Maternal use of a drug called phenothiazine has not been proven to cause problems in offspring. Animal studies show there is a risk but no definitive studies have been done on humans. Phenothiazine is used to treat mental and emotional disorders such as schizophrenia. The biggest risks are likely to occur during the first trimester (malformations) and towards the end of the pregnancy (poor muscle tone, poor reflexes and jaundice). See also Phenothiazine antenatal infection