Regulation of plasma endocannabinoids differs in pregnant versus non‐pregnant women

Endogenous cannabinoids, endocannabinoids, are lipid messengers and analogs of polyunsaturated fatty acids. The endocannabinoid metabolome is comprised of over a dozen metabolites associated with a variety of functions in central and peripheral physiology, reproduction and development. We quantified 15 plasma analytes of the endocannabinoid metabolome in pregnant women (n=34) at 20‐22 weeks versus non‐pregnant women (n=9) using liquid chromotography‐mass spectrometry. Ethanolamides were higher in pregnant versus non‐pregnant women (mean±SD): palmitoylethanolamine,; (5.32± 4.07 pg/ μl versus 1.98 ± 0.40 pg/ μl, p<0.01), oleoylethanolamine (3.08 ± 1.72 pg/ μl versus 1.37 ± 0.39 pg/ μl, p<0.01) and arachidonoylethanolamine (0.68 ± 0.22 pg/ μl versus 0.24 ± 0.10 pg/ μl, p < 0.01). The glycerols: 2‐arachidonolglyerol was significantly higher during pregnancy (133.17 ± 71.06 pg/ μl versus 9.96 ± 5.80 pg/ μl, p<0.01) while 2‐ oleoyglycerol was lower in pregnancy (472.01 ± 299.50 pg/ μl versus 1217.64 ± 466.35 pg/ μl, p<0.01); 2‐palmitoyglycerol was detected only in pregnancy (1850 ± 1254 pg/µl). In conclusion, pregnancy altered specific metabolites in the plasma endocannibinoid system.