Purpose of Review
To summarize the current state-of-the-evidence with respect to the effects of fetal exposures to opioids, amphetamine, cocaine, cigarette smoke, and cannabis on fetal growth, neonatal neurobehavior, and longer-term neurodevelopment, cognition, and behavior.
Recent Findings
Long-term fetal exposure to opioids has adverse effects on fetal growth (weight, head circumference). Exposures close to term cause neonatal signs of withdrawal that vary as a function of specific opioid. Polysubstance exposures exacerbate the signs of withdrawal. Intense non-pharmacologic therapy can improve neonatal outcomes (duration of hospitalization, cumulative postnatal opioid treatment). Other drug exposures reduce fetal growth in a dose-dependent fashion. With legalization of marijuana in many states, increased social acceptability has led to higher rates of more prolonged fetal exposure, often with preparations of higher potency than in the past.
Summary
Many methodological challenges make it difficult to identify long-term effects on neurodevelopment, cognition, and behavior of individual exposures, due to a number of confounding factors, including concomitant fetal polydrug exposures, maternal illnesses, and adverse social determinants of health that affect mother and child. A growing body of evidence does suggest that there is cause to be concerned about long-term effects of fetal cannabis exposure on long-term behavior and executive functioning.