Pilot deemed not feasible by Steering Committee due to recruitment rate.

The APPLE pilot trial is a feasibility study that is a multicentre, open-label, randomized controlled trial. Pregnant women with antiphospholipid syndrome (APS) and a history of late (≥10 weeks gestation) or recurrent early (2 <10 weeks) pregnancy loss will be recruited.

Eligible and consenting subjects will be assigned to one of two study arms: open-label low-molecular-weight heparin (LMWH) prophylaxis until 37 weeks gestation AND low-dose aspirin (ASA) daily until delivery, or open-label low-dose aspirin daily from randomization until delivery.

The purpose of this pilot trial is to determine the feasibility of conducting a multicenter randomized full trial evaluating antepartum prophylaxis with ASA versus LMWH/ASA in women with confirmed APS and a history of late or recurrent early pregnancy loss.

Given the large sample size needed to adequately power a large multicenter trial that assesses the efficacy of ASA alone versus LMWH/ASA, the investigators first need to determine if it is possible to meet minimum recruitment rates needed for a full multicenter trial. If the pilot feasibility trial is successful, then the secondary outcomes collected will be used in the analysis of the full multicenter trial.

Inclusion Criteria:

• Confirmed pregnancy;
• 18 years or older;
• Two or more unexplained pregnancy loss before the 10th week of gestation, AND/OR one or more unexplained pregnancy loss at or beyond the 10th week of gestation;
• One or more APS laboratory criteria present, according to the revised Sapporo criteria;

Exclusion Criteria:

• Greater than 11 weeks +6 days gestational age at time of randomization;
• Indication(s) for prophylactic or therapeutic-dose anticoagulation;
• Contraindication to heparin or aspirin;
• Received 7 or more doses of LMWH;
• Previous participation in the trial;
• Geographic inaccessibility;
• Refused consent.

0 participants were enrolled in the standard of care arm.

The AE reporting period for this trial begun upon randomization, and ended 30 days after receiving the last dose of study drug.

AEs were elicited, monitored and recorded throughout the study. For each participant, AEs were submitted to the trial office after each follow-up visit. The investigator is to report all directly observed AEs and all AEs spontaneously reported by the participant. In addition, each participant will be questioned about AEs at each clinic visit following initiation of treatment.