Continued cannabis use during pregnancy linked to lower birth weight and higher childhood trauma scores | Research

The takeaway

Among 256 pregnant patients in Baltimore, continued cannabis use through delivery was associated with 10% lower birthweight and correlated with higher adverse childhood experience scores in the mothers.

Obstetricians, midwives, substance abuse counselors working with pregnant patients, and trauma-informed care advocates.

10% lower birthweight with cannabis use at delivery

What the researchers found

Cannabis use at delivery was associated with 10% lower birthweight (2665g vs. 3014g, p < 0.05), lower maternal weight gain (7.9 vs. 13.3 kg), and fewer prenatal visits (7 vs. 8). Continued cannabis use was associated with higher ACE scores (16.2 vs. 13.8, p = 0.01). ACE scores alone were not associated with birth outcomes.

Why it matters

The connection between childhood trauma, continued cannabis use during pregnancy, and worse birth outcomes suggests a complex interplay where addressing maternal trauma history could help reduce prenatal cannabis use.

The numbers in context

256 patients. 87 (34%) positive for cannabis at initial visit. 39 (15.2%) positive at delivery. 45% of initial users continued to delivery. Cannabis at delivery: birthweight 2665g vs. 3014g. Maternal weight gain: 7.9 vs. 13.3 kg. Continued use associated with higher ACE scores.

How the study worked

Retrospective cohort of 256 pregnant patients in Baltimore. ACE checklist completed at enrollment. Urine toxicology at initiation of care and delivery. Multivariable logistic regression assessed relationships between ACE scores, cannabis use, and pregnancy outcomes.

What this study cannot tell us

Single urban center (Baltimore). Retrospective design. Urine toxicology is a crude measure of exposure. ACE score is a childhood measure, not current trauma. Small sample limits subgroup analyses. Cannot separate cannabis effects from socioeconomic confounders.

How to read the evidence

Single-center retrospective cohort with objective urine testing but limited by sample size and potential confounders.

When this study was published

Published in 2022.

The bigger picture

The finding that adverse childhood experiences predict continued cannabis use during pregnancy suggests that trauma-informed care approaches may be more effective than simply telling pregnant patients to stop using cannabis.

Questions still open

Would trauma-informed interventions reduce cannabis use during pregnancy more effectively than standard counseling? Is the birthweight effect from cannabis itself or from associated factors like fewer prenatal visits?

Common questions

Does using cannabis throughout pregnancy affect the baby?

In this study, continued cannabis use through delivery was associated with 10% lower birthweight (2665g vs. 3014g), though cannabis use at the start of pregnancy that was later discontinued was not associated with worse outcomes.

Why do some pregnant women continue using cannabis?

Women with higher adverse childhood experience scores were more likely to continue using cannabis through delivery, suggesting a connection between maternal trauma history and prenatal substance use.

Read the original research

Effect of maternal adverse childhood experiences (ACE) and cannabis use on pregnancy outcomes.

Archives of women's mental health, 25(6), 1097-1104

View on PubMed ↗Publisher’s paper ↗

Citation

Klasner, Carson; Brown, Jessica; Gopalakrishnan, Mathangi; Metwally, Dina El; Besse, Margaret; Mark, Katrina. (2022). Effect of maternal adverse childhood experiences (ACE) and cannabis use on pregnancy outcomes.. Archives of women's mental health, 25(6), 1097-1104. https://doi.org/10.1007/s00737-022-01269-x