Placental cannabinoid receptors expression might determine preterm delivery.

Endocannabinoid receptor (CB) plays a significant role in oogenesis, pregnancy and childbirth. CB might also play a significant role in preterm birth. The aim of the study was to investigate the association between the expression of cannabinoid receptors within the placenta and preterm delivery (PTB). A prospective, observational, multicentre preliminary study was conducted on placental material obtained from 109 women. The study comprised 95 female patients hospitalized due to preterm delivery, and they were divided into two groups. The expression of CB1 and CB1a was analyzed in Group 1 and CB2 in Group 2. The control group (Group 3) consisted of 14 women who delivered at term, and their placentas were tested for the presence of all three receptors (CB1, CB1a, CB2). The placentas were examined using reverse transcription and Real-Time PCR to assess the expression of cannabinoid receptors in the placentas. The expression of CB2, CB1 and CB1a receptors were significantly lower in placentas from preterm deliveries than term delivery placentas, p = 0.038, 0.033 and 0.034, respectively. Cannabinoid receptor mRNA was identified in human placental tissue. Determining decreased cannabinoid receptor expression in preterm delivery placentas could improve PTB prediction. KEYWORDS : Cannabinoid receptor; CB2; endocannabinoid system; preterm delivery; PTB