I suggest that you discontinue your use of saccharine while you are pregnant. You could try eating your cereal without added sugar and perhaps use some regular sugar in your tea. Saccharin has been deemed safe for the general public, however it is not metabolized and passes through the digestive tract unchanged.

Saccharine can cross the placenta barrier into fetal blood, and a fetus is much slower to clear the saccharine from its blood than the mom. So if you are consuming large amounts of saccharin, it may accumulate in the baby's bladder and potentially increase its risk for bladder problems or possibly even bladder cancer. Data is not conclusive, but some studies on saccharin suggest that a person is most vulnerable to development of saccharin-associated bladder cancer when they are exposed to high saccharin intakes in utero and throughout the rest of their life. Although there is not yet enough evidence to show that it is harmful to your unborn baby, it is probably not worth the potential risk.

Because of the still unsettled safety record of saccharin and unborn babies, both the American Dietetic Association and the American Diabetes Association recommend saccharin be used in moderation during pregnancy. I suggest that if you can control your calorie intake without the use of saccharine it would be the safest course of action.