With the increasing legalization and decriminalization of recreational cannabis across the United States, its usage has risen among various populations, including pregnant women. Despite this trend, a significant portion of pregnant women—approximately 22% according to a recent survey—do not consider weekly cannabis use to pose any risk. Many believe that cannabis can alleviate nausea without harming their unborn child.
However, this perception is at odds with existing research, which consistently reports negative associations between prenatal cannabis use and fetal outcomes. These adverse outcomes include low birth weight, a known predictor of infant mortality and morbidity, as well as developmental delays, intrauterine growth restriction, and neurobehavioral issues. Despite these concerns, the link between prenatal cannabis use and perinatal loss remains under-researched.
The Role of the Endocannabinoid System
The endocannabinoid system plays a crucial role in fetoplacental development. Preliminary evidence suggests that chronic cannabis use can impair implantation and placentation by disrupting endocannabinoid processes. This disruption could potentially lead to adverse neonatal outcomes, which the current study aimed to investigate further.
About the Study
The study evaluated the impact of cannabis use during pregnancy on various neonatal outcomes, including fetal death, preterm delivery, low birth weight, and admission to neonatal intensive care units (NICUs). The research drew data from the Stress in Pregnancy (SIP) longitudinal study, with participants recruited from two prenatal obstetric clinics in New York between 2009 and 2017.
A total of 894 participants were interviewed, and their medical records reviewed, excluding those with maternal or fetal risk factors or plans to relocate. The study also considered several variables, such as maternal weight, race, age, education, marital status, nicotine use, and history of spontaneous abortion, to ensure robust findings.
Key Findings
The study revealed that cannabis use during pregnancy nearly doubled the risk of low birth weight and increased the risk of fetal death by more than six times. These findings align with previous studies documenting similar adverse outcomes associated with prenatal cannabis use.
Risk Factors
The study controlled for various modifiable and non-modifiable covariates. Modifiable covariates included nicotine use and marital status, while non-modifiable covariates comprised maternal age and race. Even after accounting for these factors, the elevated risk associated with cannabis use remained significant.
The Role of Anandamide (AEA)
Successful embryo implantation requires tight regulation of the endocannabinoid ligand anandamide (AEA). Altered AEA levels have been linked to ectopic pregnancies, spontaneous abortions, and disrupted decidualization, which can impair embryo and placental development. These disruptions highlight the critical role of the endocannabinoid system in normal gestational development.
Contrasting Findings on Alcohol Use
Interestingly, the study did not find a significant association between alcohol use during pregnancy and adverse neonatal outcomes, contrary to previous literature. This discrepancy could be due to omitted variables, such as different patterns of alcohol use, not captured in the study.
Conclusions and Future Directions
The study underscores a significant relationship between prenatal cannabis use and adverse neonatal outcomes, particularly low birth weight and fetal death. Given the widespread use of cannabis, including among pregnant women, it is imperative to educate individuals of childbearing age about these risks.
Limitations and Recommendations
A key limitation of the study is the characterization of substance use, lacking detailed information on the mode, duration, exact timing, and amount of cannabis used during pregnancy. The absence of toxicology testing also means the self-reported data could not be verified. Additionally, the urban setting of the sample may limit the generalizability of the findings.
Future research should aim to address these limitations by conducting more extensive studies over the entire gestational period and incorporating toxicology testing to verify substance use histories. Understanding the mechanisms behind the increased risk of fetal death associated with prenatal cannabis use is crucial for developing effective interventions and public health strategies.
By raising awareness of these risks and continuing to investigate the effects of prenatal cannabis use, we can better protect the health and development of future generations.
