Pregnant women at risk for unnecessary operations due to misdiagnosis of appendicitis

Oct 24 2007

New research published in the October issue of the Journal of the American College of Surgeons suggests that pregnant women suspected of having appendicitis are often misdiagnosed and undergo unnecessary appendectomies (removal of the appendix) that can result in early delivery or loss of the fetus.

The study points to the need to require more accurate diagnosis to avoid unnecessary operations and the potential for fetal loss.

Appendicitis is difficult to diagnose in pregnant women, with signs and symptoms that are similar to those of pregnancy itself. Consequently, surgeons have historically taken an aggressive approach to the treatment of suspected appendicitis in pregnant women in order to reduce the risk and possible consequences of a ruptured appendix.

“Our study shows that the complication rate in pregnant women who undergo a negative appendectomy is nearly identical to those who suffer a ruptured appendix,” said Marcia L. McGory, MD, David Geffen School of Medicine, University of California at Los Angeles. “This finding argues for a change in the basic approach to the treatment of suspected appendicitis in pregnant women. One potential straightforward solution is to use more advanced imaging tools, such as ultrasound and magnetic resonance imaging, to increase diagnostic accuracy.”

This report presents findings from the largest study ever conducted to evaluate outcomes after appendectomy in pregnant women. Using data from a large, population-based database, this retrospective analysis included 94,789 women who underwent open or laparoscopic appendectomy, 3,133 of whom were pregnant. International Classification of Diseases Clinical Modification (ICD-CM) diagnosis codes were used to identify the presence of complicated (ruptured) or simple appendicitis.

The rate of negative appendectomy (defined as an appendectomy without a diagnosis of simple or complicated appendicitis) was significantly higher in pregnant women (23 percent versus 18 percent, p<0.05) than in non-pregnant women.

Overall, fetal loss or early delivery occurred in 11 percent of the 3,133 patients. Although the fetal loss rate was highest in patients undergoing appendectomy for complicated appendicitis (6 percent), it was still pronounced in patients undergoing appendectomy for a normal appendix (4 percent) and patients with simple appendicitis (2 percent). Appendectomy resulted in early delivery in 11 percent of patients with complicated appendicitis, 10 percent with a normal appendix and 4 percent with simple appendicitis.

The study also found that fetal loss rate after laparoscopic appendectomy in pregnant patients was significantly higher than that for open appendectomy (7 percent versus 3 percent, p<0.05). Laparoscopic appendectomy is sometimes performed because it is thought to be less invasive/traumatic for a pregnant patient.