Study demonstrates positive impact of azithromycin prior to cesarean delivery

Kim Boggess, MD, professor of maternal-fetal medicine, and fellow investigators of the Cesarean Section Optimal Antibiotic Prophylaxis (C/SOAP) study, have discovered that administering the antibiotic, azithromycin, alongside the standard recommended antibiotic regimen, cefazolin, reduces infection rates by 50 percent for women who have a non-elective cesarean delivery.

By Jennifer Rumbach

Kim Boggess, MD, professor of maternal-fetal medicine, and fellow investigators of the Cesarean Section Optimal Antibiotic Prophylaxis (C/SOAP) study, have discovered that administering the antibiotic, azithromycin alongside the standard recommended antibiotic regimen, cefazolin, reduces infection rates by 50 percent for women who have a non-elective cesarean delivery.  Adding the dose of 500 milligrams of azithromycin during a C-section also significantly decreases the use of health care resources, including re-admissions, emergency room visits, and clinic visits.

The collaborators, which span 14 hospitals across the United States and were led by the University of Alabama at Birmingham, detail their findings in the current issue of the New England Journal of Medicine.

“The risk of infection during pregnancy is among the top five causes of maternal death in the United States,” said Boggess. “It is an important, but understudied problem.”

“Women who have a C-section are at a significantly increased risk of infection compared to those who deliver vaginally,” said Alan T. N. Tita, MD, PhD, professor in the UAB division of maternal-fetal medicine and the Center for Women’s Reproductive Health, and principal investigator of the study.  “A major national goal is to reduce the risk of infection after surgery and this finding is the culmination of investigative work over decades.”

Cesarean delivery is the most common major surgical procedure, with up to five times the risk for infection than a vaginal delivery.

“There are significant costs associated with infections,” Tita said. “The reduction in re-admissions, visits, fevers and overall antibiotic use due to the intervention was higher than we expected, and translate to reduced health care costs.”

The C/SOAP clinical trial, funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, was with 2,013 women who were more than 24 weeks gestation and undergoing a C-section during labor or after membrane rupture. A randomized group of patients received either the standard antibiotic regimen to prevent infection or a modified regimen with the additional azithromycin. Pfizer Inc. donated the azithromycin and had no other role in the study.

The UAB Department of Biostatistics analyzed data gathered from the participating hospitals, including UNC and WakeMed, to reveal that the frequency of endometritis, an infection of the lining of the uterus, and infection of the cesarean wound were decreased by 50 percent in the women who received the adjunctive azithromycin compared to women who received the standard single antibiotic. The babies who were delivered with the additional azithromycin did not have an increased risk of adverse events. Additionally, hospital readmission rates and unscheduled visits to a clinic or to the emergency room were reduced.

UNC’s division of maternal-fetal medicine now includes azithromycin as a treatment option for women undergoing cesarean section based on the success of this trial. Boggess is confident the findings will further propel research to reduce infection during surgical delivery.

Additional study authors included Drs. Jeff Szychowski, Gary Cutter, and Namasivayam Ambalavanan from the University of Alabama at Birmingham, Drs. George Saade and Adi Abramovici from the University of Texas, Dr. Sherri Longo from Ochsner Health System, Drs. Erin Clark and Sean Esplin from the University of Utah, Drs. Kirsten Cleary and Ron Wapner from Columbia University, Dr. Kellett Letson from Mission Health System, Dr. Michelle Owens from the University of Mississippi, and Dr. William Andrews from the University of Virginia.

The Center for Women’s Health Research (CWHR) provided pre and post-award administration support to Boggess during the C/SOAP study. C/SOAP is in direct support of CWHR’s mission to improve women’s health through research by focusing on diseases, disorders and conditions that affect women only, women predominately, or women differently than men. As the focal point for women’s health research efforts on campus, CWHR seeks to identify and link existing efforts in women’s health research with related work in other fields, bringing multiple perspectives to bear on the complex issues inherent in studying and understanding women’s health and wellness.

This story was developed in conjunction with the University of Alabama at Birmingham.