Review of:
Forces involved with labor and delivery—a biomechanical perspective

By Sue A. Weber DC, MSc

Original article by: MICHELE J. GRIMM
Annals of Biomedical Engineering, Vol. 49, No. 8, August 2021 ( 2021) pp. 1819–1835
https://pubmed.ncbi.nlm.nih.gov/33432512/

The purpose is to review the body of research focusing on the biomechanics of labor and delivery. It describes the forces generated during the different phases of parturition, specifically, how they affect the uterus and are transferred to the fetus. It highlights what can commonly happen to delay progression of labor and delivery.

This review encompasses studies as far back as the 1800’s giving detail to the what we know about the process of contractions and the difficulty in measuring them for a biomechanical model. It describes the differences observed between forces generated during primiparous and multiparous deliveries. One specific maternal position is mentioned which is used to assist delivery by increasing forces. Two prevalent maternal systemic conditions which have a negative impact on labor and delivery are evaluated. Clinician applied forces including manual and instrumental traction are compared to the natural forces of labor. These forces are difficult to measure and are not consistent as each birth is unique. There is a discussion of how interns are trained manually in delivery and how gaining a feel for adequate force during traction is difficult.

As a review it articulates and discusses the material well and ends by giving some recommendations for studies which may provide valuable information for clinicians. It addresses where there are gaps in the literature and why there are difficulties gathering certain key bits of information. The review goes into detail about the factors which can complicate parturition. This could be better highlighted in the abstract as a major point. The conclusion points out that there is a significant complication rate during delivery, particularly during clinician assisted delivery. This could be mentioned in the abstract to make the purpose of the study clearer.