Haemorrhagic and thromboembolic outcomes in pregnant patients with mechanical heart valves who undergo interruption of anticoagulation for birth - A case series.

Background: Anticoagulant therapy prevents thrombosis and thromboembolic events in patients with mechanical heart valves. Bridging anticoagulation around the time of birth represents a unique challenge. Few retrospective reviews or case series exist examining peripartum outcomes with bridging anticoagulation.

Aims: Review of peripartum and postpartum anticoagulation management, with a focus on postpartum complications.

Materials and methods: Design: case series, single centre.

Setting: Royal Brisbane and Women's Hospital, Australia between 1 January, 2000, and 1 August, 2022.

Population: all pregnant women with mechanical heart valves (any type) who birthed.

Main outcome measures: intrapartum and postpartum haemorrhage, thrombosis, thromboembolic complications, cardiac events, readmission, and maternal death.

Results: There were 18 women, with 23 births. Sixteen births were via caesarean section (70%). Fourteen women (61%) experienced at least one significant haemorrhagic complication, one woman required a peripartum hysterectomy, one woman experienced atrial fibrillation, and one had a valvular thromboembolic complication. No maternal cerebral thromboses or maternal deaths were recorded.

Conclusions: Women with mechanical heart valves who undergo bridging anticoagulation are associated with significant maternal morbidity. Most postpartum haemorrhagic complications were associated with bridging unfractionated heparin infusions in the first postnatal week. Bridging anticoagulation practices varied widely. Ongoing pooled data are required to inform evidence-based guidelines for postpartum anticoagulation management.