have bipolar affective disorder and am concerned that my baby may develop this also. What is the risk of my baby having bipolar depression?
This is a great question but difficult to answer. Bipolar affective disorder (BPAD) is a complex condition, and inheritance may not be straightforward. While in some cases bipolar affective disorder runs through a family in a clear pattern, it often does not.
Overall, if a parent has BPAD, the chance of a child getting it is about 12 to 15 percent. The chances are greater if it has been diagnosed in multiple family members or if many relatives have mental illness/addiction problems. Remember, though that bipolar can vary tremendously in how it affects a person and that environment plays a role. While some people struggle starting in late childhood, others don't get diagnosed until they are in their 50s or even (like my aunt) in their 70s.
The best thing you can do as a mom is to be as emotionally healthy as you can. This includes taking your mood-stabilizing medications, and remaining attentive to signs of mood issues in yourself and your children over time. As you know, bipolar is treatable, and your children will have the advantage that their mother knows what to watch for and can get help early if the need arises.
Your psychiatrist should be consulted to help you make decisions about how ready you are to take on the responsibilities and stresses of parenting, and can help you adjust your medications for the best pregnancy outcome. Your OB doctor or midwife should also be able to refer you to a genetic counselor.
A genetic counselor may be able to give you more specific answers than I can, after looking at your family history and all the currently available data on BPAD inheritance.