Approximately two/thirds of all traumas during pregnancy are the result of motor vehicle crashes. An average of 40,000 pregnant women are involved in motor vehicle crashes each year and nearly 70% of them are injured. There are about 157 known fetal deaths each year due to motor vehicle crashes. In motor vehicle crashes with maternal survival, placental abruption is accounts for up to 70% of fetal losses. Placental abruption is the premature separation of the placenta from the wall of the uterus and can cause fetal death. Two main injury mechanisms for placental abruption have been proposed by the University of Michigan Transportation Research Institute. These are (1) negative pressure in the posterior uterus and (2) shear strain at the uteroplacental interface (UPI) due to local deformation of the uterine wall. The ultimate tensile strength of the UPI is believed to be 16 kPa. The goal of this project was to create a finite element uterine model to predict placental abruption. This model was incorporated into a small female human body model and used to determine fetal outcome from impact loading. In particular, the interaction of seatbelts and airbags with the pregnant abdomen was examined. (Author/publisher)
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