An updated systematic review and meta-analysis of dozens of studies reaffirms cannabis use in pregnancy can have adverse neonatal outcomes.
While women are well-versed in the risks of smoking and drinking during pregnancy, there still seems to be some disconnect in terms of awareness of potential negative impacts of cannabis use.
Researchers from Oregon Health and Science University and Veterans Affairs Portland Health Care System have updated a previous review into the issues, adding 8 new studies with more than 1.7 million participants, for a total of 51 studies.
The researchers focused on outcomes relating to:
- Preterm birth (PTB; <37 weeks of gestation)
- Small for gestational age (SGA)
- Low birth weight (LBW; <2500 g)
- Perinatal mortality – the death of a fetus or newborn around the time of birth.
They found moderate-certainty evidence cannabis use in pregnancy was associated with increased odds of LBW, PTB and SGA. While finding there was only low-certainty evidence use was associated with greater odds of perinatal mortality, this risk was previously classified as very low.
Among their conclusions, the researchers said:
“Cannabis use in pregnancy was associated with greater odds of PTB, SGA, and LBW even after adjusting for co-use of tobacco products, and confidence in these findings increased from low in the prior review to moderate in the current meta-analysis.”
The researchers say their findings may help inform patient counselling and future public health policies.
The full report has been published in the journal JAMA Pediatrics.
On a related note, rates of cannabis use during pregnancy appear to be increasing along with rates of cannabis use disorder (CUD), a recently published study (based on rather old data) out of Columbia University suggests. The yearly prevalence was found to range from 0.22% (2015) to 0.27% (2018 and 2019). Another recent study suggests a link between cannabis use and Nausea and Vomiting in Pregnancy (NVP) – aka morning sickness.
Another study from the University of Georgia College of Public Health found approximately 6% of pregnant women reported using marijuana in the previous month. One of the findings from that research were 70.9% of the pregnant women did not perceive any risk associated with weekly marijuana use.
