Is it Safe? Evening Primrose for Labor Induction

The number of natural induction methods and options have grown exponentially over the last several decades. In my practice, as an Acupuncturist, I’ve seen a huge influx in women seeking Acupuncture and alternative medicine to speed up the labor process in the avoidance of a medically induced childbirth. While most of the natural induction methods are fairly harmless and offer some benefit in triggering the natural hormonal reactions of labor, there are some that would be better left on the shelf.        ​

Written by Sarah Thompson Functional Medicine Acupuncturist & Doula

First off, we should probably address the WHY behind the number of women seeking natural options to encourage the onset of childbirth. 

The current medical model of birth is intimidating for the modern mother. The US birthing statistics are pretty dismal. Currently the US is ranked 47th in maternal care in the world, just under Iran. A 2016 report by the Center for Disease Control stated that 23.3% of births are medically induced. In fact, a survey done by Childbirth Connection found that 41% of women who delivered in US hospitals in 2011-2012 had their primary care provider attempt induction. Of those 3 out of 4 did have their labors induced. That is a frighteningly high number, and enough of a scare to cause the most medically trusting of women to consider home options for labor induction.

What is Evening Primrose

​Evening Primrose, Oenothera biennis, is a plant native to North America, Europe and Asia. It produces beautiful yellow flowers that bloom in the evening, hence the name Evening Primrose.  It has a long and rich history of use among Native Americans as a topical anti-inflammatory for conditions such as minor wound healing and eczema, and as an internal cure for sore throat and gastrointestinal conditions. Ayerveda prescribes the herb for the treatment of women’s conditions. Pliny the Elder, the ancient Greek philosopher, spoke highly of the herb and its use in the treatment of several ailments. In modern Herbology it has found a popularity in the treatment of women’s health disorders such as PMS, breast lumps and tenderness, menopausal conditions, and among midwives and lay women as an aid to induce childbirth labor. 

So, How Does it Work?

The active ingredients of Evening Primrose oil are Gamma Linolenic Acid (GLA), Linoleic Acid (LA), Oleic Acid, Palmitic Acid, and Stearic Acid, with the two most prominent compounds being GLA and LA. Both GLA and LA are polyunsaturated Omega 6 fatty acids. Linoleic Acid is considered an essential fatty acid, as it cannot be made in the body and must be consumed in the diet. Gamma Linolenic Acid is naturally produced in the body by the conversion of the LA found in the diet. Both of these Omega 6 fatty acids serve a purpose in the body, and both are part of the production of prostaglandins. As the cascade of LA conversion unfolds, LA is converted to GLA which is converted to Dihomo-Gamma Linolenic Acid (DGLA) and lastly converted into Arachidonic Acid (AA)...AA is then converted into a variety of prostaglandins and blood coagulators.

Prostaglandins and Labor

There are multiple forms of prostaglandins in the body, each with its own unique functions. When we are talking about the activation of the labor processes we are talking about the 2 series prostaglandins, or PGE2/PGF2. PGE2 prostaglandins are triggered by the naturally occurring increase in estrogens at the end of the maternal gestation period. As the estrogens increase, so does the production of PGE2 and PGF2-alpha, as well as PG receptors on the cervix. PGE2 has been shown to stimulate interleukin-8, an inflammatory cytokine that promotes the influx of neutrophils and induces remodeling of the cervical extracellular matrix, and to induce functional progesterone withdrawal. PGF2-alpha has been shown to increase the levels of oxytocin in the uterus, decrease progesterone levels and increase the production of Hyaluronic Acid in the cervix in conjunction with interleukin-8 produced by PGE2. These are all great things for the natural labor process. The importance of the cervical softening aspect of labor is, arguably, the most important part of natural labor. If the cervix is not soft, it cannot dilate.  All of this cannot happen without adequate AA.

Not all Prostaglandins Help with Labor

​DGLA can take another prostaglandin pathway to form the 1 series prostaglandins. While PGE2 is an inflammatory prostaglandin, PGE1 is an anti-inflammatory prostaglandin. PGE1 is widely used for its ability to dilate blood vessels and increase blood flow, reduce platelet aggregation and lower blood pressure. In the normal consumption of Linoleic Acid the body naturally converts the Omega 6 oil into the necessary prostaglandin forms, either 2 series for increasing inflammatory responses, or 1 series for increased vasodilation and anti-inflammatory responses. 

Evening Primrose Theory Vs. Reality

​When you read this, it is hard to see the faults. In theory Evening Primrose oil would seem a miracle for the induction of labor. I contains not only the LA which comes down the cascade to produce both PGE1 and PGE2/PGF2 prostaglandins, which is a balance of anti-inflammatory and inflammatory responses. As well as the GLA, which in theory would also induce the same response, increasing the prostaglandins as needed for either inflammatory or anti-inflammatory responses. Theories are always well placed, and in theory, if evening primrose is beneficial for other women’s health conditions, such as menopause and PMS, would it not also be beneficial for the pregnancy mother. Although Evening Primrose Oil contains both dietary Linoleic Acid and Gamma Linolenic Acid, and the body can convert both into the correct inflammatory prostaglandins, there is concern over the wide use of Evening Primrose for the induction of labor, because dietary GLA works differently than converted GLA. 

One of Evening Primrose Oil’s claims to fame is its ability to raise PGE1 levels WITHOUT raising PEG2 levels. (And there is the snap) Several research studies have given this claim backing. Dietary GLA seems to skip the AA conversion steps, not sure why or how. When GLA is consumed orally, it is converted to DGLA while the AA levels remain the same, thus increasing the production of PGE1. While this is great for those with cardiovascular disease, this can be dangerous for those at the end of pregnancy.           

Could Evening Primrose Increase the Risk of Postpartum Hemorrhage?

Increased levels of PGE1 are associated with thinner blood, and bleeding issues. The rate of postpartum hemorrhaging has risen exponentially since 1993. So much so that the standard care policy with hospital birth is to administer pitocin postpartum for prevention for all women birthing in US hospitals. Evening Primrose Oil usage can increase this risk, especially when used in conjunction with high dosed fish oils. The combination could lead to blood that is unable to clot properly.
 
​As much as we love our anti-inflammatories, and we should, labor and birth is an inflammatory process. Each of the hormonal cascades necessary to induce labor require inflammatory reactions to work properly. If we are decreasing inflammation by increasing the consumption of anti-inflammatories, this could lead to a delay in the initiation and onset of active labor, leading to an increased need for gestational inductions. Which is what women seeking these alternative methods are trying to avoid. 

Is the Risk Worth it?

As much as we love our anti-inflammatories, and we should, labor and birth is an inflammatory process. Each of the hormonal cascades necessary to induce labor require inflammatory reactions to work properly. If we are decreasing inflammation by increasing the consumption of supplemental anti-inflammatories, this could lead to a delay in the initiation and onset of active labor, leading to an increased need for gestational inductions, or birth complications. Which is what women seeking these alternative methods are trying to avoid.

There isn’t much scientific evidence for the safe use of Evening Primrose oil orally, with more research linking its usage to an increase in birthing complications. One study found the use of Evening Primrose Oil starting at the 37th week of gestation did not shorten gestation or overall length of labor and was associated with an increased incidence of prolonged rupture of membranes, increased need for medication oxytocin use, and an increase in the need for vacuum extraction.  
 
Although the use of Evening Primrose Oil for the initiation of natural labor is an often recommended herbal remedy to women looking to avoid the medical interventions that are ever growing in the United States, it may offer more risk than benefit.

Safe options are available, such as Acupuncture, Chiropractic, and the overall benefits of proper nutrition prior to delivery. If you truly want to decrease your overall risk for medical induction and complications, understand HOW nutrition affects your natural labor and delivery processes is essential and should be part of the modern maternity nutritional care.

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