Pregnancy-associated pelvic vein thrombosis: Insights from a multicenter case series.

Background: Pelvic vein thrombosis (PVT) is a rare complication of pregnancy that can lead to life-threatening complications, such as pulmonary embolism (PE).

Objective: To describe characteristics of PVT and its treatment in pregnancy in the province of Quebec, Canada.

Patients/methods: We developed a province-wide case series of PVT in pregnancy including four tertiary care centers and the Registry of Rare Diseases of the Groupe d'Étude en Médecine Obstétricale du Québec. Using diagnostic codes, we included cases with confirmed PVT on imaging during pregnancy or within 6 weeks postpartum from July 2003 to June 2018.

Results: A total of 47 cases were identified. PVT diagnosis was generally made in the early postpartum period (median of 9 [interquartile range (IQR) 4.5-12] days postpartum). Most PVT (94%) included in this series were symptomatic. Women presented primarily with abdominal pain (77%) and fever (55%), often prolonged despite antibiotics (mean 4.45 ± 2.39 days, with 39% having fever for more than 5 days). The most common risk factor was surgery (57%) and peripartum infections (54%). Thirty-eight (83%) women received antibiotics and 41 (89%) were anticoagulated. Three cases of PE (7%) occurred concomitantly, 11% of women required intensive care, and 19% had inferior vena cava (IVC) clot extension. The episode resulted in prolonged hospitalization (median 6 [IQR 3-10.75] days), with 48% being hospitalized more than 7 days.

Conclusion: Symptomatic PVT has significant clinical implications with prolonged fever and risks of extension in the IVC and PE, leading to prolonged hospitalization including in the intensive care unit. Therapeutic anticoagulation and antibiotics, when infection is documented, should be considered for management.