The lack of significant differences in adverse pregnancy and birth outcomes in treated versus untreated women with bipolar disorder is a reassuring piece of data for clinicians weighing the risks and benefits of medication during pregnancy. However, this study could not adequately address risk for malformations, which have been documented in many other studies. Importantly, women with bipolar disorder had worse pregnancy outcomes than women without bipolar disorder. Many factors were statistically controlled for; however, others, such as psychosocial stress and instability and substance use not meeting diagnostic criteria, might contribute to these group differences