Abnormal Labor

This chapter deals with abnormal labor. It provides the background information of the disorder, and discusses its prevention, diagnosis, treatment, prognosis, and evidencer. Abnormal or difficult labors (dystocias) are those that deviate from the progress seen in the majority of parturients and may be divided into protraction (slow progress) or arrest (lack of progress) disorders. Although the exact cause of abnormal labors may not always be apparent the underlying etiology may be categorized as disorders of either contractile forces or relative disproportion of the maternal pelvic size and the fetus. There are no effective primary interventions for abnormal labor. However, active management of labor may prevent the occurrence of labor abnormalities. Internal pressure catheter can be used to assess strength, frequency, and duration of contractions. Strength of contractions is reported by Montevideo units with between ≥200 MVU and ≥300 MVU in a 10-minute window as a measurement of adequacy.