Preeclampsia is a condition of pregnancy characterized by high blood pressure associated with edema and/or prote
inuria, with development from the 20th week of pregnancy. Its pathogenesis is multifactorial and the
involvement of thrombophilias – conditions that occur with greater probability of thromboembolic events –
in the pathophysiological mechanism of preeclampsia is controversial, especially
in severe cases.
Objective
Identify the prevalence of thrombophilias in patients with severe preeclampsia diagnosed before 34 weeks of gestation.
Methods
Prevalence study, with pregnant women being followed in “Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo”, because of preeclampsy or other diseases, hospitalized from October 2009 to October 2014. Women diagnosed with preeclampsia were included if they had any of the following severity criteria: systolic blood pressure ⩾160 and/or diastolic ⩾110 mmHg confirmed on two measurements with an interval of at least two hours; proteinuria ⩾ 5 g/24 h; diuresis <400 mL/day; headache, epigastric pain and visual changes simultaneously; cyanosis and/or pulmonary edema; HELLP syndrome; or when superimposed on chronic hypertension. No kidney or heart disease patients were included; also, gestational trophoblastic disease, fetal malformations, cases that did not confirm severe preeclampsia or severe manifestation after 34 weeks were not included. Patients already enrolled in the study in another pregnancy were excluded. In our service, all patients with severe preeclampsia before 34 weeks are followed in the postpartum period and laboratorially investigated for hereditary and acquired thrombophilias. This research was approved by the Research Ethics Committee (CAPPesq) da “Faculdade de Medicina da Universidade de São Paulo”.
Results
239 patients were initially selected for the study, 99 patients did not investigate thrombophilia because they missed follow-up appointments after delivery and 5 were excluded, totalizing 135 patients. Thirty-five (25.9%) patients had positive laboratory markers for thrombophilias, the most common being antiphospholipid syndrome (7,4%, N = 10) and hyperhomocysteinemia (5,2%, N = 7). Six (4.4%) patients were heterozygous for the mutation in the prothrombin gene, six (4.4%) had protein S deficiency, four (3.0%) were heterozygous for factor V Leiden, one (0,7%) showed antithrombin deficiency and one (0.7%) had protein C deficiency. Association of thrombophilias was present in one (0.7%) patient (hyperhomocysteinemia + antithrombin deficiency).
Conclusion
Thrombophilias are present in a significant proportion of severe preeclampsia cases arising before 34 weeks of gestation.
