Even in the setting of legalized marijuana use, estimated prevalence of marijuana use during pregnancy was lower by self-report than it was by umbilical cord testing.
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Torri D. Metz, MD, of the University of Utah Health, Salt Lake City, and her colleagues surveyed women at two urban hospitals in Colorado, which has legalized both medical and recreational use of marijuana. They found that, while 6% of the 116 women in the study reported using marijuana in the past 30 days, umbilical cord testing showed as many as 22% had detectable levels of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic, and 10% had levels above quantification.
The majority of studies of maternal marijuana use during pregnancy rely on self-report, so this could affect attempts to assess the effects of such prenatal use, they said.
Adverse outcomes associated with marijuana use during pregnancy include fetal growth restriction, small for gestational age, preterm birth, and adverse neurodevelopmental outcomes, studies have shown.
Read more in Obstetrics & Gynecology.