Tuesday, October 22, 2013
316 Stanley Thomas Hall
Tulane University (Uptown)
Refreshments will be served
Megan Leftwich, Mechanical and Aerospace Engineering, George Washington University
The Fluid Dynamics of Human Birth
The laboring uterus is a complex fluid system. The pulsing, elastic boundary interacts directly with the (mostly) solid fetus and with the amniotic fluid, which aids in transferring force to the baby during labor. Additionally, there is a continuous flux of fluid in the uterus throughout. A better understanding of the mechanics of delivery may reduce the need for C-sections in less severe cases—prolonged labors and slightly abnormal fetal presentations. We are investigating several aspects of this problem, including the role of the departure from vertical of the major axis of the fetus and amniotic fluid properties on the force required to deliver a baby. This experimental study was conducted by filling an elastic latex uterus with a fluid that shares the average bulk properties of amniotic fluid. The latex uterus was custom made to replicate the relative size and flexibility of the pregnant human uterus. The volume of fluid used matched the percentage of the uterus generally filled with amniotic fluid after the rupture of the fetal membrane. An oblong, solid fetus was placed in the uterus and pulled through the latex birth canal. This “pull out” experiment approximates an assisted delivery (with forceps or a vacuum extractor). The amniotic fluid remained constant (properties were matched to average human amniotic fluid) and the fetus was tilted from its major axis by 0o-30o. The force required to remove the fetus in each case was recorded. The results of this study indicate that there is an optimal fetal position for vaginal delivery in which the force to remove the fetus is the lowest. Additionally, beyond a certain point, vaginal delivery may become no longer feasible and surgical delivery necessary. In the future, the static latex uterus will be replaced with an active contracting uterus to replicate an unassisted vaginal delivery, and we will work to increase anatomical correctness.
Center for Computational Science, Stanley Thomas Hall 402, New Orleans, LA 70118 firstname.lastname@example.org