Treatment of antiphospholipid antibody syndrome (APS) in pregnancy: a randomized pilot trial comparing low molecular weight heparin to unfractionated heparin.
OBJECTIVE
To compare low molecular weight heparin (LMWH), specifically dalteparin, to unfractionated heparin (UFH) for the treatment of antiphospholipid antibody syndrome (APS) in pregnancy.


METHODS
In a tertiary referral centre, 28 women met the 1999 International Consensus Criteria for APS, based on their obstetrical history and APS serology. The women were randomized, using a random numbers table with blocks of 12, to receive either prophylactic dosing of dalteparin or UFH starting either preconceptionally or early in pregnancy. All women also received low-dose acetylsalicylic acid, started preconceptionally. The primary outcome was a live birth. The secondary outcomes were maternal and fetal complications.


RESULTS
Of the 14 women who received the LMWH, dalteparin, and the 14 women who received UFH, 1 woman in each group did not conceive. Nine of the 13 women (69%) given dalteparin had a successful pregnancy (95% confidence interval [CI], 39-91%), compared to 4 out of the 13 women (31%) in the UFH group (95% CI, 9-61%). Nine women in total had spinal or epidural anaesthesia, and there were no complications overall.


CONCLUSIONS
Dalteparin may be an effective alternative to UFH for treatment of APS in pregnancy. A multicentre randomized trial is needed to determine benefit-to-risk ratios for the use of dalteparin and UFH to treat this high-risk obstetrical condition. Pharmacokinetic and pharmacodynamic studies are also recommended to maximize therapeutic response and minimize toxicity.
Stephenson
Mary D
MD
Department of Obstetrics and Gynaecology, University of British Columbia,Vancouver.
Ballem
Penny J
PJ
Tsang
Peter
P
Purkiss
Sue
S
Ensworth
Stephanie
S
Houlihan
Edwina
E
Ensom
Mary H H
MH
D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use*; D016736:Antiphospholipid Syndrome / Q000188:drug therapy*; D001241:Aspirin / Q000627:therapeutic use; D017985:Dalteparin / Q000627:therapeutic use*; D005260:Female; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D010865:Pilot Projects; D016742:Preconception Care; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy*; D011256:Pregnancy Outcome
D000925:Anticoagulants; D006493:Heparin; D001241:Aspirin; D017985:Dalteparin