Can Low Molecular Weight Heparin During Pregnancy With Intrauterine Growth Restriction Increase Birth Weight?

Clinical purpose:

• To examine whether treatment with low molecular weight heparin in pregnant women with Intrauterine Growth Restriction (IUGR)increases the birth weight of the child. Our hypothesis is that an increased birth weight leads to reduced morbidity and mortality among these children.

Laboratory purposes:

• To evaluate three new methods to monitor the effect of LMWH.
• To investigate if 2 biochemical markers are positive predictors of IUGR IUGR is defined as a foetus that grows less than expected. IUGR is estimated to occur in up to 5% of all pregnancies, and IUGR is the second most common cause of perinatal morbidity and mortality. Thus, 75% of all stillbirths are caused by IUGR. IUGR is diagnosed by ultrasonography. In IUGR the uteroplacental blood flow is often compromised resulting in foetal growth restriction.

Design: The study is a prospective randomised study where pregnant women with suspected severe IUGR are randomised either to treatment with Innohep® or no treatment. Half of the women receive Innohep® and half of the women do not receive treatment.

Endpoints The primary endpoint is the difference in birth weight in children born of women receiving Innohep® during pregnancy and children born of women who have not received Innohep® during pregnancy

Inclusion criteria

• Singleton pregnancy
• IUGR shown by ultrasonography:
• Can understand and read Danish

Exclusion criteria

• Age below 18 years
• Pregestational weight < 90 kilograms
• Not able to give informed consent
• Chronic kidney disease with creatinine >150 μmol/l
• Chronic hypertension with blood pressure >140/90 mmHg
• Diabetes mellitus; type 1 or 2 or gestational diabetes
• Inflammatory bowel disease
• Severe heart disease (including mechanical heart valves)
• Drug or alcohol abuse
• Known coagulopathy (von Willebrand disease, thrombocytopenia, carrier of haemophilia)
• Treatment with vitamin K antagonists
• Known allergy to low LMWH
• Previous heparin-induced thrombocytopenia (HIT (type II))
• Clinically significant bleeding within the last month
• Women with indication for prophylactic treatment with LMWH during pregnancy e.g. previous thromboembolic disease or serious types of thrombophilia (deficiency of antithrombin, protein C or protein S)
• Chromosome anomaly in the child
• Severe malformations in the child
• Contraindication to Innohep®
• Gestational week > 32 weeks