The purpose of this study is to learn about the effects of bipolar disorder or the use of antimanic medications on the mother's health and wellbeing during pregnancy and for the first postpartum year. Infant health and development are also assessed during the first year. Participation in the study includes 7 study visits, three in pregnancy and four postpartum.

Inclusion Criteria for Bipolar Subjects:

• Age 18 or older
• Pregnant at 20 weeks or more
• Women must receive OB care
• English-speaking
• DSM-IV diagnosis of BP, any subtype

Inclusion Criteria for non-Bipolar Control Subject:

• Age 18 or older
• Pregnant at 20 weeks or more
• English-speaking
• Women must receive OB care.
• Women may have past or present subclinical Major Depressive Disorder according to the DSM-IV.

Exclusion Criteria for all:

• Women must have no Active Alcohol Abuse or Dependence, Active Abuse or Dependence of Opiates, Inhalants, Amphetamines including Ecstasy or LSD, Active IV Drug Abuse, or Methadone Maintenance.
• Women must not take drugs in the FDA categories D or X.

Additional Exclusion Criteria for Control Subjects:

• Women must have no lifetime history of Bipolar Disorder or antimanic drug use.

Age 18 or older Pregnant at 20 weeks or more English-speaking DSM-IV diagnosis of BP, any subtype