Effect of frozen storage on dynamic tensile properties of human placenta.

Dynamic mechanical properties of placenta tissue are needed to develop computational models of pregnant occupants for use in designing restraint systems that protect the fetus and mother. Tests were performed on 21 samples obtained from five human placentas at a rate of 1200 %/s using a set of custom designed thermoelectrically cooled clamps. Approximately half of the samples from all five subjects were tested within 48 h of delivery. The remaining samples were frozen for 5-7 days and then thawed before testing. True failure stresses and strains were not significantly different between fresh and frozen samples (p-value = 0.858 and 0.551, respectively), suggesting that soft tissue may be stored frozen up to a week without adversely affecting dynamic material response.