Uterine Activity During the Third Stage of Labor


  • Mavis N. Schorn CNM, PhD

Mavis N. Schorn, 2802 Oakland Ave. Nashville, TN 37212. E-mail: mavis.schorn@vanderbilt.edu


Introduction: The purpose of this study was to evaluate the use of intrauterine pressure catheters (IUPCs) to measure uterine activity during the third stage of labor.

Methods: The study was conducted in a tertiary-care center. All births were attended by certified nurse-midwives. Low-risk pregnant women at term gestation had intrauterine monitoring attempted during the third stage of labor. Data were analyzed using descriptive statistics and analysis of variance.

Results: Of the 36 women in the study, 19 had clear contractions recorded, 4 had unclear contractions, and 13 had flat tracings. The IUPC was useful for measuring uterine activity in a small number of women during the third stage of labor. When measured, uterine contractions were variable in strength and frequency.

Discussion: Intrauterine pressure catheters can be used as a measurement of uterine activity during the third stage of labor and should be considered for future research about third-stage physiology. Further work is needed to determine the best procedure for placement, and IUPC use before expulsion of the placenta will not be useful in all women. Effective measurement of uterine activity may guide future research on interventions to reduce the risk of postpartum hemorrhage.