Is the rate of progress the same for induced and spontaneous labors?
No. This retrospective cohort study found a significantly longer latent phase when labor was induced, compared with spontaneous labor.
Harper LM, Caughey AB, Odibo AO, Roehl KA, Zhao Q, Cahill AG. Normal progress of induced labor. Obstet Gynecol. 2012;119(6):1113–1118.
Analysis did not begin until women reached 3 cm of dilation, largely because women in spontaneous labor were typically admitted when their cervix had dilated at least 3 cm. The period before 3 cm of dilation seems to be longest when induction of labor occurs in the presence of an unfavorable cervix.
Harper and colleagues confirm a commonly held perception that women undergoing induction of labor spend a longer total time in labor than women who enter labor spontaneously.3,4 Before 6 cm, women undergoing induction of labor may take as long as 10 hours to achieve each centimeter of dilation. This pattern suggests that a diagnosis of arrest of labor before 6 cm of dilation needs to be scrutinized carefully to prevent unnecessary cesarean delivery.
William F. Rayburn, MD, MBA
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ON OBSTETRICS?
Does maternal exposure to magnesium sulfate affect fetal heart-rate patterns?
John M. Thorp, Jr, MD (October 2012)
Is elective delivery at 37 weeks’ gestation safe in uncomplicated twin pregnancies?
Steven T. Chasen, MD (September 2012)
Does mediolateral episiotomy reduce the risk of anal sphincter injury in operative vaginal delivery?
Errol T. Norwitz, MD, PhD (August 2012)
When macrosomia is suspected at term, does induction of labor lower the risk of cesarean delivery?
Jennifer T. Ahn, MD (May 2012)
Does vaginal progesterone reduce preterm delivery among asymptomatic women who have a short cervix in the midtrimester?
John T. Repke, MD (April 2012)
