A lot of people choose to be vegan. It's certainly a commitment, since vegans refrain from eating all animal products — not just meat, but also eggs, dairy products and other animal-derived foods and ingredients. And some of those people are also individuals who can, and sometimes do, get pregnant. If they do, they have to make a choice — continue their dietary restrictions through the pregnancy, or make some adjustments because of it? Unfortunately, studies about being vegan while pregnant show some pretty mixed results, so every person has to decide for themselves — with the help of a doctor, of course.
In 2015, Tania Lombrozo wrote a piece for NPR about the safety of vegan diets during pregnancy, and recounted her own experience of being both a vegan and a pregnant person at the same time (because, of course, women and other people who can get pregnant are diverse and contain multitudes, and don't cease being the other important aspects of their personalities when they also decide to follow through with a pregnancy).
Lombrozo cited an analysis of 22 studies used in a systematic review of literature on the topic, published in BJOG: An International Journal of Obstetrics and Gynaecology, the journal of the Royal College of Obstetricians and Gynaecologists. The conclusion? There just haven't been enough studies done on veganism and pregnancy to really come up with an informed conclusion.
That NPR piece reported that there was a lot of variability in both the studies in question and their results. For example, five of the studies found that vegan/vegetarian mothers had babies with lower birth weight — but just one of them reported that the difference was at all "statistically significant." Alternatively, two studies found that vegan/vegetarian mothers had babies with higher birth weights, and one of those reported a statistical significance.
For what it's worth, Lombrozo spoke to her doctor about the issue of being on a vegan diet during pregnancy, explained the answer in her column:
My (Berkeley) OB-GYN didn't bat an eye, and the nutrition and pregnancy books I'd read supported common sense: Having a nutritious diet matters (whether or not you're pregnant), but that can come in many forms.
The New York Times also recently reported on whether you can have a healthy vegetarian or vegan pregnancy, and referred to the aforementioned review involving 22 studies. The publication spoke to several doctors and other nutrition experts about the topic, and one of them, Susan Levin, the director of nutrition education for the Physicians Committee for Responsible Medicine, an advocacy organization, specifically noted:
Maternal diets high in plant foods may reduce risk of complications, including gestational diabetes.
So refraining from eating meat during gestation may actually be a good thing. According to The New York Times, a vegetarian diet in the first trimester of a pregnancy was linked to a lower chance of "excessive gestational weight gain," according to a 2010 study.
But there are, as mentioned in the BJOG review, other studies that show adverse effects of a vegan or vegetarian diet during pregnancy. According to an article in The Telegraph in 2009, for instance, research for a study conducted in Ireland found that women with low levels of B12 — which is found in meat, eggs and milk — when they conceived were at a higher risk of having a child with "neural tube defects." Yikes. The study was published in the journal Paediatrics, according to the outlet, so it seems pretty legit. But that's just one, very limited study.
So, what are we supposed to believe?
The truth is, there just isn't enough information on being vegan during pregnancy to conclusively determine whether or not it is safe. The BJOG review found that the evidence regarding vegan or vegetarian diets in pregnancy is "heterogeneous and scant."
The journal cited a lack of randomized studies as part of the reason it's hard to determine the effects of the diet on pregnancy and resulting children. But it did tentatively conclude that "vegan–vegetarian diets may be considered safe in pregnancy, provided that attention is paid to vitamin and trace element requirements."
The absolute best thing you can do if you are looking to proceed with a pregnancy while also pursuing a vegan lifestyle is talk to your doctor. Really, for anything involving your health and well-being during a pregnancy, you should talk to your doctor.
Don't just rely on the encyclopedia of Google for your information on being vegan while pregnant — trust your medical provider with your concerns, the same as you would with anything else. You'll thank yourself for it later.