Marijuana-derived cannabinoids inhibit uterine endometrial stromal cell decidualization and compromise trophoblast-endometrium cross-talk.

Marijuana (cannabis) use by pregnant women in the United States is increasing and there is a dire need to understand the beneficial or harmful effects of cannabis during pregnancy. Uterine endometrial stromal cells are fibroblast-like cells that differentiate into secretory cells, a process called decidualization, to create a microenvironment conducive for placenta formation and early embryonic growth. In this study, using model human cell lines, we for the first time demonstrate that Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) inhibit endometrial stromal cell decidualization and have adverse effects on trophoblast-endometrium cross-talk.

Marijuana use differentially affects cannabinoid receptor expression in early gestational human endometrium and placenta.

Marijuana is one of the most abused drugs among pregnant women leading to maternal and fetal abnormalities. Cannabinoids are the active ingredients of marijuana, which interact with cannabinoid receptors such as CNR1 and CNR2 to activate cellular signaling pathways. Human endometrium and placenta are known to express CNR1 and CNR2 and can respond to cannabinoid signaling. In this study, we show that marijuana use significantly increases mRNA or protein expression of CNR1 and CNR2 in human endometrium from the first and early second trimester pregnancies, with minor effects on placental expression of CNRs.