New studies focus on laboring down

Some four million babies are born each year in the United States alone, and millions more have arrived since obstetricians first began managing labor and delivery. Yet physicians still know little about the management of labor, particularly the crucial second stage when patients need clear, informed direction as to when they should push or delay trying to push the baby out.

“Once a woman progresses through labor, from zero to complete cervical dilation, it is heartbreaking to have a Caesarian section,” says Methodius Tuuli, MD, MPH, a Washington University obstetrician and maternal-fetal medicine specialist at Barnes-Jewish Hospital, as well as a Women’s Reproductive Health Research Scholar. “Yet we have very little information about managing the second stage: for example, whether to push when the woman has the urge or when she has a contraction.”

Tuuli and several colleagues—particularly Alison Cahill, MD, MSCI, and Heather Frey, MD, both Washington University maternal-fetal medicine specialists at Barnes-Jewish—have published four recent research papers, two in the American Journal of Perinatology and two in Obstetrics and Gynecology, dealing with this laboring-down or passive-descent period of labor. Three were cohort studies of patients delivered at Barnes-Jewish Hospital and one was a meta-analysis, synethsizing results of all prior randomized trials. Funding for this work came from the National Institutes of Health (NIH) and the Robert Woods Johnson Foundation.

One study identified factors that influence the use of delayed pushing: high fetal station, regional anesthesia use, a maternal body mass index over 25, among others. Another correlated passive descent in morbidly obese patients with longer active pushing. In a third, delayed pushing seemed to correspond to lower rates of spontaneous vaginal delivery and increased adverse outcomes to mother and baby. The fourth suggested few clinical differences in outcome.

Overall, these studies highlighted the need for more investigation of second-stage management. Tuuli and colleagues have already assembled investigators from Washington University and three additional medical centers—the University of Pennsylvania, University of Alabama and Oregon Health Science Univeristy—to collaborate on research comparing immediate and delayed pushing. “There is an urgent need for well-designed, randomized trials to provide evidence for practice,” says Tuuli.