BACKGROUND: Extractable nuclear antigen (ENA) and anti-double stranded DNA (anti-dsDNA) positivity and related diseases like systemic lupus erythematosus, Sjögren syndrome, and other autoimmune diseases are known to be associated with obstetrical complications and poor perinatal outcomes. OBJECTIVE: To demonstrate the importance of ENA, anti-dsDNA, antiphospholipid (APL), and anticardiolipin (ACL) antibody positivity on pregnancy outcomes. METHODS: Ninety one pregnant women with known ENA, anti-dsDNA, APL IgG and IgM, and ACL IgG and IgM antibody positivity were retrospectively compared with 91 randomly selected pregnant woman in terms of obstetrical complications and pregnancy outcomes. Beksac Obstetrics Index-pregnancy (BOIp), calculated as (number of children + (?€/10))/gravidity in the current pregnancy, was used to compare the risk level between groups. RESULTS: Significant differences were found in the median maternal age, gravidity, number of previous miscarriages, and BOIp between the groups (p= 0.04, p< 0.001, p< 0.001, and p< 0.001, respectively). Significant differences were also found between the study and control groups in the median gestational age at birth, birth weight, and APGAR1 score (p< 0.001 for all). Similarly, significant differences were found between groups in the rates of intra-uterine growth restriction, oligohydramnios, and gestational hypertension (p< 0.001, p= 0.05, and p= 0.05, respectively). There were 3 (3.3%) stillbirths in the study group and none in the control group (p= 0.123). CONCLUSION: We evaluated the impact of anti-dsDNA, ENA, APL, and ACL antibody positivity, which may cause immunologic inflammation at placenta and thereby affect pregnancy outcomes.