Obesity Is a Thrombotic Risk Factor in Pregnant Women

Abstract

Background/Objectives: Pregnancy is associated with increased procoagulant conditions, and when combined with obesity, it can elevate the risk of thrombosis. The study aims to assess thrombosis risk markers during pregnancy in relation to obesity. Methods: Somatically healthy women aged 18-42 years with spontaneous pregnancies who did not receive specific antithrombotic treatment were enrolled in the study (n = 97). The participants were divided into groups based on pregestational BMI: the first group consisted of patients who had a BMI ≤ 25 (n = 42), and the second group consisted of patients who were overweight (BMI > 25) and obese (BMI > 30) (n = 55). The control group comprised healthy, non-pregnant, non-obese women (n = 10). Results: Fibrinogen levels, elevated during pregnancy, were higher in the II and III trimesters, with gestational period having a greater influence than BMI. Moderate D-dimer accumulation was observed regardless of obesity, but higher levels were seen in obese women during the III trimester, indicating the dissolution of intravascular fibrin deposits. Soluble fibrin was significantly higher in obese and overweight women during the II trimester and elevated in both groups during the III trimester, correlating with D-dimer accumulation and indicating thrombus formation. A decrease in platelet aggregation ability was observed correlating with D-dimer and soluble fibrin patterns. Conclusions: A significant accumulation of thrombosis risk markers was observed in the III trimester compared to the II, occurring earlier in obese and overweight pregnant women and indicating a higher risk of thrombotic complications in obesity.

Keywords: D-dimer; fibrinogen; obesity; platelets; pregnancy; soluble fibrin; thrombosis.

Figure 1

Changes in fibrinogen concentration in pregnant women. (a). Determined during II trimester of pregnancy; BMI ≤ 25 (n = 26); BMI > 25 (n = 35). (b). Determined during III trimester of pregnancy; BMI ≤ 25 (n = 16); BMI > 25 (n = 20). Control—healthy, non-pregnant, non-obese women (n = 10). The Kruskal–Wallis test was used to analyze results. * Results were assumed to be significant when p < 0.05. #—significant difference between two experimental groups according to Mann–Whitney U test.

Figure 2

Changes in D-dimer concentration in pregnant women. (a). Determined during II trimester of pregnancy; BMI ≤ 25 (n = 24); BMI > 25 (n = 35). (b). Determined during III trimester of pregnancy; BMI ≤ 25 (n = 15); BMI > 25 (n = 22). Control—healthy, non-pregnant, non-obese women (n = 10). The Kruskal–Wallis test was used to analyze results. * Results were assumed to be significant when p < 0.05. #—significant difference between two experimental groups according to Mann–Whitney U test.

Figure 3

Changes in soluble fibrin concentration in pregnant women. (a). Determined during II trimester of pregnancy; BMI ≤ 25 (n = 24); BMI > 25 (n = 34). (b). Determined during III trimester of pregnancy; BMI ≤ 25 (n = 15); BMI > 25 (n = 22). Control—healthy, non-pregnant, non-obese women (n = 10). The Kruskal–Wallis test was used to analyze results. * Results were assumed to be significant when p < 0.05. #—significant difference between two experimental groups according to Mann–Whitney U test.

Figure 4

Changes in rate of platelet aggregation in pregnant women. (a). Determined during II trimester of pregnancy; BMI ≤ 25 (n = 28); BMI > 25 (n = 33). (b). Determined during III trimester of pregnancy; BMI ≤ 25 (n = 12); BMI > 25 (n = 22). Control—healthy, non-pregnant, non-obese women (n = 10). The Kruskal–Wallis test was used to analyze results. * Results were assumed to be significant when p < 0.05.

Figure 5

Changes in speed of platelet aggregation in pregnant women. (a). Determined during II trimester of pregnancy; BMI ≤ 25 (n = 28); BMI > 25 (n = 33). (b). Determined during III trimester of pregnancy; BMI ≤ 25 (n = 12); BMI > 25 (n = 22). Control—healthy, non-pregnant, non-obese women (n = 10). The Kruskal–Wallis test was used to analyze results. * Results were assumed to be significant when p < 0.05.