Influence of maternal tobacco smoking during pregnancy on uterine, umbilical and fetal cerebral artery blood flows

Development and Validation of a Novel Placental DNA Methylation Biomarker of Maternal Smoking during Pregnancy in the ECHO Program

BACKGROUND

Maternal cigarette smoking during pregnancy (MSDP) is associated with numerous adverse health outcomes in infants and children with potential lifelong consequences. Negative effects of MSDP on placental DNA methylation (DNAm), placental structure, and function are well established.

OBJECTIVE

Our aim was to develop biomarkers of MSDP using DNAm measured in placentas (N = 96 ), collected as part of the Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function double-blind, placebo-controlled randomized clinical trial conducted between 2012 and 2016. We also aimed to develop a digital polymerase chain reaction (PCR) assay for the top ranking cytosine-guanine dinucleotide (CpG) so that large numbers of samples can be screened for exposure at low cost.

METHODS

We compared the ability of four machine learning methods [logistic least absolute shrinkage and selection operator (LASSO) regression, logistic elastic net regression, random forest, and gradient boosting machine] to classify MSDP based on placental DNAm signatures. We developed separate models using the complete EPIC array dataset and on the subset of probes also found on the 450K array so that models exist for both platforms. For comparison, we developed a model using CpGs previously associated with MSDP in placenta. For each final model, we used model coefficients and normalized beta values to calculate placental smoking index (PSI) scores for each sample. Final models were validated in two external datasets: the Extremely Low Gestational Age Newborn observational study, N = 426 ; and the Rhode Island Children's Health Study, N = 237 .

RESULTS

Logistic LASSO regression demonstrated the highest performance in cross-validation testing with the lowest number of input CpGs. Accuracy was greatest in external datasets when using models developed for the same platform. PSI scores in smokers only (n = 72 ) were moderately correlated with maternal plasma cotinine levels. One CpG (cg27402634), with the largest coefficient in two models, was measured accurately by digital PCR compared with measurement by EPIC array (R 2 = 0.98 ).

DISCUSSION

To our knowledge, we have developed the first placental DNAm-based biomarkers of MSDP with broad utility to studies of prenatal disease origins. https://doi.org/10.1289/EHP13838.

The Effect of Active and Passive Maternal Smoking During Pregnancy on the Uterine Artery Blood Flow and Obstetric Outcomes: A Prospective Study

BACKGROUND AND AIM

Maternal smoking is associated with an increased risk of obstetric and neonatal complications during pregnancy. We aimed to investigate the effects of active and passive smoking on fetal-maternal blood flow and fetal complications in mid-trimester pregnant women.

METHODS

This prospective study was conducted at Zekai Tahir Burak Women's Research and Training Hospital and included women who were 20 to 22 weeks old, with no fetal anomalies, and with a singleton pregnancy. The data used in the analysis were obtained from a total of 168 pregnant women (50 smokers, 50 passive smokers, and 68 non-smokers). Starting from their 20^th week of pregnancy, the women were examined at least once in each trimester. Fetal and maternal pregnancy results were evaluated. Fetal biometry, umbilical, and uterine artery Doppler ultrasonography were performed. To evaluate the flow in these veins, the pulsatility index, resistance index, and systole/diastole (S/D) ratio were performed.

RESULTS

The mean age of study patients was 25.06 ± 4.36 years and the mean gestational week was 20.03 ± 0.6 weeks. In terms of the umbilical artery pulsatility index (UMBAPI), umbilical artery systolic/diastolic ratio (UMBAS/D),uterine artery resistance index (UARI), uterine artery pulsatility index (UAPI), and uterine artery systolic/diastolic ratio (UAS/D) levels, the mean value of the smoker group was significantly higher compared to the non-smoker group (p<0.001, p=0.043, p=0.021, p=0.020, and p=0.037, respectively). The birth weight of the fetus was significantly lower in the active and passive smoker groups than in the non-smoker group (p=0.009 and p=0.006, respectively). The number of patients diagnosed with intrauterine growth restriction (IUGR) and oligohydramnios were significantly higher in the smoker group than in the passive smoker and non-smoker groups (p=0.003 and p<0.001, respectively). The risk of low birth weight (OR, (95% CI): 3.38 (2.05 - 5.57); p=0.024), oligohydramnios (OR (95% CI): 13.44 (5.22 - 34.57); p=0.001), IUGR (OR (95% CI): 9.33 (4.50 - 19.33); p=0.001), and preterm birth (OR (95% CI): 4.56 (1.25 - 17.32); p=0.001) increased significantly in the active and passive cigarette exposure groups, compared to the non-smokers.

CONCLUSION

During pregnancy, both smoking and passive exposure to cigarette smoke adversely affect the fetus and the newborn. Uterine and umbilical artery Doppler measurements in pregnant women who smoke are significantly higher than the pregnant women who do not smoke.

The Effect of External Cephalic Version on Fetal Circulation: A Prospective Cohort Study

External cephalic version (ECV) is a cost-effective and safe treatment option for breech presentation at term. Following ECV, fetal well-being is assessed via a non-stress test (NST). An alternative option to identify signs of fetal compromise is via the Doppler indices of the umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV). Inclusion criteria were an uncomplicated pregnancy with breech presentation at term. Doppler velocimetry of the UA, MCA and DV were performed up to 1 h before and up to 2 h after ECV. The study included 56 patients who underwent elective ECV with a success rate of 75%. After ECV, the UA S/D ratio, UA pulsatility index (PI) and UA resistance index (RI) were increased compared to before the ECV (p = 0.021, p = 0.042, and p = 0.022, respectively). There were no differences in the Doppler MCA and DV before or after ECV. All patients were discharged after the procedure. ECV is associated with changes in the UA Doppler indices that might reflect interference in placental perfusion. These changes are probably short-term and have no detrimental effects on the outcomes of uncomplicated pregnancies. ECV is safe; yet it is a stimulus or stress that can affect placental circulation. Therefore, careful case selection for ECV is important.

Paternal smoking and preterm birth: a population-based retrospective cohort study among non-smoking women aged 20-49 years in rural China

Background

To comprehensively evaluate the association of paternal smoking and preterm birth (PTB).

Methods

We performed a population-based retrospective cohort study in rural areas of China among 5,298,043 reproductive-aged couples who participated in the National Free Pre-Pregnancy Checkups Project (NFPCP), regarding outcome events that occurred in 2010–2016. Multivariate Cox proportional regression was used to estimate hazard ratio (HR) and 95% confident intervals (95%CI), and restricted cubic spline (RCS) were used to estimate the dose–response relationship.

Results

Compared to neither-smoker couples, the fully adjusted HR for PTB was 1.04 (95% CI, 1.03–1.04), 1.08 (0.96–1.22), and 1.11 (1.03–1.19) in the couples where only the female smoked, only the male smoked and both, respectively. HR of PTB for paternal smoking was 1.07 (1.06–1.07), compared with women without paternal smoking. Consistent with paternal smoking, preconception paternal smoking showed 1.07-fold higher risk of PTB (95%CI, 1.06–1.09). The multivariable-adjusted HRs of PTB were 1.05 (1.03–1.06), 1.04 (1.03–1.05), 1.05 (1.04–1.07), 1.07 (1.05–1.10) and 1.13 (1.12–1.14) for participants whose husband smoked 1–4, 5–9, 10–14, 15–19, and ≥ 20 cigarettes/day respectively, compared with participants without paternal smoking. The HRs of PTB also increased with the increment of paternal smoking and preconception paternal smoking categories (P_linear < 0.05).

Conclusions

Paternal smoking and preconception paternal smoking was independently positively associated with PTB risk. The importance of tobacco control, should be emphasized during preconception and pregnancy counselling should be towards not only women but also their husband.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-022-01378-x.

Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality, as well as other system immaturity problem. But as one of important environmental tobacco smoking sources of maternal secondhand smoking in the family, paternal smoking is worthy for deep exploring of its potential impacts on PTB. Moreover, evidence on the independent role of preconception paternal smoking is still lacking. Thus, we conducted a population-based retrospective cohort study to evaluate the association between paternal smoking and risk of PTB among among 5,298,043 reproductive-aged couples who participated in the National Free Pre-Pregnancy Checkups Project (NFPCP), regarding outcome events that occurred in 2010–2016.

We found a significant association between paternal smoking and PTB. Smoking reduction should not only be advised to pregnant women but also to their partners to reduce PTB in their fetal. In addition, supporting patients to continue smoking reduction will be crucial when considering the adverse health outcome of smoking. Intervention of tobacco use before and during pregnancy, are critical for prevention of PTB. Avoiding both maternal and paternal smoking during pregnancy will benefit the developing fetus.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Impact of vitamin C supplementation on placental DNA methylation changes related to maternal smoking: association with gene expression and respiratory outcomes

BACKGROUND

Maternal smoking during pregnancy (MSDP) affects development of multiple organ systems including the placenta, lung, brain, and vasculature. In particular, children exposed to MSDP show lifelong deficits in pulmonary function and increased risk of asthma and wheeze. Our laboratory has previously shown that vitamin C supplementation during pregnancy prevents some of the adverse effects of MSDP on offspring respiratory outcomes. Epigenetic modifications, including DNA methylation (DNAm), are a likely link between in utero exposures and adverse health outcomes, and MSDP has previously been associated with DNAm changes in blood, placenta, and buccal epithelium. Analysis of placental DNAm may reveal critical targets of MSDP and vitamin C relevant to respiratory health outcomes.

RESULTS

DNAm was measured in placentas obtained from 72 smokers enrolled in the VCSIP RCT: NCT03203603 (37 supplemented with vitamin C, 35 with placebo) and 24 never-smokers for reference. Methylation at one CpG, cg20790161, reached Bonferroni significance and was hypomethylated in vitamin C supplemented smokers versus placebo. Analysis of spatially related CpGs identified 93 candidate differentially methylated regions (DMRs) between treatment groups, including loci known to be associated with lung function, oxidative stress, fetal development and growth, and angiogenesis. Overlap of nominally significant differentially methylated CpGs (DMCs) in never-smokers versus placebo with nominally significant DMCs in vitamin C versus placebo identified 9059 candidate "restored CpGs" for association with placental transcript expression and respiratory outcomes. Methylation at 274 restored candidate CpG sites was associated with expression of 259 genes (FDR < 0.05). We further identified candidate CpGs associated with infant lung function (34 CpGs) and composite wheeze (1 CpG) at 12 months of age (FDR < 0.05). Increased methylation in the DIP2C, APOH/PRKCA, and additional candidate gene regions was associated with improved lung function and decreased wheeze in offspring of vitamin C-treated smokers.

CONCLUSIONS

Vitamin C supplementation to pregnant smokers ameliorates changes associated with maternal smoking in placental DNA methylation and gene expression in pathways potentially linked to improved placental function and offspring respiratory health. Further work is necessary to validate candidate loci and elucidate the causal pathway between placental methylation changes and outcomes of offspring exposed to MSDP. Clinical trial registration ClinicalTrials.gov, NCT01723696. Registered November 6, 2012. https://clinicaltrials.gov/ct2/show/record/NCT01723696 .

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.

Association between tobacco and/or alcohol consumption during pregnancy and infant development: BRISA Cohort

Fetuses exposed to alcohol and/or tobacco are at risk for perinatal adversities. However, little is currently known about the association of the separate or concomitant use of alcohol and tobacco with infant motor and cognitive development. Thus, the objective of the present study was to investigate the association between maternal consumption of alcohol and/or tobacco during pregnancy and the motor and cognitive development of children starting from the second year of life. The study included 1006 children of a cohort started during the prenatal period (22-25 weeks of pregnancy), evaluated at birth and reevaluated during the second year of life in 2011/2013. The children were divided into four groups according to the alcohol and/or tobacco consumption reported by their mothers at childbirth: no consumption (NC), separate alcohol consumption (AC), separate tobacco consumption (TC), and concomitant use of both (ACTC). The Bayley Scale of Infant and Toddler Development Third Edition screening tool was used for the assessment of motor and cognitive development. Adjusted Poisson regression models were used to determine the association between groups and delayed development. The results indicated that only the ACTC group showed a higher risk of motor delay, specifically regarding fine motor skills, compared to the NC group (RR=2.81; 95%CI: 1.65; 4.77). Separate alcohol or tobacco consumption was not associated with delayed gross motor or cognitive development. However, the concomitant use of the two substances increased the risk of delayed acquisition of fine motor skills.

Prenatal prediction of neonatal haemodynamic adaptation after maternal hyperoxygenation

Abstract

The reactivity of the pulmonary vascular bed to the administration of oxygen is well established in the post-natal circulation. The vasoreactivity demonstrated by the fetal pulmonary artery Doppler waveform in response to maternal hyperoxia has been investigated. We sought to investigate the relationship between the reactivity of the fetal pulmonary arteries to hyperoxia and subsequent neonatal cardiac function in the early newborn period.

Methods

This explorative study with convenience sampling measured pulsatility index (PI), resistance index (RI), acceleration time (AT), and ejection time (ET) from the fetal distal branch pulmonary artery (PA) at baseline and following maternal hyperoxygenation (MH). Oxygen was administered for 10 min at a rate of 12 L/min via a partial non-rebreather mask. A neonatal functional echocardiogram was performed within the first 24 h of life to assess ejection fraction (EF), left ventricular output (LVO), and neonatal pulmonary artery AT (nPAAT). This study was conducted in the Rotunda Hospital, Dublin, Ireland.

Results

Forty-six women with a singleton pregnancy greater than or equal to 31 weeks’ gestational age were prospectively recruited to the study. The median gestational age was 35 weeks. There was a decrease in fetal PAPI and PARI following MH and an increase in fetal PAAT, leading to an increase in PA AT:ET. Fetuses that responded to hyperoxygenation were more likely to have a higher LVO (135 ± 25 mL/kg/min vs 111 ± 21 mL/kg/min, p < 0.01) and EF (54 ± 9% vs 47 ± 7%,p = 0.03) in the early newborn period than those that did not respond to MH prenatally. These findings were not dependent on left ventricular size or mitral valve (MV) annular diameter but were related to an increased MV inflow. There was no difference in nPAAT.

Conclusion

These findings indicate a reduction in fetal pulmonary vascular resistance (PVR) and an increase in pulmonary blood flow and left atrial return following MH. The fetal response to hyperoxia reflected an optimal adaptation to postnatal life with rapid reduction in PVR increasing measured cardiac output.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03403-y.

Computational modelling for the spiral flow in umbilical arteries with different systole/diastole flow velocity ratios

The systole/diastole (S/D) flow velocity ratios in umbilical arteries (UAs) have been used to assess the health status of the feto-placental circulation, yet its connection to the morphology of UAs, specifically its coiling pattern remains unclear. Spiral flow induces unbalanced wall shear stress (WSS) distribution in UAs, and may contribute to the uneven arterial wall thickness, and the chirality. In this paper, we use a 3D computational fluid dynamics (CFD) technique to quantify the wall shear stress (WSS) in UA models of two configurations, i.e. at 0.17 and 0.50 spirals per centimeter, to represent normo- and hyper-coiling, respectively. For CFD simulations we use two different S/D ratios (3.02 and 5.70) revealed from the ultrasonography waveforms of a normal and an intrauterine growth restriction (IUGR) case. We found that more coils in the UA model enhanced WSS throughout a cardiac cycle (up to 24%) with the same inflow condition. In addition, time-averaged WSS are generally increased and more uneven in the hyper-coiling model. We suggest that the large WSS difference between the peak systole and end diastole (62% higher in the IURG case than the normal case) may induce uneven stenosis distribution at UAs, and contribute to UA chirality.

Electronic cigarettes may not be a "safer alternative" of conventional cigarettes during pregnancy: evidence from the nationally representative PRAMS data

Background

Conventional cigarette (CC) smoking is one of the most preventable causes of adverse birth outcomes. Although electronic cigarettes (ECs) are considered to be safer than CCs during pregnancy, the evidence is yet to be presented. This study examines the effects of prenatal EC use on neonatal birth outcomes compared to those of CC smokers and complete tobacco abstainers.

Methods

Data was extracted from 55,251 pregnant women who participated in the Phase 8 survey of the Pregnancy Risk Assessment Monitoring System between 2016 and 2018. Participants were classified into three groups based on their smoking behaviors in the third trimester: complete tobacco abstinence, exclusive CC smoking, or exclusive EC use. Adverse outcomes included infants being small-for-gestational-age (SGA), having low birthweight (LBW), and being born at preterm. EC users were matched to complete abstainers and CC smokers who share the same baseline characteristics in race/ethnicity, age, educational attainment, income, prenatal care adequacy, and first- and second-trimester CC smoking statuses. The association between EC use and adverse birth outcomes were examined by survey-weighted logistic regression analyses in the matched population.

Results

Among participants, 1.0% of women reported having used ECs during the third trimester, 60% of which reported using ECs exclusively. Neonates of EC users were significantly more likely to be SGA (OR 1.76; 95% CI 1.04, 2.96), have LBW (OR 1.53; 95% CI 1.06, 2.22), or be born preterm (OR 1.86; 95% CI 1.11, 3.12) compared to tobacco abstainers. However, odds of EC users’ pregnancies resulting in SGA (OR 0.67; 95% CI 0.30, 1.47), LBW (OR 0.71; 95% CI 0.37, 1.37), or preterm birth (OR 1.06; 95% CI 0.46, 2.48) were not significantly lower than those of CC smokers.

Conclusions

Even after accounting for shared risk factors between prenatal tobacco use and adverse birth outcomes, EC use remains an independent risk factor for neonatal complications and is not a safer alternative to CC smoking during pregnancy. Until further research is completed, all pregnant women are encouraged to abstain from all tobacco products including ECs.

A Pilot Study on Secondhand Smoke Exposure Among Pregnant Women in Chongqing, China: A Combined Questionnaire, Saliva Cotinine Test, and Ultrasound Flow Index Analysis

Objective: The aim of the study was to gain updated data on SHS exposure among pregnant women in Chongqing city, one of the four municipalities of China. Study Design and Setting: Pregnant women attending routine ultrasound checks at an obstetrics and gynecology center voluntarily participated in the survey of SHS exposure. Some participants were also invited to have saliva cotinine tests using a NicAlert kit. The pulsatility index (PI) of the umbilical artery was compared between the SHS and non-SHS groups. Results: A total of 548 pregnant women (74.82 and 25.18% at 12 and 24 weeks' gestation, respectively) participated in the survey from July to November 2019. SHS exposure was reported by 29.44% of participants. "Workplace" was listed as the top location for SHS exposure. Twenty-three of the 31 participants who tested cotinine-negative in their saliva samples self-reported SHS exposure in the survey questionnaire. However, two of the eight participants who tested cotinine-positive in their saliva samples self-reported SHS-exposure negative. The mean PI in the SHS group is higher than that in the non-SHS group (1.10 vs. 1.02) in fetuses at 24 weeks' gestation. However, the PI may not be suitable as an index for SHS exposure at 12 weeks' gestation due to frequent absent or reversed diastolic flow. Conclusion: The first survey on SHS exposure in pregnant women that combines a questionnaire, saliva cotinine tests, and ultrasound flow index analysis has been performed in China and provided valuable data for ensuing studies.

Can sonographic assessment of pulmonary vascular reactivity following maternal hyperoxygenation predict neonatal pulmonary hypertension? (HOTPOT study protocol)

Background

Persistent pulmonary hypertension of the newborn (PPHN) is a condition that occurs in 0.5–7 per 1000 live births and can result in significant cardiovascular instability in the newborn. It occurs when there is a failure of the normal circulatory transition in the early newborn period. Recent studies have shown that fetal pulmonary vasculature reacts to maternal hyperoxygenation (MH). The aim of the study is to assess if the in-utero response to MH can predict pulmonary hypertension in the early newborn period.

Methods

We will perform a prospective cohort study. It will evaluate the use of fetal echocardiographic Doppler assessment of the pulmonary vasculature prior to and following MH to predict fetuses that may develop pulmonary hypertension in the neonatal period. The study will be undertaken in the Rotunda Hospital, Dublin, Ireland. A fetal ultrasound and echocardiography will be performed on fetuses in the third trimester. Blood flow velocity waveforms will be recorded during periods of fetal quiescence. Pulsatility index (PI), Resistance index (RI), Peak systolic (PSV) and end diastolic velocity (EDV), time-averaged velocity (TAV), acceleration time (AT), and ejection time (ET) will be measured within the fetal distal pulmonary artery (PA). The acceleration-to-ejection time ratio (AT: ET) will be used to assess pulmonary vascular resistance (PVR). Doppler measurements will be taken at baseline and repeated immediately following MH for 10 min (O2 100% v/v inhalational gas) at a rate of 12L/min via a partial non-rebreather mask. Doppler waveform measurements from the umbilical artery (UAD), middle cerebral artery (MCA) ductus arteriosus (DA), aortic isthmus (AoI) and ductus venosus (DV) will also be obtained. After birth, a comprehensive neonatal functional echocardiogram will be performed within the first 24 hours of life.

Discussion

This study proposes to validate methods described to date in investigating the fetal pulmonary vascular response to MH, with expansion of the study subjects to include fetuses at risk of PPHN. Evaluation of the different at-risk subgroups will be informative in relation to the fetal circulatory adaptation close to term. Prediction of neonatal pulmonary hypertension may help guide the pharmacological and neonatal ICU strategies that optimise postnatal survival.

Maternal Tobacco Smoke Exposure Causes Sex-Divergent Changes in Placental Lipid Metabolism in the Rat

Maternal tobacco smoke exposure (MTS) affects fetal acquisition of long-chain polyunsaturated fatty acids (LCPUFA) and increases the risk of obesity and cardio-metabolic disease in the offspring. Alterations in fetal LCPUFA acquisition in maternal smoking are mediated by the placenta. The handling of LCPUFA by the placenta involves protein-mediated transfer and storage. Molecular mediators of placental LCPUFA handling include PPARγ and the fatty acid transport proteins. We previously demonstrated, in a rat model, that MTS results in programming of adult-onset obesity and metabolic disease in male, but not female, offspring. In this study, we test the hypothesis that in utero MTS exposure alters placental structure, placental LCPUFA handling, and fetal fatty acid levels, in a sex-divergent manner. We exposed pregnant rats to tobacco smoke from embryonic day 11 to term gestation. We measured placental and fetal fatty acid profiles, the systolic/diastolic ratio (SD ratio), placental histology, and expression of molecular mediators in the placenta. Our primary finding is that MTS alters fatty acid profiles in male, but not female fetuses and placenta, including increasing the ratio of omega-6 to omega-3 fatty acids. MTS also increased SD ratio in male, but not female placenta. In contrast, the expression of PPARγ and FATPs was upregulated in female, but not male placenta. We conclude that MTS causes sex-divergent changes in placental handling of LCPUFA in the rat. We speculate that our results demonstrate an adaptive response to MTS by the female placenta.

Effects of maternal smoking on human placental vascularization: A systematic review

The abnormal development of placental vascularization leads to placental insufficiency, which further reduces the nutrient and trace exchange between maternal circulation and fetal circulation. These changes cause maternal and fetal complications. The objective of our systematic review was to explore the effects of maternal smoking on placental vascularization. The eligibility criteria were: articles with experimental, quasi-experimental or observational design, performed on human subjects, that study the association, correlation or causation between maternal smoking and changes in placental vascular network. A total of 33 full-text papers were assessed for eligibility, resulting in 12 original articles that were included in the systematic review. Doppler studies confirm reductions in blood flow velocity waveforms and increase in RI in the uterine, umbilical and fetal middle cerebral arteries. These findings are confirmed by morphometric measurements of fetal capillaries in villi that were shown to be smaller in smoke exposure groups.

The contribution of environmental exposure to the etiology of autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition of heterogeneous etiology. While it is widely recognized that genetic and environmental factors and their interactions contribute to autism phenotypes, their precise causal mechanisms remain poorly understood. This article reviews our current understanding of environmental risk factors of ASD and their presumed adverse physiological mechanisms. It comprehensively maps the significance of parental age, teratogenic compounds, perinatal risks, medication, smoking and alcohol use, nutrition, vaccination, toxic exposures, as well as the role of extreme psychosocial factors. Further, we consider the role of potential protective factors such as folate and fatty acid intake. Evidence indicates an increased offspring vulnerability to ASD through advanced maternal and paternal age, valproate intake, toxic chemical exposure, maternal diabetes, enhanced steroidogenic activity, immune activation, and possibly altered zinc-copper cycles and treatment with selective serotonin reuptake inhibitors. Epidemiological studies demonstrate no evidence for vaccination posing an autism risk. It is concluded that future research needs to consider categorical autism, broader autism phenotypes, as well as autistic traits, and examine more homogenous autism variants by subgroup stratification. Our understanding of autism etiology could be advanced by research aimed at disentangling the causal and non-causal environmental effects, both founding and moderating, and gene-environment interplay using twin studies, longitudinal and experimental designs. The specificity of many environmental risks for ASD remains unknown and control of multiple confounders has been limited. Further understanding of the critical windows of neurodevelopmental vulnerability and investigating the fit of multiple hit and cumulative risk models are likely promising approaches in enhancing the understanding of role of environmental factors in the etiology of ASD.

The effect of prenatal smoke exposure on child neuropsychological function: a prospective mother-child cohort study

Objective: To study prospectively the effect of prenatal smoke exposure (PSE) on child neuropsychological function and intelligence quotient (IQ).Background: PSE has been associated with adverse effects on child neurodevelopment. However, some studies reported that these associations disappear after adjustment for potential confounders.Methods: A cohortof 248 mothers-child dyad was followed from the first trimester of pregnancy until children were 7.5 years old. PSE was recorded during pregnancy by questionnaire and plasma cotinine. The Wechsler Intelligence Scale for Children, the Neuropsychological Assessment of Executive Functions for Children (ENFEN) and the School Neuropsychological Maturity Questionnaire were administered at 7.5 years of age. The effect of PSE on child IQ and neuropsychological function was assessed with ANCOVA, adjusting for obstetric, neonatal and sociodemographic factors.Results: Children whose mothers smoked throughout pregnancy scored lower in interference (ENFEN) compared to unexposed children (F = 4.1; p = .008). The results showed no differences in other executive functions, verbal and visual memory and IQ between the PSE groups.Conclusion: PSE had little effect on child neuropsychological outcome and was limited to mental flexibility. Nevertheless, these findings support further efforts aimed at encouraging mothers to quit smoking in pregnancy.

Prenatal air pollution exposure, smoking, and uterine vascular resistance

BACKGROUND

Prenatal exposure to air pollution and smoking increases the risk of pregnancy complications and adverse birth outcomes, but pathophysiologic mechanisms are still debated. Few studies to date have examined the influence of air pollution on uterine vascular resistance and no studies have examined the independent impact of these exposures. We aimed to assess the impact of prenatal exposure to traffic-related air pollution and smoking on uterine vascular resistance.

METHODS

Our study included 566 pregnant women recruited between 1993 and 1996 in Los Angeles who completed visits at three gestational ages. Information on smoking was collected and uterine vascular resistance was measured at each visit by Doppler ultrasound. We calculated three resistance indices: the resistance index (RI), the pulsatility index (PI), and the systolic/diastolic (S/D) ratio. We estimated exposure to NO2 at the home address of the mother using a land use regression (LUR) model and to NOx using CALINE4 air dispersion modeling. We used generalized linear mixed models to estimate the effects of air pollution and smoking on uterine vascular resistance indices.

RESULTS

LUR-derived NO2 and CALINE4-derived NOx exposure increased the risk of high uterine artery resistance in late pregnancy. Smoking during pregnancy also increased the risk of higher uterine resistance and contributed to bilateral notching in mid-pregnancy.

CONCLUSION

Our results suggest that uterine vascular resistance is a mechanism underlying the association between smoking and air pollution, and adverse birth outcomes.

Maternal fish consumption during pregnancy and smoking behavioural patterns

n-3 Highly unsaturated fatty acids (HUFA), are essential components of neuronal membranes and mediate a range of complex bioactive properties including gene expression, myelination, cell-signalling and dopaminergic function. Deficits in n-3 HUFA have been linked to increased risks for addictive disorders, thus we posited that lower fish consumption would be associated with greater risks for perinatal smoking among 9640 mothers enroled in the Avon Longitudinal Study of Parents and Children. We used univariable and multivariable regression models to examine relationships between self-reported prenatal dietary intakes of n-3 HUFA-rich foods (fish and shellfish) and maternal smoking; outcomes included cessation and the number of cigarettes smoked per d. Both before and during pregnancy, there was consistent evidence (P<0·001) of protective fish intake-smoking associations; relative to mothers reporting no fish consumption, those who reported some fish consumption (<340 g/week) and high fish consumption (340 g+/week) at 32 weeks of gestation showed lower likelihoods of smoking (adjusted P values <0·001). Respective OR for these relationships were 0·87 (95% CI 0·77, 0·97) and 0·73 (95% CI 0·61, 0·86). Although the prevalence of smoking diminished, from a high of 31·6% (pre-pregnancy) to a low of 18·7% (second trimester), the magnitude of fish intake-smoking associations remained stable following adjustment for confounders. These observations suggest that greater fish or n-3 HUFA consumption should be evaluated as an intervention to reduce or prevent smoking in randomised clinical trials.

A Tale of Smoking Cessation Promotion: The Utilization of a Children's Book to Increase Screening and Counseling in the Pediatric Clinic

OBJECTIVES

The rate at which pediatricians promote smoking cessation in clinical settings is low. The literature demonstrates that interventions paired with tangible health promotion materials may significantly increase screening rates to the pediatric office. The aim of this study was to investigate whether the addition of a children's book in the pediatric clinic could result in an increase in the rate in which pediatricians screened for secondhand smoke exposure (SHSe) and counseled caregivers to stop smoking.

STUDY DESIGN

This randomized controlled study was performed at 7 pediatric clinics.

METHODS

Seven pediatric clinic sites were randomly assigned to either an intervention or control group. Pediatricians in the intervention group were given children's books about SHSe to distribute to their patients while the control group did not receive any materials.

RESULTS

At baseline, there was no difference between the control group and intervention group in rates at which pediatricians screened for SHSe ( P = .8728) and counseled caregivers to stop smoking ( P = .29). After the intervention, screening for SHSe and counseling caregivers to stop smoking were statistically significantly greater in the intervention group, when compared to controls ( P < .01 and P < .001, respectively).

CONCLUSIONS

The use of a health promotion children's book in the pediatric setting can increase the rate at which pediatricians screen for SHSe and counsel caregivers to stop smoking. Future research should examine the effect of the storybook on various parameters of smoking cessation and future smoking behaviors.

Doppler screening and predictors of adverse outcomes in high risk pregnancies affected by tobacco

OBJECTIVE

The purpose of this study was to investigate associations between Doppler measurements and adverse outcomes in an obstetric population with high tobacco use.

METHODS

This retrospective study included patients with Doppler data (umbilical systolic/diastolic velocity ratios (S/D), uterine S/D, uterine left/right ratio index (RI)). Receiver operator characteristic curve analysis determined cut-off elevated Doppler indices. Stepwise logistic regression was used to predict adverse outcomes.

RESULTS

338 of 745 patients (45.4%) had adverse outcomes. Doppler artery indices identified significant associations with IUGR, preeclampsia, low birth weight, pre-term birth and composite adverse outcome variable. An elevated Umbilical S/D was 2.1 (95% Confidence Interval (CI): 1.5-2.9; p<0.001) times was more likely to have an adverse outcome. For left uterine artery S/D and nulliparity, the odds ratios were 1.8 (95% CI: 1.3-2.5) and 1.4 (95% CI: 1.0-1.9), respectively.

CONCLUSION

Umbilical and uterine left S/D indices and nulliparity are significant independent predictors of adverse outcomes.

The Difference a Decade Makes: Smoking Cessation Counseling and Screening at Pediatric Visits

INTRODUCTION

There has been a sharp decline in adolescents who smoke cigarettes but no national-level study evaluating the impact of smoking cessation counseling by pediatricians or other clinicians who care for children.

METHODS

Combined data from ambulatory portions of the National Hospital Ambulatory Care Survey and National Ambulatory Medical Care Survey from 1997-1999 and 2009-2011 were analyzed to determine changes in the frequency of pediatric visits that included clinician-reported tobacco counseling and how such counseling varied by child, family, and clinician characteristics.

RESULTS

In 1997-1999, 1.5% of all medical visits for children aged below 19 years included tobacco counseling; this increased to 3.8% in 2009-2011 (P < .001). A marked increase from 4.1% to 11.1% was noted at well-child visits (P < .001). There were significant increases in counseling by pediatricians but not mid-level providers or general/family physicians. Provision of counseling did not result in greater visit length during either time point. During 2009-2011, visits with a diagnosis of asthma were four times as likely (OR 4.2, 95% CI 2.8-6.2) and visits for otitis media two times as likely (OR 2.1, 95% CI 1.2-3.7) to include smoking cessation counseling than sick visits for all other diagnoses.

CONCLUSION

These results demonstrate a significant increase in tobacco counseling by pediatric providers within the last decade, especially at well-child visits. However, the American Academy of Pediatrics' recommendation that pediatricians counsel about the harms of tobacco use and secondhand smoke exposure has not yet been exhaustively implemented.

IMPLICATIONS

A significant increase in smoking cessation counseling at pediatric medical appointments, especially at well-child visits, occurred from 2009-2011 compared with 1997-1999, paralleling a large decrease in smoking prevalence. These improvements in counseling rates have been predominantly noted for pediatricians but not mid-level providers or general practitioners. Counseling was not associated with increased visit lengths. Although improved counseling practices by pediatricians have been demonstrated, there is still room for improvement.

Amelioration strategies fail to prevent tobacco smoke effects on neurodifferentiation: Nicotinic receptor blockade, antioxidants, methyl donors

Tobacco smoke exposure is associated with neurodevelopmental disorders. We used neuronotypic PC12 cells to evaluate the mechanisms by which tobacco smoke extract (TSE) affects neurodifferentiation. In undifferentiated cells, TSE impaired DNA synthesis and cell numbers to a much greater extent than nicotine alone; TSE also impaired cell viability to a small extent. In differentiating cells, TSE enhanced cell growth at the expense of cell numbers and promoted emergence of the dopaminergic phenotype. Nicotinic receptor blockade with mecamylamine was ineffective in preventing the adverse effects of TSE and actually enhanced the effect of TSE on the dopamine phenotype. A mixture of antioxidants (vitamin C, vitamin E, N-acetyl-l-cysteine) provided partial protection against cell loss but also promoted loss of the cholinergic phenotype in response to TSE. Notably, the antioxidants themselves altered neurodifferentiation, reducing cell numbers and promoting the cholinergic phenotype at the expense of the dopaminergic phenotype, an effect that was most prominent for N-acetyl-l-cysteine. Treatment with methyl donors (vitamin B12, folic acid, choline) had no protectant effect and actually enhanced the cell loss evoked by TSE; they did have a minor, synergistic interaction with antioxidants protecting against TSE effects on growth. Thus, components of tobacco smoke perturb neurodifferentiation through mechanisms that cannot be attributed to the individual effects of nicotine, oxidative stress or interference with one-carbon metabolism. Consequently, attempted amelioration strategies may be partially effective at best, or, as seen here, can actually aggravate injury by interfering with normal developmental signals and/or by sensitizing cells to TSE effects on neurodifferentiation.

Fetal middle cerebral artery and umbilical artery pulsatility index: effects of maternal characteristics and medical history

OBJECTIVE

To define the contribution of maternal variables which influence the measured fetal middle cerebral artery (MCA) and umbilical artery (UA) pulsatility index (PI) in the assessment of fetal wellbeing.

METHODS

Maternal characteristics and medical history were recorded and fetal MCA-PI and UA-PI (n = 36,818) were measured in women with singleton pregnancies attending a routine hospital visit at 30 + 0 to 37 + 6 weeks' gestation. For pregnancies delivering phenotypically normal live births or stillbirths ≥ 30 weeks' gestation, variables among maternal demographic characteristics and medical history that are important in the prediction of MCA-PI and UA-PI were determined by multiple linear regression analysis.

RESULTS

Significant independent contributions to MCA-PI were provided by gestational age at assessment, East Asian racial origin, being parous and birth-weight Z-score of the neonate of the previous pregnancy. Significant independent contributions to UA-PI were provided by gestational age at assessment, Afro-Caribbean, East Asian and mixed racial origin, cigarette smoking, being parous and birth-weight Z-score of the neonate of the previous pregnancy. Multiple linear regression analysis was used to define the contribution of maternal variables that influence the measured MCA-PI and UA-PI and express the values as multiples of the median (MoMs). The cerebroplacental ratio (CPR) MoM was calculated by dividing MCA-PI MoM by UA-PI MoM. The model was shown to provide an adequate fit of MoM values for all covariates, both in pregnancies that delivered small-for-gestational-age neonates and in those without this pregnancy complication.

CONCLUSIONS

A model was fitted to express MCA-PI, UA-PI and CPR as MoMs after adjusting for variables from maternal characteristics and medical history that affect this measurement.

Vitamin C supplementation ameliorates the adverse effects of nicotine on placental hemodynamics and histology in nonhuman primates

OBJECTIVE

We previously demonstrated that prenatal nicotine exposure decreases neonatal pulmonary function in nonhuman primates, and maternal vitamin C supplementation attenuates these deleterious effects. However, the effect of nicotine on placental perfusion and development is not fully understood. This study utilizes noninvasive imaging techniques and histological analysis in a nonhuman primate model to test the hypothesis that prenatal nicotine exposure adversely effects placental hemodynamics and development but is ameliorated by vitamin C.

STUDY DESIGN

Time-mated macaques (n = 27) were divided into 4 treatment groups: control (n = 5), nicotine only (n = 4), vitamin C only (n = 9), and nicotine plus vitamin C (n = 9). Nicotine animals received 2 mg/kg per day of nicotine bitartrate (approximately 0.7 mg/kg per day free nicotine levels in pregnant human smokers) from days 26 to 160 (term, 168 days). Vitamin C groups received ascorbic acid at 50, 100, or 250 mg/kg per day with or without nicotine. All underwent placental dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) at 135-140 days and Doppler ultrasound at 155 days to measure uterine artery and umbilical vein velocimetry and diameter to calculate uterine artery volume blood flow and placental volume blood flow. Animals were delivered by cesarean delivery at 160 days. A novel DCE-MRI protocol was utilized to calculate placental perfusion from maternal spiral arteries. Placental tissue was processed for histopathology.

RESULTS

Placental volume blood flow was significantly reduced in nicotine-only animals compared with controls and nicotine plus vitamin C groups (P = .03). Maternal placental blood flow was not different between experimental groups by DCE-MRI, ranging from 0.75 to 1.94 mL/mL per minute (P = .93). Placental histology showed increased numbers of villous cytotrophoblast cell islands (P < .05) and increased syncytiotrophoblast sprouting (P < .001) in nicotine-only animals, which was mitigated by vitamin C.

CONCLUSION

Prenatal nicotine exposure significantly decreased fetal blood supply via reduced placental volume blood flow, which corresponded with placental histological findings previously associated with cigarette smoking. Vitamin C supplementation mitigated the harmful effects of prenatal nicotine exposure on placental hemodynamics and development, suggesting that its use may limit some of the adverse effects associated with smoking during pregnancy.

Psychosocial predictors of fetoplacental blood flow during pregnancy

BACKGROUND

Although a number of studies have found significant associations between maternal psychological distress, anxiety and changes in fetoplacental blood flow, findings remain inconsistent. A recent pilot study by our group highlighted some of these inconsistencies. In the current study, we expanded this pilot analysis to include psychological distress, anxiety and a range of antenatal variables, with the aim of identifying predictors of fetoplacental blood flow.

METHODS

Healthy pregnant women (n=148) underwent Doppler flow studies on uterine, umbilical and fetal arteries; as well as assessments of distress, anxiety and other antenatal variables (e.g. perceived social support, resilience, nicotine and alcohol use) in each trimester.

RESULTS

Stepwise regression analyses found that state anxiety was associated with lower mid-cerebral artery pulsatility index at trimester 3.

LIMITATIONS

Subjects were recruited from selected midwife obstetric units in the same health district, so the generalizability of our results may be limited. While most subjects received Doppler assessment at trimesters 2 and 3, only approximately half of our sample was assessed at trimester 1.

CONCLUSION

The finding that anxiety is associated with increased blood flow to the fetal brain during trimester 3 of pregnancy, coincide with previous work. The findings emphasize a growing appreciation of the potential importance of psychological well-being during pregnancy for infant development. However, as associations were small and variable, further research using multivariate models to determine the precise mechanisms underlying these associations would be warranted.

Smoking and Preterm Birth

Premature birth is a significant global problem and the leading cause of newborn deaths. Tobacco smoking has been associated with premature birth for over 50 years. The mechanisms through which smoking exerts its effects on pregnancy outcomes remain unclear. In this review, we discuss rates of prematurity and smoking in pregnancy, the evidence of a causal relationship between tobacco and preterm birth, and proposed biochemical pathways through which the interaction is mediated. The suggested mechanisms include nicotine-induced vasoconstriction, carbon monoxide-induced fetal hypoxia, cadmium disruption of calcium signaling, altered steroid hormone production, disruption of prostaglandin synthesis, and changed responses to oxytocin. The relative importance of each of these pathways is yet to be ascertained. Further research is necessary to explore the mechanisms through which smoking exerts its effect on gestational length and the process of parturition. Moreover, the risks of nicotine replacement in pregnancy should be investigated further.

Maternal smoking during pregnancy and growth in infancy: a covariance structure analysis

Background

Smoking during pregnancy is related to fetal constraint and accelerated postnatal growth. However, the pathways between these factors have not been clarified. Pathway analyses that link these factors can help us better understand the mechanisms involved in this association. Therefore, this study aimed to examine pathways between maternal smoking during pregnancy and growth in infancy.

Methods

Participants were singletons born between 1993 and 2006 in rural Japan. The outcome was the change in weight z-score between birth and 3 years of age. Pathways from maternal smoking and other maternal factors (such as maternal body mass index and work status) to growth in infancy via birth factors (such as birth weight and gestational age) and breastfeeding were examined using structural equation modeling.

Results

Complete data were available for 1524 children (775 boys and 749 girls). The model fit appeared adequate. Lower birth weight and non-exclusive breastfeeding mediated the association between maternal smoking during pregnancy and rapid growth in infancy. Maternal smoking was also directly linked to rapid growth in infancy (standardized direct effects 0.06, P = 0.002). Taking all pathways into account, the standardized total effect of maternal smoking on growth in infancy was 0.11.

Conclusions

Maternal smoking during pregnancy may both indirectly, through birth weight and breastfeeding status, and directly influence growth during infancy; however, there may be other pathways that have not yet been identified.

Physical, behavioral, and cognitive effects of prenatal tobacco and postnatal secondhand smoke exposure

The purpose of this review is to examine the rapidly expanding literature regarding the effects of prenatal tobacco and postnatal secondhand smoke (SHS) exposure on child health and development. Mechanisms of SHS exposure are reviewed, including critical periods during which exposure to tobacco products appears to be particularly harmful to the developing fetus and child. The biological, biochemical, and neurologic effects of the small fraction of identified components of SHS are described. Research describing these adverse effects of both in utero and childhood exposure is reviewed, including findings from both animal models and humans. The following adverse physical outcomes are discussed: sudden infant death syndrome, low birth weight, decreased head circumference, respiratory infections, otitis media, asthma, childhood cancer, hearing loss, dental caries, and the metabolic syndrome. In addition, the association between the following adverse cognitive and behavioral outcomes and such exposures is described: conduct disorder, attention-deficit/hyperactivity disorder, poor academic achievement, and cognitive impairment. The evidence supporting the adverse effects of SHS exposure is extensive yet rapidly expanding due to improving technology and increased awareness of this profound public health problem. The growing use of alternative tobacco products, such as hookahs (a.k.a. waterpipes), and the scant literature on possible effects from prenatal and secondhand smoke exposure from these products are also discussed. A review of the current knowledge of this important subject has implications for future research as well as public policy and clinical practice.

Maternal lifestyle and environmental risk factors for autism spectrum disorders

BACKGROUND

Over the past 10 years, research into environmental risk factors for autism has grown dramatically, bringing evidence that an array of non-genetic factors acting during the prenatal period may influence neurodevelopment.

METHODS

This paper reviews the evidence on modifiable preconception and/or prenatal factors that have been associated, in some studies, with autism spectrum disorder (ASD), including nutrition, substance use and exposure to environmental agents. This review is restricted to human studies with at least 50 cases of ASD, having a valid comparison group, conducted within the past decade and focusing on maternal lifestyle or environmental chemicals.

RESULTS

Higher maternal intake of certain nutrients and supplements has been associated with reduction in ASD risk, with the strongest evidence for periconceptional folic acid supplements. Although many investigations have suggested no impact of maternal smoking and alcohol use on ASD, more rigorous exposure assessment is needed. A number of studies have demonstrated significant increases in ASD risk with estimated exposure to air pollution during the prenatal period, particularly for heavy metals and particulate matter. Little research has assessed other persistent and non-persistent organic pollutants in association with ASD specifically.

CONCLUSIONS

More work is needed to examine fats, vitamins and other maternal nutrients, as well as endocrine-disrupting chemicals and pesticides, in association with ASD, given sound biological plausibility and evidence regarding other neurodevelopmental deficits. The field can be advanced by large-scale epidemiological studies, attention to critical aetiological windows and how these vary by exposure, and use of biomarkers and other means to understand underlying mechanisms.

Effects of maternal tobacco-smoke exposure on fetal growth and neonatal size

Exposure to tobacco smoke, through both active and passive measures, has a significant impact on women's health, including effects on the cardiovascular, pulmonary and reproductive systems. Of particular interest is the effect of smoking on pregnancy outcomes. One crucial outcome that has been linked to the subsequent development of both neonatal and adult disease is intrauterine or fetal growth restriction. In this article, we will summarize the effects of smoking on newborn size and fetal growth. We will review evidence showing that tobacco consumption during pregnancy leads to a reduction in birthweight, largely through affecting specific anthropometric measures and newborn body composition. We will highlight the role of genetic susceptibility to these effects and discuss how smoking cessation prior to the third trimester results in a reduction in the risk of fetal growth restriction.

Housing and child health

The connection between housing and health is well established. Physical, chemical, and biological aspects of the child's home, such as cleanliness, moisture, pests, noise, accessibility, injury risks, and other forms of housing environmental quality, all have the potential to influence multiple aspects of the health and development of children. Basic sanitation, reduced household crowding, other improvements in housing and expanded, and improved housing regulations have led to advances in children's health. For example, lead poisoning prevention policies have profoundly reduced childhood lead exposure in the United States. This and many other successes highlight the health benefits for families, particularly children, by targeting interventions that reduce or eliminate harmful exposures in the home. Additionally, parental mental health problems, food insecurity, domestic violence, and the presence of guns in children's homes all are largely experienced by children in their homes, which are not as yet considered part of the Healthy Homes agenda. There is a large movement and now a regulatory structure being put in place for healthy housing, which is becoming closely wedded with environmental health, public health, and the practice of pediatrics. The importance of homes in children's lives, history of healthy homes, asthma, and exposures to lead, carbon monoxide, secondhand/thirdhand smoke, radon, allergy triggers is discussed, as well as how changes in ambient temperature, increased humidity, poor ventilation, water quality, infectious diseases, housing structure, guns, electronic media, family structure, and domestic violence all affect children's health.

Chronic carbon monoxide inhalation during pregnancy augments uterine artery blood flow and uteroplacental vascular growth in mice

End-tidal breath carbon monoxide (CO) is abnormally low in women with preeclampsia (PE), while women smoking during pregnancy have shown an increase in CO levels and a 33% lower incidence of PE. This effect may be, in part, due to lowered sFLT1 plasma levels in smokers, and perhaps low-level CO inhalation can attenuate the development of PE in high-risk women. Our previous work showed maternal chronic CO exposure (<300 ppm) throughout gestation had no maternal or fetal deleterious effects in mice. Our current study evaluated the uteroplacental vascular effects in CD-1 maternal mice that inhaled CO (250 ppm) both chronically, gestation day (GD) 0.5 to 18.5, and acutely, 2.5 h on each of GD 10.5 and 14.5. We demonstrated, using microultrasound measurements of blood velocity and microcomputed tomography imaging of the uteroplacental vasculature, that chronic maternal exposure to CO doubled uterine artery blood flow and augmented uteroplacental vascular diameters and branching. This finding may be of benefit to women with PE, as they exhibit uteroplacental vascular compromise. The ratio of VEGF protein to its FLT1 receptor was increased in the placenta, suggesting a shift to a more angiogenic state; however, maternal circulating levels of VEGF, sFLT1, and their ratio were not significantly changed. Doppler blood velocities in the maternal uterine artery and fetal umbilical artery and vein were unaltered. This study provides in vivo evidence that chronic inhalation of 250 ppm CO throughout gestation augments uterine blood flow and uteroplacental vascular growth, changes that may protect against the subsequent development of preeclampsia.

The effect of long term nicotine exposure on nicotine addiction and fetal growth

OBJECTIVE

To investigate the effect of nicotine exposure starting before coitus and continuing during pregnancy and lactation period on delivery rate, fetal growth and nicotine addiction in rats.

MATERIAL AND METHODS

Ten female Swiss Albino rats were divided into 2 groups as the nicotine group (NG) (n=5), and the control group (n=5), conceived by adding 2 male rats to each group. While the control group was given only normal drinking water, 0.4 mg/kg body weight (BW)/day nicotine was given to the NG in drinking water. After delivery, the BWs of pups were recorded weekly for 6 weeks and their drinking water preferences were assessed. Meanwhile, pups of the NG continued to receive 0.4 mg/kg/day nicotine for 12 months while the controls continued with normal drinking water.

RESULTS

At the end of the 6(th) week, it was determined that 30 (69%) rats out of 43 in the NG and only 7 rats (20%) out of 35 in the control group preferred the nicotine added drinking water (p<0.05). No significant difference was observed between control and NGs in post-natal birth weights and BWs recorded for 6 weeks. On the contrary, a significant decrease (p< 0.05) was observed in the BWs of NG at the end of 12 months nicotine exposure.

CONCLUSION

Use of maternal nicotine in pregnancy and lactation periods, even at a low dose, may be effective in nicotine addiction development although it may not affect delivery rate, and BWs of pups after delivery and during six weeks follow up in the lactation period.

The impact of intrauterine tobacco exposure on the cerebral mass of the neonate based on the measurement of head circumference

The objective of the study was to assess cerebral mass, based on head circumference measurements in neonates exposed to tobacco smoke in utero, and to determine the relative proportions of the cerebral and body mass. The study included 147 neonates born in the period 2003-2004 at the Princess Anna Mazowiecka University Hospital and admitted to the Neonatal and Intensive Care Department of the Medical University in Warsaw. Subjects were divided into three groups on the basis of maternal status as active, passive, or nonsmokers determined by maternal urinary cotinine concentration and a questionnaire. Neonates whose mothers were active smokers throughout the whole period of pregnancy had a lower head circumference and in consequence a lower cerebral mass significantly more frequently when compared with those whose mothers were nonsmokers, P= 0.002. (Median difference in cerebral mass was 48.27 g.) The risk of lower cerebral mass was 3.9 (1.4-10.8, CI 95%) in the group of neonates whose mothers actively smoked cigarettes during pregnancy. A negative correlation was seen between cerebral mass and maternal urinary cotinine concentration (correlation coefficient r=-23, P= 0.006). The ratio of the cerebral to body mass was similar for neonates in all three groups. Active smoking during pregnancy had a negative effect on the cerebral mass of the neonate, however no such effect was observed in neonates whose mothers were passive smokers. The deficiency in cerebral mass increased with greater smoking intensity. Active smoking by the mother during pregnancy inhibits the growth of the brain as well as that of the body mass of the neonate.

Maternal active smoking and newborn body composition

OBJECTIVE

Maternal smoking during pregnancy is associated with a reduction in birth size but very few studies have collated changes in neonatal anthropometry. Our aims were both to assess body composition differences by anthropometry between new-borns from smoking mothers and those from non-smoking mothers, and to show whether these differences affect proportional body mass distribution.

METHODS

Caucasian mothers and their full term singleton new-borns (N=1216) were selected during 2009. A structured questionnaire was completed regarding obstetric and demographic data, as well as tobacco consumption. Women were categorized, according to their smoking habits, into a non-smoking group (never smoked or stopped smoking prior to pregnancy) and a smoking group (smoked throughout pregnancy).

RESULTS

22.1% of mothers smoked during pregnancy (median: 6 cigarettes/day, range: l-40). Smoking mothers were significantly younger than non-smoking mothers but there were no differences regarding other aspects which could affect infant weight. Infants from non-smoking mothers were heavier, longer, and body circumferences were all larger than those from smoking mothers (p<0.001), but the Ponderal Index showed no statistical differences. Skinfold thicknesses were significantly lower in new-borns from smoking mothers but these differences were less evident than those from body size. Subcutaneous fat distribution did not show statistical differences between the two groups. After gestational age, to smoke during gestation is the second main determinant of birth weight.

CONCLUSIONS

Smoking during pregnancy involves a generalized reduction of most axiological parameters as a result of proportionate fetal growth impairment. In those infants born from mothers who smoked during gestation, neonatal lean body mass appears to be more affected than body fat, and distribution of subcutaneous fat is not different.

Newborn neurobehavioral patterns are differentially related to prenatal maternal major depressive disorder and serotonin reuptake inhibitor treatment

BACKGROUND

Prenatal serotonin reuptake inhibitor (SRI) exposure has been related to adverse newborn neurobehavioral outcomes; however, these effects have not been compared to those that may arise from prenatal exposure to maternal major depressive disorder (MDD) without SRI treatment. This study examined potential effects of MDD with and without SRI treatment on newborn neurobehavior.

METHODS

This was a prospective, naturalistic study. Women were seen at an outpatient research center twice during pregnancy (26-28 and 36-38 weeks gestational age (GA)). Psychiatric diagnoses were assessed using the Structured Clinical Interview for the DSM-IV; medication use was measured with the Timeline Follow-Back instrument. Three groups were established based upon MDD diagnosis and SRI use: Control (N = 56), MDD (N = 20), or MDD + SRI (N = 36). Infants were assessed on a single occasion within 3 weeks of birth with the NICU Network Neurobehavioral Assessment Scale. Generalized Linear Modeling was used to examine neurobehavioral outcomes by exposure group and infant age at assessment.

RESULTS

Full-term infants exposed to MDD + SRIs had a lower GA than CON or MDD-exposed infants and, controlling for GA, had lower quality of movement and more central nervous system stress signs. In contrast, MDD-exposed infants had the highest quality of movement scores while having lower attention scores than CON and MDD + SRI-exposed infants.

CONCLUSION

MDD + SRI-exposed infants seem to have a different neurobehavioral profile than MDD-exposed infants in the first 3 weeks after delivery; both groups may have different neurobehavioral profiles with increasing age from birth.

Transcriptome alterations in maternal and fetal cells induced by tobacco smoke

OBJECTIVES

Maternal smoking has a negative effect on all stages of pregnancy. Tobacco smoke-related defects are well established at the clinical level; however, less is known about molecular mechanisms underlying these pathologic conditions. We thus performed a comprehensive analysis of transcriptome alterations induced by smoking in maternal and fetal cells.

STUDY DESIGN

Samples of peripheral blood (PB), placenta (PL), and cord blood (UCB) were obtained from pregnant smokers (n = 20) and gravidas without significant exposure to tobacco smoke (n = 52). Gene expression profiles were assayed by Illumina Expression Beadchip v3 for analysis of 24,526 transcripts. The quantile method was used for normalization. Differentially expressed genes were analyzed in the Limma package and the P-values were corrected for multiple testing. Unsupervised hierarchical clustering was performed using average linkage and Euclidean distance. The enrichment of deregulated genes in biological processes was analyzed in DAVID database.

RESULTS

Comparative analyses defined significant deregulation of 193 genes in PB, 329 genes in PL, and 49 genes in UCB of smokers. The deregulated genes were mainly related to xenobiotic metabolism, oxidative stress, inflammation, immunity, hematopoiesis, and vascularization. Notably, functional annotation of the affected genes identified several deregulated pathways associated with autoimmune diseases in the newborns of smokers.

CONCLUSIONS

The study demonstrated maternal smoking causes significant changes in transcriptome of placental and fetal cells that deregulate numerous biological processes important for growth and development of the fetus. An activation of fetal CYP genes showed a limited ability of the placenta to modulate toxic effects of maternal tobacco use.

Prenatal tobacco exposure influences cerebral oxygenation in preterm infants

AIM

Our aim was to determine the influence of prenatal tobacco exposure on regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) in preterm infants. We hypothesized that as a result of vasoconstriction caused by prenatal tobacco exposure r(c)SO(2) would be lower and FTOE would be higher during the first days after birth in infants exposed to tobacco during pregnancy.

METHODS

Sixty preterms were included in this prospective, observational cohort study (median gestational age 29.9 weeks, range 26.0-31.8, median birth weight 1248 g, range 615-2250). Fourteen infants had been exposed to tobacco during pregnancy. All mothers smoked more than five cigarettes a day till delivery. We measured r(c)SO(2) and transcutaneous arterial oxygen saturation (tcSaO(2)) in all infants on days 1-5, 8, and 15. FTOE was calculated: FTOE=(tcSaO(2)-r(c)SO(2))/tcSaO(2).

RESULTS

In preterm infants exposed to tobacco during pregnancy, r(c)SO(2) was lower during days 1, 2, and 8 after birth, median 73% versus 81%, 73% versus 80% and 71% versus 78% respectively. FTOE was higher during days 1 and 8 after birth, median 0.24 versus 0.15 and 0.26 versus 0.19 respectively. On the second day, FTOE tended to be higher, 0.18 versus 0.14.

CONCLUSIONS

During the first two days and day 8 after birth cerebral oxygen saturation is lower and oxygen extraction higher in preterm infants following prenatal tobacco exposure. Our data suggest that prenatal tobacco exposure may have an effect on cerebral oxygenation of the infant.

Longitudinal study of smoking cessation before pregnancy and children's cognitive abilities at 56 months of age

BACKGROUND

An inverse relationship exists between the rates of maternal smoking during pregnancy and children's cognitive abilities. The effect of maternal cessation of smoking before pregnancy on child's cognitive development is less clear.

AIMS

To study whether maternal cessation of smoking before pregnancy is associated with children's cognitive abilities.

STUDY DESIGN AND SUBJECTS

The original cohort included all 1535 live-born infants admitted to the neonatal wards during 1 year and 658 randomly recruited non-admitted infants. The present study sample comprised 1019 (68.2%) children of the original sample born at term and free of any major impairment followed up to 56 months.

OUTCOME MEASURES

Child's general reasoning, visual-motor integration, verbal competence, and language comprehension at 56 months of age.

RESULTS

The results showed that children whose mothers smoked >10 cigarettes per day before pregnancy but none during pregnancy, fared 12.07 (95% confidence interval [CI]: 4.07 to 20.08) and 11.23 (95% CI: 2.81 to 19.66) age-standardized points poorer in general reasoning and in language comprehension tests, respectively, than children of never-smokers. All results were adjusted for the sex, gestational age-adjusted birth weight, multiple/singleton pregnancy, birth order, preeclampsia, maternal diabetes, admission to neonatal ward, 5-minute Apgar score (<7), breastfeeding, parental level of education, maternal age, BMI at the end of pregnancy and single parenting.

CONCLUSIONS

Heavy smoking before pregnancy is associated with children's lower cognitive abilities even if the mother has quit smoking before pregnancy. Identification and intervention of heavy smoking women of fertile age would potentially improve not only their odds to become pregnant but also benefit the offspring's cognitive functioning.

Quantitative effects of tobacco smoking exposure on the maternal-fetal circulation

BACKGROUND

Despite the existence of various published studies regarding the effects of tobacco smoking on pregnancy, and especially in regards to placental blood flow and vascular resistance, some points still require clarification. In addition, the amount of damage due to tobacco smoking exposure that occurs has not been quantified by objective means. In this study, we looked for a possible association between flow resistance indices of several arteries and the levels of urinary cotinine and the concentration of carbon monoxide in the exhaled air (COex) of both smoking and non-smoking pregnant women. We also looked for a relationship between those findings and fetal growth and birth weight.

METHODS

In a prospective design, thirty pregnant smokers and thirty-four pregnant non-smokers were studied. The volunteers signed consent forms, completed a self-applied questionnaire and were subjected to Doppler velocimetry. Tobacco smoking exposure was quantified by subject provided information and confirmed by the measurement of urinary cotinine levels and by the concentration of carbon monoxide in the exhaled air (COex). The weight of newborns was evaluated immediately after birth.

RESULTS

Comparing smoking to non-smoking pregnant women, a significant increase in the resistance index was observed in the uterine arteries (P = 0.001) and umbilical artery (P = 0.001), and a decrease in the middle cerebral artery (P = 0.450). These findings were associated with progressively higher concentrations of COex and urinary cotinine. A decrease in the birth weight was also detected (P < 0.001) in association with a progressive increase in the tobacco exposure of the pregnant woman.

CONCLUSIONS

In pregnant women who smoke, higher arterial resistance indices and lower birth weights were observed, and these findings were associated with increasing levels of tobacco smoking exposure. The values were significantly different when compared to those found in non-smoking pregnant women. This study contributes to the findings that smoking damage during pregnancy is dose-dependent, as demonstrated by the objective methods for measuring tobacco smoking exposure.

Maternal smoking and impaired endothelium-dependent nitric oxide-mediated relaxation of uterine small arteries in vitro

OBJECTIVE

This study aimed to investigate the endothelium-dependent relaxation of uterine small arteries from pregnant nonsmokers, smokers, and ex-smokers who stopped smoking early in pregnancy.

STUDY DESIGN

Uterine arteries were dissected from myometrial biopsies obtained during elective cesarean sections of 34 uncomplicated, singleton pregnancies, and the vascular function was assessed in a wire myograph for isometric recordings. Serum cotinine verified self-reported smoking; 15 were nonsmokers, 10 were smokers, and 9 were ex-smokers.

RESULTS

Arteries from smokers and ex-smokers had reduced bradykinin-induced relaxation compared to arteries from nonsmokers (P < .05). The relaxation response to the nitric oxide donor sodium nitroprusside was similar in arteries from nonsmokers and smokers but was better in arteries from ex-smokers (P < .05).

CONCLUSION

The findings suggest that maternal smoking reduces endothelium-dependent nitric oxide-mediated relaxation in uterine small arteries and that smoking cessation early in pregnancy does not fully abolish this deleterious effect, despite improvement in relaxation to nitroprusside.