Prenatal tobacco exposure, biomarkers for tobacco in meconium, and neonatal growth outcomes

Prenatal Substance Exposure: Associations with Neurodevelopment in Middle Childhood

OBJECTIVE

 Single-substance exposure effects on neurodevelopmental outcomes, such as problem behavior and intelligence quotient (IQ), have been studied in children for decades. However, the long-term consequences of polysubstance exposure are poorly understood.

STUDY DESIGN

 Longitudinal neurodevelopmental data were gathered from cohorts across the United States through the Environmental Influences on Child Health Outcomes Program. Data on prenatal exposure to opioids, nicotine, marijuana, and alcohol were collected from children ages 6 to 11 years (N = 256). Problem behavior was assessed using the Child Behavior Checklist (school-age version), and verbal IQ (VIQ) and performance IQ (PIQ) were assessed using the Weschler Intelligence Scale for Children, Fifth Edition. We first identified latent profiles in the overall sample, then evaluated differences in profile membership for children with and without prenatal substance exposure.

RESULTS

 Latent profile analysis identified two mutually exclusive categories: average VIQ and PIQ, with typical problem behavior, and below-average VIQ with average PIQ and clinically significant problem behavior. Children with prenatal nicotine and polysubstance exposures were more likely to be classified in the below-average VIQ, elevated problem behavior profile compared with children without prenatal nicotine exposure.

CONCLUSION

 The presence of clinically significant behavior problems in children with average PIQ, but below-average VIQ, could represent a unique endophenotype related to prenatal nicotine exposure in the context of other prenatal substance exposures.

KEY POINTS

· The neurodevelopmental consequences of prenatal polysubstance exposure are poorly understood.. · Children with prenatal polysubstance exposure exhibited reduced IQ and elevated problem behavior.. · We found significant behavior problems in children with average PIQ and below-average VIQ.. · This may represent a unique endophenotype related to prenatal nicotine exposure..

A prediction model for classifying maternal pregnancy smoking using California state birth certificate information

BACKGROUND

Systematically recorded smoking data are not always available in vital statistics records, and even when available it can underestimate true smoking rates.

OBJECTIVE

To develop a prediction model for maternal tobacco smoking in late pregnancy based on birth certificate information using a combination of self- or provider-reported smoking and biomarkers (smoking metabolites) in neonatal blood spots as the alloyed gold standard.

METHODS

We designed a case-control study where childhood cancer cases were identified from the California Cancer Registry and controls were from the California birth rolls between 1983 and 2011 who were cancer-free by the age of six. In this analysis, we included 894 control participants and performed high-resolution metabolomics analyses in their neonatal dried blood spots, where we extracted cotinine [mass-to-charge ratio (m/z) = 177.1023] and hydroxycotinine (m/z = 193.0973). Potential predictors of smoking were selected from California birth certificates. Logistic regression with stepwise backward selection was used to build a prediction model. Model performance was evaluated in a training sample, a bootstrapped sample, and an external validation sample.

RESULTS

Out of seven predictor variables entered into the logistic model, five were selected by the stepwise procedure: maternal race/ethnicity, maternal education, child's birth year, parity, and child's birth weight. We calculated an overall discrimination accuracy of 0.72 and an area under the receiver operating characteristic curve (AUC) of 0.81 (95% confidence interval [CI] 0.77, 0.84) in the training set. Similar accuracies were achieved in the internal (AUC 0.81, 95% CI 0.77, 0.84) and external (AUC 0.69, 95% CI 0.64, 0.74) validation sets.

CONCLUSIONS

This easy-to-apply model may benefit future birth registry-based studies when there is missing maternal smoking information; however, some smoking status misclassification remains a concern when only variables from the birth certificate are used to predict maternal smoking.

Determination of nicotine in newborn meconium by high-Resolution ambient mass spectrometry using wooden-Tip spray

Prenatal exposure to nicotine that are mainly produced from tobacco smoke has been reported to affect infants. Therefore, nicotine exposure is one of important health concerns for newborn screening. Detecting nicotine and its metabolites such as cotinine in meconium were widely used to evaluate the tobacco exposure of pregnancy. In this study, disposable wooden tips were applied for touch sampling of meconium from newborn infants, and then were directly mounted on mass spectrometer (MS) to perform rapid screening of nicotine and cotinine. Choice of extraction/spray solvents was optimized. The limits of detection, reproducibility, linear response for direct analysis of meconium were also investigated. It is found the limits of detection (S/N = 3) to be as low as 0.36 ng/mg and 1.18 ng/mg for nicotine and cotinine, respectively, while the limits of quantitation (S/N = 10) to be 1.19 ng/mg and 3.94 ng/mg for nicotine and cotinine, respectively. The relative standard deviations (RSD) were found to be at 8.4%-19.8% (n = 6) for nicotine and cotinine, a good linear range from 5-500 ng/mL (R ² > 0.99). These analytical performances are well-accepted levels for ambient mass spectrometer analysis. In this study, evaluation of nicotine and cotinine in 22 puerpera volunteers were conducted by the established wooden-tip spray mass spectrometry (WTS-MS). These results showed that wooden-tip spray mass spectrometry would be useful for newborn screening of nicotine and cotinine in meconium with high reproducibility, speed, sensitivity, and specificity. Owing to the use of disposable wooden tips that involves no sample preparation and no chromatographic separation, our results show that wooden-tip spray mass spectrometry is a powerful tool for determination of nicotine in newborn meconium.

Smoking Ban Law in Chile: Impact in Newborns' Birth Weight by Women's Age Groups and by City Population Density

Objectives: We examined the short-term impact of the Smoking Ban Law (SBL) enacted in Chile in 2013 on low birth weight (LBW) rates in cities and its differential effects by different maternal age groups and city density. Methods: We included 885,880 live births from 21 Chilean cities of ≥100,000 inhabitants. We examined the smoking and LBW prevalence distribution before and after the SBL. Through Poisson mixed effect models, we determined whether a meaningful change in LBW rate occurred after SBL implementation in the whole sample and stratified by city population density and maternal age group. Results: LBW prevalence remained stable before and after the SBL implementation (6.1% and 6.3%, respectively), while women's smoking prevalence had a relative reduction of 25.9% (p < 0.00001). No significant changes in LBW rate occurred after the implementation of SBL in the total sample or stratified by city density tertiles or maternal age groups. Conclusion: SBL implementation did not show short-term impact on LBW rate in Chile. Further studies need to examine long-term impact of SBL on low birthweight.

Assessment of Tobacco Exposure During Pregnancy by Meconium Analysis and Maternal Interview

Smoking during pregnancy can have serious obstetric and fetal complications. Therefore, it is essential to identify in utero exposure to tobacco, being meconium the matrix of choice for this purpose. Meconium (n = 565) was analyzed for nicotine, cotinine and hydroxycotinine by LC-MS-MS. Then, tobacco meconium results were compared with smoking habits during pregnancy and neonatal outcomes measures (birth weight, length, head circumference, gestational age and Apgar scores). Although meconium analysis increased identification of in-utero exposure to tobacco (17.7% meconium positive specimens vs 13.5% mothers admitting tobacco use during pregnancy), there was a statistically significant relationship between meconium results and interview answers (P < 0.001). Birth weight was significantly lower for newborns with meconium positive results in males (P = 0.023) and females (P = 0.001), while for length significance was only observed in females (P = 0.001); however, when excluding meconium specimens positive for other drugs, a statistically significant difference was only found for female weight (P = 0.045). Meconium analysis proved to be more reliable for tobacco prenatal exposure detection than maternal interview. In addition, positive meconium results increased the probability for low birth weight, especially in females.

Effects of Fetal Exposure to Heat-Not-Burn Tobacco on Testicular Function in Male Offspring

Several studies show that maternal conventional cigarette smoking during pregnancy has been associated with reduced sperm concentration in sons. The development of heat-not-burn (HnB) tobacco has gained a growing following. However, the effects of prenatal HnB tobacco smoking on male offspring are as yet unknown. Pregnant CD-1 mice were exposed to I-Quit-Ordinary-Smoking (IQOS) (HnB tobacco) aerosol from heat sticks, mainstream smoke from 3R4F (conventional cigarettes) or clean air, using a whole-body exposure system. Adult male offspring mice were divided into six groups: control (5- and 15-weeks-old offspring), IQOS (5 and 15-weeks-old) and 3R4F (5 and 15-weeks-old). Spermatogenesis, sperm characteristics, serum testosterone, and seminiferous tubule morphology were evaluated. Prenatal IQOS exposure increased abnormal seminiferous tubule morphology and decreased sperm production at 5 weeks, but 3R4F exposure did not. Prenatal exposure to IQOS aerosol delays sexual maturation of male offspring or adversely affects the male testicular function of the offspring more than smoke from a combustion cigarette.

Does early maternal responsiveness buffer prenatal tobacco exposure effects on young children's behavioral disinhibition?

Children with prenatal tobacco exposure (PTE) exhibit early self-regulatory impairments, reflecting a life-course persistent propensity toward behavioral disinhibition. Previously, we demonstrated the protective role of parental responsiveness for reducing the risk of exposure-related disruptive behavior in adolescence. Here, we expanded this line of inquiry, examining whether responsiveness moderates the relation of PTE to a broader set of behavioral disinhibition features in early childhood and testing alternative diathesis-stress versus differential susceptibility explanatory models. PTE was assessed prospectively using interviews and bioassays in the Midwestern Infant Development Study (MIDS). Mother-child dyads (N = 276) were re-assessed at approximately 5 years of age in a preschool follow-up. We quantified maternal responsiveness and child behavioral disinhibition using a combination of directly observed activities in the lab and developmentally sensitive questionnaires. Results supported a diathesis-stress pattern. Children with PTE and less responsive mothers showed increased disruptive behavior and lower effortful control compared with children without PTE. In contrast, exposed children with more responsive mothers had self-regulatory profiles similar to their non-exposed peers. We did not observe sex differences. Findings provide greater specification of the protective role of maternal responsiveness for self-regulation in children with PTE and help clarify mechanisms that may underscore trajectories of exposure-related behavioral disinhibition.

The use of electronic nicotine delivery systems during pregnancy and the reproductive outcomes: A systematic review of the literature

INTRODUCTION

Use of electronic nicotine delivery systems (ENDS) among pregnant women is of great concern. To our knowledge the current literature provides conflicting views regarding the uncertainties of the effects of ENDS use during pregnancy on the health of the fetus.

METHODS

We searched PubMed, CINAHL, and EMBASE, for the period 2007 to October 2017 for terms to identify publications on ENDS use during pregnancy and the reproductive outcomes. We updated the search for the period November 2017 to November 2018 using Ovid Medline. We obtained full text of articles and present a summary of the contents.

RESULTS

We found no studies of pregnant women exposed to ENDS use and its effect on their fetus or neonates. However, there is a growing body of experimental studies in animals that suggest that nicotine in ENDS alters DNA methylation, induces birth defects, reduces the birth weight, and affects the development of the heart and lungs of their offspring. A large population-based cohort study in the United States estimated that 5% of pregnant women were current ENDS users in 2014; most of them also smoked cigarettes. Surveys conducted among practitioners indicate that there is a need to screen and counsel pregnant women. Systematic reviews and meta-analysis of studies of women who used smokeless tobacco during pregnancy suggest that prenatal nicotine alone is a risk factor for low birth weight, premature delivery, and stillbirth.

CONCLUSIONS

There were no previous studies assessing the reproductive effects of ENDS use during pregnancy. However, prenatal exposure to nicotine is known to be harmful to the fetus and the pregnancy.

The effects of amniotic fluid and foetal cord blood cotinine concentrations on pregnancy complications and the anthropometric measurements of newborns

Our objective was determining the effects of amniotic fluid (AF) and fetal cord blood (FCB) cotinine concentrations on pregnancy complications and the anthropometric measurements in the newborns whose mothers underwent amniocentesis. This study was conducted as a case-control study, in Turkey. A total of 250 pregnant women with amniocentesis indication were recruited into the study and the cotinine levels in the AF and FCB were determined. A smoking habit did not statistically affect the incidence of pregnancy complications (p>.05). The birth weights of the newborns were negatively correlated with the AF cotinine levels. The incidences of low birth weight, low Apgar scores and RDS were positively correlated with higher levels of cotinine in AF and FCB. It is important for healthcare staff to provide training and consultancy services for the health improvement of pregnant women and the prevention of smoking during pregnancy. Impact statement What is already known on this subject? The pre-pregnancy smoking habit usually continues during the pregnancy. A significant negative correlation was present between the foetal cord blood cotinine levels and the birth weight. What do the results of this study add? The anthropometric measurements of the newborns born from mothers with high AF cotinine levels were lower than newborns born from mothers with low amniotic fluid cotinine levels. Respiratory Distress syndrome is more often determined in newborns born from mothers with high AF cotinine levels. What are the implications of these findings for clinical practice and/or further research? Future studies should be performed to investigate the effects of cigarette smoking on the health problems, the growth characteristics and the neurological development of newborns and infants within the first year of life.

Exposure to tobacco smoke and validation of smoking status during pregnancy in the MIREC study

Given that prenatal exposure to tobacco smoke can lead to increased risks of adverse health effects, having valid measures of exposure is important. In a Canadian cohort (n = 2000), maternal and infant biospecimens were analysed for cotinine. Sensitivity and specificity of self-reported active smoking status were estimated. Regression modelling was used to identify potential predictors of maternal and infant plasma cotinine in non-smoking women. During the first trimester, 60.6% of the women reported never smoking, 27.3% were former smokers, 6.1% had quit when they found out they were pregnant, 5.8% were smokers and 42% of the non-smokers reported exposure to secondhand smoke (SHS). Low detection of tobacco biomarkers in meconium limited its ability to identify exposure to SHS. The sensitivity and specificity for self-reported smoking during the 1st trimester were 85.37 and 99.45%, respectively. The lowest sensitivity was found in participants with the highest level of education and income, oldest women and those born outside Canada. Non-smoking women living in an apartment had 1.7 times higher odds of detectable plasma cotinine than those living in a single home after adjusting for other variables. Our results suggest that while self-reports are fairly accurate, they may be less so in populations with higher socio-economic status. This investigation underscores the need to consider the participant socio-economic characteristics and dwelling type when using questionnaires to estimate active and passive tobacco exposure.

Developmental nicotine exposure affects larval brain size and the adult dopaminergic system of Drosophila melanogaster

BACKGROUND

Pregnant women may be exposed to nicotine if they smoke or use tobacco products, nicotine replacement therapy, or via e-cigarettes. Prenatal nicotine exposure has been shown to have deleterious effects on the nervous system in mammals including changes in brain size and in the dopaminergic system. The genetic and molecular mechanisms for these changes are not well understood. A Drosophila melanogaster model for these effects of nicotine exposure could contribute to faster identification of genes and molecular pathways underlying these effects. The purpose of this study was to determine if developmental nicotine exposure affects the nervous system of Drosophila melanogaster, focusing on changes to brain size and the dopaminergic system at two developmental stages.

RESULTS

We reared flies on control or nicotine food from egg to 3rd instar larvae or from egg to adult and determined effectiveness of the nicotine treatment. We used immunohistochemistry to visualize the whole brain and dopaminergic neurons, using tyrosine hydroxylase as the marker. We measured brain area, tyrosine hydroxylase fluorescence, and counted the number of dopaminergic neurons in brain clusters. We detected an increase in larval brain hemisphere area, a decrease in tyrosine hydroxylase fluorescence in adult central brains, and a decrease in the number of neurons in the PPM3 adult dopaminergic cluster. We tested involvement of Dα7, one of the nicotinic acetylcholine receptor subunits, and found it was involved in eclosion, as previously described, but not involved in brain size.

CONCLUSIONS

We conclude that developmental nicotine exposure in Drosophila melanogaster affects brain size and the dopaminergic system. Prenatal nicotine exposure in mammals has also been shown to have effects on brain size and in the dopaminergic system. This study further establishes Drosophila melanogaster as model organism to study the effects of developmental nicotine exposure. The genetic and molecular tools available for Drosophila research will allow elucidation of the mechanisms underlying the effects of nicotine exposure during development.

Assessment of tobacco, alcohol and cannabinoid metabolites in 645 meconium samples of newborns compared to maternal self-reports

Prenatal psychoactive substance exposure has significant impact on neonatal health and child development and the development of reliable biomarkers is critical. Meconium presents several advantages for detecting prenatal exposure to psychoactive substances, as it is easy to collect and provides a broad time frame of exposure (third trimester). The aim of our study was to compare the prevalence of alcohol, tobacco and/or cannabis use during the third trimester of pregnancy (using maternal self-reports) with the results of meconium testing of their metabolites in newborns (cotinine, ethyl-glucuronide (EtG) and cannabinoid metabolites). Among all deliveries (993) that occurred in all maternities in Rouen (Normandy) during a defined time period (5 consecutive weeks in August, 2010 and August, 2011), 724 mothers were included and 645 meconium samples were collected. Maternal self-reports, using the Addiction Severity Index (5th edition), and meconium samples were collected within 72 h of delivery. Cotinine detection appears highly correlated to maternal self-reports (Kappa value: 0.79; [95%CI: 0.73-0.85]). Moreover, detection in meconium seems more accurate in the prediction of neonatal consequences of prenatal tobacco exposure as compared to maternal self-reports. In contrast, we have found a lower concordance between maternal self-reports and meconium testing for EtG and cannabinoid metabolites (Kappa value: 0.13; [95%CI: 0.04-0.22] and: 0.30; [95%CI: -0.03-0.63], respectively); however the total number of EtG- and cannabinoid-positive meconium samples was small. Interestingly, meconium samples with the highest levels of EtG mainly corresponded to negative maternal self-reports. Fetal exposure to alcohol, tobacco or cannabis may also considerably differ as displayed in our pairs of dizygotic twins. Finally, a polyconsumption of these psychoactive substances was not frequently observed according to meconium testing. In conclusion, cotinine detection appears as a valuable meconium biomarker. EtG measurement in meconium samples seems interesting if there is any risk of high fetal exposure, whereas assessment of prenatal cannabis exposure, using meconium testing, needs to be improved.

Camellia sinensis Prevents Perinatal Nicotine-Induced Neurobehavioral Alterations, Tissue Injury, and Oxidative Stress in Male and Female Mice Newborns

Nicotine exposure during pregnancy induces oxidative stress and leads to behavioral alterations in early childhood and young adulthood. The current study aimed to investigate the possible protective effects of green tea (Camellia sinensis) against perinatal nicotine-induced behavioral alterations and oxidative stress in mice newborns. Pregnant mice received 50 mg/kg C. sinensis on gestational day 1 (PD1) to postnatal day 15 (D15) and were subcutaneously injected with 0.25 mg/kg nicotine from PD12 to D15. Nicotine-exposed newborns showed significant delay in eye opening and hair appearance and declined body weight at birth and at D21. Nicotine induced neuromotor alterations in both male and female newborns evidenced by the suppressed righting, rotating, and cliff avoidance reflexes. Nicotine-exposed newborns exhibited declined memory, learning, and equilibrium capabilities, as well as marked anxiety behavior. C. sinensis significantly improved the physical development, neuromotor maturation, and behavioral performance in nicotine-exposed male and female newborns. In addition, C. sinensis prevented nicotine-induced tissue injury and lipid peroxidation and enhanced antioxidant defenses in the cerebellum and medulla oblongata of male and female newborns. In conclusion, this study shows that C. sinensis confers protective effects against perinatal nicotine-induced neurobehavioral alterations, tissue injury, and oxidative stress in mice newborns.

Protecting Children From Tobacco, Nicotine, and Tobacco Smoke

This technical report serves to provide the evidence base for the American Academy of Pediatrics' policy statements "Clinical Practice Policy to Protect Children From Tobacco, Nicotine, and Tobacco Smoke" and "Public Policy to Protect Children From Tobacco, Nicotine, and Tobacco Smoke." Tobacco use and involuntary exposure are major preventable causes of morbidity and premature mortality in adults and children. Tobacco dependence almost always starts in childhood or adolescence. Electronic nicotine delivery systems are rapidly gaining popularity among youth, and their significant harms are being documented. In utero tobacco smoke exposure, in addition to increasing the risk of preterm birth, low birth weight, stillbirth, placental abruption, and sudden infant death, has been found to increase the risk of obesity and neurodevelopmental disorders. Actions by pediatricians can help to reduce children's risk of developing tobacco dependence and reduce children's involuntary tobacco smoke exposure. Public policy actions to protect children from tobacco are essential to reduce the toll that the tobacco epidemic takes on our children.

Meconium Atazanavir Concentrations and Early Language Outcomes in HIV-Exposed Uninfected Infants With Prenatal Atazanavir Exposure

OBJECTIVE

To investigate whether prenatal atazanavir (ATV) exposure, assessed by meconium antiretroviral (ARV) quantification, predicts early child language outcomes. Prenatal ATV exposure previously was associated with poorer language development in 1-year olds.

METHODS

Pregnant women with HIV and their uninfected infants enrolled in the Surveillance Monitoring of Antiretroviral Therapy Toxicities study. Meconium ARV concentrations were quantified by liquid chromatography-tandem mass spectrometry. Language development at 1 year was assessed with MacArthur-Bates Communicative Development Inventory (CDI) and Bayley Scales of Infant and Toddler Development-Third Edition (Bayley-III). Late language emergence was defined as ≥ 1 of 4 CDI scores ≤ 10th percentile for age. Associations between fetal ATV exposure timing and duration, meconium ATV concentration, and language outcomes were evaluated, adjusting for potential confounders.

RESULTS

Through 2013, meconium samples were available from 175 of 432 infants with prenatal ATV exposure. Valid Bayley-III (n = 93) and CDI (n = 106) assessments also were available. After adjustment for potential confounders, higher ATV meconium concentrations were associated with lower late language emergence risk (P = 0.04) and cumulative ATV exposure duration also was associated with higher Bayley-III Language scores (P = 0.03). Maternal ATV duration and initiation week correlated with ATV meconium concentrations (positively and negatively, respectively).

CONCLUSIONS

Higher meconium ATV concentrations were protective against developmental language delays at 1 year, suggesting the importance of fetal ATV detoxification into meconium. This information supports ATV exposure safety for infant language development. ATV is a preferred ARV for pregnant women with HIV, suggesting the importance of ATV safety investigations. Additionally, further pursuit of the influences on language development in HIV-exposed uninfected infants is required.

Meconium Tenofovir Concentrations and Growth and Bone Outcomes in Prenatally Tenofovir Exposed HIV-Uninfected Children

BACKGROUND

Maternal tenofovir disoproxil fumarate (TDF) treatment among HIV-infected pregnant women results in fetal tenofovir (TFV) exposure. Fetal TFV toxicity was demonstrated in animals, but most clinical investigations have not observed toxicity in humans.

METHODS

We evaluated HIV-exposed, uninfected infants in the Surveillance Monitoring for Antiretroviral Therapy Toxicities cohort of the Pediatric HIV/AIDS Cohort Study whose mothers were prescribed TDF for ≥ 8 third trimester weeks. Infant dual-energy X-ray absorptiometry scans were obtained at 0-4 weeks to measure whole body bone mineral content. Meconium TFV concentrations were quantified by liquid chromatography-tandem mass spectrometry.

RESULTS

Fifty-eight TFV-exposed infants had meconium TFV quantified. Detectable concentrations were 11-48,100 ng/g; 3 infants had undetectable concentrations. Maternal TDF prescription duration ranged from 8 to 41 gestational weeks; infant gestational ages were 36-41 weeks. Meconium TFV concentrations were not correlated with TFV exposure duration or timing and did not vary by concomitant prescription of protease inhibitors. Increased meconium TFV concentrations were associated with greater gestational ages (ρ = 0.29, P = 0.03) and lower maternal plasma HIV RNA before delivery (ρ = -0.29, P = 0.04). Meconium TFV concentrations were not associated with infant weight, length (n = 58) or bone mineral content (n = 49).

CONCLUSIONS

For the first time, we explored associations between meconium TFV concentrations and infant growth and bone measurements; we did not observe a meconium concentration-dependent relationship for these infant outcomes. These findings support other clinical research failing to show dose-response relationships for growth and bone outcomes among intrauterine TFV-exposed infants. High meconium TFV concentrations correlated with low maternal viral load, suggesting maternal TDF adherence significantly contributes to meconium TFV concentrations.

Antiretroviral Drugs in Meconium: Detection for Different Gestational Periods of Exposure

OBJECTIVES

To determine whether antiretroviral (ARV) medications can be detected in meconium from second or third trimester, labor and delivery (L&D), or postnatal exposures.

STUDY DESIGN

Twenty ARV medications were quantified by liquid chromatography-tandem mass spectrometry in 598 meconium samples from uninfected infants born to pregnant women with HIV enrolled in the Pediatric HIV/AIDS Cohort Study.

RESULTS

ARV detection in meconium following third trimester exposure was 85.7%-94.4% for all ARVs except stavudine (0%, n = 2), likely because of low doses and a high limit for quantification. Of 107 samples with some second trimester only ARV exposures, meconium was positive for only lopinavir, tenofovir, or efavirenz in 11.8%-14.3% of exposed neonates; administration of these ARVs occurred between gestational weeks 25-28 in the positive samples. Days without lopinavir or tenofovir before delivery significantly correlated with decreasing concentrations of lopinavir and tenofovir in meconium. Tenofovir and lamivudine concentrations significantly correlated with increasing gestational age among infants with continuous second and third trimester exposure. Zidovudine given during L&D or for neonatal prophylaxis was detected in 95.1% and 94.6% of meconium samples, respectively.

CONCLUSIONS

Changes in ARV treatments during pregnancy offered a unique opportunity to investigate ARV detection in meconium. ARVs in meconium primarily reflect third trimester ARV exposures, although 6 of 107 second trimester only exposures were detected. Zidovudine administration during L&D was detected in meconium indicating potential urine contamination or rapid incorporation into meconium. These data will improve interpretation of meconium drug test results.

Tobacco control campaign in Uruguay: Impact on smoking cessation during pregnancy and birth weight

We analyzed a nationwide registry of all pregnancies in Uruguay during 2007-2013 to assess the impact of three types of tobacco control policies: (1) provider-level interventions aimed at the treatment of nicotine dependence, (2) national-level increases in cigarette taxes, and (3) national-level non-price regulation of cigarette packaging and marketing. We estimated models of smoking cessation during pregnancy at the individual, provider and national levels. The rate of smoking cessation during pregnancy increased from 15.4% in 2007 to 42.7% in 2013. National-level non-price policies had the largest estimated impact on cessation. The price response of the tobacco industry attenuated the effects of tax increases. While provider-level interventions had a significant effect, they were adopted by relatively few health centers. Quitting during pregnancy increased birth weight by an estimated 188 g. Tobacco control measures had no effect on the birth weight of newborns of non-smoking women.

Recent advances in MS methods for nicotine and metabolite analysis in human matrices: clinical perspectives

Tobacco smoking is a major global health issue and represents the leading cause of preventable death in the developed countries. Nicotine is a major alkaloid found in tobacco products and its detection with its metabolites in human matrices is generally used for assessing tobacco consumption and second hand exposure. Several analytical techniques have been developed for the detection of nicotine and its metabolites, and MS coupled with chromatography is considered the standard reference method because of its superior sensitivity and specificity. In this work, we reviewed nicotine metabolism, clinical MS and the latest (2009-2014) development of MS-based techniques for measurement of nicotine and metabolites in human matrices. Appropriate biomarker and matrix selection are also critically discussed.

Simultaneous quantification of tobacco alkaloids and major phase I metabolites by LC-MS/MS in human tissue

INTRODUCTION

Insurance agencies might request laboratories to differentiate whether a deceased has been a smoker or not to decide about refunding of his nonsmoker rate. In this context, the question on a solid proof of tobacco alkaloids and major metabolites in tissues came up. Currently, an appropriate assay is still lacking to analyze tissue distribution in smokers or nonsmokers. Nicotine (NIC), nornicotine (NNIC), anatabine (ATB), anabasine (ABS), and myosmine (MYO) are naturally occurring alkaloids of the tobacco plant; most important phase I metabolites of NIC are cotinine (COT), norcotinine (NCOT), trans-3'-hydroxycotinine (HCOT), nicotine-N'-oxide (NNO), and cotinine-N-oxide (CNO). An analytical assay for their determination was developed and applied to five randomly selected autopsy cases.

METHODS

Homogenates using 500 mg aliquots of tissue samples were analyzed by liquid chromatography/tandem mass spectrometry following solid phase extraction. The method was validated according to current international guidelines.

RESULTS

NIC, COT, NCOT, ABS, ATB, and HCOT could be detected in all tissues under investigation. Highest NIC concentrations were observed in the lungs, whereas highest COT concentrations have been found in the liver. MYO was not detectable in any of the tissues under investigation.

CONCLUSIONS

The assay is able to adequately separate isobaric analyte pairs such as NIC/ABS/NCOT and HCOT/CNO thus being suitable for the determination of tobacco alkaloids and their phase I metabolites from tissue. More autopsy cases as well as corresponding body fluids and hair samples will be investigated to differentiate smokers from nonsmokers.

Risk factors associated with hospital readmission in pediatric asthma

Asthma is a leading cause of hospitalization among children, and about 15-50% of pediatric patients are readmitted after an index admission. The purpose of this integrative review is to explore contemporary scientific findings on the association between pediatric asthma readmission and various demographic, environmental, psychosocial and clinical risk factors. An electronic database search resulted in a sample of 29 studies. African American, public or no insurers, previous admission and complex chronic comorbidity were identified as risk factors associated with pediatric asthma readmission. However, more interdisciplinary and well-designed investigations are warranted to further explicate the spectrum of environmental and psychosocial correlates.

Smoking during pregnancy affects foetal brain development

Environmental factors such as maternal smoking can significantly modulate genetically programmed brain development during foetal life. This review looks at how prenatal smoking exposure modulates brain development, including new evidence on the effects of smoking on foetal brain development and function.

CONCLUSION

Smoking during pregnancy exposes the foetus to thousands of health-threatening chemicals, restricting foetal body and head growth. Alterations in brain structure and function have been seen in children exposed to prenatal smoking.

Developmental consequences of fetal exposure to drugs: what we know and what we still must learn

Most drugs of abuse easily cross the placenta and can affect fetal brain development. In utero exposures to drugs thus can have long-lasting implications for brain structure and function. These effects on the developing nervous system, before homeostatic regulatory mechanisms are properly calibrated, often differ from their effects on mature systems. In this review, we describe current knowledge on how alcohol, nicotine, cocaine, amphetamine, Ecstasy, and opiates (among other drugs) produce alterations in neurodevelopmental trajectory. We focus both on animal models and available clinical and imaging data from cross-sectional and longitudinal human studies. Early studies of fetal exposures focused on classic teratological methods that are insufficient for revealing more subtle effects that are nevertheless very behaviorally relevant. Modern mechanistic approaches have informed us greatly as to how to potentially ameliorate the induced deficits in brain formation and function, but conclude that better delineation of sensitive periods, dose-response relationships, and long-term longitudinal studies assessing future risk of offspring to exhibit learning disabilities, mental health disorders, and limited neural adaptations are crucial to limit the societal impact of these exposures.

Determination of nicotine and cotinine in meconium from Greek neonates and correlation with birth weight and gestational age at birth

Tobacco exposure during pregnancy is a major factor of morbidity and mortality for both the pregnant woman and the fetus. Several studies in the past have detected and quantified tobacco smoke biomarkers in infant meconium samples. Aim of this study was to measure prenatal exposure to tobacco smoke by detecting nicotine and cotinine in meconium and to try to evaluate the extent of exposure to smoke through passive smoking as well as the relationship between tobacco biomarker meconium concentrations and neonatal outcomes. Tobacco smoke biomarkers nicotine and cotinine were detected and quantitated in meconium from tobacco exposed and non-exposed Greek neonates using liquid chromatography-tandem mass spectrometry. The study included 45 neonates from active, passive and non-smoking women during pregnancy. The results showed significant values of nicotine and cotinine concentration in neonates from both active and passive smokers which reached 125 ng g(-1) for nicotine and 98.5 ng g(-1) for cotinine and varied according to the type and level of exposure. In general nicotine and cotinine concentrations correlated with the degree of active smoking by the mother. Similarly, nicotine and cotinine were measured in the meconium of infants of passive smokers at concentrations comparable to those of infants whose mothers were moderate smokers. Our findings show that exposure of the fetus to tobacco biomarkers can be substantial even in passive maternal smoking and there is a statistically significant negative correlation between nicotine or cotinine concentrations in meconium and birth weight or gestational age at birth.

Use of meconium in perinatal epidemiology: potential benefits and pitfalls

PURPOSE

Meconium is a biomarker matrix that can be used to assess cumulative exposures in epidemiologic studies of prenatal risk factors. Depending on when meconium is collected, different exposure windows during pregnancy can be measured. However, little guidance exists regarding the extent to which timing of meconium collection will influence resulting effect estimates.

METHODS

We performed a simulation study of prenatal tobacco smoke exposure (assessed from meconium nicotine) and birth weight. We discuss four typical meconium collection methods capturing different exposure windows and assess the biases induced by these methods.

RESULTS

In simulations assuming that exposure to tobacco smoke only during late gestation was of etiologic relevance to birth weight, use of a meconium collection method that captured exposure windows other than late gestation resulted in biased estimates of the true nicotine-birth weight association.

CONCLUSIONS

Using meconium collection methods that do not reflect an exposure window of etiologic relevance can lead to biased results and erroneous conclusions regarding the nature of prenatal exposure-outcome associations. Understanding how prenatal exposure patterns vary across the pregnancy and exposure windows of etiologic relevance is essential in determining when and how to collect meconium for use in biomarker studies of prenatal exposure.

Cotinine in children admitted for asthma and readmission

OBJECTIVE

To explore the relationship between tobacco smoke exposure (reported versus biomarker) and rates of readmission for children hospitalized for asthma.

METHODS

We enrolled a prospective cohort of 774 children aged 1 to 16 years admitted for asthma or bronchodilator-responsive wheezing. The primary outcome was at least 1 asthma- or wheeze-related readmission within 1 year. Caregivers reported any tobacco exposure at home, in a secondary residence, or in the car. We measured serum and saliva cotinine levels with mass spectrometry. We used logistic regression to evaluate associations between tobacco exposure and readmissions.

RESULTS

A total of 619 children had complete tobacco exposure data; 57% were African American and 76% had Medicaid. Seventeen percent of children were readmitted within 1 year. Tobacco exposure rates were 35.1%, 56.1%, and 79.6% by report, serum, and saliva measures, respectively. Caregiver report of any tobacco exposure was not associated with readmission (adjusted odds ratio: 1.18; 95% confidence interval: 0.79-1.89), but having detectable serum or salivary cotinine was associated with increased odds of readmission (adjusted odds ratio [95% confidence interval]: 1.59 [1.02-2.48] and 2.35 [1.22-4.55], respectively). Among children whose caregivers reported no tobacco exposure, 39.1% had detectable serum cotinine and 69.9% had detectable salivary cotinine. Of the children with reported exposure, 87.6% had detectable serum cotinine and 97.7% had detectable salivary cotinine.

CONCLUSIONS

Detectable serum and salivary cotinine levels were common among children admitted for asthma and were associated with readmission, whereas caregiver report of tobacco exposure was not.

High cotinine levels are persistent during the first days of life in newborn second hand smokers

BACKGROUND

Despite the adverse effects of maternal smoking during pregnancy on the newborn's health are well-known, in the pediatric population, a high prevalence exists that is very much affected by second hand smoke (SHS). This study aims to investigate the impact of maternal smoking habits during pregnancy on cotinine levels in newborns during the first days of life. The high association between cotinine concentration in maternal and umbilical cord blood (UCB) has been previously reported, but the levels of blood cotinine that remain in infants born to smokers is unknown.

METHODS

Cotinine concentration was measured in UCB, in maternal and newborn peripheral blood. Data from UCB sample dyads of ninety mothers and from seventy-one newborns were analyzed.

RESULTS

Cotinine levels were significantly different among non-smokers (9.9 ± 5.9 ng/ml), moderate (67.3 ± 7.4 ng/ml), and heavy smokers (137.7 ± 19.5 ng/ml) (p<0.0001). Significant correlations were found between maternal and UCB cotinine (r=0.748; p<0.001), and between UCB and newborn plasma cotinine at 48 h after birth (r=0.541; p<0.001). The smokers exposed their infants to cotinine with a median of 31.7 ± 8.6 ng/ml (moderate) or 59.1 ± 13.3 ng/ml (heavy smokers) until at least, 48 h after birth. Reduced birth weight and length were significantly related with UCB cotinine levels.

CONCLUSIONS

A positive association between UCB and plasmatic cotinine in newborns was found. The high cotinine levels detected in newborns from smoker mothers indicates that their infants are subjected to elevated SHS from birth. These results can help to reinforce the awareness of the adverse effects of smoking during pregnancy.