As part of anational Finnish study on reproductive health of women with severe mental disorders, we compared pregnancy- and delivery-, and postpartum-related outcomes between women with schizophrenia (n = 3444) and those with schizoaffective disorder (n = 985), focusing on their singleton pregnancies after illness onset (n = 708 and n = 242, respectively). For comparison, data also included 22,101 controls with 3668 pregnancies. The Finnish Medical Birth Register, the Register of Congenital Malformations and the Child Welfare Register were used. Despite known differences between the two disorders, we found no robust differences between these patient groups.