In utero exposure to smoking and newborn neurobehavior: how to assess neonatal withdrawal syndrome?

Evaluation of three-year neurodevelopmental outcomes in infants prenatally exposed to substance use

INTRODUCTION

Prenatal exposure to substance use is associated with long-term deficits in the neurodevelopment of children. The objective was to investigate the association between cognitive, motor, and language neurodevelopment at three years of age in infants prenatally exposed to substance use.

MATERIAL AND METHODS

A prospective matched case-control study was conducted. Biomarkers of fetal exposure were measured in meconium samples. The Bayley Scales of Infant and Toddler Development (BSID-III) were used to calculate neurodevelopment scores.

RESULTS

32 non-exposed and 32 exposed infants were evaluated, of which 16 were exposed to cannabis, 8 to ethanol, 2 to cocaine and 6 to more than one substance. Normal BSID-III scores ≥85 in all domains, were detected in 23 exposed infants to any substance and 29 infants non-exposed. Neurodevelopmental delay was detected in the language domain, specifically in male infants exposed to cannabis. Two infants exposed to cannabis had a severe developmental delay (score<70). Infants exposed to any substance obtained significantly lower total scores than control infants in all domains. Infants exposed to cannabis obtained significantly lower composite scores in the cognitive and motor domains. Infants exposed to more than one substance had lower scores in motor skills. By gender, only males exposed obtained significantly lower composite scores than non-exposed males in the cognitive domain.

CONCLUSIONS

The most common and severe neurodevelopmental delay at 36 months was detected in the domain of language in male infants prenatally exposed to cannabis. Neurodevelopmental disorders detected can enable an early intervention and plan therapeutic strategies.

Nicotinic regulation of microglia: potential contributions to addiction

Clinical and preclinical studies have identified immunosuppressive effects of nicotine, with potential implications for treating nicotine addiction. Here we review how nicotine can regulate microglia, the resident macrophages in the brain, and corresponding effects of nicotine on neuroimmune signaling. There is significant evidence that activation of α7 nicotinic acetylcholine receptors (nAChRs) on microglia can trigger an anti-inflammatory cascade that alters microglial polarization and activity, cytokine release, and intracellular calcium concentrations, leading to neuroprotection. These anti-inflammatory effects of nicotine-dependent α7 nAChR signaling are lost during withdrawal, suggesting that neuroimmune signaling is potentiated during abstinence, and thus, heightened microglial activity may drive circuit disruption that contributes to withdrawal symptoms and hyperkatifeia. In sum, the clinical literature has highlighted immunomodulatory effects of nicotine and the potential for anti-inflammatory compounds to treat addiction. The preclinical literature investigating the underlying mechanisms points to a role of microglial engagement in the circuit dysregulation and behavioral changes that occur during nicotine addiction and withdrawal, driven, at least in part, by activation of α7 nAChRs on microglia. Specifically targeting microglial signaling may help alleviate withdrawal symptoms in people with nicotine dependence and help to promote abstinence.

Abnormal neurological soft signs in babies born to smoking mothers were associated with lower breastfeeding for first three months

AIM

We examined associations between neurological alterations in infants born to smoking mothers and breastfeeding success at discharge and three months of age.

METHODS

This 2016 study compared 35 normal weight infants born to smoking mothers at 37-41 weeks and 35 matched controls born to non-smoking mothers at the Maternity Hospital of Careggi University, Florence, Italy. Neonatal behaviour was evaluated using the neurological soft signs (NSS) component of the Graham-Rosenblith Scale. Breastfeeding variables were measured using the LATCH score that covers: breast latching, audible swallowing, type of nipple, mother's comfort and help they needed to hold their baby to their breast. A questionnaire on excessive crying and feeding was distributed at discharge, and further data were collected during a three-month telephone interview.

RESULTS

At discharge, the infants born to smoking mothers had a significantly lower LATCH score and significantly poorer performance on several items of the NSS component than the controls. The LATCH score and number of NSS were inversely proportional. At the three-month follow-up only 57.1% of the smoking group infants were breastfeeding compared with 87.5% of the control infants (p < 0.01).

CONCLUSION

Infants with smoking mothers displayed altered neurobehavioural profiles and had a difficult start to breastfeeding.

Management of neonatal abstinence syndrome in the newborn nursery

Maternal drug use and neonatal abstinence syndrome (NAS) are being seen across the United States. NAS occurs with withdrawal disturbances in response to the cessation of the pregnancy exposure. The clinical presentation of a newborn with NAS can include gastrointestinal, neurologic, vasomotor and respiratory symptoms. Assessment of newborns with NAS can often present as a challenge to maternal-child nurses. Treatment can include supportive care as well as pharmacologic therapies.

Altered placental DNA methylation patterns associated with maternal smoking: current perspectives

The developmental origins of health and disease hypothesis states that adverse early life exposures can have lasting, detrimental effects on lifelong health. Exposure to maternal cigarette smoking during pregnancy is associated with morbidity and mortality in offspring, including increased risks for miscarriage, stillbirth, low birth weight, preterm birth, asthma, obesity, altered neurobehavior, and other conditions. Maternal cigarette smoking during pregnancy interferes with placental growth and functioning, and it has been proposed that this may occur through the disruption of normal and necessary placental epigenetic patterns. Epigenome-wide association studies have identified a number of differentially methylated placental genes that are associated with maternal smoking during pregnancy, including RUNX3, PURA, GTF2H2, GCA, GPR135, and HKR1. The placental methylation status of RUNX3 and NR3C1 has also been linked to adverse infant outcomes, including preterm birth and low birth weight, respectively. Candidate gene analyses have also found maternal smoking-associated placental methylation differences in the NR3C1, CYP1A1, HTR2A, and HSD11B2 genes, as well as in the repetitive elements LINE-1 and AluYb8. The differential methylation patterns of several genes have been confirmed to also exhibit altered gene expression patterns, including CYP1A1, CYP19A1, NR3C1, and HTR2A. Placental methylation patterns associated with maternal smoking during pregnancy may be largely gene-specific and tissue-specific and, to a lesser degree, involve global changes. It is important for future research to investigate the mechanistic roles that these differentially methylated genes may play in mediating the association between maternal smoking during pregnancy and disease in later life, as well as to elucidate the potential influence of emerging tobacco product use during pregnancy, including the use of electronic cigarettes, on placental epigenetics.

Care of Drug-Addicted Pregnant Women: Current Concepts and Future Strategies – an Overview

This review focuses on drug use during pregnancy and the perinatal period, a constellation that is seen more often. Drug use in pregnant women poses an increased risk for adverse health outcomes both for the mother and child. Care is often complicated by social and environmental factors, as well as psychiatric comorbidities. It is, therefore, very important to provide drug-using pregnant women with optimal ante-, peri- and post-natal care. Health professionals should approach them in a nonjudgmental and supportive way, and provide them with the same care and attention as nondrug-using women. Adequate care requires interdisciplinary teams. Ideally, healthcare providers should be specialized in the care of drug-using pregnant women.

Sex differences in the association between prenatal smoking and decreased birthweight, and intensive health care of the neonate

Gender-specific associations between prenatal smoking and birthweight, and neonate intensive health care were studied. Cross-sectional data from 11,583 newborns in the continuous National Health and Nutrition Examination Survey (NHANES) 2003-2008 early childhood data sets were used. Change in infant birthweight and likelihood of receiving neonatal intensive care by prenatal smoking exposure were assessed. Multivariable regression models were used to assess the influence of prenatal smoking on birthweight and likelihood of receiving intensive neonatal health care. Compared with infants from nonsmoking mothers, prenatal smoking associated with significant decrease in infant birthweight, -203.0 g ± 32.5, P < 0.001. The change in birthweight differed between infant boys, -220.2 g ± 44.5, and girls, -184.1 g ± 38.8. Newborns exposed to prenatal smoking were more likely to have low birthweight, odds ratio 1.46, P < 0.03, and to receive neonatal intensive health care, odds ratio 1.20; P < 0.04. It is imperative that prenatal counseling emphasizes prenatal maternal smoking.

A longitudinal study on the effects of maternal smoking and secondhand smoke exposure during pregnancy on neonatal neurobehavior

Maternal smoking during pregnancy is one of the most modifiable causes of morbidity and mortality for both pregnant women and their fetuses. The long-term effects of prenatal exposure to smoke on child behavior and development have been the subject of more extensive research than have the short-term effects. Therefore, the aim of this work is to examine the effects of smoke exposure during pregnancy on neonatal behavior, including in our study a group of mothers exposed to secondhand smoke. The behavior of 282 healthy full-term newborns was assessed using the Neonatal Behavior Assessment Scale (NBAS) at 48-72 h of life. Sixty-two mothers smoked during pregnancy (no mother smoked more than 15 cig/day) and 17 were exposed to secondhand smoke. After adjusting for socio-demographic and obstetric factors, both newborns whose mothers smoked and those whose mothers were exposed to secondhand smoke showed significantly lower scores in the habituation cluster than non-smoking mothers. Exposure to secondhand smoke was also related to lower motor system cluster scores as well as some supplementary items and the newborns of smoking mothers showed significantly lower scores in the state regulation cluster and in some items of the state organization cluster than the newborns of non-smoking mothers. We conclude that active and passive smoking during pregnancy affects several aspects of neurobehavioral development, regardless of socio-demographic, obstetric and pediatric factors.

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.

Sleep problems in children with prenatal substance exposure: the Maternal Lifestyle study

OBJECTIVE

To examine the associations between sleep problems and prenatal exposure to cocaine, opiates, marijuana, alcohol, and nicotine in children aged 1 month to 12 years.

DESIGN

Sleep data were collected by maternal report in a prospective longitudinal follow-up of children participating in the Maternal Lifestyle multisite study.

SETTING

Hospital-based research centers in Providence, Rhode Island; Miami, Florida; Detroit, Michigan; and Memphis, Tennessee.

PARTICIPANTS

There were 808 participants, 374 exposed to cocaine and/or opiates, and 434 comparison subjects.

MAIN EXPOSURE

Prenatal cocaine, opiate, marijuana, alcohol, and/or nicotine exposure.

OUTCOME MEASURE

Sleep problems in early, middle, and/or late childhood, assessed as composites of maternal report items.

RESULTS

Of the 5 substances, prenatal nicotine exposure was the only unique predictor of sleep problems (B = 0.074, R(2) change = 0.008, P = .01), with adjustment for covariates, including socioeconomic status, marital status, physical abuse, prenatal medical care, and postnatal cigarette smoke exposure.

CONCLUSIONS

Prenatal exposure to nicotine was positively associated with children's sleep problems persisting throughout the first 12 years of life. Targeting of this group of children for educational and behavioral efforts to prevent and treat sleep problems is merited given that good sleep may serve as a protective factor for other developmental outcomes.

Longitudinal study of maternal report of sleep problems in children with prenatal exposure to cocaine and other drugs

Sleep data were collected by maternal report in a prospective longitudinal follow up of cocaine-exposed and unexposed children. There were 139 participants: 23 with no prenatal drug exposure, 55 exposed to cocaine alone or in combination with other drugs, and 61 exposed to drugs other than cocaine. Characteristics differed between exposure groups including birth size, caretaker changes, maternal socioeconomic status, and postnatal drug use. Compared to those with no drug exposure, children with prenatal drug exposure other than cocaine experienced greater sleep problems (p = .026). Prenatal nicotine exposure was a unique predictor of sleep problems (p = .048). Early sleep problems predicted later sleep problems (all ps < .01). Together, these preliminary findings suggest possible neurotoxic sleep effects that persist over time. Larger studies, however, need to be conducted that better control for potential postnatal confounding factors.

Assessment of foetal exposure to cigarette smoke after recent implementations of smoke-free policy in Italy

AIM

We investigated foetal exposure to cigarette smoke following maternal active and passive smoking at the end of the pregnancy in a cohort of mother-infant dyads after recent implementation of the Italian smoke-free legislation and information campaigns against smoking.

METHODS

Study subjects were 979 mothers and their newborns attended at one of the major Florence hospitals between the end of 2004 and during 2005, when smoking banning legislation in all the enclosed places of employment was completely enforced. A structured questionnaire was completed by mothers and cord serum cotinine was used as a biomarker of foetal exposure to maternal smoke at the end of the pregnancy.

RESULTS

Women (53.9%) declared to be non-smokers not exposed to environmental tobacco smoke (ETS), 33.5% to be exposed non-smokers, while 12.6% reported daily smoking during pregnancy. Based on the levels of cord serum cotinine, 78.9% newborns were not exposed to ETS, 13.5% were exposed to ETS and 7.7% were exposed to active maternal smoke.

CONCLUSIONS

Smoke-free policies can be an effective strategy for reducing both first-hand and second-hand exposure to cigarette smoke in pregnant women and their newborns. Due to the implementation of smoke-free legislation and information campaigns against smoking, a significant trend towards less active smoking during pregnancy was observed in our study cohort, as well as a minimal exposure to ETS in non-smoking pregnant women and their newborns.

Neonatal urinary cotinine correlates with behavioral alterations in newborns prenatally exposed to tobacco smoke

Altered behavior due to prenatal smoke exposure was examined in 25 neonates born from smoking mothers who consumed at least 5 cigarettes/d during the entire gestation. Data were compared with 25 matched neonates born from nonsmoking mothers. Neonatal behavior was evaluated using the Brazelton Neonatal Behavioral Assessment Scale (BNBAS). Antenatal exposure to tobacco smoke at the end of the pregnancy was determined by measurement of urinary cotinine. Newborns from smoking mothers showed significant lower scores in various BNBAS items compared with neonates from nonsmoking mothers. A strong correlation was observed between infant irritability and urinary cotinine in newborns from smoker and nonsmoking mothers and with number of daily smoked cigarettes and maternal nicotine daily intake of infants exposed to active maternal smoking. Linear regression analysis showed that urinary cotinine was the best predictor of infant irritability (r(2) = 0.727). The latter was also associated to the neonate's low level of attention and poor response to inanimate auditory stimuli. Among infants from nonsmoking mothers, paternal smoking significantly correlated with infant urinary cotinine and infant irritability, being also the best predictor of irritability (r(2) = 0.364). Neonatal behavior can be significantly altered in a dose-dependent manner even after modest prenatal exposure to tobacco smoke.

Liquid chromatography/electrospray ionization tandem mass spectrometry assay for determination of nicotine and metabolites, caffeine and arecoline in breast milk

A procedure based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) is described for the determination of nicotine and its principal metabolites cotinine, trans-3-hydroxycotinine and cotinine-N-oxide, caffeine and arecoline in breast milk, using N-ethylnorcotinine as internal standard. Liquid/liquid extraction with chloroform/isopropanol (95:5, v/v) was used for nicotine, cotinine, trans-3-hydroxycotinine, cotinine-N-oxide and caffeine under neutral conditions and for arecoline under basic conditions. Chromatography was performed on a C(8) reversed-phase column using a gradient of 50 mM ammonium formate, pH 5.0, and acetonitrile as a mobile phase at a flow rate of 0.5 mL/min. Separated analytes were determined by electrospray ionization tandem mass spectrometry in the positive ion mode using multiple reaction monitoring. Limits of quantification were 5 microg/L for nicotine, cotinine, trans-3-hydroxycotinine, cotinine-N-oxide and caffeine, and 50 microg/L for arecoline using 1 mL human milk per assay. Calibration curves were linear over the calibration ranges for all the substances under investigation, with a minimum r(2) > 0.998. At three concentrations spanning the linear dynamic range of the assay, mean recoveries from breast milk ranged between 71.8 and 77.4% for different analytes. This method was applied to the analysis of analytes in human milk to assess substance exposure in breast-fed infants in relation to eventual clinical outcomes. This LC/MS/MS assay provides adequate sensitivity and performance characteristics for the simultaneous quantification of biomarkers of three of the drugs most commonly used worldwide (tobacco, caffeine and areca nut).

TDM Grand Rounds: Neonatal Nicotine Withdrawal Syndrome in an Infant Prenatally and Postnatally Exposed to Heavy Cigarette Smoke

A heavy smoking, lactating mother delivered a baby that exhibited spontaneous tremors, fluctuations of muscular rigidity, and opisthotonus at 48 hours of life. Although the symptoms did not disappear within the following days, they could be controlled by swaddling or wrapping the baby in a blanket. The absence of any other etiology generated a suspicion of prenatal exposure to heavy tobacco smoke and potential neonatal nicotine withdrawal syndrome. This diagnosis was supported by extremely high concentration of hair nicotine and cotinine in the infant's hair and in different segments of maternal hair. The presence of non-negligible amounts of nicotine and cotinine in breast milk confirmed that the mother did not quit smoking after delivery, despite her reports. The breast-fed newborn continued to have 3 to 4 crises of spontaneous tremors and alternant muscular rigidity per day for a month. More studies are needed to establish neonatal nicotine withdrawal.