Cannabis - Pregnancy and Breastfeeding

Dr. Claude ALLOUCHE, Gynecologist-ObstetricianCannabis ia english
Clinic Ahuza, Raanana, Israel
058 726 02 64


(Based on the CRAT sheet updated May 21, 2021)

Dried cannabis leaves and resinous extracts of the plant (hashish) are used for recreational purposes in various forms, particularly smoked with tobacco. The plant contains numerous compounds (cannabinoids), each with varied effects. The main active ingredient is delta-9-tetrahydrocannabinol (THC). THC is highly lipophilic, meaning it quickly distributes in the brain and adipose tissues, where it accumulates.

The duration THC and its metabolites can be detected in urine is highly variable and depends on consumption habits:

  • 2 to 7 days after the last exposure for occasional users
  • 7 to 21 days or more for regular users

Regular and/or heavy cannabis use may indicate an underlying maternal condition that is inadequately managed, such as anxiety or depression.

CURRENT KNOWLEDGE

1. Placental Transfer
THC crosses the placenta.

2. Malformative Aspect
Extensive data on pregnant women exposed to cannabis during the first trimester show no evidence of malformations.

3. Neonatal Aspect
For occasional use, no neonatal effects are observed.
For regular and heavy use (around six times per week or more), the following effects have been suggested:

  • Prematurity
  • Intrauterine growth restriction
  • Small for gestational age
  • Neonatal tremors, which usually subside within about a month

It is difficult to distinguish the effects of cannabis from those of tobacco smoked with it.

4. Long-term Effects
In children aged 10 to 16 whose mothers used cannabis regularly and heavily during pregnancy, IQ appears normal. However, the following effects have been observed: Cannabis - Grossesse et allaitement

  • Attention deficits
  • Hyperactivity
  • Disruption in certain behavioral tests and executive functions

PRACTICAL RECOMMENDATIONS

A) Pre-pregnancy / Preconception
It is preferable to plan a future pregnancy without cannabis exposure.
Regular and/or heavy cannabis use may require investigating:

  • An underlying maternal condition that is inadequately managed (anxiety, depression, etc.)
  • The use of other substances (e.g., tobacco, alcohol, drugs, medications)

B) During Pregnancy
Reassure pregnant women about the lack of malformative risk associated with cannabis exposure during the first trimester.
However, cannabis use during pregnancy is not recommended based on current knowledge.
Regular and/or heavy cannabis use may justify investigating:

  • An underlying maternal condition that is inadequately managed (anxiety, depression, etc.)
  • The use of other substances (e.g., tobacco, alcohol, drugs, medications)

C) Breastfeeding
THC and its metabolites pass into breast milk and can remain detectable for several days after cannabis use. THC may concentrate in breast milk, and in cases of regular use, it can be found in concentrations up to eight times higher than in maternal plasma.

THC has also been found in the stools and urine of breastfed infants.

There is no relevant data on the neurodevelopment of children breastfed by mothers who use cannabis.

Given this, cannabis use during breastfeeding is discouraged.

CRAT - Reference Center on Teratogenic Agents
Armand Trousseau Hospital, 26 Avenue du Docteur Arnold Netter, 75012 PARIS
Fax: +33 (0)144735395 – Reserved for medical professionals.
www.lecrat.fr

In summary, cannabis:

  • Crosses the placenta
  • Does not cause malformations
  • Has no neonatal effects if used occasionally
  • Regular and heavy use (more than 6 times per week) may lead to:
    • Prematurity
    • Intrauterine growth restriction
    • Neonatal tremors

At a distance (ages 10-16):

  • Attention deficits

  • Hyperactivity

  • Disruption in certain behavioral tests and executive functions

  • IQ remains normal

  • Passes into breast milk

  • Is not recommended during pregnancy and breastfeeding