Ich medicine is essentially poison. The theory behind it is that it is worse for the ich than the fish. I can't imagine any type of poison being harmless to a pregnant animal, but any results would hardly be noticable I'm guessing. Fish are so overly inbred as it is for their colors, shapes, and sizes that you are not likely to see anything out of the ordinary that breeding a line for many generations would not come about anyway. I wouldn't worry about it too much. If you do feel like you're seeing more deformations than normal, using a heat method to treat ich might be in order for the next time. Temperatures at 87F and up will kill ich. Leave the heat there for two weeks after the last signs of ich disappear.