Researchers explore prenatal marijuana use in legalized environment

Researchers at the University of Colorado Anschutz Medical Campus are studying the detection of prenatal marijuana use in a legalized environment. The study of marijuana use in pregnancy is only possible in a few states.

Although physicians tell women they should not use marijuana in pregnancy, it is difficult to provide them with data to support the recommendation. The need for data-supported information grows as marijuana laws change nationwide.

The Colorado Clinical and Translational Sciences Institute recently awarded a Child and Maternal Health Pilot Grant to Assistant Professor Torri Metz, MD, to develop a questionnaire for new mothers about marijuana use during their pregnancy.

"If you look at the literature now, you find very mixed results," Metz said. "About half of the studies say there is an association between marijuana use and adverse outcomes; about half say there is no association."

As a high-risk obstetrician and maternal-fetal medicine specialist, Metz provides care for pregnant mothers and delivers babies at University of Colorado Hospital.

"I am seeing more and more self-reported marijuana use in the clinic," Metz said. "I don't know if this is a reflection of women using more marijuana or of the women being more willing to tell us about their use."

The study will enable Metz and her colleagues to develop a survey tool for new mothers to ascertain self-reported marijuana use. With the patients' consent, researchers will administer a survey to the new mothers and, upon delivery, take a sample of the umbilical cord to determine if the mother did use marijuana through pregnancy and to what extent. Researchers will compare the self-report with the umbilical cord sample, allowing researchers to determine the best way to collect information about marijuana use during pregnancy for future studies.

Further study is needed on the association between marijuana use and fetal growth restriction, hypertension in pregnant mothers, stillbirth, spontaneous preterm birth and other conditions.

"These are the obstetric issues we face every day and we don't understand the impact of marijuana use on these outcomes," Metz said. "I want to change that."