Review of cannabis effects on pregnancy, fetus, and newborn finds significant concerns | Research

The takeaway

A review of cannabis use during pregnancy found evidence of effects on newborns and developmental delays in the first two years, while also noting significant gaps in the research.

Obstetricians, neonatologists, pregnant women considering cannabis use, and pediatricians.

Developmental delay documented through first 2 years in prenatally exposed infants

What the researchers found

The review summarizes evidence that prenatal cannabis exposure is associated with lower birth weight, neonatal effects, and developmental delays during the first two years of life. It also highlights the increasing use of synthetic cannabinoids during pregnancy, which may pose even greater risks due to their higher potency.

Why it matters

Cannabis use during pregnancy is increasing, often to treat nausea. This review consolidates what is known about risks to help inform clinical guidance in a space with many unanswered questions.

The numbers in context

Developmental delay documented in first 2 years of life in exposed infants; synthetic cannabinoids noted as having greater psychotropic activity and harm potential.

How the study worked

Narrative review covering legislation, physiology, pathophysiology of perinatal cannabis use, neonatal effects, breastfeeding considerations, and developmental outcomes in the first two years.

What this study cannot tell us

Narrative review format; many cited studies have confounding factors (tobacco, alcohol, socioeconomic status); limited ability to isolate cannabis effects; most evidence is observational.

How to read the evidence

Moderate: synthesizes existing evidence including observational studies, but narrative format and many confounders in underlying research.

When this study was published

Published 2020.

The bigger picture

The growing availability of both natural and synthetic cannabis products creates urgent need for better evidence on prenatal exposure. The gap between increasing use and limited research leaves clinicians and patients making decisions with incomplete information.

Questions still open

Does the route of cannabis administration affect fetal exposure? Are synthetic cannabinoids a growing concern in pregnant populations?

Common questions

Is cannabis safe during pregnancy?

Based on this review, there is evidence of associations with lower birth weight and developmental delays in the first 2 years. The evidence has significant gaps, but the available data raises concerns.

What about breastfeeding and cannabis?

The review discusses breastfeeding recommendations and notes that THC can be present in breast milk, raising concerns about infant exposure.

Read the original research

Marijuana: the effects on pregnancy, the fetus, and the newborn.

Journal of perinatology : official journal of the California Perinatal Association, 40(10), 1470-1476

View on PubMed ↗Publisher’s paper ↗

Citation

Martin, Gilbert I. (2020). Marijuana: the effects on pregnancy, the fetus, and the newborn.. Journal of perinatology : official journal of the California Perinatal Association, 40(10), 1470-1476. https://doi.org/10.1038/s41372-020-0708-z