Over the last 50 years, we have witnessed some incredible advancements that have vastly improved maternal and fetal outcomes, even in the face of the most complex obstetrical dilemmas. As our practice and the research continues to evolve, it is increasingly important that we carefully review our practice standards to ensure that every woman and her baby receives the most up-to-date medical care.
This month’s Master Class highlights a critical area of obstetrics where the convergence of technology, clinical observation, and research stimulated a change in practice guidelines: the use of the labor curve to monitor normal versus abnormal labor. Until quite recently, ob.gyns. had based labor criteria on the “Friedman Curve,” first established in the mid-1950s, and supported by other smaller and less comprehensive studies. This work was adopted by the American College of Obstetricians and Gynecologists.
Dr. E. Albert Reece
For more than half a century, we used these parameters to determine if a woman had entered active-phase arrest, and to make the very important decision of whether to perform a cesarean section. However, work in the early 2000s strongly suggested that the old criteria no longer applied to the full course of labor in contemporary patients ( Am J Obstet Gynecol. 2002 Oct;187:824-8 ). A 2010 comprehensive study showed that we needed to consider a new approach to labor management ( Am J Obstet Gynecol. 2010 Oct;203:326.e1-326.e10 ).
It may seem incredible that it took such a long time to update our thinking about what constitutes normal versus abnormal labor progression. However, we must keep in mind that many studies supported the original labor curve, and advanced tools to assess fetal health during labor were just being developed. The first commercially available fetal heart rate monitor would not be produced until 1968, and debates about the utility of these devices would continue into the early 1990s.
Additionally, our patient population has changed. As we have discussed in previous columns, the incidence and severity of other chronic conditions, such as diabetes and obesity, has increased significantly and deeply impacted labor progression.
Just as technology has advanced and our patients’ needs have changed, so, too, must our practice standards. We have invited Dr. Alison G. Cahill , associate professor and chief of the division of maternal-fetal medicine in the department of obstetrics and gynecology at Washington University, St. Louis, to discuss the importance and implications of the new labor curve.
Dr. Reece, who specializes in maternal-fetal medicine, is vice president for medical affairs at the University of Maryland, Baltimore, as well as the John Z. and Akiko K. Bowers Distinguished Professor and dean of the school of medicine. Dr. Reece said he had no relevant financial disclosures. He is the medical editor of this column. Contact him at firstname.lastname@example.org.