Could you explain in simple terms how the study links cannabis use during pregnancy with specific childhood cancers?
The study investigated the link between a mother’s use of substances during pregnancy and specific types of childhood cancers. We surveyed parents from more than 3,000 families affected by a childhood cancer diagnosis. We found that illicit drug use during pregnancy was associated with the development of specific forms of childhood cancer, namely tumors in the brain and eyes.
What were the main types of childhood cancers found to be associated with cannabis use during pregnancy?
Prenatal illicit drug use, including marijuana, was associated with an increased prevalence of embryonal tumors of the central nervous system (CNS), including medulloblastomas (embryonal tumors of the cerebellum) and supratentorial primitive neuroectodermal tumors or PNETs (embryonal tumors of the cerebrum). Retinoblastoma, a cancer of the eye, was also associated with prenatal drug exposure.
Why did the study specifically focus on cannabis use during pregnancy, even though it also considered substances like alcohol and tobacco?
A large number of studies have investigated gestational exposure to tobacco with mixed results. We also looked at this exposure but did not observe any particular cancer type to be associated with maternal smoking during pregnancy (although it was associated with reduced birthweight in our data, consistent with prior literature). Prenatal use of illicit drugs has received less attention but is an increasing concern for public health practitioners. Unlike alcohol and tobacco, cannabis use has increased in the population – including among expectant mothers. There is emerging evidence that cannabis use during pregnancy may contribute to certain neurologic disorders in children, including autism. We observed an association between gestational drug use and a a specific subset of childhood cancer that is believed to arise from disordered neurogenesis. This observation complements prior studies of other neurologic disorders and suggests that fetal exposure to cannabinoids may be broadly disruptive to neuronal development.
How did you ensure the accuracy of the parents' recollections about substance use during pregnancy?
The study relied on self-reported data from parents about maternal substance use during pregnancy. It’s often hard to study how much mothers are exposed to illicit substances during pregnancy because not many moms do it (3% reported using ,illicit substances in our sample, and only 14% reported using any substance). Relying on self-reported exposures is especially tricky when comparing parents of kids with cancer (case parents) to those without cancer (control parents), as they might recall past exposures differently based on the current health of their child. To make sure the information we got from parents was as accurate as possible, we designed the study to include parental responses only from parents whose children had been diagnosed with cancer and then made comparisons across different cancer subtypes. It is important to note that despite these efforts, self-reported data (especially about sensitive topics like substance use during pregnancy) may still be subject to some level of inaccuracy or bias. However, observing many expected associations in our sample, such as gestational tobacco use and reduced birthweight, gave us more confidence in the parental reports.
Were there any surprising findings in your study about the effects of tobacco and alcohol use during pregnancy on childhood cancers?
Yes, the study revealed some surprising findings related to the effects of tobacco and alcohol use during pregnancy on childhood cancers. Unexpectedly, we found that smoking tobacco during pregnancy was not associated with an increased prevalence of any childhood cancer type. On the other hand, moderate to heavy alcohol use during pregnancy showed a strong positive association with a hematologic cancer called non-Hodgkin lymphoma (NHL). This unexpected association highlights the complexity of the relationship between maternal substance use during pregnancy and childhood cancer risk. Also, it suggests that prior studies looking at low levels of alcohol use may merit re-analysis to investigate the effects of more intensive consumption specifically.
Can you clarify the difference in cancer risk between moderate and heavy alcohol consumption during pregnancy?
We found a strong, positive association between moderate-to-heavy alcohol use during pregnancy and an increased risk of non-Hodgkin lymphoma (NHL) in offspring. This suggests that there may be a link between consuming moderate to heavy amounts of alcohol while pregnant and the development of NHL in children. The distinction between moderate and heavy alcohol consumption can vary in different studies and guidelines. Generally, moderate drinking might be considered up to one drink per day, while heavy drinking would involve higher amounts. Our survey asked how often the child’s mother drank alcohol while pregnant on a 1-7 scale (with one being “not at all” and seven being “often”). For analysis, we counted responses of 5 or greater as “moderate to heavy” alcohol use, representing only about 1% of our study population. This suggests that the level of alcohol use associated with NHL is substantially higher than what most women consider to be a typical or acceptable level.
How do you suggest healthcare providers discuss these findings with pregnant women considering cannabis use for morning sickness?
Healthcare providers should approach discussions about cannabis use during pregnancy with sensitivity and provide balanced information to pregnant women. It's important to communicate the potential risks associated with cannabis use during pregnancy, especially in light of the study's findings linking illicit drug use to specific childhood cancers. Healthcare providers can highlight that the developing fetus is sensitive to various substances, that cannabinoids can cross the placental barrier, and that they may impact neurodevelopment.
For pregnant women experiencing morning sickness, healthcare providers can explore alternative, evidence-based approaches for managing nausea and vomiting during pregnancy. Open and non-judgmental conversations about the potential risks and benefits of various options, including lifestyle modifications, dietary changes, or alternative medications with proven safety profiles during pregnancy, can help pregnant women make informed decisions about managing their symptoms.
Ultimately, the goal is to provide comprehensive and personalized care, considering both the well-being of the pregnant woman and the potential impact on the developing fetus. Encouraging open communication and addressing any concerns or questions the pregnant woman may have can contribute to a collaborative and informed decision-making process.
What further research is needed to understand the long-term effects of prenatal cannabis exposure on child development?
To better understand the long-term effects of prenatal cannabis exposure on child development, further research is crucial. Several areas warrant investigation:
- Specific Developmental Outcomes: Future studies should delve into specific developmental outcomes in children exposed to cannabis during pregnancy, including cognitive function, behavioral patterns, and neurodevelopmental disorders. Understanding how prenatal cannabis exposure affects various aspects of a child's development, particularly neurodevelopment, is essential.
- Timing and Dose Effects: Research should explore whether the timing of cannabis exposure during pregnancy (first trimester, second trimester, third trimester) and the dosage play a role in determining the extent of potential adverse health outcomes in children. Identifying critical periods and dose-response relationships can provide more nuanced insights.
- Mechanisms of Impact: Investigating the underlying biological and molecular mechanisms through which cannabinoids affect fetal development is essential but will likely require experimental animal models, such as mice.
- Comparative Studies: Conducting comparative studies that account for other factors such as socioeconomic status, maternal health, maternal comorbidities, and lifestyle choices can help tease apart the specific contribution of prenatal cannabis exposure to child developmental outcomes.
- Educational Campaigns: Investing in educational campaigns for pregnant women and healthcare providers is crucial. These campaigns should provide evidence-based information about the potential risks of prenatal cannabis exposure and alternative, safer approaches for managing pregnancy-related symptoms.
- Policy Implications: Research can inform policy decisions regarding the regulation of cannabis use during pregnancy. Understanding the potential risks allows policymakers to implement measures that protect maternal and child health.
By addressing these research gaps, scientists can contribute to a more comprehensive understanding of the long-term effects of prenatal cannabis exposure, informing healthcare practices, policies, and public health initiatives.
How does this study contribute to the existing body of research on prenatal substance use and child health outcomes?
The study expands the focus beyond traditional substances like tobacco and alcohol, shedding light on the potential impact of illicit drug use, which has received less attention in previous literature. The observed associations between prenatal illicit drug use and specific childhood cancers, such as embryonal tumors of the CNS and retinoblastoma, offer novel insights into potentially modifiable risk factors. The study's large sample size, including over 3000 families of childhood cancer patients, allows for a detailed examination of the associations between maternal substance use during pregnancy and subtype-specific childhood cancer risks. Including various demographic and gestational factors in the analysis helps control for potential confounding variables, contributing to the robustness of the findings. Despite its limitations, including reliance on self-reported data, the study findings emphasize the importance of continued research in this area, and the need for educational efforts targeting women of childbearing age. This is valuable information for healthcare providers, policymakers, and researchers working towards better maternal and child health outcomes.
Given the rise in cannabis use during pregnancy, what public health strategies do you recommend to address this issue?
Addressing the rise in cannabis use during pregnancy requires a multifaceted approach involving public health strategies, education, and support. Some recommendations include:
- Public Awareness Campaigns: Implement targeted public awareness campaigns to educate women of childbearing age about the potential risks of cannabis use during pregnancy. These campaigns should be evidence-based, accessible, and culturally competent.
- Healthcare Provider Training: Provide comprehensive training for healthcare providers to ensure they can effectively communicate the risks associated with prenatal cannabis use to their patients in an open and non-judgmental conversational framework.
- Accessible Resources: Make educational resources readily available to pregnant women, offering clear information on the risks and potential consequences of cannabis use. This could include brochures, online materials, and informational sessions during prenatal care visits.
- Integration into Prenatal Care: Integrate discussions about substance use, including cannabis, into routine prenatal care. Encourage healthcare providers to routinely inquire about substance use, provide cessation support, and address concerns without stigmatization.
- Community Outreach Programs: Implement community-based outreach programs that specifically target populations with higher rates of cannabis use during pregnancy. Engage community leaders, organizations, and influencers to disseminate information and support.
- Support Services: Enhance access to support services for women struggling with substance use disorders during pregnancy, including counseling, substance use treatment and cessation programs, and mental health support.
- Research and Surveillance: Continue research efforts to understand the long-term effects of prenatal cannabis exposure. Invest in surveillance systems to monitor trends in cannabis use during pregnancy, including collecting this information in long-form birth certificates (as is currently done with maternal smoking behaviors in several states).
- Policy Development: Develop and implement policies that address cannabis use during pregnancy, which may include regulations on advertising, product labeling, and public health messaging. Collaborate with lawmakers to strike a balance between regulation and individual autonomy.
- Collaboration with Stakeholders: Foster collaboration between public health agencies, healthcare providers, community organizations, and policymakers to create a coordinated and comprehensive approach to addressing prenatal cannabis use.
- Postpartum Support: Extend support services into the postpartum period to address potential challenges faced by mothers who used cannabis during pregnancy. This may include parenting support, mental health services, and substance use recovery programs.
By implementing these strategies, public health efforts can aim to reduce the prevalence of cannabis use during pregnancy and mitigate potential adverse effects on maternal and child health. Education, support, and collaboration are key components of a holistic approach to addressing this complex public health issue.
To read the original press release, visit https://corporate.dukehealth.org/news/survey-finds-link-between-drugcannabis-use-during-pregnancy-and-certain-childhood-cancers