PHILADELPHIA – compared with infrequent use or no use of marijuana by the male partner, Alyssa F. Harlow, MPH, reported at the annual meeting of the American Society for Reproductive Medicine.
The male partner’s use of marijuana “one or more times per week in the past 2 months during the preconception period in our study was associated with an increased risk of spontaneous abortion,” said Ms. Harlow, a PhD candidate at Boston University. “The association attenuated for later pregnancy losses, and persisted for those with shorter [pregnancy] attempt time at [study] entry.”
Ms. Harlow and colleagues prospectively collected data from 1,535 couples in the Pregnancy Study Online (PRESTO) study, a preconception cohort study examining risk factors for adverse pregnancy outcomes. PRESTO enrolled women aged 21-45 years and their male partners aged 21 years or older who were attempting to conceive without the use of fertility treatment.
The researchers administered a screening and baseline questionnaire to the women, who then included their male partners in the study. The male partners completed their own baseline questionnaire that asked about demographics, medical history, and lifestyle or behavioral factors including marijuana use. The questions centering around marijuana use asked whether the partner had used marijuana within the past 2 months, and the frequency of marijuana use during that period.
Women in PRESTO were followed every 8 weeks until a pregnancy occurred, or up to 12 months if no pregnancy occurred. If they became pregnant, the women were asked additional questions at less than 12 weeks’ gestation and then again at 32 weeks’ gestation, including questions about any miscarriages, and how long a pregnancy lasted if a miscarriage did occur.
At baseline, 1,267 couples (83%) reported no marijuana use by male partners, 140 couples (9%) reported use less than 1 time per week, and 128 couples (8%) reported marijuana use at least 1 time per week. Men at baseline were similar in age and body mass index among groups, but men who used marijuana were more likely to be cigarette smokers (24% vs. 4%), were more likely to have partners who were cigarette smokers (11% vs. 2%), and were more likely to have partners who use marijuana (43% vs. 3%), compared with couples where the male partners did not use marijuana. Male partners who used marijuana also were less likely to be taking a daily multivitamin (25% vs. 37%), and were more likely to have been diagnosed with anxiety (14% vs. 7%) or depression (20% vs. 9%) compared with male partners who did not use marijuana.
Overall, 269 spontaneous abortions (17.5%) occurred during the study period, and couples where male partners used marijuana one or more times per week had approximately twice the rate of spontaneous abortions, compared with no marijuana use (hazard ratio, 1.99; 95% confidence interval).
Couples in which men who used marijuana less than 1 time per week had a slightly increased risk of spontaneous abortion, but this did not reach statistical significance.
When the results were adjusted for female nonusers of marijuana, the results were “essentially identical,” said Ms. Harlow.
Couples who were trying to conceive for three or fewer cycles at baseline (1,045 couples) had a lower rate of spontaneous abortion than that of couples trying for three or more cycles (490 couples). When the results were stratified by gestational age at loss, the results persisted for couples with a pregnancy loss at less than 8 weeks (1,533 couples), but the effect of marijuana use was reduced for couples with a loss at 8 weeks or more (1,113 couples).
Ms. Harlow noted several limitations to the study, including lack of data on time-varying marijuana use, potential selection bias, and residual confounding. There also is likely misclassification of exposure among some participants because marijuana use was self-reported, she added.
Ms. Harlow reported no relevant conflicts of interest.
SOURCE: Harlow AF et al. ASRM 2019. .