By Dr. Colin Michie
How we live becomes important when planning a baby. Fertility, pregnancy, feeding and caring for an infant, the achievements of gorgeous plenty, are challenged in each generation by lifestyles and environments. At carnival time when cannabis is used by the crowds of young people, questions about reproduction arise: Is the growing acceptance of cannabis – its greater use and increasing potency, its legal status – important? Given that the global human population is not growing, but slowing, is there a connection?
Legalisation in 2018 in British Colombia was followed by an increase in cannabis use of 71% by women before conception. Cannabis vaping in adolescents with c-liquid is rising; marijuana use among university students is widespread. Cannabis today can be up to 10 times stronger than that traded 50 years ago. Medical applications of a diversity of cannabis products are growing for all age groups. For instance, cannabidiol (CBD) is particularly successful in childhood epilepsy syndromes such as Dravet or Lennox-Gastaut; tetrahydrocannabinol (THC) or dronabinol is used to manage nerve pain, nausea after chemotherapy, or to stimulate appetite. Estimates document that between 2020 and 2022, a third more patients enrolled into US medical cannabis programmes.
Cannabis sativa plants have followed human migrations for millenia, growing on our rubbish heaps. Medicinal and recreational uses are found in many cultures: they produce a large number of pharmacologically active compounds, as well as hemp fibres. Narrow leaf types produce phyto-cannabinoids at higher levels. One of these, THC, has uniquely powerful and well described psychological effects. Over a hundred artificial, neo- or designer-cannabinoids such as K2 and Spice copied THC; some synthetics are more concentrated than plant sources and come as gummies, sprays or skin patches. Early studies of cannabis discovered that cannabinoids use our build-in endocannabinoid signalling networks, found in most vertebrates, including sharks. We are not the only species to scavenge for cannabinoids either – goats, rodents and raccoons can become opportunistic scavengers of cannabis plants or discarded product.
Endocannabinoid signalling systems use two main transmitters and arrays of different receptors. For instance, receptors to which THC binds in the nervous system influence mood, concentration and pain. Others in the gut regulate appetite, gut movement, nausea, liver functions and metabolism. Immune system receptors influence inflammatory responses. These networks have hour-to-hour “housekeeping” functions, working as you read this, but challenging to study because they vary greatly between individuals.
Cannabidiol (CBD) and THC hijack these networks. They are small molecules stored in out cuddly fat tissues. They easily cross into the brain and disappear from the bloodstream within hours of consumption, but they persist in fat, or in her milk if a mum is feeding an infant. Indeed, the great fat content of breastmilk means it can have much higher cannabinoid levels than mother’s blood. Most cannabinoid breakdown products are removed steadily in faeces and urine; they are evident for several weeks after use.
Cannabinoids are found in the sperm of those using cannabis. In some men, this links to reduced counts and damaged sperm functions. Endocannabinoid signals work on the blood supply of the placenta: Cannabis use is associated with lower birthweights and a higher risk of hospitalisation of the newborn into a neonatal unit.
Of greater concern and agreement between human and animal studies is that cannabinoids change the DNA within sperm, eggs and the foetus. They may therefore influence family roots, the next generation. Tools for accurately measuring the developmental outcomes of children exposed before birth suggest they are more likely to suffer cognitive and neuropsychiatric challenges later in life – no superpowers here. Cannabinoids can pose significant threats to many infant brains. Potential parents need to imagine their child’s future before using these drugs.
Cannabis may not be the highest ranking risk to human fertility. Age, alcohol, obesity, sleep deprivation, tobacco abuse and testosterone therapy all contribute powerfully to this particular problem. Environmental toxins including air pollutants, pesticides, phthalates, heavy metals and excessive heat all contribute too. However, cannabis can additionally compromise reproductive processes and delicate neurological systems of a foetus.
Cannabis plants are impressive pharma factories – they produce many pharmacologically active molecules. Ironically, botanists suggest the plants use these compounds to attract pollinators to help with their own reproduction. Some cannabinoids are strong antioxidants that can reduce tissue or nerve damage, for instance, in treating fatty liver disease. Nabiximols is a THC-based oral spray – the first medication of its type licensed in the UK to treat muscle spasticity in patients with multiple sclerosis. Products from Cannabis sativa are likely to be developed into numerous future pharmacological therapies.
Having a baby needs many careful considerations. There are no clear benefits and many risks associated with cannabis use. A precautionary approach seems wiser when considering the promises, the potential treasures of a new infant.
Useful resource: cdc.gov/cannabis/health-effects/pregnancy.html
Dr. Colin Michie specializes in paediatrics, nutrition, and immunology. Michie has worked in the UK, southern Africa and Gaza as a paediatrician and educator and was the associate Academic Dean for the American University of the Caribbean Medical School in Sint Maarten a few years ago.
