The study included pregnant women aged 23-41 years with preeclampsia and gestation-associated arterial hypertension at weeks 27-40 and patients with essential arterial hypertension developing under conditions of the metabolic syndrome and without it. Frequency analysis of polymorphisms of the renin—angiotensin system genes (ACE, AGT, and AGTR1), ITGB3, FTO and their associations confirmed the syndrome nature of hypertensive disorders in pregnancy. The presence allele T of AGT gene and/or allele C of AGTR1 gene in the genotype of patients with preeclampsia was associated with higher BP and pressure load over 24 h. Allele D of ACE gene was also essential for BP parameters (pressure load) in patients with preeclampsia and gestation-associated arterial hypertension. Due to high genetic heterogeneity of the preeclampsia syndrome and genetic differences in the incidence of the studied gene polymorphisms in preeclampsia and gestation-associated arterial hypertension, no direct associations between these gestation disorders and polymorphic markers of the renin—angiotensin system genes can be established. However, polymorphisms of the renin—angiotensin system genes are essential for the 24-h dynamics of BP and pressure load under conditions of hypertensive disorders in pregnancy. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.