Fentanyl And The Fetus: Does Analgesic Exposure During Labor Predispose Babies To Recreational Fentanyl Drug Addiction Later In Life?

Published by Sarah White, Kajsa Brimdyr, and Karin Cadwell

Healthy Children Project, Inc., 327 Quaker Meeting House Road, East Sandwich, MA

These findings are described in the article entitled A plausible causal relationship between the increased use of fentanyl as an obstetric analgesic and the current opioid epidemic in the US, recently published in the journal Medical Hypotheses (Medical Hypotheses 119 (2018) 54-57). This work was conducted by Kajsa Brimdyr and Karin Cadwell from the Healthy Children Project.

Meticulous research must be conducted on fentanyl. With over 2.5 million Americans estimated to be addicted to opioids (both prescription and heroin), the US is facing a public health epidemic that cannot be denied. The CDC has reported that the crisis has become exacerbated, with a 28% increase in deaths from 2015 to 2016. The initial emphasis on the abuse of prescription drugs has now shifted to overdoses due to heroin and non-pharmaceutical fentanyl.

While prescribing rates have not risen, fentanyl deaths have increased by 79 percent. Many of these deaths are attributed to illicitly-manufactured fentanyl (IMF). There has also been an increase in the number of adolescent deaths. Following the FDA’s approval of fentanyl in 1968, it only took two short years for it to surface on the illicit drug scene. Fentanyl also increased in popularity for surgical use in the late 1970s and early 1980s when administration of the drug was broadened from intravenous to both spinal and epidural.

Epidurals used in labor are typically are a combination of both an opioid and a local anesthetic, Fentanyl – which is significantly more potent than both heroin and morphine – is the most commonly prescribed opioid incorporated into epidurals.

The hypothesis that exposing the fetus to fentanyl during labor through analgesia causes a predisposition to use the drug recreationally later in life is based in science. Research has shown that later taste preferences are regulated by the fetus being exposed to labor medications. It is similar to “imprinting,” where a certain memory becomes embossed during the hours before birth, leading to behavioral effects during adulthood. Flavors included in the maternal diet are disseminated to the amniotic fluid, and simultaneously to the fetus, since at 12 weeks gestation the fetus begins to swallow. This leads to the preferences for these flavors following weaning. Essentially, the opioid system plays a unique part during the time period when taste preferences are being acquired. Toward the very end of gestation, the fetus can readily obtain chemosensory preferences, and the opioid system is an integral aspect of the learning taking place in this critical stage. For example, research has shown that these very last days of gestation significantly increase the effect of a conditioned preference for ethanol. This sensitive period in utero leaves a lasting impression on the fetus as it recognizes ethanol intoxication ultimately as a positive reinforcer.

The use of epidurals in obstetrics has been increasing. In 2016, more than 83% of women in France had an epidural, while in the UK the rate was 17%. About 73% of mothers in the US currently have epidural analgesia during labor, with the opiate fentanyl commonly administered with other drugs in order to make the epidural take effect faster. To manage the pain of contractions, fentanyl acts locally while also passing into the maternal circulation and crossing the placenta to the fetus, who also tastes the drug in the amniotic fluid. If the research that’s been done on other opiates is proven to be applicable to fentanyl, it’s fathomable that the continuing use of fentanyl in obstetrics means continuing to “imprint” the next generation with a “taste” of fentanyl, potentially leading to later drug abuse.

The statistics are alarming. Drug overdose deaths have doubled in the US in the past 10 years. Sixty-three percent of the deaths from drug overdoses in 2015 were from opioids. In the pediatric age range (under 18 years old), hospitalizations from overdoses caused by opioids rose by 165% from 1997 to 2012. Unfortunately, labor medications aren’t yet on the radar of agencies such as The National Institute on Drug Abuse as a potential catalyst to the growing crisis. While there are legitimate interventions that can reduce later risks, exposing fetuses to fentanyl is doing just the opposite. 

The bottom line is that there is a legitimate need for fentanyl to be fastidiously examined and studied. Rigorous clinical research must be conducted to delve into the postulated link/trend toward fentanyl abuse to the increased popularity of this obstetrical drug. In the United States, 75% of women give birth with epidural medications. The focus on alternative medications and other strategies for managing the pain of labor is clearly not on the forefront. It’s costing in economics a half a trillion dollars annually. More importantly, what it’s costing in lives is immeasurable.