growth retardation induced by prenatal nicotine exposure (PNE) are susceptible to osteoarthritis (OA) and to explore the underlying programming mechanisms. Pregnant rats were treated with nicotine or saline at 2.0 mg/kg/d from gestational d 11 to 20. The female adult offspring with or without PNE were forced with a strenuous treadmill running for 6 wk to induce OA. Nicotine's effects on fetal articular chondrocytes were studied by exposing chondrocytes to nicotine for 10 d, and dihydro-β-erythroidine, a selective α4β2-nicotinic acetylcholine receptor (nAChR) inhibitor, was used to identify the change of nicotine's effect. For adult offspring, increased cartilage destruction and accelerated OA progression were observed in the PNE group with running; the expression of α1 chain of type II collagen (Col2A1), aggrecan, SRY-type high mobility group box 9 (Sox9), and IGF1 signaling molecules in the cartilage of PNE offspring were decreased. For fetuses, elevated serum corticosteroid and nicotine levels and suppressed IGF1 levels were observed; expression of Col2A1, aggrecan, Sox9, and IGF1 were reduced. The result of chondrocytes revealed that nicotine impeded the expression of Col2A1, aggrecan, and IGF1; blocking α4β2-nAChR rescued nicotine's suppression. In conclusion, PNE increases the susceptibility of adult offspring to OA; the potential mechanism involves IGF1 low-functional programming in articular cartilage caused directly by the action of nicotine on α4β2-nAChR.

Nicotine Exposure During Pregnancy Results in Persistent Midline Epithelial Seam With Improper Palatal Fusion

INTRODUCTION

Nonsyndromic cleft palate is a common birth defect (1:700) with a complex etiology involving both genetic and environmental risk factors. Nicotine, a major teratogen present in tobacco products, was shown to cause alterations and delays in the developing fetus.

METHODS

To demonstrate the postpartum effects of nicotine on palatal development, we delivered three different doses of nicotine (1.5, 3.0, and 4.5mg/kg/d) and sterile saline (control) into pregnant BALB/c mice throughout their entire pregnancy using subcutaneous micro-osmotic pump. Dams were allowed to deliver (~day 21 of pregnancy) and neonatal assessments (weight, length, nicotine levels) were conducted, and palatal tissues were harvested for morphological and molecular analyses, as well as transcriptional profiling using microarrays.

RESULTS

Consistent administration of nicotine caused developmental retardation, still birth, low birth weight, and significant palatal size and shape abnormality and persistent midline epithelial seam in the pups. Through microarray analysis, we detected that 6232 genes were up-regulated and 6310 genes were down-regulated in nicotine-treated groups compared to the control. Moreover, 46% of the cleft palate-causing genes were found to be affected by nicotine exposure. Alterations of a subset of differentially expressed genes were illustrated with hierarchal clustering and a series of formal pathway analyses were performed using the bioinformatics tools.

CONCLUSIONS

We concluded that nicotine exposure during pregnancy interferes with normal growth and development of the fetus, as well results in persistent midline epithelial seam with type B and C patterns of palatal fusion.

IMPLICATIONS

Although there are several studies analyzing the genetic and environmental causes of palatal deformities, this study primarily shows the morphological and large-scale genomic outcomes of gestational nicotine exposure in neonatal mice palate.The previous version was incorrect. New authors Ali Nawshad, Hasan Otu, Janki Sharma, and Elizabeth Sheldon have been included in this version; the funding and acknowledgement sections have been updated accordingly; the article title, some text, and one supplementary data file have been edited; and the corresponding author has been changed. The original corresponding author regrets these earlier errors.

Neurotoxicological effects of nicotine on the embryonic development of cerebellar cortex of chick embryo during various stages of incubation

Long-acting nicotine is known to exert pathological effects on almost all tissues including the cerebellar cortex. The present work was designed to elucidate the effect of nicotine on the development of cerebellar cortex of chick embryo during incubation period. The fertilized eggs of hen (Gallus gallus domesticus) were injected into the air space by a single dose of long acting nicotine (1.6 mg/kg/egg) at the 4th day of incubation. The embryos were taken out of the eggs on days 8, 12 and 16 of incubation. The cerebellum of the control and treated embryos at above ages were processed for histopathological examination. The TEM were examined at 16th day of incubation. The results of the present study revealed that, exposure to long-acting nicotine markedly influence the histogenesis of cerebellar cortex of chick embryo during the incubation period. At 8th day of incubation, nicotine delayed the differentiation of the cerebellar analge; especially the external granular layer (EGL) and inner cortical layer (ICL). Furthermore, at 12th day of incubation, the cerebellar foliation was irregular and the Purkinje cells not recognized. By 16th day of incubation, the cerebellar foliations were irregular with interrupted cerebellar cortex and irregular arrangement of Purkinje cells. Immunohistochemical analysis for antibody P53 protein revealed that the cerebellar cortex in all stages of nicotine treated groups possessed a moderate to weak reaction for P53 protein however; this reaction was markedly stronger in the cerebellar cortex of control groups. Moreover, the flow cytometric analysis confirmed that the percentage of apoptosis in control group was significantly higher compared with that of nicotine treated group. At the TEM level, the cerebellar Purkinje cells of 16th day of treated groups showed multiple subcellular alterations in compared with those of the corresponding control group. Such changes represented by appearing of vacuolated mitochondria, cisternal fragmentation of RER, irregular grooves of Golgi tubules. Also, multiple cytoplasmic vacuoles and aggregation of Nissl granules were recorded around pyknotic nucleus.