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Cannabis and nicotine use during pregnancy linked to infant mortality

A team of researchers led by Oregon Health Science University (OHSU) has found significant risks associated with the combined use of cannabis and nicotine during pregnancy. 

The research highlights a greater likelihood of poor outcomes for newborns when both substances are used together compared to using either independently throughout pregnancy.

“These findings suggest that co-occurring maternal use of cannabis and nicotine products in pregnancy is associated with an increased risk of infant and neonatal death and maternal and neonatal morbidity compared with use of either substance alone,” wrote the study authors. 

“Given the increasing prevalence of combined cannabis and nicotine use in pregnancy, these findings can help guide health care practitioners with preconception and prenatal counseling, especially regarding the benefits of cessation.”

Combined use of substances during pregnancy

What is particularly concerning, according to the researchers, is that half of individuals who use cannabis in pregnancy also use tobacco or nicotine products.

“Numerous studies have demonstrated the detrimental effects of prenatal tobacco exposure, primarily nicotine exposure, on perinatal outcomes, including prematurity, low birth weight, and stillbirth. Currently there is a paucity of epidemiological data regarding the effects of combined prenatal exposure to both cannabis and nicotine products.”

“Emerging evidence indicates that cannabis use exacerbates the negative impacts of nicotine product exposure, and dual abstinence may result in better outcomes following cessation.”

Cannabis and nicotine use 

Study senior author Jamie Lo is an associate professor of obstetrics and gynecology at OHSU. 

“With the growing legalization of cannabis around the country, there is often a perception that cannabis is safe in pregnancy,” said Professor Lo.

“Because we know that many people who use cannabis often use tobacco or nicotine products, we wanted to better understand the potential health implications on both the pregnant individual and the infant.”

“There is still a great deal of stigma around the use of substances during pregnancy,” she added. “With limited research to support official clinical recommendations, it can be a difficult topic for both patients and providers to navigate. Our hope is that this research supports more open and productive conversations that ultimately result in a healthier pregnancy.”

Higher rate of infant mortality 

The research team analyzed data from over three million pregnant individuals, identifying significant increases in adverse outcomes such as small for gestational size, preterm delivery, and infant mortality when both cannabis and nicotine were used. 

Most notable was the rate of infant death, which was found to be four times higher in users of both substances compared with non-users. Moreover, the rate was almost two times higher compared with users of just cannabis or nicotine alone.

These findings will likely have a significant impact in future counseling and educational efforts in prenatal care. 

Decreasing the pregnancy risks 

“Our findings suggest that avoiding use of just one of these substances can decrease the pregnancy risks we see when both substances are used together, which is a critical piece of information providers can highlight when counseling patients,” said lead author Adam Crosland, an assistant professor of obstetrics and gynecology at OHSU.

Mitigating adverse outcomes 

The research also incorporated insights from other experts at OHSU, including Eliot Spindel and Cindy McEvoy, who are investigating methods to mitigate adverse outcomes among children born to parents who smoke

One intervention highlighted is the supplementation of vitamin C to pregnant smokers, which has shown to significantly improve respiratory outcomes in offspring.

Cannabis and nicotine during pregnancy 

Looking ahead, the researchers aim to delve deeper into the effects of dual substance use during pregnancy, examining variables such as potency, frequency, and timing, to better educate pregnant patients about the associated risks. 

The team also plans to continue exploring viable prenatal interventions, like vitamin C supplementation, to aid individuals who struggle to quit smoking during pregnancy.

“These findings suggest that more effective public health measures and counseling prior to conception and during pregnancy are warranted to mitigate the potential for adverse offspring outcomes from combined prenatal cannabis and nicotine use,” wrote the researchers.

The study is published in the journal JAMA.


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