Is that condition genetic? If it isn't then it shouldn't effect the baby negatively at all.
Hydrocephaly can arise from an inherited genetic deformity as a congenital condition. Acquired hydrocephaly happens sometime during birth or a point afterward.
No, teacup puppies are usually more work than a regular dog since they are very often unhealthy and more fragile than a "regular" dog. Some of the problems that may be encountered are both genetic and congenital in these tiny dogs and the list is a long one; The risk of open fontanels (soft spot from the cranial bone not forming), portosystemic shunts (PSS- abnormal vessel that allows blood to bypass the liver. As a result the blood is not cleansed by one of the bodies filters: the liver.), hypoglycemia, cardiac problems, collapsing trachea, luxating patellas, Leggs Calves Perthes disease, seizures, hydroencephaly, blindness and digestive problems can be increased in these teacup dogs.