Tehran University Medical Journal

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Background: Ovarian hyper stimulation syndrome (OHSS) and its consequences, especially thromboembolic events, are of the most dangerous complications of assisted reproductive technologies (ART). It is unclear whether a thrombophilic predisposition or changes in blood components during clinical presentation of OHSS increase thrombotic risks. Testing for certain thrombophilias in selected high risk patients may help risk assessment and decision-making about prophylactic measures.

Methods: In this study carried out in April 2010 to March 2011, 108 in vitro fertilization candidates with ≥20 follicles following ovarian stimulation were recruited. Protein S, protein C, antithrombin, lupus anticoagulant and anticardiolipin antibodies were measured. Blood tests were compared between severe and non-severe OHSS groups and their changes were traced after onset of clinical OHSS in 43 patients presenting with severe symptoms by repeating the tests at hospital admission.

Results: Mean protein S activity was lower in severe OHSS group (101.7±16.3 vs. 118.4±17.0 P<0.001). After clinical presentation of severe OHSS, this level decreased to 91.6±20.1 (P<0.001). Antithrombin levels decreased 2.09% after the onset of symptoms in the group with severe OHSS, but this difference was not statistically significant (P=0.051). Protein C, lupus anticoagulant and anticardiolipin antibodies were not correlated to severe OHSS development.

Conclusion: Patients with relatively lower protein S activity were at higher risk for the development of severe OHSS, and its dangerous consequences. During clinical OHSS presentation, protein S decreased even more, and patients were more vulnerable to hypercoagulability states. These points should be kept in mind in risk assessment and adoption of prophylactic strategies.

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Background: Cerebral venous thrombosis (CVT) is uncommon after cesarean section. Although it can be a leading cause of maternal mortality. CVT may occur during pregnancy because of hypercoagulable states such as preeclampsia, thrombophilias, antiphospholipid antibody syndrome and sepsis.
Case presentation: A 31 years old woman G2 Ab1 at 37 weeks gestational age with  premature rupture of membrane underwent cesarean section because breech presentation and preeclampsia. Spinal anesthesia was done for emergent cesarean section. On the second day after cesarean section, she developed headache, vomiting, focal neurologic deficits, paresthesia, blurred vision. Brain magnetic resonance imaging (MRI) showed thrombosis in anterior half of superior sagittal sinus. Treatment consisted of anticoagulation. 
Conclusion: Thrombophilias, pregnancy-related hypertension and cesarean section are the predisposing factors for thromboembolism. Unfractionated heparin and low molecular weight heparin (LMWs) are effective drugs for thromboprophylaxis. It is vital to prevent venous thrombosis to reduce mortality during both intrapartum and postpartum periods. Consideration of cerebral venous thrombosis in similar cases is recommended.