Cannabis use during pregnancy and labour remains a controversial issue among scientists, women and cannabis advocates. The scientific community has published volumes of literature, many with contradictory results. The anecdotal evidence, however, suggests that for some women, cannabis may alleviate morning sickness, pain associated with pregnancy and labour pains.
The issue of whether it is safe to use cannabis during pregnancy is one that has caused a great deal of controversy in recent years, as this beneficial herb becomes ever more medically and socially acceptable and consumption rates continue to climb.
Current consensus holds that heavy cannabis use during pregnancy may lead to a reduction in infant birth weight, and possibly increase the risk of conditions such as pre-eclampsia. However, the extent to which this occurs may depend on the method of consumption, as well as various other factors.
Even in light of scientific research that warns of the dangers of cannabis during pregnancy, there is also plenty of evidence which suggests otherwise. Although not commonplace, cannabis during labour is said to improve the labour experience by reducing pain and offering a fresh perspective.
New research suggests a link between cannabis and early developmental problems
It may be safe to administer small quantities of cannabis at certain points throughout a pregnancy, and opting for a method other than smoking may reduce the risk of developmental problems. However, a 2012 study found that in the very early stages of pregnancy, even slight variation in endocannabinoid levels could affect embryonic development. Researchers found that either silencing or enhancing endocannabinoid (anandamide) signalling via CB1 in pregnant mice altered the rate at which new placental cells (specifically trophoblasts) form and migrate towards the wall of the uterus.
Although the results have not been replicated in humans, the similarity between the function of the endocannabinoid system in mice and humans led the researchers to conclude that “exposure to cannabis products may adversely affect early embryo development that is then perpetuated later in pregnancy”.
Under normal circumstances, the trophoblasts combine with the endometrium to form the placenta, so that the embryo can receive the nutrients it needs to survive. Reduction in the trophoblast migration rate can cause irregularities in foetal implantation, which may increase risk of miscarriage and later developmental issues.
Early trophoblast dysfunction has also been implicated in later miscarriages (some forms), involving reduction in placental activity and foetal growth before foetal death ultimately occurred. However, further research is required before firm conclusions can be drawn on the relationship between endocannabinoid levels and trophoblast dysfunction.
Cannabis use in early pregnancy and brain dysfunction in later life
The researchers also postulated that as the endocannabinoid system is so closely linked with neuronal activity in the central nervous system, use of cannabis in early pregnancy may have an effect on initial brain development. THC, which can pass through the placental and foetal blood-brain barrier to directly affect the developing foetus, is particularly considered to influence the development of cognitive skills.
However, a study by the Christchurch School of Medicine (New Zealand) found that while maternal cannabis use during pregnancy was associated with detectably lower birth weight, this reduction averaged just 90g lighter (considered statistically insignificant), and there was no link to miscarriage or postnatal special care admission for the infant.
A 1986 study investigated if there were differences between races, with interesting results. White women who reported regular cannabis use during pregnancy had a significantly higher risk of low-birth-weight delivery or ‘small for gestational age infant’, and increased risk of premature labour. However, non-white women were at no greater risk beyond that already associated with ethnicity.
Lastly, a 2018 study found that maternal cannabis use was not associated with psychotic symptoms.
The effect of culture, ethnicity and socio-economic background
An oft-cited study, Effects of Marijuana Use during Pregnancy on Newborn Cry (Dreher et al, 1989), demonstrated that infants of cannabis-smoking mothers in Jamaica exhibited cries that were shorter in duration, more dysphonic (hoarse), and a higher and more variable fundamental frequency.
These acoustic characteristics are thought to present commonly in infants who experienced perinatal risk, and who often go on to exhibit developmental disorders. Interestingly, this effect was limited to cannabis-smoking mothers; those that ingested cannabis tea delivered offspring with cries within the normal acoustic range.
Dreher went on to document the neurobehavioral effects of prenatal marijuana exposure on neonates (24 exposed and 20 nonexposed newborns). Exposed and nonexposed neonates were compared at 3 days and 1 month old, half of whose mothers had consumed cannabis with varying frequency during pregnancy. No discernible difference was noted in birth weight between groups.
When the infants were tested according to the Brazelton Neonatal Behavioral Assessment Scale (NBAS), there was initially no difference, but by 30 days the offspring of those who used cannabis (both smoked and ingested as tea) were scoring significantly higher on the reflex and autonomic stability (ability to regulate the autonomic nervous system) assessments. Children of using mothers were less irritable and socialized more easily; the mothers themselves reported experiencing relief from fatigue and nausea during pregnancy.
Social acceptance of cannabis may reduce risk of developmental problems
However, in this sample, cannabis-using mothers were often of greater economic independence, and more frequently enjoyed the benefits of close, extensive social networks. This cultural phenomenon is well-established in Jamaica, where social smoking is seen as a way to strengthen relationships.
Furthermore, communal-style living arrangements are relatively common among the various spiritualist groups found in the country. Indeed, the heavier the use of cannabis, the greater the woman’s level of independence and social integration. This rich environment may in part explain the improved development in the offspring of users.
Conversely, in the USA, users are associated with lower educational attainments, lower income, greater dependence on welfare, and a lower level of overall life satisfaction.
The heaviest users in the Jamaican study consumed cannabis every day, whereas the Boston study documented a group of at least seven times per week, a group of no more than one episode per week during the last 3 months, and a group of no everyday users. To ascertain the exact relationship between problems in pregnancy, ethnicity, and cultural attitudes to cannabis, further cross-national research must be done, with care taken to assess the effect of frequency of usage.
Cannabis during labour
Historically, cannabis and hemp were used to naturally induce labour or stop bleeding, to alleviate pain or to start the process of lactation.
While giving birth, some women find that cannabis can trigger anxiety and possibly even paranoia, whilst others respond with a sense of relaxation, sense of humour, curiosity and openness.
In an interview, Ina May Gaskin, an American midwife who has been described as “the mother of authentic midwifery“, asserts that a sense of humour and laughter are entirely beneficial during labour. Cannabis is believed to have a significant impact on contractions and possess a hormonal influence. It is also supposed to give a fresh perspective on the birth, labour and delivery.
A lot of what happens during labour has to do with instinct and occurs way below the level of the conscious mind. Cannabis can help a woman put her trust in the birthing process and not over-think the process. Mrs. Gaskin also references to the fact that labour should be as uninhibited as possible and that women should be encouraged to follow their own gut instincts.
Historical clues for the use of cannabis in midwifery
Historic references to the therapeutic use of cannabis for a variety of female conditions go back to the 7th century BC. In his book “Cannabis Treatments in Obstetrics and Gynaecology: A Historical Review” Dr Ethan Russo writes that parts of the cannabis plant, including its flowers and seeds, were used in the Ancient World to induce contractions, prevent miscarriages/stillbirths and reduce postnatal bleeding.
According to tradition, Vikings and medieval Germans used cannabis as a remedy for labour pains.
In the mid-nineteenth century, cannabis tinctures were a popular product in Western cultures and a range of cannabis-based prescriptions arose. For example, just a few drops mixed with warm water was an effective formula against pain during delivery, as well as for hysteria and menstrual cramps. In the mid-nineteenth century, virtually every chemist produced their own tincture.
Studies on the use of cannabis in midwifery
Together with colleagues, Dr Melanie Dreher has studied cannabis consumption in pregnant women in Jamaica over a period of many years and reports that the plant has traditionally been used to treat nausea and to stimulate the appetite. Admittedly, consumption of cannabis is not officially encouraged in Jamaica, and in fact the opposite applies. Nevertheless, Jamaican women regard the custom of therapeutic cannabis consumption for themselves and their unborn child as an aid and remedy.
During her earlier mentioned study on cannabis consumption in pregnancy, Dr Dreher concluded that, so far, there is no definitive scientific proof that consumption of cannabis is harmful to the human foetus.
In their book “Marijuana Myths, Marijuana Facts: A Review of the Scientific Evidence” John P. Morgan and Lynn Zimmer state that “marijuana has no reliable impact on birth size, length of gestation … or the occurrence of physical abnormalities” among infants. This finding appears to have been corroborated by studies in Great Britain, the Netherlands and Australia as well.
Hyperemesis gravidarum (severe morning sickness and vomiting in pregnancy)
Hyperemesis gravidarum is characterised by extreme and persistent nausea and vomiting throughout the day, as well as at night and on an empty stomach, and also weight loss. Hyperemesis gravidarum is a serious pregnancy condition which, if left untreated, can be fatal for mother and child. Approximately 0.3 to 3.0% of pregnant women display serious symptoms of hyperemesis gravidarum.
Case study reports involving expectant mothers describe how cannabis is the most effective – and also the only – drug that helps against these complaints. It eliminates the nausea and vomiting, stimulates the appetite and is a digestant. In some states in the USA, medicinal cannabis is permitted to treat hyperemesis gravidarum. This is not yet the case in Europe or the rest of the world.
Dr Wei-Ni Lin Curry, a woman affected by this condition, described her own situation as follows:
“Within two weeks of my daughter’s conception, I became desperately nauseated and vomited throughout the day and night. … I vomited bile of every shade, and soon began retching up blood. … I felt so helpless and distraught that I went to the abortion clinic twice, but both times I left without going through the with the procedure. … Finally I decide to try medical cannabis. … Just one to two little puffs at night, and if I needed in the morning, resulted in an entire day of wellness. I went from not eating, not drinking, not functioning, and continually vomiting and bleeding from two orifices to being completely cured. … Not only did the cannabis save my [life] during the duration of my hyperemesis, it saved the life of the child within my womb.“
Cannabis compared to other herbal remedies for morning sickness
It may be wise to avoid consumption of cannabis if attempting to become pregnant, as (similarly to alcohol) even small quantities in the first few days may disrupt initial foetal growth. However, many women are opting for cannabis tea as a relatively safe and side-effect-free antiemetic to combat prolonged nausea.
No pharmaceuticals are approved for nausea in pregnant women in the USA, partly due to the panic caused by Thalidomide in the 1960s, and relatively few are available elsewhere. According to many enthusiasts, herbal cannabis drunk as an infusion is simply another remedy in a naturopathic pharmacopeia which has been used for centuries around the globe.
Studies have been done on the safety and efficacy of common herbal antiemetics used in pregnancy. While research on ginger confirms it has an antiemetic effect greater than a placebo, there is also a suggestion that it leads to a sharp increase in early miscarriage in rats.
Peppermint, another widely used anti-nausea remedy, may also stimulate bleeding. Ginseng can cause emmenagogue and abortifacient effects, although this is disputed. While it is thought these incidences arise so infrequently as to be of negligible significance, caution is advised when seeking to self-medicate with these herbal remedies.
Countless women have used these remedies over thousands of years, with little discernible detriment to overall societal health. As with all medications, seeking advice from a trusted healthcare practitioner is critical before embarking on a course of treatment. However, it is likely that cannabis is in fact safer than several herbal remedies, and also than many anti-nausea medications currently in use throughout the world.
As more research is done on the precise interactions between individual cannabinoids and how they affect foetal development, what constitutes “safe” and “unsafe” consumption will become clear. This classification will depend on numerous factors, including the type of cannabis consumed and the ratio of cannabinoids it contains, the method of consumption, and even the socio-economic and ethnic background of the mother.
- Disclaimer:This article is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with your doctor or other licensed medical professional. Do not delay seeking medical advice or disregard medical advice due to something you have read on this website.