Marijuana Use during Pregnancy and Preterm Birth: A Prospective Cohort Study

Area of Science:

• Perinatal Health
• Reproductive Toxicology
• Obstetrics

Background:

• Marijuana use during pregnancy is a growing public health concern.
• Understanding the impact of prenatal marijuana exposure on birth outcomes is critical.

Purpose of the Study:

• To estimate the association between marijuana use during pregnancy and total, spontaneous, and indicated preterm birth.
• To investigate if marijuana use increases the risk of preterm birth in a high-risk cohort.

Main Methods:

• Prospective cohort study including 363 women receiving antenatal care.
• Marijuana use assessed via questionnaires, record abstraction, and urine toxicology.
• Statistical analysis using Poisson regression and proportional hazard models.

Main Results:

• Marijuana use was not associated with total preterm birth (adjusted RR: 1.04).
• Spontaneous preterm birth risk was significantly elevated among users (adjusted HR: 2.16), especially for births <28 weeks.
• Indicated preterm birth risk was not significantly different between users and non-users.

Conclusions:

• Prenatal marijuana use was not associated with an increased risk of overall preterm birth in this high-risk cohort.
• A significant association was observed between marijuana use and an increased risk of spontaneous preterm birth.
• Further research is needed to understand the mechanisms and clinical implications of these findings.