Background/Aim. One of the complications that can oc-cur during pregnancy is the development of preeclampsia (PE). The main characteristics of this condition are high blood pressure and very often signs of kidney damage or other organ damage. The condition affects 5–7% of all pregnant women and is one of the main factors of maternal and perinatal morbidity and mortality worldwide. The aim of this study was to investigate the structural and functional modifications of high-density lipoprotein (HDL) particles during high-risk pregnancies (HRP) for PE development. Methods. The longitudinal prospective study included a to-tal of 91 pregnant women with a HRP for developing PE. Out of this total number, 71 women did not develop PE until delivery, and this group was designated as the group without PE (WPE). The rest of the 20 HRP women devel-oped PE before delivery and were designated as the PE group. The blood was sampled toward the end of each tri-mester and before the delivery. The distribution of HDL particles was determined by the vertical 3–31% polyacryla-mide gradient gel electrophoresis method. The antioxidative capacity of HDL particles was measured by the activity of the HDL-associated enzyme – paraoxonase 1 (PON1). PON1 activity was determined by the method of kinetic spectrophotometry from serum samples. Results. The re-sults have shown that the proportions of HDL_2b particles significantly increased in the 2^nd trimester (p ˂ 0.05) and remained increased until the end of pregnancy in the WPE group. PON1 activity was significantly higher in the 3rd tri-mester (p < 0.05) of the WPE group. In the PE group, we found that the proportions of HDL_3a particles significantly decreased in the 2^nd trimester (p < 0.05) and remained de-creased until the end of pregnancy. PON1 activity has not changed in the PE group during pregnancy. Conclusion. Dyslipidemia in pregnancy could be associated with differ-ent modifications of HDL particles. The adaptive pregnancy mechanisms expressed as a functional modification of HDL particles in pregnant women who develop PE seem inade-quate and, therefore, lose their atheroprotective role.