Maternal Cannabis Use Disorder Did Not Increase the Risk of a Blinding Disorder in Preterm Infants
As of February 2026, 24 U.S. states and the District of Columbia have legalized recreational and medicinal use of cannabis (marijuana), with an additional 15 states allowing medicinal use only. Increasing legalization of and access to cannabis products has led to more widespread recreational use of the drug, but questions and concerns remain about how the use of cannabis during pregnancy could affect fetal development. This is of particular concern among pregnant women who have been diagnosed with Cannabis Use Disorder, as they likely have heavier and more frequent use of marijuana. Our Study of Outcomes in Mothers and Infants (SOMI) team partnered with colleagues in the UC San Diego Department of Ophthalmology to specifically examine whether a maternal diagnosis of Cannabis Use Disorder affected the occurrence of retinopathy of prematurity, a blinding disorder that is one of the leading causes of preventable visual impairment in preterm infants.
What did we study? We accessed data in the SOMI platform for live-born, single births across the state of California from 2011 to 2020. From this group, we then identified infants who (a) were born preterm (between 22 – 30.99 gestational weeks) and/or were born small for gestational age (weighing less than 3.3 pounds at birth); and (b) survived until the retinopathy of prematurity exam took place, for a total of 31,110 infants. Based on linked data to maternal health records, the infants were divided into two groups: those born to mothers with a diagnosis of Cannabis Use Disorder (997 infants) and those born to mothers who did not have this disorder (30,113 infants).
What did we find? The rates of retinopathy of prematurity were very similar: the rate was 32.1% in preterm infants born to moms who had Cannabis Use Disorder versus 33.3% in preterm infants born to moms without this diagnosis. Thus, there was no meaningful difference between the two groups.
What’s the takeaway? In our study, preterm infants who were born to mothers with a Cannabis Use Disorder diagnosis did not have an increased or decreased risk of developing retinopathy of prematurity when compared to infants who were born prematurely to mothers who lacked this diagnosis. While this result is preliminarily reassuring, it must be noted that major medical groups advise against cannabis use during pregnancy as it has been associated with pregnancy complications and possible later learning effects on infants.