Wernicke Encephalopathy Can Be a Pregnancy Complication

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Wernicke encephalopathy (WE) is a neurological condition resulting from a thiamine deficiency, also called vitamin B1. WE can be triggered by the administration of intravenous fluids with glucose (sugar) before the person is given supplemental thiamine. Potentially fatal if not recognized and treated early, WE is characterized by three neurological abnormalities, all of which occur in most cases:

  • Weakness of the muscles that move the eyes (ophthalmoparesis) with rapid, repetitive movement of the eyes back and forth (nystagmus).
  • Lack of full control of voluntary muscles and coordinated body movements (ataxia)
  • Confusion

Outside of pregnancy, the typical victim of WE is an alcoholic, but in pregnancy WE can develop as a complication of hyperemesis gravidarum (HG). HG is a condition that features severe nausea and vomiting (beyond common nausea and vomiting of pregnancy), with weight loss and liver problems. The extreme vomiting of HG together with the fact that pregnancy increases the need for thiamine can make a thiamine deficiency so severe as to the cause the development of WE.

As for the statistics, WE is present in approximately 0.04-0.13 percent of nonalcoholics, but many of such non-alcoholic cases are in women suffering from HG, which strikes approximately 0.3-3 percent of pregnancies. To be sure, the rate of occurrence of HG differs in different countries and among ethnic groups and national populations with an incidence as high as 10 percent reported for some populations Asian and Middle Eastern women. Incidence of HG also is high among young, non-Caucasian women in their first pregnancy. The chances of developing a thiamine deficiency are elevated in those who avoid foods that are abundant in thiamine, such as whole grains, legumes, and breakfast cereals.

Nearly all packaged foods that contain grain are enriched with thiamine, but there is a particular group of people who miss out on thiamine —people who avoid gluten. They are at particular risk of inadequate thiamine intake, because gluten-free foods are foods that are made without wheat. This is yet one more example of the negative consequences of “gluten free” diets, which are appropriate, only if you have celiac disease. To learn more about this issue, read my post titled High Gluten Food Is Good for Your Pregnancy Health.

Other factors that put you at risk for thiamine deficiency include HIV/AIDS, bariatric surgery, and diuretic medication, such as furosemide. Smoking apparently decreases the risk for developing HG, but this does not mean that you should smoke, since everything else that smoking does is bad, both for you and your baby.

There is no specific test for WE, so it is diagnosed clinically based on a combination of factors, including the presence of a risk factor for thiamine deficiency. This includes the frequent, severe vomiting of HG and the finding of neurological abnormalities typical of WE, such as disturbances of eye motion, difficult or uncoordinated body movements, memory problems, or an altered mental state. Magnetic resonance imaging (MRI) of the brain also may be ordered to look for a serious condition call central pontine myelinolysis (CPM), a problem with cells of a part of the brain stem called the pons, which may develop in connection with WE.

Women with WE during pregnancy are confused and tired. They often experience double vision, due to weakness of the muscles that move the eyes, but the eyes also make repetitive movements back and forth (nystagmus). Those with WE also suffer from ataxia, lack of full control and coordination of body movements. Women with WE also may suffer from CPM, which can lead to severe neurological dysfunction in those who survive. One of the most feared complications of CPM is called locked-in syndrome, sometimes called a pseudocoma. This condition is characterized by the brain not being able to communicate with the outside world, because it cannot control any voluntary muscles, other than some limited control of the eyes. Along with these serious consequences for the mother, WE during pregnancy entails an elevated risk of spontaneous abortion (miscarriage) and stillbirth.

WE is treated with thiamine given intravenously. Recommendations of the dosage of thiamine varies among authorities and reports from 100-200 mg daily to higher doses, divided into one to three doses for up to seven days. After this, treatment can shift to oral thiamine supplementation. Thiamine therapy must begin before the woman is given any glucose (dextrose).

Like pregnancy, breastfeeding increases your need for thiamine, due to the thiamine needs of the baby. Rather being a risk for a nursing baby, thiamine supplementation is vital to assure that your milk supplies the baby with adequate thiamine. If your doctor determines that your thiamine status is not good, then you may need to feed your infant with formula.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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