Determination of Reference Values for Diluted Russell's Viper Venom Time (dRVVT) Specific to Pregnant Women (GRAPL) (GRAPL)

Thrombophilia Assessment and Pregnancy: Determination of Reference Values for dRVVT in Pregnant Women

Pregnancy is associated with significant changes in several aspects of haemostasis, especially an imbalance between procoagulant and anticoagulant factors. These changes contribute to creating a state of hypercoagulability, mainly at the end of pregnancy and during the post-partum period, protecting pregnant women from delivery haemorrhage, but exposing them to a major thromboembolic risk.

Vascular diseases of pregnancy (VDP) are obstetric diseases which are linked to an ischaemic origin associated with placental thrombosis. These include pre-eclampsia, retroplacental haematoma, intrauterine growth retardation and even foetal death in utero. A number of risk factors have been identified for these VDPs, some of which have extremely serious consequences, the main one being antiphospholipid syndrome (APS).

The diagnosis of VDP in a current or previous pregnancy requires close monitoring and joint management by an obstetrician, haemostasis physician, internist and medical biologist, particularly in terms of pre, peri- and post-partum anticoagulation in patients at increased risk of thromboembolism.

The aim of treating APS during pregnancy is : to reduce the occurrence of maternal arterial or venous thrombotic complications in one hand and in the other hand to reduce the occurrence of obstetric complications, which are responsible of a significant morbimortality rate. The detection of a possible APS during pregnancy will therefore determine the specific management of patients.

The latest guidelines from the Groupe Français d'Etude sur l'Hémostase et la Thrombose (GFHT) in 2022 recommended a diluted Russell's viper venom time (dRVVT) and an activated partial thromboplastin time (APTT) measured using a sensitive reagent such as silica (SCT) should be used to assess the presence of LA.

Study Overview

• Status: Completed
• Conditions: Normal Pregnancy
• Intervention / Treatment: Other: dosage dRVVT

Detailed Description

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• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• France
  • Lyon, France
    • Dr Céline BAZIN

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Selection by the gynaecologist of pregnant women at the Croix Rousse maternity hospital, who presenting a physiological pregnancy with no history of thromboembolic or autoimmune pathology or vascular disease of pregnancy

Description

Inclusion Criteria:

Control group :

• patients with normal pregnancies at the HCL.
• Affiliation to a social security regime

Case group :

• Patients followed at the HCL who had an increased dRVVT ratio during pregnancy, investigated as part of the development of VDP during pregnancy.
• Affiliation to a social security regime

Exclusion Criteria:

• History of thromboembolic disease
• History of autoimmune disease
• History of VDP

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
cases; Patients treated at HCL who have had an increased dRVVT ratio during pregnancy, investigated in the context of the development of VDP during pregnancy	Other: dosage dRVVT; Blood test dRVVT assay on two tubes of blood in the haemostasis laboratory of the Center de Biologie et de Pathologie Est
Controls; Patients with normal pregnancies followed at the Croix Rousse maternity hospital	Other: dosage dRVVT; Blood test dRVVT assay on two tubes of blood in the haemostasis laboratory of the Center de Biologie et de Pathologie Est

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
dRVVT value during pregnancy.	Carrying out the dRVVT in the haemostasis laboratory of the Centre de Biologie et de Pathologie Est	through study completion, an average of 9 months

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon
• Investigators: Principal Investigator: Céline DR BAZIN, DR, Laboratoire d'hémostase CBPE HCL

Study record dates

Study Major Dates

• Study Start (Actual): March 28, 2024
• Primary Completion (Actual): September 28, 2025
• Study Completion (Actual): September 28, 2025

Study Registration Dates

• First Submitted: November 10, 2023
• First Submitted That Met QC Criteria: November 14, 2023
• First Posted (Actual): November 15, 2023

Study Record Updates

• Last Update Posted (Estimated): January 2, 2026
• Last Update Submitted That Met QC Criteria: December 29, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Pregnancy; Antiphospholipid syndrome; Thrombophilia; Vascular diseases of pregnancy; Diluted Russell viper venom time
• Additional Relevant MeSH Terms: Autoimmune Diseases; Immune System Diseases; Hematologic Diseases; Hemic and Lymphatic Diseases; Thrombophilia; Antiphospholipid Syndrome
• Other Study ID Numbers: 69HCL23_1016

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No