Dalteparin for the prevention of recurrence of placental-mediated complications of pregnancy in women without thrombophilia: a pilot randomized controlled trial.

BACKGROUND

The role of anticoagulants for the prevention of placental-mediated pregnancy complications is uncertain.

OBJECTIVES

Our aim was to investigate the effectiveness of dalteparin, a low-molecular-weight heparin, in preventing the recurrence of these complications in women without thrombophilia.

PATIENTS/

METHODS

Between August 1 2000 and June 20 2007, 116 pregnant women with: (i) <or= 16 weeks' gestation, (ii) no detectable thrombophilia, (iii) previous severe pre-eclampsia, newborn weight <or= 5th percentile, unexplained intrauterine death or abruptio placentae were randomized to either a prophylactic daily dose of dalteparin (n = 58) or no dalteparin (n = 58). The primary outcome was a composite of one or more of: severe pre-eclampsia, newborn weight <or= 5th percentile or major abruptio placentae. Secondary outcomes included non-severe pre-eclampsia, newborn weight at the 6-10th percentile and gestational age at delivery. Analyses were by intention to treat. P < 0.05 was considered to be significant. This study is registered as an International Standard Randomized Controlled Trial, number ISRCTN78732833.

RESULTS

Among the 110 women included in the final analysis, dalteparin was associated with a lower rate of the primary outcome [5.5% (n = 3/55) vs. 23.6% (n = 13/55), adjusted odds ratio (OR) 0.15, 95% confidence interval (CI) 0.03-0.70]. Secondary outcomes were not statistically different between the groups. Bleeding problems or thrombocytopenia did not occur.

CONCLUSION

In this pilot study, dalteparin is effective in decreasing the recurrence of placental-mediated complications in women without thrombophilia. Our results require confirmation in further randomized trials.