Proteins are essential at pregnancy, and a good protein shake can be a good source of these important mineral. But protein powder is not all that safe as you think. Just like any other drink, they have their shortcomings too. And these few downsides of protein shake should not be trivialized. They can be quite effective, so be careful the next time you grab a glass.
Heavy metals in proteins
Most, if not all proteins, have some naturally occurring trace heavy metals. Veggie proteins tend to have higher heavy metal counts as do lower quality proteins. Animal based proteins tend to have much lower heavy metal counts; whey and whey isolate proteins in particular.