Are Keto Diets Safe for Pregnant Women?

Medically Reviewed by Traci C. Johnson, MD on April 19, 2023
3 min read

Perhaps no other diet in recent memory has stirred such passionate debate than the keto diet. Many who follow this high-fat, low-carbohydrate plan are convinced it's the solution to many health problems. Others believe it can cause considerable health risks if followed long term. People either love it or hate it — there seems to be no middle ground, and science is still trying to catch up.

Add pregnancy to the keto diet discussion, and the decision becomes even more difficult for expectant moms who want to control their weight. Keto diets can be extremely limiting, and for most pregnant women, doctors suggest a diet with a variety of foods. 

If you’re pregnant and wondering if the keto diet might be right for you, here are some things to consider for both you and your baby. 

Keto is a term commonly used for diets that are high in fats and protein and low in carbohydrates. Popular diets such as Atkins, South Beach, and Paleo often fall into the keto category. However, the actual “keto” diet focuses more specifically on the percentage of fat eaten. 

The true keto diet has been used since the 1920s for the treatment of epilepsy. It requires around 75% to 90% of daily calories come from fat, and is done for specific health reasons, often under medical supervision. In recent years, this type of keto diet has become the hottest plan for anyone looking to lose weight. 

The keto diet — in the traditional sense — is based on a function known as ketogenesis. This term refers to your body’s production of organic compounds called ketones. The cells in your body depend on glucose as an energy source. When you consume fewer carbohydrates, less glucose is available, so your body will begin to burn fat for energy. Ketones are the byproduct of burning this fat. When this happens, your body is in a state known as ketosis

When excessive ketones are produced, blood pH falls below the normal base of 7.35 and the body enters a state known as ketoacidosis. A healthy body uses insulin to keep ketone body production in balance, so ketoacidosis can be a sign of uncontrolled diabetes and may become a health emergency. 

What you eat during your pregnancy is important because your body is working overtime to maintain a healthy weight, while supplying the nutrients needed for a fetus to develop. On average, a fetus will require 340 calories daily for healthy development. The nutritional makeup of these calories is extremely important and include the following recommended nutrients:

  • Calcium
  • Iron
  • Iodine
  • Choline
  • Vitamin A
  • Vitamin D
  • Vitamin B6
  • Vitamin B12
  • Folic Acid

Following a keto diet during pregnancy poses two specific risks:

  1. Folic acid is key to brain and spine development and is found in carbohydrate-rich foods like fortified cereal, enriched bread, and beans. Removing these from an expectant mother’s diet can be dangerous.
  2. Most doctors recommend limiting saturated fats to control pregnancy weight gain. This also helps avoid complications like pregnancy-related high blood pressure.

A keto diet is low in carbohydrates and high in saturated fat, making it difficult for pregnant moms to follow these guidelines and get enough nutrients. Instead, doctors recommend a balanced diet of fruits, vegetables, grains, lean protein, and dairy products to ensure that the nutritional needs of mom and baby are met.

Although the keto diet remains popular, many questions remain unanswered about its safety. For most healthy people, a short-term keto diet is harmless, although most people regain the weight when they begin eating carbohydrates. If you have chronic health conditions — especially kidney or liver disease — the risk of making these conditions worse may not be worth the short-term weight loss.

For pregnant women, it's widely believed that restricting foods can be dangerous to both the woman and baby. A true keto diet, in which you severely limit carbohydrates, is not recommended. While there are always exceptions to the rule, women should avoid a keto diet when they're trying to conceive, pregnant, or lactating.

Check with your doctor about any significant diet changes you're considering — especially if you're pregnant or hope to be soon. They can help you make the best decision for you and your future bundle of joy.