If you take Ritalin or Concerta for attention-deficit/hyperactivity disorder (ADHD) and you plan to become pregnant, you might want to talk to your doctor about switching your medication first. A new study found a small increased risk of having a baby with a heart defect if Ritalin/Concerta (methylphenidate) was taken by the mother-to-be. However, taking amphetamines for ADHD did not carry the same risk, researchers said.