Epidural hysteria


Judy Slome Cohain doesn’t know anything about pharmacology, but that doesn’t stop her from making hysterical, unsubstantiated allegations about epidurals.

Two million American women will take an epidural trip this year during childbirth. In most cases, they’ll be ill-informed as to possible side effects or alternate methods of pain relief. In many ways, epidurals are the drug trip of the current generation. Similar to street drug pushers, most anesthesiologists in the delivery rooms maintain a low profile, avoid making eye contact and threaten to walk out if they don’t get total cooperation. Women get epidurals for one of the main reasons so many women smoked pot in the 1970s—their friends are doing it.

Gee, Judy, why don’t you tell us what you really think about epidurals and the women who choose them?

Today, health authorities tout epidural analgesia as the safest, most effective method of pain relief available for childbirth. You could not pull that off on my generation. We lost enough creative artists—Janis Joplin, John Belushi, Jim Morrison and Lenny Bruce—to injectable pain killers. We are aware of the potential of painkillers that are injected into your body—let alone into the delicate spinal cord—by someone else …

While we can figure out why Judy is hysterical: she is desperate to convince women to forgo the most effective form of pain relief in labor, her utter ignorance of chemistry and biology may not be as apparent to the lay people who read her garbage article. Judy is very, very confused. She does not know the difference between intravascular injections and epidural injections. And she apparently thinks the placenta is a sieve, allowing direct transmission of everything in the mother’s blood stream. Judy needs a lesson in pharmacology.

The basics:

1. To get to the baby, a medication needs to get to the mother first. Specifically, the medication must enter the mother’s blood stream. A medication can enter directly through intravenous administration, but if the medication is injected elsewhere, only some of it will find its way to the mother’s bloodstream. Epidurals are injected into the epidural space and that means that considerably less medication (local anesthetics and/or opiods like fentanyl) ends up in the mother’s blood stream.

2. Dose counts. In her frantic rush to indict epidurals, Cohain conveniently forgets to mention that the effect of a medication depends on the dose. Janis Joplin, John Belushi, Jim Morrison and Lenny Bruce OVER-dosed on medication. They were not using the drugs in question for approved uses, either.

3. The placenta is not a sieve. Cohain imagines that whatever is in the mother’s blood stream always and easily crosses the placenta. The reality is quite different. The chapter of the Obstetric Anesthesia Handbook entitled Perinatal Pharmacology has a brief explanation:

Substances in the maternal circulation can cross the placenta by one of four mechanisms. The majority of substances are subject to passive diffusion, in which the compound flows across lipid membranes down a concentration gradient… Some substances are subject to facilitated diffusion, in which a carrier protein in the lipid membrane aids passage of the substance … Glucose crosses from the maternal to fetal circulation in this way. Active transport refers to an energy-requiring process in which a transporter molecule moves the substance … Amino acids appear to cross from the maternal to fetal circulation in this way, co-transported with sodium… Finally, some large molecules, such as immunoglobulins, are transferred via pinocytosis …

And even molecules that theoretically can pass freely across the placenta (passive diffusion), there are additional factors that modify how much gets across. These include utero-placental blood flow, maternal protein binding, and lipid solubility, among others.

The bottom line is that what is gets to the baby is far smaller than the amount of medication injected into the mother’s epidural space. Therefore, if an epidural does not sedate the mother, it certainly won’t sedate the baby.