Diagnostic accuracy of ultrasound in diagnosing acute appendicitis in pregnancy: a systematic review and meta-analysis

Background Lack of timely diagnosis of acute appendicitis (AA) can lead to perforation and peritonitis, which might be associated with complications such as miscarriage, preterm delivery, fetal loss, and even maternal mortality. The aim of the present systematic review and meta-analysis was to evaluate the accuracy of ultrasonography (US) for diagnosing AA in pregnant patients. Methods We performed the present systematic review and meta-analysis based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Using a pre-designed standard datasheet, the two authors summarized the data of each study independently. Pregnant women with diagnosed or suspected AA, who have undergone ultrasonography, as well as using CT scan or surgery as the standard method, were included. Results A total of 8 studies consisting of 1593 patients were included. The main analysis showed that the overall sensitivity and specificity were 77.6% and 75.3% for US in diagnosing AA in pregnancy. The sensitivity of US in the first, second, and third trimesters of pregnancy were 69%, 63%, and 51%, respectively. While the corresponding figures for specificity were 85%, 85%, and 65%. There was a significant difference in the diagnostic performance of US between the first two trimesters and the third one. The DORs in these three trimesters were 36, 26, and 1.92, respectively. Conclusions Ultrasound evaluation showed a low diagnostic accuracy for acute appendicitis in pregnant women, especially during the third trimester. These patients should be diagnosed early and accurately to prevent both complications and unnecessary operations. It can be recommended to consider alternative imaging, mostly after negative or uncertain US.