The Health Effects of Cannabis: The Reproductive System

Most human male and female reproductive tissues, such as uterus and testis, manufacture and degrade endocannabinoids to control hormones, fertility, implantation and development of the embryo, and inflammation.  The plant cannabinoids interact with this same cellular machinery, and have the potential to both enhance or inhibit optimal function of these systems.

Cannabis use by pregnant women is difficult to study because controlled experiments are unethical and observational studies are fraught with challenges in reporting and confirming cannabis use, concurrent use of other drugs, and lack of information on dosage.  While few studies have been conclusive, the most consistent evidence of adverse effects associated with illicit cannabis use during pregnancy are low birth weight, prematurity, and cognitive deficits in the offspring that often resolve as the children age.  Other studies in Jamaican women, who traditionally use cannabis as a tonic during pregnancy and to aid in childbirth, found their offspring to have more resilience to stress, better sleep-wake organization, and improved socialization early in life, but found no differences at age 5.

The safety profile of cannabis in pregnancy, from the little data available, is comparable to other medications in category C (suspected of causing harmful effects on the fetus that may be reversible).  Category C drugs are used in pregnancy only when safer medicines are not available or effective, and the health benefit to mother and baby outweigh the potential harm.  Maternal stress and malnutrition are well known to increase the likelihood of adverse outcomes in pregnancy, and in some situations a healthcare provider may determine that the potential benefits of using cannabis to treat pain, PTSD, seizures, or vomiting in pregnancy outweigh the risks.  Non-smokable delivery methods should always be used to avoid exposing the fetus to carcinogens and other products of combustion.

The cannabinoids, terpenoids, and flavonoids in cannabis all can affect hormone levels, especially when taken acutely.  Long-term cannabis users, however, have normal hormone levels when compared with non-users.  THC has been shown to have a detrimental effect on sperm counts and sperm motility, but regular male users can certainly still produce a pregnancy.  Though a small study reported cannabis causing irregular menstrual cycles in women, many patients report that cannabis can bring balance to their cycle and relieve many premenstrual and menstrual symptoms.  One study found that women with more severe menstrual symptoms had lower levels of their own endocannabinoids, a case for administering additional cannabinoids from a plant source to help with this potential “deficiency.”

Cannabis can affect sexual function, often helping relieve stress, enhance erection, and increase the enjoyment of sexual activity.  It can dry vaginal secretions, like it does in the mouth, so cannabis users may benefit from added lubrication.  From a practical standpoint, cannabis can enhance one’s sex-life if used correctly, but it can also interfere.  Dosage is important – a small dose can be stimulating, while high doses may be too sedating or intoxicating to promote good sex.  Animal and human studies also point to differences amongst genders, with females more consistently stimulated by cannabinoids, and males sometimes stimulated and sometimes inhibited.

Abstracts: Medical Studies 

‘Prenatal marijuana exposure and neonatal outcomes in Jamaica: an ethnographic study.’

Dreher, Melanie C., Kevin Nugent, and Rebekah Hudgins. 

Pediatrics 93.2 (1994): 254-260.

OBJECTIVE:

To identify neurobehavioral effects of prenatal marijuana exposure on neonates in rural Jamaica.

DESIGN:

Ethnographic field studies and standardized neuro-behavior assessments during the neonatal period.

SETTING:

Rural Jamaica in heavy-marijuana-using population.

PARTICIPANTS:

Twenty-four Jamaican neonates exposed to marijuana prenatally and 20 nonexposed neonates.

MEASUREMENTS AND MAIN RESULTS:

Exposed and nonexposed neonates were compared at 3 days and 1 month old, using the Brazelton Neonatal Assessment Scale, including supplementary items to capture possible subtle effects. There were no significant differences between exposed and nonexposed neonates on day 3. At 1 month, the exposed neonates showed better physiological stability and required less examiner facilitation to reach organized states. The neonates of heavy-marijuana-using mothers had better scores on autonomic stability, quality of alertness, irritability, and self-regulation and were judged to be more rewarding for caregivers.

CONCLUSIONS:

The absence of any differences between the exposed on nonexposed groups in the early neonatal period suggest that the better scores of exposed neonates at 1 month are traceable to the cultural positioning and social and economic characteristics of mothers using marijuana that select for the use of marijuana but also promote neonatal development.

‘Male–female differences in the effects of cannabinoids on sexual behavior and gonadal hormone function.’

Gorzalka, Boris B., Matthew N. Hill, and Sabrina CH Chang.

Hormones and behavior 58.1 (2010): 91-99. Hayes, Janice S., et al.

Abstract

The putative role of the endocannabinoid system and the effects of cannabis use in male and female sexual functioning are summarized. The influence of cannabis intake on sexual behavior and arousability appear to be dose-dependent in both men and women, although women are far more consistent in reporting facilitatory effects. Furthermore, evidence from nonhuman species indicate somewhat more beneficial than debilitating effects of cannabinoids on female sexual proceptivity and receptivity while suggesting predominantly detrimental effects on male sexual motivation and erectile functioning. Data from human and nonhuman species converge on the ephemeral nature of THC-induced testosterone decline. However, it is clear that cannabinoid-induced inhibition of male sexual behavior is independent of concurrent declines in testosterone levels. Investigations also reveal a suppression of gonadotropin release by cannabinoids across various species. Historical milestones and promising future directions in the area of cannabinoid and sexuality research are also outlined in this review.

‘Five-year follow-up of rural Jamaican children whose mothers used marijuana during pregnancy.’

Hayes JS1, Lampart R, Dreher MC, Morgan L. 

The West Indian medical journal 40.3 (1991): 120-123.

Abstract

This research provides data on the development of 59 Jamaican children, from birth to age 5 years, whose mothers used marijuana during pregnancy. Approximately one-half of the sample used marijuana during pregnancy and were matched with non-users according to age, parity, and socioeconomic status. Testing of the children was done at 1, 3, and 30 days of age with the Brazelton Neonatal Behavioral Assessment Scales and at ages 4 and 5 years with the McCarthy Scales of Children’s Abilities. Data about the child’s home environment and temperament were collected from direct observations as well as from standardized questionnaires. The results show no significant differences in developmental testing outcomes between children of marijuana-using and non-using mothers except at 30 days of age when the babies of users had more favourable scores on two clusters of the Brazelton Scales: autonomic stability and reflexes. The developmental scores at ages 4 and 5 years were significantly correlated to certain aspects of the home environment and to regularity of basic school (preschool) attendance.

‘Cannabis, cannabinoids and reproduction.’

Park, Boram, John M. McPartland, and Michelle Glass.

Prostaglandins, leukotrienes and essential fatty acids 70.2 (2004): 189-197.

Abstract

In most countries Cannabis is the most widely used illegal drug. Its use during pregnancy in developed nations is estimated to be approximately 10%. Recent evidence suggests that the endogenous cannabinoid system, now consisting of two receptors and multiple endocannabinoid ligands, may also play an important role in the maintenance and regulation of early pregnancy and fertility. The purpose of this review is therefore twofold, to examine the impact that cannabis use may have on fertility and reproduction, and to review the potential role of the endocannabinoid system in hormonal regulation, embryo implantation and maintenance of pregnancy.