Material properties of the placenta under dynamic loading conditions

Area of Science:

• Biomechanics
• Materials Science
• Obstetrics

Background:

• Traumatic injuries during pregnancy, particularly from car crashes, are a significant cause of fetal loss.
• Abruptio placentae is a leading cause of fetal demise, necessitating better understanding of placental mechanics.
• Existing research lacks data on placental behavior under compressive loading.

Purpose of the Study:

• To experimentally characterize the mechanical behavior of fresh placental tissue under compression.
• To provide data for improving material models of the gravid uterus for automotive safety simulations.
• To investigate the quasi-symmetrical mechanical response of the placenta in tension and compression.

Main Methods:

• Conducted 80 indentation tests on fresh placental tissue to simulate compressive loading.
• Collected stress-strain data and established experimental corridors.
• Utilized inverse analysis with finite element models to derive material parameters.

Main Results:

• Presented hyperelastic-like stress-strain curves for placental tissue under compression.
• Compared compression test results with existing tensile data, suggesting quasi-symmetrical behavior.
• Proposed parameters for an Ogden material model for the placenta.

Conclusions:

• The placenta exhibits a quasi-symmetrical mechanical behavior in both tension and compression.
• The developed Ogden material model accurately represents placental behavior under both loading conditions.
• This research enhances computational models for pregnant occupant safety, potentially reducing fetal injury and loss.