Objectives: Multidirectional influence of endometriosis on fertility impairments is well known. Altered implantation and placentation among affected patients raised concerns regarding possible negative influence on the course of pregnancy. The primary objective of the study was to assess the course of gestation and the incidence of pregnancy complications among women with endometriosis. It also aimed to determine whether the method of conception might impact the primary results. Material and methods: A single-center cohort study included 64 women with confirmed endometriosis and 296 healthy controls. Data concerning treatment of endometriosis related infertility, course of pregnancy and perinatal outcomes were evaluated. Results: Patients with endometriosis were older than controls (33.6 +/- 4.2 y vs 31.8 +/- 4.6, p = 0.01) and more often gave birth for the first time (87.5% vs 43.9%, p = 0.001). The age at the time of first delivery was significantly higher within the study group (33.1 y +/- 4.1 vs 29.9 +/- 4.6, p < 0.001). In the study, 81.2% of patients with endometriosis had the diagnosis of infertility. Patients suffering from endometriosis were significantly more prone to spontaneous placental abruption during pregnancy and delivery (4.7 vs 0.3%, odds ratio = 14.5). Several complications occurred more often in endometriotic patients (gestational diabetes mellitus, small-for-gestational-age and anemia); however, without statistical significance. The risk of pregnancy complications was independent from stage of endometriosis and way of conception. The incidences of adverse neonatal outcomes (preterm delivery, low Apgar score, lower birth weight) were similar in both groups. Conclusions: Endometriosis may adversely affect perinatal outcomes, especially due to increased risk of placenta abruption and operative delivery. Stage of endometriosis and method of conception does not enhance these complications.