Pregnancy can mimic diseases seen in the non-pregnant state. Both pregnancy and epilepsy can cause seizures, for example, but seizures in pregnancy are usually associated with pregnancy-induced hypertension (PIH, also called pre-eclampsia), so there are other signs and symptoms to tip off the obstetrician that a seizure is not epilepsy of the non-pregnant variety.
The "Grand Mal" and "Petite Mal"
Epilepsy is serious business, and people still die from it–-either from the seizure itself or because of having a seizure in the wrong place or at the wrong time. There are currently two to three million epilepsy patients in the United States.
The very severe uncontrolled jerking of the muscles in a seizure can cause a person to be in considerable danger of head injury, tongue injury, or even suffocation. Also, it must be remembered that the seizure itself begins from a point of injury of the brain, with a domino effect of stimulated brain cells firing off down the line to the muscles. It is possible to have a sudden burst of brain seizure activity without the convulsions. This is seen often with seizures in the brain that are "quiet" from a muscular stimulation standpoint. Usually the convulsive seizures are termed "grand mal" (the big and bad) and the ones unaccompanied by convulsions are termed "petite mal."
Seizures due to PIH in pregnancy are easily differentiated from seizures of epilepsy, and the pregnancy-caused "eclamptic" seizures are more dangerous. But a patient with epilepsy is still considered high risk because epilepsy itself is high risk for the mother, and anything that can hurt the mother hurts the life support for the baby. If morning sickness interferes with proper pill taking, it follows that the epilepsy can get worse. But otherwise pregnancy seems to have little effect on the epilepsy--provided the epilepsy is well controlled. It's only when the epilepsy is poorly controlled that the extra burden of pregnancy can make the seizures worse or more frequent.
With a well controlled epilepsy in pregnancy, the major concern is whether the medicines used to control the epilepsy are safe for the developing baby. The goal of therapy of epilepsy during pregnancy, like the goal of any therapy during pregnancy, is to use the least amount of medicine that will still control the seizures. In this respect, it becomes a risk vs. benefit issue in evaluating the epilepsy medication.
The FDA uses five categories, "A," "B," "C," "D," and "X," to rate a medication's risk to the fetus. An "A" label is considered the safest risk, an "X" designation is for medications known to put the baby at definite and severe risk. Most of the drugs used to treat epilepsy are of the "C" or "D" type.
This may sound pretty bad, but in spite of the dire warnings about the C and D category medications, in reality, the chances are still more likely than not that there will be no problems.
In my practice, these are the most common drugs used to treat epilepsy:
Depakote (Valproic Acid): Valproic acid is associated with brain and spinal problems, but even so the risk is less than 10%.
Dilantin (diphenylhydantoin): Dilantin, which is related to phenytoin, is associated with a well-recognized "Fetal Hydantoin Syndrome" (FHS), which includes abnormalities of the skull, face, and limbs.
Phenobarbital: Studies on abnormal development in babies exposed to phenobarbital have been inconclusive in that it isn't clear whether the increase in the minor defects (cleft lip, for example) are a result of the phenobarbital or of the disease of epilepsy itself–or a combination of the two. A definite problem with phenobarbital is that, being a barbiturate, it is addictive, and babies so exposed may have withdrawal once born and cut off from it. They may also experience bleeding problems, since phenobarbital may interfere with the newborn's Vitamin K, necessary for health clotting ability.
Magnesium sulfate: Magnesium sulfate differs from the rest in that it's the only agent that is a "B" category, which poses no undue risk to the fetus. But magnesium sulfate is used in acute situations, via intravenous.
I have to emphasize that as scary as all of this sounds, still the risk of major problems is less than the disastrous outcome of epilepsy gone untreated. Risk to babies exposed to these necessary drugs is three to four times higher than the general population, but that may translate to anywhere from two to thirty percent, depending on the agent used. A Maternal-Fetal Medicine consult by a perinatologist can give the odds to a particular situation as well as perform a Level III ultrasound to look the baby over thoroughly for any tell-tale signs of abnormal development.
These drugs may just have to be a necessary evil until newer drugs come along that can move the FDA-assigned risk up the alphabet into "A" or "B" categories. Until that time, the nature of epilepsy is such that treatment with what we have is mandatory. Otherwise, a baby has no chance at all if the epilepsy creates the worst scenarios for the expectant mother.