Bleeding and antithrombotic therapy during pregnancy in women with poor aPL-related obstetric outcomes A survey of 1075 cases from EUROAPS registry

BACKGROUND The combination of low-dose aspirin (LDA) and low-molecular-weight heparin (LMWH) until the end of gestation are the currently the accepted standard of care for the treatment of antiphospholipid-related obstetric disorders. In refractory cases, hydroxychloroquine (HCQ) can be added to this standard of care. OBJECTIVE To evaluate the haemostatic safety of LDA and LMWH (medium to high prophylactic doses) during pregnancy and the puerperium in women with both full-blown obstetric antiphospholipid syndrome (OAPS) (Sydney criteria) and noncriteria - incomplete - OAPS. STUDY DESIGN Retrospective/prospective multicentre observational study. Obstetric background, laboratory categories, delivery mode, antithrombotic regimens and bleeding complications were compared. SETTING A total of 30 tertiary European hospitals. PATIENTS Mainly, Caucasian/Arian pregnant women were included. Other ethnicities were minimally present. Women were controlled throughout pregnancy and puerperium. MAIN OUTCOME MEASURES The primary end-point was to evaluate the number of major and minor haemorrhagic complications in this cohort of women. Neuraxial anaesthetic bleeding complications were particularly assessed. Secondly, we aimed to compare local/general bleeding events between groups. RESULTS We studied 1650 women, of whom 1000 fulfilled the Sydney criteria of the OAPS and 650 did not (noncriteria OAPS). Data on antithrombotic-related complications were available in 1075 cases (65.15%). Overall, 53 (4.93%) women had bleeding complications, with 34 being considered minor (3.16%) and 19 major (1.76%). Neither obstetric complications nor laboratory categories were bleeding-related. Assisted vaginal delivery and caesarean section were related to local haemorrhage. Heparin doses and platelet count were not associated with major bleeding. CONCLUSIONS LDA and medium to high prophylactic LMWH during pregnancy in women with full-blown OAPS/noncriteria OAPS are safe. A slight increase in bleeding risk was noted in instrumental deliveries. No women who underwent spinal or epidural anaesthesia suffered bleeding complications. No haemorrhage was observed in cases where HCQ was added to standard therapy.