Shannon Shisler

Identifying Prenatal Cannabis Exposure and Effects of Concurrent Tobacco Exposure on Neonatal Growth

BACKGROUND Cannabis is the most frequently used illicit drug among pregnant women, but data describing the effects of prenatal cannabis exposure and concurrent nicotine and cannabis exposures on neonatal growth are inconsistent. Testing of meconium, the first neonatal feces, offers objective evidence of prenatal cannabis exposure, but the relative ability of meconium testing and maternal self-report to identify affected neonates remains unclear. METHODS Eighty-six pregnant women provided detailed self-reports of daily cannabis and tobacco consumption throughout pregnancy. Cannabinoids and tobacco biomarkers were identified in oral fluid samples collected each trimester and quantified in meconium at birth. RESULTS Cannabis-using women were significantly more likely to also consume tobacco, and smoked similar numbers of cigarettes as non-cannabis-using tobacco smokers. As pregnancy progressed, fewer women smoked cannabis and those who continued to use cannabis reported smoking a smaller number of cannabis joints, but positive maternal oral fluid tests cast doubt on the veracity of some maternal self-reports. More neonates were identified as cannabis exposed by maternal self-report than meconium analysis, because many women quit cannabis use after the first or second trimester; meconium was more likely to be positive if cannabis use continued into the third trimester. Cannabis exposure was associated with decreased birth weight, reduced length, and smaller head circumference, even after data were controlled for tobacco coexposure. CONCLUSIONS Prenatal cannabis exposure was associated with fetal growth reduction. Meconium testing primarily identifies prenatal cannabis exposure occurring in the third trimester of gestation.

Predictors of Changes in Smoking From Third Trimester to 9 Months Postpartum

INTRODUCTION While much has been written about postpartum smoking relapse prevention, few have examined changes in smoking behavior from pregnancy (third trimester) through 9 months postpartum among pregnant smokers, particularly for the large number of women who decrease tobacco consumption during pregnancy but do not quit altogether. METHODS Data were obtained from 168 women who smoked during their pregnancy. Women were followed longitudinally from their first prenatal appointment through 9 months postpartum. Maternal substance use was assessed using the Timeline Followback and verified by maternal salivary analyses. Breastfeeding, other substance use, and partner smoking were assessed through maternal interviews at each time point and were considered as potential predictors of change in smoking. RESULTS Women returned to more than half of their levels of preconception tobacco consumption by 9 months postpartum. There was one significant predictor of changes in smoking patterns pregnancy to postpartum. Women who breastfed their infants for at least 90 days smoked far less postpartum than women who breastfed for a short time or did not breastfeed at all. CONCLUSIONS As noted in previous research of pregnant quitters, postpartum relapse prevention or harm reduction interventions should ideally be timed early in the postpartum period. Additionally, promoting breastfeeding among pregnant smokers and supporting women through at least 3 months of breastfeeding may be beneficial to such interventions.

Smoking in Pregnancy and Fetal Growth: The Case for More Intensive Assessment

Introduction Many studies on prenatal tobacco exposure (PTE) effects have relied on single item retrospective measures of PTE. However, it is unclear how these single item measures may relate to more intensive maternal self-reports and to biological markers of maternal use and/or fetal exposure. It is also unclear whether these measures may be more valid predictors of fetal growth (gestational age, birthweight, head circumference, and birth length). Methods Data were obtained from 258 women during their pregnancy. PTE was assessed by four methods: a single item question, a calendar-based self-report measure from each trimester of pregnancy, maternal salivary cotinine assays, and nicotine and metabolites in infant meconium. We hypothesized that the more intensive measures and biological assays would account for additional variance in birth outcomes, above and beyond the single item measure. Results The single item self-report measure was not related to fetal growth. However, the more intensive calendar based self-report measure and the biological assays of PTE (ie, maternal salivary assays and infant meconium) were significant predictors of poor fetal growth, even with the single item measure in the model. Conclusions The negative effects of PTE on important child outcomes may be greatly underestimated in the literature as many studies use single item self-report measures to ascertain PTE. Whereas more intensive self-report measures or biological assays may be cost prohibitive in large scale epidemiological studies, using a combination of measures when possible should be considered given their superiority both identifying prenatal smokers and predicting poor fetal growth. Implications The present work underscores the importance of measurement issues when assessing associations between PTE and fetal growth. Results suggest that we may be greatly underestimating the negative effects of prenatal smoking on fetal growth and other important child outcomes if we rely solely on restricted single item self-report measures of prenatal smoking. Researchers should consider more intensive prospective self-report measures and biological assays as viable and superior alternatives to single item self-report measures.

Pre- and postnatal tobacco and cannabis exposure and child behavior problems: Bidirectional associations, joint effects, and sex differences

AIMS We examined prospective associations between pre-and-postnatal tobacco and cannabis exposure on child behavior problems from 2 to 3 years of child age, sex differences in these associations, and bidirectional associations between maternal postnatal substance use and child behavior problems across time. METHODS The sample consisted of 247 primarily young, unmarried, low-income, minority mothers and their children (97 prenatally exposed to tobacco and cannabis, 81 exposed to tobacco only, and 69 non-exposed). Mothers were assessed during each trimester of pregnancy, at 2, 9, 16 months, 2 and 3 years of child age. RESULTS Bivariate results indicated significant differences mainly for girls. Girls in the prenatal tobacco exposure group had higher internalizing problems compared to the other two groups, and higher attention and sleep problems at 3 years compared to the control group. Higher number of cigarettes per day during pregnancy was significantly associated with higher anxiety/depression and higher attention problems at 3 years, and the associations were stronger for girls compared to boys. In model testing controlling for prenatal exposure, results indicated bidirectional associations between behavior problems at 2 years and maternal postnatal cannabis use, such that higher cannabis use across the infant toddler period predicted higher behavior problems at 2 years, which in turn predicted higher cannabis use a year later. CONCLUSIONS Results add to the literature on joint effects of tobacco and cannabis, highlight the importance of considering bidirectional associations between maternal substance use and child behavior problems, and indicate generally stronger prenatal tobacco exposure effects for girls.

Effects of fetal tobacco exposure on focused attention in infancy

This study examined the association between fetal tobacco exposure (FTE) and focused attention at 9 months of child age, and the role of child sex and infant behavioral reactivity as potential moderators of this association. Data were obtained from 203 mothers and their infants (105 fetally exposed and 98 non-exposed) on infant focused attention and behavioral reactivity to a frustration task. FTE was ascertained via nicotine metabolites in infant meconium, reflecting primarily third trimester fetal exposure. Results demonstrated a main effect of FTE on focused attention, such that exposed infants exhibited lower levels of focused attention than non-exposed infants. Behavioral reactivity, but not infant sex, moderated the relationship between FTE and focused attention, such that exposed infants who were highly reactive to frustration had the lowest levels of focused attention. Results suggest that smoking interventions, even in the third trimester, may have a positive impact on attentional outcomes for infants.

Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003–2015)

BACKGROUND Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB. METHODS Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately. RESULTS Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p < .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation. CONCLUSIONS In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes.

Co-use of tobacco and marijuana during pregnancy: Pathways to externalizing behavior problems in early childhood

Use and co-use of tobacco and marijuana during pregnancy are associated with the development of social, cognitive, and behavioral problems for infants and children. However, less is known about the potential developmental impact of the use of tobacco and marijuana in tandem. The present study examined an etiological model for the development of externalizing behavior problems (EBP) in early childhood in a high risk sample (N = 247) of mother-infant dyads with prospective data from pregnancy to 36 months of child age. Co-use during pregnancy and continued maternal tobacco and marijuana use from infancy through early childhood were investigated. Although direct pathways from exposure during pregnancy to EBP were not significant, there was a significant indirect pathway from prenatal tobacco use to EBP via lower breastfeeding duration to lower maternal warmth/sensitivity to EBP, and a pathway from higher maternal affective dysregulation to higher EBP. These results highlight the importance of considering cascading effects of substance use during pregnancy on parental processes within the context of developmental risk and protection.

Prenatal exposure to tobacco and cannabis: Effects on autonomic and emotion regulation

Tobacco and cannabis are often used together in pregnancy and both have effects on childrens regulatory system. Yet, little is known about the impact of co-use on the development of emotion regulation at the developmentally salient age of 2 years. One pathway linking co-exposure to tobacco and cannabis to toddler regulation may be via poor autonomic regulation in infancy. In addition, substance using mothers may be more dysregulated themselves, which may have direct effects on toddler regulation, but may also affect parenting, particularly maternal sensitivity during mother-child interactions. Thus, a second pathway linking exposure to toddler regulation may be via maternal dysregulation and low maternal sensitivity. We examined a conceptual model linking prenatal exposure to toddler regulation via these two pathways in a prospective sample (N = 247) of mother-child dyads recruited in the first trimester of pregnancy. Results indicated significant effects of co-exposure on poor autonomic regulation in infancy, which in turn predicted poor toddler emotion regulation. Mothers who used both tobacco and cannabis displayed lower sensitivity during play interactions with their infants. Maternal sensitivity was modestly stable from infant to toddler period and was predictive of higher toddler emotion regulation. Continued postnatal exposure to tobacco was also a significant, unique predictor of lower toddler emotion regulation. Results highlight the importance of examining co-exposure effects and suggest that this common pattern of use may be associated with higher infant/toddler risks.

Prenatal and postnatal cigarette and cannabis exposure: Effects on Secretory Immunoglobulin A in early childhood

AIMS Secretory Immunoglobulin A (SIgA) plays a critical role in immune functioning by preventing pathogens from adhering to epithelial mucosa. Most infectious agents enter the body via mucosal surfaces, thus SIgA serves in the defense against respiratory, intestinal, and urinogenitary infections, as well as periodontal disease and caries. This study examined the possibility that pre- and postnatal exposure to cigarette and cannabis is associated with individual differences in Secretory Immunoglobulin A (SIgA) levels in early childhood. METHODS Participants were 50 mother/infant (29 boys; 35% Caucasian) dyads recruited at their first prenatal appointment in a large northeastern community hospital in the United States. Repeated assessments of pre- and postnatal cigarette and cannabis were conducted beginning in the first trimester of pregnancy, using multiple methods (i.e., saliva, meconium, self-report). Infants were grouped into those prenatally exposed to either cigarette only (n = 19), cigarette and cannabis (n = 19), or with no prenatal substance exposure (n = 12). At age 5 years, the childrens saliva was collected and assayed for SIgA. RESULTS There were group differences in SIgA levels as a function of prenatal exposure to cigarette and cannabis - children in the cigarette only and the cigarette and cannabis groups had higher SIgA levels compared to the non-exposed children. Children who experienced the combination of postnatal exposure to cigarette and cannabis had higher levels of SIgA, even after accounting for prenatal exposures and other covariates relevant to immune system functioning. CONCLUSIONS Prenatal and postnatal exposure to cigarette and cannabis may be associated with hyperactivity of mucosal immunity in early childhood. Links between cigarette and cannabis exposure and health problems in early childhood may be partially explained by prenatal and postnatal exposure-related changes in mucosal immunity.

Physiological reactivity during object manipulation among cigarette-exposed infants at 9 months of age☆

The purpose of this study was to examine the association between prenatal exposure to cigarettes and heart rate during an object manipulation task at 9 months of age. Second-by-second heart rate was recorded for 181 infants who were prenatally exposed to cigarettes and 77 nonexposed infants during the manipulation of four standardized toys. A series of longitudinal multilevel models were run to examine the association of prenatal smoking on the intercept and slope of heart rate during four 90-second object manipulation tasks. After controlling for maternal age, prenatal marijuana and alcohol use, duration of focused attention and activity level, results indicated that the heart rates of exposed infants significantly increased during the object manipulation task. These findings suggest casual rather than focused attention and a possible increase in physiological arousal during object manipulation.