Low‐molecular‐weight heparin added to aspirin in the prevention of recurrent early‐onset pre‐eclampsia in women with inheritable thrombophilia: the FRUIT‐RCT

Summary. Background: Early‐onset hypertensive disorders (HD) of pregnancy and small‐for‐gestational age infants (SGA) are associated with placental vascular thrombosis, these often recur and are also associated with inheritable thrombophilia. Aspirin reduces the recurrence risk. Objectives: Adding low‐molecular‐weight heparin (LMWH) to aspirin at < 12 weeks gestation reduces the recurrence of HD in women with previous early‐onset HD (pre‐eclampsia, hemolysis, elevated liver enzymes and low platelets HELLP] syndrome and eclampsia) and/or SGA, in the context of inheritable thrombophilia without antiphospholipid antibodies. Patients/methods: In a multicenter randomized control trial (RCT), 139 women included were < 12 weeks gestation. Inclusion criteria: previous delivery < 34 weeks gestation with HD and/or SGA; inheritable thrombophilia (protein C deficiency, protein S deficiency, activated protein C resistance, factor V Leiden heterozygosity and prothrombin gene G20210A mutation heterozygosity); and no antiphospholipid antibodies detected. Intervention: either daily LMWH (dalteparin, 5000 IU weight‐adjusted dosage) with aspirin 80 mg or aspirin 80 mg alone. Main outcome measures: Primary outcomes: recurrent HD onset (i) < 34 weeks gestation and (ii) irrespective of gestational age. Secondary outcomes: recurrent SGA, preterm birth, maternal/neonatal hospitalization, spontaneous abortion and individual HD. Analysis by intention‐to‐treat. Results: Low‐molecular‐weight heparin with aspirin reduced recurrent HD onset < 34 weeks gestation (risk difference RD] 8.7%: confidence interval CI] of RD 1.9–15.5%; P = 0.012; number needed to treat NNT] 12). Recurrent HD irrespective of gestational age was not different between the arms. No women withdrew as a result of adverse effects. Trial Registration: http://www.isrctn.org ) (isrctn87325378). Conclusions: Adding LMWH to aspirin at < 12 weeks gestation reduces recurrent HD onset < 34 weeks gestation in women with inheritable thrombophilia and prior delivery for HD/SGA <34 weeks. However, close monitoring of the mother and fetus remains important throughout pregnancy.