The effect of medical abortion and spontaneous miscarriage on the localisation of endocannabinoid system in first trimester trophoblast. Images are representative of 60 surgical and 25 medical terminations, and 16 spontaneous miscarriages. Spontaneous abortion is characterised by a marked decrease in the expression of CB1, increased CB2 and FAAH expression, whilst NAPE-PLD expression is unaffected. By contrast, medical termination of pregnancy is characterised by a small decrease in CB1 expression, a small increase in NAPE-PLD expression and a marked increase in cytotrophoblastic FAAH expression that does not occur in spontaneous miscarriage, which is characterised by a marked decrease in mesenchymal FAAH expression. Images were taken at 200× magnification. Bar = 50 μm. Surgical termination of pregnancy was used as the control condition.