Is the Endocannabinoid System – A Preterm Labor Predictor?

The ECS plays a vital role in the body, much like other well-understood systems. Researches tried to find a connection between the endocannabinoids and the prediction of preterm birth
Written by 
Trista Best, Registered Dietitian.
|Last Updated:

The Endocannabinoid System (ECS) was discovered in the early 1990s and while researchers are still discovering all that this system entails, some impressive benefits have been revealed. The ECS is composed of three primary components; endocannabinoids, receptors, and enzymes. There are two endocannabinoids; anandamide (AEA) and 2-arachidonylglyrol (2-AG).

The body produces these two and uses them to keep various body-systems running optimally. When there is a need the body produces more if it is able. These compounds interact with receptors, CB1 and CB2. The CB1 receptors are connected to the central nervous system and are responsible for relieving pain. The CB2 receptors are concerned with immune function and inflammation. Once the body uses the endocannabinoids enzymes to break them down to remove them from the body.

What About External Cannabinoids?  

There are two primary external cannabinoids that are found in the cannabis plant. These are cannabidiol (CBD) and tetrahydrocannabidiol (THC). CBD products have become widely popular over the past few years for its supposed health benefits by interacting with the ECS when endocannabinoids are low. THC is the psychoactive cannabinoid responsible for the high associated with marijuana. CBD is produced by industrial hemp which is grown with little to no THC present.

Most Recent Discovery

In recent years research has shown the ECS has some interesting connections to uterine function.1Estrogen plays a role in breaking down AEA by producing FAAH, the protein necessary for this process.

Some latest research is pointing to the potential that endocannabinoid levels could be an indicator of preterm birth, delivery child before 37 weeks’ gestation. Two specific studies are leading the way in research related to this topic.

The first study was conducted by scientists from Qatar, Italy, and Britain. They checked specific lipid and cannabinoid levels of 217 pregnant women at risk for preterm birth. Exact chemicals checked were FAAH, AEA, as well as two other lipids known as PEA and OEA.

Because plasma AEA typically increases throughout pregnancy until labor the researchers sought to find a potential threshold to determine preterm labor. Their findings indicated an AEA concentration of 1.095 nanomolar (nM) was a fair indicator of preterm labor.

The researchers took this study a step further to determine a true negative rate, which would indicate how effective this threshold is at predicting preterm birth. This rate would only miss 1 out of every 10 cases. Along those same lines the false positives were 3 out of 4.

While these numbers aren’t ideal, especially in regard to the false positives, the researchers confidently concluded the use of AEA as an indicator of preterm birth was more beneficial than current methods. Current methods are both invasive and less accurate than the use of AEA. The study showed that PEA may also be a useful indicator.

A second study also looked at AEA levels as a preterm birth indicator and reached a similar conclusion.2The difference between the two conclusions was in regard to the predictor AEA level. The first study stated an AEA level of 1.095 nM was a good indicator while the second study stated 0.6 to 0.8 nM of AEA in the blood would indicate the likelihood of preterm birth.

An interesting point the second study made was the need for consistency in the timing of blood collection. These levels fluctuate throughout the day making it necessary to draw blood for testing around the same point in the day each time.

Final Thoughts

As research continues to show, the ECS plays a vital role in the body, much like other well-understood systems. If a single blood test can predict preterm labor with better accuracy than current methods, it is certainly worth further research and investigation.


  1. Hill, MN, Karacabeyli, ES, Gorzalka, BB. Estrogen Recruits The Endocannabinoid System To Modulate Emotionality. Psychoneuroendocrinology. 2007; 32(4):350-357.


  1. Hanlon, EC. Impact of circadian rhythmicity and sleep restriction on circulating endocannabinoid (eCB) N-arachidonoylethanolamine (anandamide). Psychoneuroendocrinology. 2019;


Trista Best
Trista Best
Registered Dietitian
Trista Best is a Registered Dietitian, Public Health Dietitian, and former college Nutrition Professor. She completed her Bachelor of Science in Health Science from Armstrong Atlantic State University in 2009, Masters of Public Health Nutrition from Liberty University in 2014, and Bachelors of Science in Food and Environmental Sciences from the University of Alabama in 2018. Her dietetic background is in Public Health, Medical Grade Supplements, and Childhood Nutrition.

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