Women’s pelvic tissue tears during childbirth unstudied, until now

(Press-News.org) Millions of women undergo episiotomies during childbirth every year, yet the mechanics behind these surgical cuts remain largely unstudied. A new research project is poised to change that, addressing this significant gap in women’s health.

An episiotomy involves cutting the pelvic-floor muscles to aid delivery, a technique currently guided largely by a surgeon’s personal judgment and experience. While intended to prevent severe vaginal tears or other complications during delivery, the procedure itself can lead to lasting pain, incontinence, infection, and sexual dysfunction.

The study is funded by a $600,000 grant from the National Science Foundation’s BRITE program or Boosting Research Ideas for Transformative and Equitable Advances. It is a collaboration between UC Riverside and Northern Arizona University, or NAU. The funding supports experimental work lead by Mona Eskandari, assistant professor of mechanical engineering at UCR, and computational modeling conducted by Heidi Feigenbaum, professor of mechanical engineering at NAU.

By integrating advanced experimental techniques with predictive computational simulations, the study offers a comprehensive approach to understanding childbirth mechanics and how different techniques affect the way an incision spreads.

The softening and stretching of pelvic-floor muscles makes them particularly vulnerable to tearing and it is important to understand how incisions made during episiotomies spread. The findings could pave the way for safer, more effective surgical practices that alleviate suffering for countless women.

Eskandari’s bMECH lab is renowned for developing innovative techniques to solve complex and underexplored biomechanics problems. Her prior research includes using uniquely designed apparatuses and a cutting-edge imaging system—one of only two in Southern California—to study lung tissue and other soft biological materials.  

“This work is an exciting new way of studying tearing during childbirth,” Feigenbaum said. “Episiotomies create very large stresses at the tip on the incision, making tears starting from there possible, potentially even likely. By understanding when and how the incision will grow, this research has the potential to make deliveries safer and less traumatic for mothers.”

The stresses and tears associated with episiotomies are poorly understood. Human cadaveric testing is not possible, so the researchers are using related rat models to produce critical biomechanical data. The research team hopes its work will result in better guidance for surgeons, improving surgical outcomes and reducing the physical toll on mothers.

“In addition to informing clinical practice, this work could also challenge longstanding assumptions in biomechanics,” Eskandari said. “For example, we’re investigating how the nonlinear, finite strain, and viscoelastic properties of pelvic tissues impact the likelihood of tearing—something not traditionally considered in surgical planning.”

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