Technology for Quantifying the Postpartum Blood Loss

The aim of the study was to develop a technology for determining postpartum hemorrhage volume based on gravimetry and 3D modeling of the results of the US postpartum uterus examination.

The study was conducted at the perinatal center of the Regional Clinical Hospital (Chita) and the Kuvatov Republican Clinical Hospital (Ufa). A prospective analysis of 40 births from 2018-2019 was performed. Two groups were formed: group 1 - 30 women with physiological blood loss in the postpartum period; group 2 - 10 women with early hypotonic bleeding.The volume of blood loss was determined in three ways: visually, by a gravimetric method, and by the integrated use of the gravimetric method and 3D modeling of the results of US of postpartum uterine cavity. Uterus sonography in the early postpartum period was performed with a MySono U6 portable ultrasound scanner (Samsung Medison, Korea). Using local systems for changing the positions of points, lines, and polygons, the Autodesk 3ds Max program was tuned to simulate the shape of the postpartum uterus, which changed dynamically in accordance to the input ultrasound parameters.

In group 1, the volume of postpartum blood loss was quantified by the visual method as 275.0 (267.2; 282.8) ml, by the gravimetric method - as 375.0 (364.5; 388.2) ml, and by a combination of the gravimetric method and sonography-based 3D modeling of the postpartum uterus - as 420.0 (412.5; 435.4) ml. In group 2, the volume of postpartum blood loss was estimated visually as 725.0 (716.8; 773.2) ml, by gravimetry - as 1010.0 (1006.2; 1085.7) ml, and by gravimetry combined with the 3D modeling of the uterine cavity - as 1240.0 (1195.4; 1286.6) ml.

The proposed technology allows one to determine the volume of postpartum hemorrhage with a minimum error making it possible to reduce the frequency of massive postpartum bleeding and optimize the management of patients with medium and high risks.