Cannabis is becoming increasingly socially acceptable.

In many countries – including Germany – the way the plant is handled has changed significantly in recent years.

What used to be taboo is now commonplace: cannabis is medically prescribed, sold in coffee shops, or consumed for relaxation.

However, one topic is often left out: cannabis use during pregnancy.

While alcohol and nicotine have long been considered no-gos, some believe cannabis is the “natural” and harmless alternative – especially for nausea, sleep problems, or stress during pregnancy.

But is that really true? What does science say about it? And what consequences can cannabis have for the unborn child?

In this article, we take an honest, scientifically based look at the risks, myths, and unanswered questions surrounding cannabis in pregnancy.

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Why expectant mothers turn to cannabis in the first place

Before discussing risks, it is worth looking at the causes. Studies show that women usually do not consume cannabis during pregnancy for fun, but for self-medication reasons.

The most common reasons according to a study by Ko et al. (2020):

• Nausea and vomiting (especially in the first trimester)

• Anxiety, stress or sleep disturbances

• Loss of appetite

• Chronic pain or migraines

Many affected individuals report that cannabis helps them to make everyday life more bearable – especially when conventional medications are to be avoided due to possible side effects.

But the assumption that cannabis is "herbal and therefore safe" is dangerous – because natural does not automatically mean harmless.

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How cannabis works in the body – and why that is problematic in pregnancy

The main psychoactive substance, THC (tetrahydrocannabinol), easily crosses the placental barrier – the barrier between mother and fetus.

This means: What the mother consumes also reaches the unborn child.

In the fetal brain, cannabinoid receptors (CB1) are present from the 14th week of pregnancy, playing a central role in the development of nerve cells, synapses, and neuronal communication (Wang et al., 2003).

When THC influences these receptors, it directly interferes with the fetus's brain development – particularly in the areas responsible for:

• memory,

• attention,

• emotional regulation, and

• motor skills.

A study by the University of Ottawa (2008) found that even occasional cannabis use during pregnancy can lead to altered brain structures in the fetus – especially in the prefrontal cortex, which is responsible for impulse control and learning.

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What studies say about the consequences

Research on cannabis in pregnancy is extensive – and the results are clearly concerning.

1. Lower Birth Weight & Preterm Births

A meta-analysis by Gunn et al. (2016) with over 24,000 participants shows that children of cannabis users are, on average, 110–130 grams lighter at birth and are more likely to be born prematurely.

This is due, among other things, to the fact that THC impairs oxygen and nutrient transport across the placenta.

2. Cognitive and Emotional Developmental Disorders

Children exposed to cannabis prenatally, according to El Marroun et al. (2019, JAMA Psychiatry), more frequently exhibit:

• Attention deficits,

• hyperactivity,

• poorer memory performance, and

• emotional instability.

These effects occurred independently of the mother's alcohol or tobacco consumption – cannabis alone was a significant risk factor.

3. Brain Changes

An MRI study by Columbia University (2020) showed deviations in gray matter and neural networks related to anxiety and impulse control in 11-year-olds who were exposed to cannabis prenatally.

4. Increased Risk for Mental Illnesses

Long-term studies (Day et al., 2015) suggest that cannabis exposure during pregnancy can increase the risk of anxiety disorders, depression, and ADHD in adolescence.

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CBD in Pregnancy – Safe or Underestimated?

Many consider CBD products (cannabidiol) to be a safe alternative because they are not psychoactive.

In fact, CBD has anti-inflammatory, anxiolytic, and antispasmodic effects – but:

There are hardly any studies on the safety of CBD in pregnancy.

Animal studies (Philippine et al., 2021) show that high CBD doses can affect fetal liver development and disrupt hormone balance.

CBD is also transported across the placenta – and because dosages in over-the-counter products vary greatly, no safe level can be determined.

In short:

There is no evidence that CBD is safe in pregnancy – but there are indications that it carries risks.

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How Cannabis Affects Newborn Behavior

In the first weeks of life, babies whose mothers have used cannabis often exhibit:

• Excessive crying

• Sleep problems

• Tremor (shaking)

• Irritability or apathy

These symptoms resemble a mild withdrawal syndrome, as the baby suddenly no longer has access to THC after birth.

Long-term studies (Goldschmidt et al., 2012) also show that such children develop more concentration and social problems during school age.

The effect is dose-dependent – the more consumed, the more pronounced the abnormalities.

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Combination with alcohol, tobacco, or medication

Another problem: Many users mix cannabis with tobacco (e.g., in joints).

This creates a toxic cocktail that further increases the risk of premature birth, placental abruption, and developmental disorders.

In combination with medication (e.g., antidepressants or painkillers), cannabis can also alter liver metabolism and unpredictably influence the effects of other substances.

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Why many risks are underestimated

One reason for the trivialization is that cannabis is considered "natural."

However, modern cannabis products today contain 2 to 5 times more THC than 20 years ago (UNODC World Drug Report, 2023).

This means that the psychotropic and biological effects are significantly stronger – and thus potentially more dangerous for the unborn child.

Another problem:

Many studies rely on self-reports, and expectant mothers often do not fully disclose their consumption for fear of stigmatization.

The actual number of affected individuals is therefore likely to be significantly higher.

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How doctors advise today

The medical recommendation is clear:

During pregnancy and breastfeeding, cannabis – whether THC or CBD – should be completely avoided.

The German Society of Gynecology and Obstetrics (DGGG) explicitly advises against using cannabis to alleviate pregnancy symptoms.

Instead, doctors recommend alternative methods:

• For nausea: Acupressure, ginger preparations, light meals

• For sleep problems: Relaxation techniques, magnesium, exercise

• For stress: Mindfulness training, talk therapy

For severe symptoms, a doctor can also specifically prescribe safe medications – many are better researched and less risky than cannabis.

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What studies say about breastfeeding and breast milk

THC is stored in breast milk – and for several days.

A study by the American Academy of Pediatrics (2018) found that babies who ingest THC through breast milk may show reduced motor reflexes and developmental delays.

Since THC is fat-soluble, a single use is enough for it to remain in the mother's fatty tissue and be gradually released to the child through milk.

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Societal pressure and misinformation

Countless videos and posts circulate on social media in which mothers tout cannabis as a "safe, herbal remedy."

This development is problematic because it is based on anecdotal experiences rather than scientific findings.

An analysis by Jarlenski et al. (2021) found that over 80% of cannabis-related pregnancy posts on TikTok and Instagram contained no warnings – and instead presented cannabis as an "alternative to medication."

Experts therefore call for better education to stop myths and dangerous misinformation.

Long-term consequences – what research shows about school-aged children

While many studies focus on pregnancy and birth, newer research provides valuable insights into the long-term consequences of prenatal cannabis use.

A large-scale study by the University of Colorado (2022) tracked 1,500 children whose mothers had consumed cannabis during pregnancy over 10 years.

The result:

These children showed increased concentration problems, emotional fluctuations, and weaker performance in math and language during school age.

The differences were particularly evident in families where cannabis use continued throughout pregnancy.

Researchers suspect that THC significantly influences the development of synapses and neural plasticity – that is, the brain's ability to form new connections and learn.

Furthermore, it was found that affected children exhibited higher stress susceptibility and stronger reactions to frustration. These changes, according to Hurd et al. (2019, Nature Neuroscience), can be traced back to adolescence and are related to an overactivity of the endocannabinoid system in early development.

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Cannabis as a painkiller – a dangerous misconception

Another reason why pregnant women turn to cannabis is the hope of pain relief – for back pain or nausea, for example.

However, unlike medical patients outside of pregnancy, the benefit here is not proven.

Although THC has pain-relieving effects by activating CB1 receptors, it also constricts blood vessels and can reduce blood flow to the placenta.

In the worst case, this can lead to growth retardation or oxygen deficiency in the fetus.

Even the use of vaporizers or edibles is not considered a safe alternative – as the dosage is difficult to control and residues of solvents or pesticides further increase the risk.

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What affected individuals should know – and what help is available

If an expectant mother has already consumed cannabis, it does not automatically mean that the child will be harmed.

It is crucial to speak openly with doctors or midwives. Many clinics now offer anonymous consultations to discuss consumption without fear – and to jointly reduce possible risks.

Programs like the "FrühStart" network in Germany or the "MotherToBaby" project in the USA offer individual support, education, and guidance for affected families.

Experts emphasize: Early openness is the best protection for mother and child.

Because the sooner the medical environment is informed, the more targeted prevention measures, examinations, and support services can be implemented.

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Conclusion: Cannabis in pregnancy – not a harmless herb

Cannabis is many things – medicine, intoxicant, cultivated plant.

But in pregnancy, it is above all one thing: a risk to unborn life.

The scientific evidence is clear:

• THC crosses the placenta and reaches the baby's brain.

• It can disrupt neuronal development and have long-term consequences.

• CBD has also not yet been sufficiently researched and is therefore not a safe alternative.

The seemingly "harmless" consumption against nausea or stress can lead to permanent developmental disorders – a price no child should have to pay.

Anyone experiencing problems during pregnancy should contact professionals – doctors, midwives, therapists. There are safe, well-researched ways to alleviate symptoms – without the risks that cannabis entails.

Because in the end, it's true:

"Natural" is not automatically "safe."

And the well-being of the child begins with informed decisions.