AntiPhospholipid Syndrome Low-molecular-weight Heparin Pregnancy Loss Evaluation: The Pilot Study

A Pilot Study Assessing the Feasibility of a Randomized Controlled Trial Evaluating Aspirin Versus Low-molecular-weight Heparin (LMWH) and Aspirin in Women With Antiphospholipid Syndrome and Pregnancy Loss

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.