TDS is directly related to the purity of water and the quality of water purification systems and affects everything that consumes, lives in, or uses water, whether organic or inorganic, whether for better or for worse.
Both you and your babies may be happier. Chocolate is a stress reliever. It boosts and improves a pregnant woman's mood. Researchers point out that pregnant women under a lot of stress can give birth to livelier and happier babies if they often eat chocolate. Chocolate contains essential antioxidants. Chocolates have flavonoids which contain potent antioxidants that improve immunity.
My concern would be limiting, if you eat more than one or two a day, those calories are going to pack on as fat and you'll have a hard time dropping it after birth. Also when you look at the corn syrup and other chemicals, that's just not good for anyone, pregnant or not. You can make your own donuts, it's so easy....