Call for unified approach to VWD in pregnancy

New evidence has shown wide-spread variation in the management of type 2B von Willebrand disease in pregnant and postpartum women, highlighting the urgent need for international, consensus guidelines, researchers say.

A high frequency of bleeding rates alongside diverse clinical practice was revealed by the research, which was based on a literature review of 2,080 studies, the ISTH type 2B VWD registry, and an ISTH international physician’s survey on management of women with the condition in pregnancy and postpartum.

Authors of the review noted that a target safe VWF level and ideal monitoring approach was yet to be determined and high-quality evidence to guide clinical decision-making was lacking.

And “despite the significant bleeding phenotype, delayed diagnoses of 2B VWD were frequently observed”, they said, further making the case for a unified approach to managing the condition in pregnant women.

Co-author Dr Sajidi Kazi, a consultant haematologist in Newcastle, UK, told the limbic that these challenges in managing women with Type 2B VWD during pregnancy are in line with what is seen in the UK.

“The study highlights the complexity of managing Type 2B VWD predominantly as it is such a heterogeneous condition with variable clinical and laboratory presentations,” she said.

The study

In the study, published in the Journal of Thrombosis and Haemostasis, 19 of 36 pregnancies (53%) reported clinically significant bleeding (18 postpartum haemorrhages (PPHs) and 1 antepartum haemorrhage).

Postpartum haemorrhage (PPH) occurred more frequently in women who had a third trimester platelet count of <50 × 109/L versus those with a platelet count of >50 × 109/L, the researchers noted.

Also, in many cases PPH occurred despite the use of prophylaxis, “with VWF replacement therapy and platelet transfusion applied in 90% and 73% of those who developed PPH, respectively,” according to the paper.

And there was a higher frequency of clinically significant bleeds in women who were not taking antifibrinolytics (75%) compared to those who were (38.5%).

The authors also reported a significant variation in the response of VWF and FVIII in individuals, with “a mild or modest increase” in VWF:RCo seen in most toward the end of pregnancy”.

“Third trimester plasma VWF:RCo levels of >50 IU/dL were observed in 20 of 30 pregnancies for which third trimester data were available. However, the median third trimester VWF:RCo value in the whole group of these women remained low at 63.4 ± 40 IU/dL, which is far lower than the expected value in a healthy pregnancy,” they noted.

Significant thrombocytopenia was seen in the third trimester, with platelet counts of <50 × 109/L and <20 × 109/L, recorded in 55% and 26% of pregnancies, respectively, though this varied among even among women with the same 2B VWD driving mutation.

Differing treatment approaches

Analysis of data from the literature and registry showed that prophylaxis and treatment of antepartal, peripartal, and postpartum bleeding “varied significantly with respect to drug therapy or blood product administration”, the authors said.

Of particular note, the majority of clinicians (83.9%) recommended that delivery take place at a haemophilia treatment centre, “recognising the complexity of peripartum management of women with type 2B VWD”.

However, there were other key differences, including disparity neuraxial anesthesia, with 66% of physicians allowing its use after correction of VWF activity and/or VWF:Ag and platelet count, and 34% deeming it not suitable for use type 2B VWD patients.

All-in-all findings of the study, and the diversity and uncertainty of the evidence underpinning practice, “call for international consensus and guidance to improve both patient care and clinical outcomes”, the authors concluded.

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