LMWH for Treatment of Early Fetal Growth Restriction (HepaGrowth)

Prior treatment

• use of LMWH or NFH in the index pregnancy before randomization or start of any of these medications for another indication if the patient is in the control group

Other illness

• evidence of fetal infection (serological or after invasive testing);
• maternal history of allergy to LMWH or non-fractionated heparin (NFH);
• hypersensitivity to pork products;
• maternal history of heparin-induced thrombocytopenia;
• history of maternal hemophilia or Von Willebrand disease
• active clinically significant bleeding and conditions with a high risk of hemorrhage, including recent hemorrhagic stroke, gastrointestinal ulcer, presence of malignant neoplasm at high risk of bleeding, recent brain, spinal or ophthalmic surgery, known or suspected esophageal varices, arteriovenous malformations, vascular aneurysms or major intraspinal or intracerebral vascular abnormalities;
• known or suspected hepatic impairment;

Lab values

• maternal thrombocytopenia (platelets \< 100 000);
• history of severe renal disease (eGFR \<30mL/min);

Other

• multiple gestation;
• diagnosed fetal chromosomal abnormalities;
• associated fetal morphological malformations;
• present use of systemic salicylates in anti-inflammatory dosage (\> 150mg/day) or NSAIDs (including ketorolac)
• presence of placental hematoma;
• maternal diabetic retinopathy;
• bacterial endocarditis;
• persistent blood pressure \> 160/100 mmHg, despite optimal anti-hypertensive regimen;
• current participation in another clinical trial;
• patients that are not part of the national health system (SNS);
• delivery already scheduled, or predicted in the next 7 days.

• being 18 years old or older
• being able to provide consent
• having a viable singleton pregnancy with diagnosed early FGR confirmed in our unit according to the 2020 International Society of Ultrasound in Obstetrics \& Gynecology (ISUOG) criteria (one solitary parameter: estimated fetal weight/ abdominal circumference lower than the 3rd centile or absent end-diastolic flow in umbilical artery; or estimated fetal weight/abdominal circumference below the 10th centile combined with either umbilical artery pulsatility index \> 95th centile or uterine artery mean pulsatility index \> 95th centile)