Apr 19, 2023 • 6 min read

Is the Keto Diet Safe While Pregnant?

Medically Reviewed by Kim Langdon, MD on 4.19.23
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The basis of the ketogenic diet—most commonly referred to as keto—is low carbohydrate intake with moderate protein intake and very high fat intake.

This diet puts your body into a state of ketosis which means it burns fat instead of glucose. It can cause rapid weight loss, reduce inflammation, and stabilize blood sugar levels which helps manage conditions like diabetes.

But is the keto diet safe during pregnancy? The short answer is no, the keto diet is generally not considered safe during pregnancy.

Pregnant women are naturally prone to ketosis, so an increase in ketones is okay. But when you stress your body more with a keto diet, the potential for adverse health consequences increases.

This guide goes over the risks of doing the keto diet during pregnancy and provides healthy alternatives. We’ll talk about whether there are any special circumstances that would make a keto diet acceptable during pregnancy and share how a prenatal nutritionist can help you make informed decisions about these issues.

Is the keto diet safe during pregnancy?

The keto diet is high in fat and low in carbohydrates, while protein is eaten in moderation. Because carbs are the cell’s main source of energy and because these are absent in a keto diet, they burn fat instead.

Ketone bodies are produced by the liver and then used by the rest of the cells of the body for fuel. The brain and other nerve cells prefer carbohydrates but will survive on ketone bodies if needed.

Many people have had success with this diet in the short term for both weight loss and management of chronic illnesses, but the long-term health implications are not clear. And while the keto diet has not been studied in humans, related research has made it clear that the diet would be harmful during pregnancy.

For example, researchers looked at ketosis in the pregnancy of small animals. Those that consumed a keto diet were found to have offspring with higher rates of failure of all or some organs to develop properly. Researchers indicated that the likelihood of future behavioral problems in human babies would be high if this was a human pregnancy.

Another study looked at the effects of having higher-than-normal ketone bodies by evaluating levels in the urine of pregnant women. The women who had higher ketone body levels had children with higher rates of neural tube defects. Neural tube defects are very severe and include spina bifida with paralysis and anencephaly (failure of brain development).

Still, other research studies showed that higher ketone body levels in women were linked to lower IQ scores in their infants. While these women had diabetes and other issues, experiencing ketosis during pregnancy seemed to be an independent risk factor for low IQ in babies and children.

This research combined with the known risks listed below makes it clear that the keto diet is not safe to do during pregnancy.

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Healthy mom, healthy baby: Get support from a prenatal dietitian

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Risks of the keto diet during pregnancy

The risks of keto dieting are felt to be greater than the benefits for most individuals—even those who are not pregnant. Some of the risks of attempting a keto diet while pregnant are:

  • Low folic acid intake. Folic acid is essential to the health of your baby’s nervous system. Without folic acid—even in the months prior to conceiving—your baby risks having a neural tube defect. These defects (anencephaly and spina bifida) can cause death and permanent disabilities.
  • Limited glucose intake. Glucose is your body’s main fuel. The only source of glucose is the carbohydrates you consume in your diet.
  • Excess fat intake. Fat offers very little in the way of nutrients. Too much fat in your diet will not necessarily mean that you’ll gain weight during your pregnancy, but fat is twice as energy-dense as protein and carbohydrates, making excess weight gain possible.
  • Low fiber intake. Fatty foods are rarely high in fiber. Fiber reduces the risk of constipation. While on a keto diet, you will rarely get the chance to eat the fiber you need for optimal GI health.
  • Nutrient deficiencies. Most of the nutrients you need for optimal health and your baby’s development come from carbohydrate-containing foods and proteins. Vitamin C, many B vitamins, magnesium, and many phytonutrients are only found in foods that have carbohydrates in them. When you don’t get those nutrients, your chances of passing a vitamin or mineral deficiency on to your baby are greater. Lack of nutrients means your baby may not develop properly before birth.
  • Risk of hypoglycemia. Most people won’t develop hypoglycemia (low blood sugar) on a low-carb diet; however, if you have prediabetes or type 2 diabetes, your insulin levels are automatically higher than most people. You risk low blood sugar when you don’t take in enough carbohydrate-containing food. Those with adrenal insufficiency may also suffer from low blood sugar.

Healthy alternatives to a keto diet during pregnancy

The ideal pregnancy diet is a balanced one. You need nutrients for your overall wellness and for the proper growth and development of your baby. One idea from the keto diet, however, that can benefit pregnancy is keeping blood sugar levels stable.

“Try to make your meals low-glycemic and balanced,” says Carlyn Rosenblum MS, RD, one of Zaya Care’s pregnancy nutritionists. “A low glycemic meal will be digested and absorbed more slowly resulting in stable blood sugar. It also supports healthy weight gain and emphasizes nutrient-dense whole foods such as fruits, vegetables, lean proteins, and healthy fats. These provide essential nutrients that support fetal growth and development.”

Rosenblum suggests the following tips to support stable blood sugar during pregnancy:

  • Include protein-rich foods at meals and snacks.
  • Make at least 1/3 of your plate non-starchy vegetables like leafy greens, broccoli, cauliflower, zucchini, eggplant, mushrooms, onion, and peppers.
  • Include healthy fats at all meals and snacks such as olive oil, avocado, nuts, and seeds.
  • Don’t eat “naked carb meals,” meaning just a slice of toast or a bag of tortilla chips. Always pair carbs with a fat, fiber, or protein source.

In terms of the best foods to eat during pregnancy, you should consume a balanced menu with foods of all kinds:

  • Fruits. These contain vitamin C, fiber, and many phytonutrients for your immunity and cellular health.
  • Vegetables. These also contain many vitamins, including vitamins A, C, and E, as well as folate and iron. The colorful substances in veggies are great antioxidants for cellular health.
  • Whole grains. These are rich in B vitamins, folate, and fiber. Most grains are high in complex carbs for all-day energy and stamina.
  • Lean meats. These have the amino acids needed for your baby’s development as well as vitamin B, iron, and other minerals for optimal health.
  • Healthy fats. Instead of excess fat, much of which is saturated or trans fats, healthy fats found in fish, nuts, seeds, coconuts, and avocados are best for you during pregnancy.

>> Learn more: How much protein do you need in pregnancy?

Can the keto diet help with gestational diabetes?

Some individuals with type 2 diabetes turn to the keto diet to lower insulin levels and reduce weight. Sudden or accelerated weight loss is sometimes necessary to gain control over diabetes. However, losing weight during pregnancy is not considered safe and could have severe consequences for you and your baby.

There is also no evidence that those with gestational diabetes benefit from consuming a keto diet and plenty of reasons to question its safety, particularly for your baby. The lack of nutrients alone is a good reason to avoid this diet.

>> Learn more: Gestational diabetes signs & symptoms

What if I’m overweight while pregnant?

As mentioned, losing weight during pregnancy is generally not considered safe for your baby. Instead, eat a balanced diet that provides enough nutrients for your baby’s health.

If you are overweight when you get pregnant, you will want to learn how many calories to eat and how much weight gain is right for your specific body weight.

This alone will help you avoid gaining more weight than necessary and may lead to weighing less after delivery than you were at the time of conception.

How a prenatal nutritionist can help with your pregnancy diet

You’re not alone if you feel overwhelmed by what to eat for a healthy pregnancy. To resolve some of your concerns, you may wish to see a prenatal nutritionist for advice and guidance on how you should maintain a healthy diet throughout pregnancy.

Prenatal nutritionists have years of training in advanced nutrition practices with an emphasis on prenatal and postpartum nutrition. They know what it takes to have a healthy diet during pregnancy and how to manage the most complex pregnancy-related nutritional issues.

If you’re already on a keto diet or were following this plan before conception, a prenatal nutritionist can guide you through the transition to eating for your baby’s health by making nutritious food choices. There are also keto dietitians and nutritionists that may also be worth consulting with for advice.

If you’re interested in finding the ideal diet for your pregnancy, we can help you find a prenatal nutritionist that accepts your insurance here at Zaya Care. Simply browse through our network of licensed providers, find one that fits your needs, and book completely online!

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Healthy mom, healthy baby: Get support from a prenatal dietitian

90% of Zaya Care patients pay $0 for one-on-one counseling with a Registered Dietitan

Christine Traxler MD is a family physician, lifelong writer, and author with a special interest in mental health, women’s healthcare, and the physical after-effects of psychological trauma. As a contributing writer and editor for numerous organizations, she brings a holistic focus to her work that emphasizes healing and wellness through daily self-care, connecting with others, and setting stepwise goals toward achieving more balanced and authentic lives.