Health Outcomes of Cannabis Use During Pregnancy
For the pregnant or lactating person, negative health effects remain the
same within and outside of pregnancy; harms include respiratory and
cardiovascular disorders as well as mental health and addiction
challenges 22-27. There is evidence that pregnant
cannabis users are at greater risk for anemia than non-pregnant users28.
Evidence about fetal harms of cannabis use during pregnancy is not yet
clear. There have been contradictory findings on whether the use of
cannabis during pregnancy has effects on birth weight, stillbirth or
miscarriage, preterm birth and neonatal effects 27-30.
Meta-analyses have reported that some studies show a decrease in birth
weight with cannabis use 28, 31, 32, while others
report no association 27, 29. There are also
inconsistencies about whether cannabis use increases the risk for
preterm delivery 28, 29, 32-34, or if it poses an
increased risk for neonatal intensive care unit admission28, 29, 33. Prenatal exposure to cannabis may also
affect longer term neurodevelopmental outcomes including attention,
hyperactivity, impulsivity in early childhood 34, 35,
emotional and behaviour problems 35, and autism
spectrum disorder 36. Very few studies have analyzed
the harms of cannabis exposure through lactation; there is conflicting
evidence about the potential for delays in infant motor development27, 37-39.
To help clinicians understand the decisional challenges about cannabis
use faced by pregnant and lactating people, we conducted a systematic
review to synthesize existing knowledge about how pregnant people’s
experiences, attitudes, and beliefs about cannabis use in pregnancy and
during lactation.