When can i start eating steak tartare and sushi after my pregnancy? must i wait till no longer breastfeeding?

You're okay: Eating steak tartare, of course, is asking to get toxoplasmosis, which is usually mild but can affect your unborn child. Once junior is born, do what you want. Some people love the stuff.

Finish nursing first: Depending of the type and source of sushi, one must consider that mercury exposure is a risk. Consiidering that mercury and other heavy metals easily pass into the blood. Breast milk, by extension, will contain the heavy metals. So, if it's in your food, it gets to the unborn.