No abstract

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.

Introduction: Many women continue tobacco use during pregnancy despite known adverse consequences on neonatal growth and development. Testing meconium, the first neonatal feces, for tobacco biomarkers offers objective evidence of prenatal tobacco exposure. However, relationships between the amount, frequency, and timing of cigarette smoking during gestation and tobacco biomarker meconium concentrations and neonatal outcomes are unclear.Methods: Eighty-seven pregnant women provided detailed self-reports of daily tobacco consumption throughout pregnancy. Nicotine, cotinine, and trans-3-hydroxycotinine were quantified in neonatal meconium by liquid chromatography-tandem mass spectrometry.Results: Among nonsmokers, all meconium specimens were negative, whereas nearly all meconium specimens were positive if the mother self-reported tobacco use into the third trimester. Tobacco biomarker concentrations were significantly albeit weakly correlated with mean cigarettes per day in the third trimester. Reduced birth weight, gestational age, or head circumference were observed if meconium contained one or more tobacco biomarkers, but deficits did not correlate with biomarker concentrations. Conclusion:While previously thought to reflect second and third trimester drug exposure, meconium appears to reliably identify only third trimester drug use. While a 10 ng/g nicotine, cotinine, or trans-3-hydroxycotinine cutoff in meconium was previously proposed to differentiate tobacco-exposed from nonexposed or passively exposed neonates, improved maternal self-reporting techniques in this cohort suggest that a lower cutoff, equivalent to the analytic limits of quantification, is more appropriate.

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.

Tobacco and cannabis are often used together in pregnancy and both have effects on children's 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.