BACKGROUND Uterine defects are the most common malformations of the female reproductive system. They can lead to many obstetric complications, e.g. preterm delivery, intrauterine growth restriction, oligohydramnios and operational delivery. OBJECTIVES Our aim was to analyze the impact of different types of uterine defects on pregnancy outcomes. MATERIAL AND METHODS The study involved 94 pregnant women with different types of uterine defects hospitalized at the Department of Fetal--Maternal Medicine and Gynecology, RIPMMH in Łódź, between 1994 and 2012. The patients were divided into 5 groups on the basis of diagnosed defects: arcuate (n=6), bicornuate (n=50), duplex (n=29), septate (n=5) and unicornuate uterus (n=4). In order to avoid correlated data in statistical analysis, our research did not consider the total number of pregnancies and births but the number of patients. The first pregnancy of each patient, if completed after 22-week gestation, was studied and analyzed. RESULTS Preterm delivery was the most common complication in pregnancy (55 women, 58.5%). The caesarean section was performed in 73 (78%) women. IUGR was diagnosed in 16% of cases. Placental abruption occurred in 13 (14%) and cervical insufficiency in 10 cases (11%), respectively. Prenatal diagnostic showed abnormalities in 12 fetuses (13%). The Apgar score from 0 to 4 points was assigned to 9 newborns (9.6%), 5-7 to 20 children (21.3%) and 8-10 points to 75 cases (69.1%). Normal birth weight (>2500 g) was determined in 51 newborns (54.3%). CONCLUSIONS Women with uterine defects are subject to an increased risk of complications in pregnancy and delivery, including premature births, low birth weights, births by cesarean section.