Ketosis During Pregnancy: Is It Safe? - Perfect Keto

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Ketosis During Pregnancy


Ketosis is a safe state of metabolism for most adults and has many health benefits. However, those who are pregnant or looking to get pregnant might be wondering if the ketogenic diet and ketosis can fit into this cycle of life, too.


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Whether ketosis is safe and beneficial to pregnant women is a very important thought to ponder. In this article, we’ll cover in more details this important question, so you can make informed decisions when considering ketosis during pregnancy.

Pregnancy and Ketones

When a woman is pregnant, the body goes through a lot of changes. Even when a couple is trying to conceive, they’re likely more aware of the choices they make about food. Let’s look at how ketosis fits into the life of a woman trying to get pregnant and through pregnancy.

Getting Pregnant in Ketosis

Ketosis may actually be helpful for getting pregnant. For example, it’s been recommended for women with polycystic ovarian syndrome (PCOS) who have struggled with getting pregnant (a common symptom of PCOS). In a pilot study on PCOS, two of the women in the study became pregnant even though they had previously dealt with infertility [1].

In addition, just as a well-planned ketogenic diet is safe for the average person, it’s also safe for women who are trying to get pregnant, especially if she was eating high-carb or Standard American Diet foods before switching to low-carb ketogenic and improving her health.

So with that, the next question becomes, “is it safe to continue ketosis throughout the pregnancy?” While ketosis can be helpful for getting pregnant, the rules are a little different during pregnancy.

Safety of Ketosis During Pregnancy

Before we get into ketosis during pregnancy, let’s examine some of the common beliefs about ketosis during this time of life—because there’s a lot of misguided information out there.

Misconceptions about Ketosis During Pregnancy

When anyone talks about ketosis being unsafe in pregnancy, they’re likely referencing studies on diabetic ketoacidosis (DKA), which actually is very harmful and entirely different than nutritional ketosis.

Let’s look at the differences:

  • DKA is a very dangerous metabolic state seen in people with diabetes where insulin or diet isn’t properly managed. DKA includes levels of ketones that are unnaturally high and blood sugar levels three or more times higher than the norm. This creates a dangerous acid-base balance in the body. Ketoacidosis should be avoided by all pregnant women (and anyone in general).
  • Nutritional ketosis is a natural metabolic state in which the body is primarily using fat for energy instead of carbohydrates. It includes very low ketone levels and blood sugar that is normal, as well as a healthy acid-base balance in the body.

When there’s confusion about the difference, it can cause professionals to assume nutritional ketosis has the same effect as DKA, especially since studies have suggested DKA is harmful to brain development of the fetus [2]. This has led to a widely accepted belief that ketosis during pregnancy is harmful to the baby; however, this is misinformation.

Let’s look at some of the facts.

Natural Instances of Ketosis in Pregnant Women

Most pregnant women suffer from morning sickness, at least in the beginning of their pregnancy. Between that, nausea, low appetite and food aversions, it’s not uncommon for eating to be sporadic and often in low amounts, at least during the early stages of pregnancy. This will naturally occur taking pregnant women temporarily in and out of ketosis.

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We should note here that ketosis is a natural part of being human. For example, between the time we eat dinner and wake up to have our first meal, the body is in a fasting state (think about it: our traditional first meal of the day is literally called breakfast). This is true for everyone including pregnant women.

Additionally, the state of pregnancy may even favor ketosis. That’s because the blood ketone levels in healthy pregnant women after a fast overnight are around three times higher than that of women who aren’t pregnant [3].

Ketosis in Late Stage Pregnancies

It appears ketosis happens naturally quite often in women who are pregnant, especially in the late stage pregnancies. The fetus uses ketones before and immediately after birth to make essential fats in the brain during growth [5]. In fact, researchers believe fetuses might even make their own ketones. This could be the reason ketosis is more common in pregnant women during the third trimester.


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During the late stage of pregnancy, a woman’s metabolism also switches to a catabolic state (the breaking down of molecules). This means ketosis is happening more often [2]. Note the frequent occurrence of food aversions and nausea experienced by many pregnant women. This alone will naturally reduce the frequency and amount of food intake, which more easily puts you into ketosis.

Low-Carb and Pregnancy

As registered dietitian Lily Nichols says in this article, it seems safe for women to eat lower carb during pregnancy as long as they are still eating certain foods for proper nutrition.

Fetuses require both glucose and ketones to grow, so a balance is key. What’s important is to ensure the mother has normal blood sugar levels and is getting enough calories.


Although ketosis is natural and safe if done effectively, big changes happen in a woman’s body and extra precautions must be taken during this cycle of life. Here are some things to keep in mind for those who are pregnant, whether in ketosis or not:

Don’t aim for weight loss. We know the ketogenic diet is effective for weight loss, but for most pregnant women, pregnancy is not the time to pursue it. No matter what way of eating is being followed, getting enough calories and proper nutrition is most important.

Eat whole foods. Speaking of nutrition, it’s especially vital when you’re growing a baby. That being said, there are some foods with carbohydrates that are important for pregnant women to include in their diets: vegetables and fruits, nuts and seeds, legumes, and sometimes dairy.

Avoid refined grains, added sugars, and processed foods. The quality of carbohydrates is important to ensure the diet is nutrient-dense and both mom and baby are getting the good stuff they need to thrive.

Don’t do intermittent fasting. While intermittent fasting has a variety of benefits for the average person, it’s not appropriate during pregnancy when it’s most important to listen to your own hunger cues and ensure mother and baby are getting enough nutrients for growth.

Take Away Message

While extra considerations definitely must be taken regarding diet during pregnancy, don’t let fear mongering convince you that a healthy ketogenic diet is damaging—especially compared to the standard diet most people are eating.


[1] Mavropoulos, John C et al. “The Effects of a Low-Carbohydrate, Ketogenic Diet on the Polycystic Ovary Syndrome: A Pilot Study.” Nutrition & Metabolism

[2] (2005): 35. PMC. Web. [2] Rizzo, Thomas A., Sharon L. Dooley, Boyd E. Metzger, Nam H. Cho, Edward S. Ogata, and Bernard L. Silverman. “Prenatal and Perinatal Influences on Long-term Psychomotor Development in Offspring of Diabetic Mothers.” American Journal of Obstetrics and Gynecology 173.6 (1995): 1753-758. Web.

[3] Felig, P., and V. Lynch. “Starvation in Human Pregnancy: Hypoglycemia, Hypoinsulinemia, and Hyperketonemia.” Science 170.3961 (1970): 990-92. Web.

[4] Herrera, E. “Metabolic Adaptations in Pregnancy and Their Implications for the Availability of Substrates to the Fetus.” European Journal of Clinical Nutrition 54 (2000): n. pag. Web.

[5] Coetzee, E. J., W. P. U. Jackson, and P. A. Berman. “Ketonuria in Pregnancy–With Special Reference to Calorie-restricted Food Intake in Obese Diabetics.” Diabetes 29.3 (1980): 177-81. Web.


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11 thoughts on “Ketosis During Pregnancy

  1. Hi, I am 5 weeks pregnant with my eleventh child. I am also nursing my 8 month old who doesn’t eat a lot of table foods yet. I have been on the keto diet for close to 2 weeks, and am liking it a lot. My favorite foods are dairy, meat, and veggies (in that order), and so this is a very easy diet for me to follow. But today, I started feeling extremely dizzy and have had something similar to hot flashes. I have been trying to keep my fat grams to around 90, carbs around 25-35 grams, and protein at 70 or so grams. I don’t always meet those numbers (I am probably lacking in all of them). I also drink about a gallon of water/herbal tea per day. I would like to continue this diet while pregnant, and know I need to change my numbers, but since I am new to this, what would that look like? I don’t want to up my healthy carbs too much while eating such high levels of fat, etc. I am also 35, 5’8″, and about 165 pounds. Any information would be awesome! Thank you!

    1. It looks to me that you are experiencing some symptoms of keto flue, it should go away after couple of days, as you are will get more keto adapted. It takes about 1 to 2 weeks, sometimes longer to get into ketosis for people who were eating standard high carb diet. It took me 4 days to get into ketosis but I was already eating low carb paleo diet and did every day 16-18 hour fasts, I experienced a bit of dizziness and cold flashes at night, when I would get up at night shaking from cold when outside were +30: it lasted about 3-4 days then everything went normal. But be cautious you are pregnant and breastfeeding make sure you get enough calories. I was only breastfeeding when I went keto. Another thing don’t drink too much water, only drink when you are thirsty, you loose valuable and much needed electrolytes when you unnecessarily drink too much. It’s a myth that we need to drink 2 litre of water each day-simply not true. Also make sure you increase your good quality salt consumption, it will ease your keto flue symptoms.

    1. Hi Sue, we don’t have any articles on breastfeeding and ketosis/IF at the moment, but thank you for this as this is a topic we will submit to our writers.

  2. Where is the 5th citation? I’d like to read that article and I don’t actually see it in the citations. Thanks!

    1. Hi Angela, the citation is in the Sources list:
      [5] Coetzee, E. J., W. P. U. Jackson, and P. A. Berman. “Ketonuria in Pregnancy–With Special Reference to Calorie-restricted Food Intake in Obese Diabetics.” Diabetes 29.3 (1980): 177-81. Web.

  3. Just found out I was pregnant with 3 home test and have been keto but fasting? Will that do any harm to the baby??

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