Abnormal Labor Workup

Updated: Oct 07, 2022
  • Author: Nina S Olsen, MD; Chief Editor: Ronald M Ramus, MD  more...
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Laboratory Studies

No specific laboratory studies are used to assess abnormal labor.

Other tests

The simplest test used to evaluate abnormal labor is to plot the patient's labor progress (cervical dilation vs duration in hours) on a labor curve.

A second test used to address adequate labor is the review of the uterine contraction pattern by determining adequacy of contractions with use of an intrauterine pressure catheter.

Most importantly, the fetal heart tracing must be reassuring throughout the labor course.



Clinical pelvimetry, at a minimum, must address the angles of the spinous processes (convergent, divergent, straight), the bi-ischial diameter (>8 cm), the distance to the sacral promontory from the symphysis pubis (>12 cm), and the relation of the bony pelvis to the fetal head.

Clinical pelvimetry requires experience and deliberate attention to the question of pelvic adequacy. It cannot account for fetal size or strength/frequency of contractions, but, in experienced hands, it may reliably identify a pelvis as adequate, borderline, or contracted.

An estimate of the fetal weight must be documented in the hospital chart early in the labor course. If concern for macrosomia exists, this must be addressed with the patient and the labor/delivery team in order to anticipate and prepare for labor dystocia.