Majority of Cesarean Hysterectomies Are Performed to Control Blood Loss

National Institute of Child Health and Human Development (NICHD; Bethesda, MD, USA). The researchers identified 39,244 women who underwent cesarean delivery at 13 academic medical centers across the United States between 1999 and 2000. Data were abstracted from the medical record by study nurses, and outcomes included procedure frequency, indications, and complications. The study cohort comprised 186 of these women (0.5%) who also required a subsequent hysterectomy.

The results of the study showed that the leading indications for hysterectomy were placenta accreta (38%) and uterine atony (34%). Of the hysterectomy cases with a diagnosis recorded as accreta, 18% accompanied a primary cesarean delivery, while 82% had a prior procedure. Of the hysterectomy cases with atony recorded as a diagnosis, 59% complicated primary cesarean delivery, whereas 41% had a prior cesarean. These data, claim the researchers, show a significant trend between the risk of hysterectomy and the number of prior cesarean deliveries, from 0.3% for a first cesarean to 2.9% for women with three or more prior procedures; in addition, the researchers found that 46% of the hysterectomies occurred in patients who delivered at a gestational age of less than 37 weeks.

However, while 71% of all cases of placenta accrete lead to hysterectomy, this occurred in only 4% of the atony cases. Major maternal complications of cesarean hysterectomy included blood loss that required transfusion of red blood cells (84%) and other blood products (34%). Other complications included ileus, exploratory laparotomy, hospital readmission, cuff abscess, and bowel injury. Three of the women (1.6%) died. The researchers also found that accreta hysterectomy cases were more likely than atony hysterectomy cases to require ureteral stents, and to instill sterile milk into the bladder. The study was published in the August 2009 issue of Obstetrics & Gynecology.

"Despite the use of effective therapies and procedures to control hemorrhage at cesarean delivery, a small proportion of women continue to require hysterectomy to control hemorrhage from both uterine atony and placenta accrete,” said lead author Cynthia Shellhaus, M.D., of OSU. "With the decline in use of vaginal birth after cesarean in the past several years, accreta may rise in frequency as an indicator in the future.”

Placenta accreta is a severe obstetric complication involving an abnormally deep attachment of the placenta, through the endometrium and into the myometrium (the middle layer of the uterine wall). Atony, which refers to a muscle that has literally lost its strength, usually requires only oxytocic agents to treat it.

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U.S. National Institute of Child Health and Human Development