Clinical trial NCT06133621: Determination of Reference Values for Diluted Russell's Viper Venom Time (dRVVT) Specific to Pregnant Women (GRAPL)
Official title: Thrombophilia Assessment and Pregnancy: Determination of Reference Values for dRVVT in Pregnant Women
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Normal Pregnancy
Keywords: Pregnancy
Thrombophilia
Antiphospholipid syndrome
Vascular diseases of pregnancy
Diluted Russell viper venom time
Lead sponsor: Hospices Civils de Lyon
Sponsor class: OTHER
First posted: 2023-11-15
Enrollment: 100
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
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

Brief summary: 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.

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Eligibility criteria: 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

Primary outcomes:
measure: dRVVT value during pregnancy.
timeFrame: through study completion, an average of 9 months
Secondary outcomes:
Other outcomes:
Locations:
city: Lyon
country: France
facility: Dr Céline BAZIN
Study officials:
affiliation: Laboratoire d'hémostase CBPE HCL
name: Céline DR BAZIN, DR
role: PRINCIPAL_INVESTIGATOR
References: