You will see it all over the web that ketosis is dangerous for the fetus, but you won't find evidence. I see three classes of the so-called evidence. There is evidence that if you have diabetic ketoacidosis it is not good for the fetus, but we know that you can't compare benign dietary ketosis to diabetic ketoacidosis. There is animal evidence that if you starve pregnant rats, which also produces ketosis, it is not good for the fetuses. The flaw in that reasoning should be obvious. Finally, there is one experiment where they sliced up the brains of rat fetuses and soaked them in ketones, and the brain cells survived but the slices stopped producing new brain cells. This is supposed to be evidence of ketosis causing retardation.

On the other hand, a fetal metabolism text will tell you that fetuses are naturally using ketones themselves before and immediately after birth. This study shows that a pregnant pigs who are put on a ketogenic diet have fetuses with "increased fetal brain weight, protein content, and cell size." This text book article says "During early pregnancy there is an increase in body fat accumulation, associated with both hyperphagia and increased lipogenesis. During late pregnancy there is an accelerated breakdown of fat depots, which plays a key role in fetal development. Besides using placental transferred fatty acids, the fetus benefits from two other products: glycerol and ketone bodies. Although glycerol crosses the placenta in small proportions, it is a preferential substrate for maternal gluconeogenesis, and maternal glucose is quantitatively the main substrate crossing the placenta. Enhanced ketogenesis under fasting conditions and the easy transfer of ketones to the fetus allow maternal ketone bodies to reach the fetus, where they can be used as fuels for oxidative metabolism as well as lipogenic substrates..." In this study they inject pregnant rats with ketones and show that the fetuses readily use them for fuel. Similar here with sheep. In this one they took embryos and soaked them in ketones which either had no effect or caused them to grow.

Emily Deans also wrote something relevant and telling recently

Let me put it this way. Breastmilk is high in fat. Newborns (should) spend a lot of time in ketosis, and are therefore ketoadapted. Being ketoadapted means that babies can more easily turn ketone bodies into acetyl-coA and into myelin. Ketosis helps babies construct and grow their brains. (Update - looked more into this specifically and it seems that babies are in mild ketosis, but very young babies seem to utilize lactate as a fuel in lieu of glucose also - some of these were rat studies, though - and the utilization of lactate also promotes the same use of acetyl-CoA and gives the neonates some of the advantages of ketoadaptation without being in heavy ketosis.)

Couple those with the fact that some cultures like the Inuit ate an all meat diet, and that we probably evolved on it, I am not concerned about it.

This is n=1 so take it with the requisite grain of salt. My wife was diagnosed with gestational diabetes during her first pregnancy. To avoid drugs, she controlled her blood sugars through diet. In fact this was when, thanks to my parents, we discovered the Paleo diet. For the rest of her pregnancy, her doctor gave her grief over the ketone level in her urine and she managed a net weight loss after delivery. Our daughter, now two years old, is very healthy, somewhat advanced for her age, and loves bacon.

I contrast our case with a friend who had a similar pregnancy but didn't heed my dietary advice. She ended up being induced for fear of pre-eclampsia, which led to a c-section.

This is anecdotal of course, but in my opinion it's completely safe.

I have an n=1 story as well. I gave birth to my fourth child almost 4 weeks ago. I've always tended to loss weight (or not gain much) with every pregnancy. This time I stayed on a primal diet and was in ketosis for most of my pregnancy. I have a much easier pregnancy, hardly any swelling and a fast and easy birth. My midwife didn't like the ketosis, but she did like the fact I'm eating much better and am 70 pounds lighter than my 3rd pregnancy 3 years ago. My blood pressure was also better. I looked but never found anything that would make me feel like it was dangerous to be in ketosis during pregnancy. I didn't restrict calories (obviously) and currently I'm over 20 pounds lighter when I got pregnant. I don't know why the hormones work that way for me, but I joke with my husband that a couple more kids and I'll be at my ideal weight.

I'm currently 18 weeks pregnant and have been eating paleo the whole time. Although I had lost a significant amount of weight before becoming pregnant I have continued to lose weight. Now, my weight loss hasn't been nearly as rapid, and I did include more carbs (fruits, and I included a few potatoes into my diet, mostly to get me through the first trimester) but I feel great and have had an easy pregnancy so far :o)

My first prenatal appt. I let my OBGYN know how I have changed my eating habits (this will be my 3rd baby, and I saw her for the first 2). She asked me to describe the paleo diet, so I did in a nutshell, She said that it sounded great and that's how everyone should eat (YAY) she said that even though I'm not getting carbs from breads I'll get them from fruits so she was cool with that. She told me that as long as I'm not cutting calories and skipping meals to try to lose weight then she has no problems with it.

Good luck and Congratulations on your pregnancy!

It was before I learned about paleo or WAPF but I started my pregnancy 70 pounds overweight too and so I was very fearful of getting gestational diabetes so I ate pretty low carb. I ate some potatoes once a week or so and ate plenty of fruit but I stayed mostly under about 150 carbs a day. I only gained 15 pounds and had a very healthy 9 pound boy who could lift his head up in the first hour of life, plenty of breastmilk, and my son is 6 months old and has never been sick. I started paleo about 3-4 months ago and was WAPF the last month of my pregnancy and the first 2 months post partum.

I don't know if I would stay in full on Ketosis but I think it's important to keep the carbs low while pregnant and concentrate on nutrient dense foods. Lots of Grassfed beef, liver, whole fat yogurt, butter, kefir, dark leafy greens like kale, etc. I don't think it's bad to be in Ketosis.. You're probably in Ketosis at night anyway because you burn so many calories while pregnant but I think the focus should be on whole nutrient dense foods, not macronutrients.

Oh... Eat lots of salmon eggs. They are inexpensive at Russian/European markets and full of highly absorbable vitamin D

If I recall correctly, during your pregnancy you'll gain about 40% more blood volume plus the weight of the baby, placenta, amniotic fluid, etc. plus fat stores to help with lactation. That weighs a bunch. You should not be losing weight during pregnancy.

That does not mean you should start eating poorly, though.

(We were trained many years ago in teaching the Bradley Method.)

Robb Wolf addressed the issue of ketosis (and gestational diabetes) in this post: link text

This story is amazing - http://hawaiianlibertarian.blogspot.com/2011/05/paleo-baby.html

He put his wife on a paleo diet during her pregnancy. She gained baby and lost fat and had a very healthy pregnancy and a very healthy paleo baby!

Probably shouldn't try to lose weight during pregnancy, but I'm sure your current diet is far healthier for the fetus than the SAD. I suspect that a lot of the ADD, ADHD, autism etc. is the result of various preservatives and other synthetics that mothers consume while pregnant and during early development during breastfeeding. That's just my gut feeling though. You could always keep your weight roughly stable during the next 8-9 months and then drop all the weight afterward. Now that I think of it, it'd probably be hard to maintain an excess amount of fat on our biologically correct diet, pregnant or not. In any case, good luck.

I'm 20 weeks pregnant and haven't gained a thing, even eating starch at every meal, 3 meals a day, and often half a piece of fruit for dessert. I would love to be 30 pounds lighter, but 10-15 pounds lighter would be within a "normal, healthy" BMI, FWIW. I do expect to start gaining weight soon with the way my belly is currently filling out. I don't know if I'm in ketosis because my midwives don't check that, but I'm sure I'm not heavily into it with all the starch I'm eating. I personally think that with a reasonable amount of starch, your body will still do the right thing for itself, and everything I read about paleo said to go easy on the ketosis during pregnancy, because the effect are not known. I don't remember where I read this, but it was a paleo blog: there was an experiment on dogs' diets during gestation, and the dogs in ketosis had pups that did more poorly. I figure that I'm not out to prove anything with my diet, and a bit of starch is obviously fine for my pregnancy.

I'd have some regular kidney function tests done. When I go into ketosis, I tend to get backaches, which turned out to be strain on my kidneys. During pregnancy, that could make you more prone to toxemia or other problems with unwanted things building up in your blood.

Michael eades "The medical literature (at least with animal studies; no one could ethically do such studies with humans) is pretty clear that ketogenic diets are NOT good for the developing fetus.

I’m not an expert on this issue as it applies to developing fetuses, so I check with my friend Larry McCleary who is a pediatric neurosurgeon, low-carb advocate, and well read in the nutritional fetal development literature. He says that in the fetal brain most of the lipid synthesis is from glucose and to a smaller degree, lactate. Beta hydroxybutyrate (a ketone) is not a major contributor. In addition, the enzymes in the pathway from BHB to acetyl CoA in the fetal brain are poorly developed. Post natally they activate. Hence, BHB is not a major provider for ATP generation in the fetal brain.

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I know that pregnancy is associated with strong cravings. It may be particularly difficult to maintain ketosis or keep carb intake low.

I have to maintain ketosis for medical reasons, and I found that a daily meal of ground beef + eggs in a ratio of 250 g beef to 1 egg kills cravings quite effectively.

Here's the link: http://www.blog.sethroberts.net/2011/02/20/meat-only-diet-crave-carbs-meat-egg-no-craving/

I, too, am a pregnant paleo. This is my third pregnancy, my first with this lifestyle. It should be noted that most/many women in their first trimester eat very, very little. With my first pregnancy I lost ten pounds in my first trimester. Right now, I take a children's multivitamin in order to ensure my folic acid levels stay high. Neural tube defects are a real risk to any pregnant woman with low folate, regardless of lifestyle. I also take a calcium supplement as I am totally dairy free and in my mid 30's. I take a magnesium supplement as well. I struggle with insomnia during my first trimesters and it also seems to really, really help with heartburn. All my supplements are plant based and organic.

So what's my point. Cover your bases. This is a very short time in your life, as a woman, as a mother. The worst case scenario is you'll gain some weight during your pregnancy. Assuming you are not at risk for gestational diabetes, there are worse things that can happen than packing on a little baby weight. We all know how to take it back off when these forty weeks are over. Listen to your body. Eat bananas. Eat sweet potatoes. Drink juice. There's no need to go out and eat a pizza but giving yourself some extra, clean carbs is not the end of the world and, on some days, they may be all you want.

The bottom line is this is a very short time in your life. Don't put vanity before safety. Eating a piece of fruit never caused anyone to get gestational diabetes. I promise.