Technische Universität München

The Entrepreneurial University

Cannabinoids exert their effects through the activation of two specific receptors located on the surface of the target cells. Recent evidence suggests that multiple endocannabinoid ligands may also play an important role in the maintenance and regulation of early pregnancy and fertility. Furthermore, endocannabinoids are involved in the anterior pituitary and hypothalamic control of sex hormones. Marijuana, tetrahydrocannabinol (THC), and other exogenous cannabinoids exert potent effects on this homeostasis.
In males, cannabis smoking decreases serum LH concentrations. In some studies chronic marijuana use has been shown to be associated with decreased plasma testosterone levels, but other studies have failed to reproduce these findings. Reduced sperm counts in males have been more consistently seen.
In women, acute administration of THC suppresses the secretion of LH in the luteal phase. In chronic users, it shortens the menstrual cycle, the effect being predominately a short luteal phase leading to menstrual irregularities and anovulation. Some data suggest that the decreased release of hypothalamic GnRH into the pituitary is responsible for the suppressed level of LH. The possible mechanism of this effect of THC is modulation of neuronal systems known to inhibit GnRH secretion.
Several experimental and clinical studies have shown adverse effects of marijuana exposure on embryo development and in early pregnancy. In women cannabis use during pregnancy is correlated with low birth weight, prematurity, intrauterine growth retardation, presence of congenital abnormalities and perinatal death.