Substance Use and Fertility

Cannabis

Has the highest use rate among all illicit drugs.

Consists of dried leaves and flowers from the marijuana plant (Cannabis sativa), is smoked to release the psychoactive cannabinoid compound called delta‐9‐tetrahydrocannabinol (THC).

Human studies consistently conclude that THC negatively affects male reproductive physiology. Cannabis smoking has been shown to negatively impact male fertility, with an effect on hypothalamus-pituitary-gonadal axis, spermatogenesis, and sperm function.

Regular use was found to be associated with an impairment in semen quality. An association between cannabis use and decreased sperm count, which persisted in the following 4-week recovery period. More than one‐third of the chronic exclusive marijuana smokers studied had oligospermia.

It reduces sperm motility in a dose‐dependent manner and inhibits the capacitation‐induced acrosomal reaction.

Cocaine

Evidence consistently demonstrates the teratogenic effects of cocaine use on foetal development when abused by women during pregnancy, but studies on the impact of cocaine on male and female fertility are lacking.

Men with sperm counts less than 20 million per mL were two times more likely to have used cocaine within the past 2 years than men who had not used cocaine. Also, men with a 5‐year or greater history of cocaine use were two times more likely to have low sperm motility.

Cocaine use affects the menstrual cycle by increasing levels of prolactin. High prolactin levels stop ovulation and can cause delayed and irregular periods. Prolactin is also increased during periods of cocaine withdrawal, so detoxing from cocaine might prevent ovulation for days or months after detox.

Cocaine should never be used during pregnancy, and it can cause many different types of birth defects, which are commonly referred to as congenital disabilities.


The following are some common consequences associated with drug abuse during pregnancy:

• Low birth weight.
• Lower IQ.
• Miscarriage.
• Premature birth.
• Stroke and brain damage in the foetus.

MDMA

Amphetamines and MDMA act upon the dopaminergic and serotoninergic systems, influencing the secretion of GnRH.

Animal studies evaluating the impact of Ecstasy on reproductive neuroendocrine function found MDMA suppressed GnRH (Gonadotropin-releasing hormone) and serum testosterone levels, which significantly altered the hypothalamic‐pituitary‐testicular axis.

Amount of prenatal MDMA exposure predicted poorer infant mental and motor development at 12 months in a dose-dependent manner. Heavily exposed infants were delayed in motor development.

Opioids

Opioids act on the hypothalamic-pituitary axis by inhibiting GnRH secretion: the resulting suppression of FSH and LH release consequently leads to impaired spermatogenesis and reduced testosterone concentrations.

Sperm concentration and quality are impaired in opioid abusers: increased rates of DNA fragmentation.

The risk of menopause and abnormal menstruation was increased in long-term opioid users.

Anabolic Steroids

The use of anabolic steroids has become one of the main causes of preventable male factor infertility.

Increasing numbers of men; including teenagers, are now taking these steroids to help build up muscle.

Anabolic steroids increase testosterone production within the body, which helps build up muscle bulk. However, this blocks the production of testosterone in the testicles themselves, which is a necessary ingredient for sperm production.

If used for long enough and in high enough doses, the damage to male fertility can become permanent. In some case, it may take up to a year for sperm production to return to normal having stopped the anabolic steroids.