Q&A: Can I Use Saccharin While I'm Pregnant?
No, sorry. You should stay away from saccharin because it’s unclear whether it’s safe to consume during pregnancy. Saccharin does cross the placenta, so baby can get exposed to it, and even though it’s safe for adults, there aren’t any studies that say it won’t harm a fetus. Better skip it to be safe.
Some other sweeteners, such as aspartame (NutraSweet or Equal Classic), sucralose (Splenda) and Truvia are considered safe to consume during pregnancy, so use one of those instead — or skip the sweetener altogether.