Pregnant women who inject themselves with the anti-clogging drug herapin have been warned that the treatment ‘has no positive benefits for mother or child’.
Up to one in 10 pregnant suffer from a condition called thrombophilia, which causes blood clots to develop in their veins. This can lead to an increased risk of common placenta-related pregnancy complications, including pre-eclampsia, intrauterine growth restriction (IUGR), placental abruption, recurrent miscarriage and stillbirth.
However, new research from a major drug trial has found that taking heparin is ineffective in preventing these conditions - and it may even be causing more harm than good, because of increasing bleeding, increasing rates of induced labour and reducing access to anesthesia during delivery.
Heparin (LMWH) is administered by injection and mums-to-be inject the drug daily in the aim of preventing blood clots; a painful process that the trial has proved pointless. Professor Marc Rodger, from Ottawa Hospital Research Institute, Canada, who led the study, said, ‘These results mean that many women around the world can save themselves a lot of unnecessary pain during pregnancy.
‘Using low molecular weight heparin (LMWH) unnecessarily medicalises a woman’s pregnancy and is costly.'
‘While I wish we could have shown that LMWH prevents complications, we actually proved it doesn’t help,’ he added.
The trial involved 292 women with thrombophilia in 36 centres in five countries and was published online in The Lancet medical journal.
Altogether 143 women taking part were assigned to daily injections up to 20 weeks’ pregnancy, and twice daily until 37 weeks of pregnancy, while 141 women had no treatment (three women were not able to take part).
The trial revealed that regular drug treatment did not reduce the chance of major complications, including the loss of blood clots, and the occurrence of major bleeding did not differ between the two groups. Minor bleeding was common in the group who received injections.
As noted in the findings, this could cause pregnant women some minor harm because bleeding increases their rates of induced labour and may mean they cannot have anaesthetica during childbirth.
All women with thrombophilia need blood thinners to prevent blood clots after delivery and some are advised to take low-does aspirin while pregnant to help prevent complications.
Professor Roberts concluded, ‘These findings allow us to move on, to pursue other, potentially effective, methods for treating pregnant women with thrombophilia and/or complications from placenta blood clots.’