La importancia de la suplementación antes y durante el embarazo

Creating the optimal environment for a developing fetus is a critical part of pregnancy planning for all those considering becoming pregnant. For patients with epilepsy, a healthy supplementation routine can help reduce certain risks and promote healthy pregnancy outcomes.

La suplementación con ácido fólico se recomienda en todas las personas con epilepsia en edad fértil, independientemente de los planes inmediatos de embarazo. Idealmente, las pacientes deben comenzar a tomar suplementos prenatales antes de intentar quedar embarazadas, así que discuta los beneficios de la suplementación con pacientes en edad fértil lo antes posible. Es importante que la persona comience a suplementarse con ácido fólico mucho antes del embarazo y lo continúe durante todo el embarazo, durante la lactancia y entre bebés.

Los temas que se tratan en esta página incluyen:

El valor del ácido fólico durante la edad fértil

Los pacientes deben tomar ácido fólico diariamente. Debido a que algunos estudios encontraron que hasta el 65% de las mujeres con epilepsia informaron al menos un embarazo no planificado, los médicos deben comenzar a administrar ácido fólico a las pacientes tan pronto como la paciente entre en edad fértil.  

The benefits of folic acid supplementation prior to and continuing through pregnancy are well-documented. It is associated with:

  • Lower risk of neural tube defects in the general population.
  • Improved neurodevelopmental outcomes, including a decreased risk of autism spectrum disorder, in both patients with epilepsy and the general population.

Recomendaciones para la dosificación de ácido fólico

We recommend that patients with epilepsy and childbearing potential should take at least 400-1000 mcg of folic acid daily. In the United States, 1000 mcg (1 mg) can be prescribed as a tablet. This supplementation should continue throughout their childbearing years, including pregnancy, breastfeeding, and between babies. Patients seeking pregnancy should add prenatal vitamins to the folic acid. Most prenatal vitamins have around 800 mcg of folic acid. A common practice is to prescribe 1000 mcg (1 mg) of folic acid and add a prenatal vitamin (1800 mcg or 1.8 mg total dose). If the patient isn’t on either folic acid or prenatal vitamins prior to pregnancy, both should be started immediately upon detection of pregnancy.

NOTE:  Historically, “high dose” folic acid (> 4000 mcg) was recommended to all patients with epilepsy. There is little evidence, however, that this has benefit for most pregnant patients and there may be some associated risks. High dose folic acid may reduce the risk of neural tube defects in the setting of a personal or family history of neural tube defects. In patients of childbearing potential taking valproic acid, primidone, or carbamazepine, some clinicians consider higher doses of folic acid.

Other Vitamin Supplements

Folic acid isn’t the only supplement recommended during pregnancy. We recommend:

  • Prenatal vitamins ideally three months prior to trying for pregnancy (this will add 800-1000 mcg of folic acid).
  • Checking a patent's B12 level to ensure folic acid is not masking a B12 deficiency and supplement accordingly.
  • Measuring vitamin D levels ahead of (or even during) pregnancy and supplement accordingly.

Guíe a sus pacientes

Folic acid supplementation (and later prenatal vitamins and other supplements) is a critical step to creating the best possible environment for a developing fetus and a healthy baby. Due to the high chance of unplanned pregnancy, folic acid should be prescribed and emphasized even before pregnancy planning.

Folic acid (and prenatal vitamins) should be addressed as part of pregnancy planning discussions that include other planning steps like switching to a lower-risk ASM that set the patient up for better outcomes. 

Reviewed by: EPMC Expert Panel, March 2025