Is Keto Safe While Pregnant? What Are the Risks?

Pregnancy introduces a multitude of physiological changes, prompting expectant mothers to reconsider their dietary choices. The keto diet, renowned for its low-carbohydrate, high-fat composition, emerges as a subject of scrutiny while pregnant.

This comprehensive article will discuss the potential benefits and risks of doing the keto diet while pregnant based on available scientific data.

Key Takeaways:

• The keto diet is a high-fat, low-carb diet, and its safety is solely dependent on the individual, though experts suggest it poses risks.
• The keto diet may offer benefits for pregnant women, like glycemic control, epilepsy control, and healthy weight management.
• Some of the risks of doing keto during pregnancy are increased risks of birth defects, nutrient deficiencies, keto flu, ketoacidosis, and elevated OGTT results.
• There is evidence that low-carb diets can control glycemic levels among women with gestational diabetes.
• A well-balanced, flexible, low-carb approach is a safer alternative for pregnant women.

Table of Contents:

• What Is a Keto Diet?
• Is the Keto Diet Safe While Pregnant?
• Potential Benefits of Keto for Pregnant Women
• Potential Risks of the Keto Diet While Pregnant
• Can Keto Help With Gestational Diabetes?
• What if I’m Overweight While Pregnant?
• Are There Safer Alternatives to Keto During Pregnancy?

What Is a Keto Diet?

The keto diet is characterized by a meticulous macronutrient distribution, typically consisting of approximately 5-10% carbohydrates, 15-20% protein, and 70-75% fat.

This deliberate combination induces a state of ketosis, where the body shifts from utilizing carbohydrates to predominantly burning fat for energy.

Being in the state of ketosis offers multiple health benefits, including weight loss, improved metabolic, heart, and cognitive health, reduced inflammation, and managing epilepsy.

While this dietary approach has demonstrated efficacy in various contexts, its safety during the unique circumstances of pregnancy warrants careful examination.

Is the Keto Diet Safe While Pregnant?

Here’s the thing: pregnancy is delicate and very personal in the sense that each woman experiences it differently. With that said, the safety of doing the keto diet during pregnancy depends on the individual.

Personal experiences from women doing the keto diet during pregnancy yielded no negative results for both the mothers and babies, claiming that keto has stopped their severe nausea and vomiting.

Still, there is a lack of scientific data to support these claims, as most women are not advised to get into keto by their healthcare providers.

But here’s what we know so far: pregnant women are more prone to ketosis, and ketone bodies can pass through the placenta¹ and directly affect the growing child.

However, the effects of increased ketone bodies on the fetus are yet to be explored. Mice studies² conclude that keto in pregnancy results in a larger heart but a smaller brain, smaller pharynx, cervical spinal cord, and other parts of the brain.

Now, there are also human studies on low-carb diets and their effect on pregnancy,³ but they are primarily pointing to the lack of vitamins and minerals that are often found in fortified carb-rich foods.

These studies highlight the lack of folate that may increase the risk of developing neural tube defects.

Moreover, gestational diabetes is becoming more common, putting pregnant women at risk for diabetic ketoacidosis,⁴ where both glucose and ketone levels are elevated, which can be fatal.

You can best follow your doctor’s advice, as they are in charge of your and your child’s health.

Potential Benefits of Keto for Pregnant Women

Glycemic Control

For pregnant women grappling with diabetes or gestational diabetes, the ketogenic diet may offer positive effects on glycemic control.

However, here’s the slight hiccup: pregnant women should generally avoid diets that elevate ketone levels, so most studies in this category use way higher carbohydrate intake, of about 40%,⁵ and did not see any notable difference. 

Epilepsy Control

The ketogenic diet’s historical link to epilepsy management extends its influence on pregnancy.

Anecdotal evidence and some studies suggest that maintaining a ketogenic diet during pregnancy may lead to a reduction in seizure frequency for women with epilepsy.

Specifically, this study of two epileptic pregnant women on ketosis⁶ showed a reduction in seizure frequency down to once a month.

One of the mothers had normal fetal and child growth, while the other child was born with bilateral ear deformities of unknown significance but with normal neurodevelopment.

These data may be small but have a significant impact on keto’s ability to provide positive effects against epilepsy during pregnancy.

Healthy Weight Management

Weight management during pregnancy is pivotal for maternal and fetal health. The ketogenic diet encourages nutrition-rich foods that may aid in maintaining a healthy weight gain during pregnancy.

Keto has been noted to reduce cravings among non-pregnant individuals, which contributes to reduced snacking and unnecessary caloric intake.

Potential Risks of the Keto Diet While Pregnant

Birth Defects

Limited evidence, primarily derived from animal studies, raises concerns about potential birth defects associated with exposure to ketones or following a ketogenic diet during pregnancy.

While these findings are inconclusive for humans, ketone bodies can easily pass through the placenta. They could directly affect the child’s development, especially the brain, as the brain uses ketones as an energy source.

Nutrient Deficiencies

The nature of the ketogenic diet, which restricts certain food groups, raises concerns about potential nutrient deficiencies. Essential vitamins and minerals,⁷ crucial for fetal development, might be compromised due to the limited variety of foods allowed.

Some necessary supplements include folic acid, iron, calcium, vitamin D, choline, omega-3 fatty acids, B vitamins, and C.

Keto Side Effects

Pregnancy itself brings about various physiological changes,⁸ and when coupled with the ketogenic diet, specific side effects may emerge. These could include digestive issues, constipation, and fluctuations in energy levels.

Additionally, the strict dietary restrictions might exacerbate nausea or aversions experienced during pregnancy, making adherence to the diet challenging for some women.

Ketoacidosis

While ketoacidosis is a rare occurrence in the context of the ketogenic diet, it remains a serious concern, especially during pregnancy, when the body is prone to ketosis.

Ketoacidosis⁹ is characterized by elevated blood glucose levels and high ketone levels, posing potential risks to both the mother and the developing infant, especially when the mother has gestational diabetes.⁴

Effects on OGTT

The Oral Glucose Tolerance Test (OGTT),¹⁰ a standard screening test for gestational diabetes, may yield altered or false positive results for women following a ketogenic diet.

Here’s what happens when the body gets used to the keto diet: it uses fat as the primary energy source and gets used to the lack of it, and when you get introduced to it in the form of the glucose drink during the test, your blood sugar levels increase immediately.

Can Keto Help With Gestational Diabetes?

Here’s the unfortunate truth: there are not enough studies on keto and gestational diabetes, but there are some on CHO restriction and its positive effects on lowering maternal glucose levels¹¹ in women with gestational diabetes.

This is mostly due to the ability of a low-carb diet to reduce insulin sensitivity. However, the data are mostly based on low-carb diets and not specifically keto.

Nevertheless, these data suggest that with medical supervision, proper nutrition, and supplementation, pregnant women would benefit from taking low levels of carbohydrates, like in keto.

What if I’m Overweight While Pregnant?

Rapid weight loss is never a good thing during pregnancy. According to experts,¹² the best way to go is to manage your weight before planning to get pregnant to prevent any fetal side effects.

However, they suggest increasing moderate-intensity exercise as it can effectively manage glycemic levels and help one lose weight at a more regulated pace.

Are There Safer Alternatives to Keto During Pregnancy?

Choosing safer alternatives is the best way for pregnant women seeking weight loss and other benefits from the keto diet. Here are our recommendations:

Flexible Low-Carb Approaches

Opting for a flexible low-carb approach emerges as a potentially safer alternative during pregnancy. This allows for a moderate intake of carbohydrates, typically within the range of 75-150 grams per day.

Balanced Nutrient-Dense Diets

Along with the low-carb approach, embracing a well-balanced diet will help you get a more holistic approach to a healthier pregnancy.

This approach involves a diverse and well-rounded selection of foods, encompassing fruits, vegetables, lean proteins, healthy fats, and high-quality carbs, like sweet potatoes.

Frequently Asked Questions (FAQ)

References

¹Bronisz, A., Ozorowski, M., & Hagner-Derengowska, M. (2018). Pregnancy Ketonemia and Development of the Fetal Central Nervous System. International Journal of Endocrinology, 2018. https://doi.org/10.1155/2018/1242901

²Sussman, D., Wong, M. D., Adamson, S. L., & Henkelman, M. (2013). Effects of a ketogenic diet during pregnancy on embryonic growth in the mouse. BMC Pregnancy and Childbirth, 13, 109. https://doi.org/10.1186/1471-2393-13-109

³Desrosiers, T. A., Siega-Riz, A. M., Mosley, B. S., Meyer, R. E., & National Birth Defects Prevention Study (2018). Low carbohydrate diets may increase risk of neural tube defects. Birth defects research, 110(11), 901–909. https://doi.org/10.1002/bdr2.1198Desrosiers, T. A., Siega-Riz, A. M., Mosley, B. S., Meyer, R. E., & National Birth Defects Prevention Study (2018). Low carbohydrate diets may increase risk of neural tube defects. Birth defects research, 110(11), 901–909. https://doi.org/10.1002/bdr2.1198

⁴Villavicencio, C. A., Franco-Akel, A., & Belokovskaya, R. (2022). Diabetic Ketoacidosis Complicating Gestational Diabetes Mellitus. AACE Clinical Case Reports, 8(5), 221-223. https://doi.org/10.1016/j.aace.2022.07.002

⁵Moreno-Castilla, C., Hernandez, M., Bergua, M., Alvarez, M. C., Arce, M. A., Rodriguez, K., Martinez-Alonso, M., Iglesias, M., Mateu, M., Santos, M. D., Pacheco, L. R., Blasco, Y., Martin, E., Balsells, N., Aranda, N., & Mauricio, D. (2013). Low-carbohydrate diet for the treatment of gestational diabetes mellitus: a randomized controlled trial. Diabetes care, 36(8), 2233–2238. https://doi.org/10.2337/dc12-2714

⁶van der Louw, E. J., Williams, T. J., Henry-Barron, B. J., Olieman, J. F., Duvekot, J. J., Vermeulen, M. J., Bannink, N., Williams, M., Neuteboom, R. F., Kossoff, E. H., Catsman-Berrevoets, C. E., & Cervenka, M. C. (2017). Ketogenic diet therapy for epilepsy during pregnancy: A case series. Seizure, 45, 198–201. https://doi.org/10.1016/j.seizure.2016.12.019

⁷Jouanne, M., Oddoux, S., Noël, A., & Voisin-Chiret, A. S. (2021). Nutrient Requirements during Pregnancy and Lactation. Nutrients, 13(2). https://doi.org/10.3390/nu13020692

⁸Kepley JM, Bates K, Mohiuddin SS. Physiology, Maternal Changes. [Updated 2023 Mar 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539766/

⁹Ghimire P, Dhamoon AS. Ketoacidosis. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534848/

¹⁰Eyth E, Basit H, Swift CJ. Glucose Tolerance Test. [Updated 2023 Apr 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532915/

¹¹Farabi, S. S., & Hernandez, T. L. (2019). Low-Carbohydrate Diets for Gestational Diabetes. Nutrients, 11(8). https://doi.org/10.3390/nu11081737

¹²Fitzsimons, K. J., Modder, J., & Greer, I. A. (2009). Obesity in pregnancy: Risks and management. Obstetric Medicine, 2(2), 52-62. https://doi.org/10.1258/om.2009.090009