Delaying laparoscopic surgery in pregnant patients with an equivocal acute appendicitis: a step-wise approach does not affect maternal or fetal safety

Background: Accurate and timely diagnoses of acute appendicitis (AA) during pregnancy avoids maternal and fetal morbidity and mortality. We present our experience of using an initial transabdominal ultrasound (US) performed at presentation to diagnose AA in pregnant patients as well as the value of a delayed repeat study in those who remain equivocal. We explore the sensitivity and specificity of this algorithm as well as the maternal and fetal safety of this approach. Methods: Of the 225 patients identified within the study period who underwent laparoscopic appendectomy, 216 met the inclusion criteria and were retrospectively analyzed. If the US performed on presentation revealed AA, surgery was performed. Patients with a non-diagnostic US were admitted with surgery performed if there was clinical and/or biochemical deterioration. Patients who remained equivocal underwent a repeat delayed study. The results of the initial versus delayed studies were compared. Maternal and fetal complications were recorded and contrasted. Results: Of the 216 patients included, 164 (75.9%) had AA, 14 (6.5%) had complicated AA and 38 (17.6%) had a normal appendix. Initial US was diagnostic for 125/216 (57.9%) of patients and 19/34 (55.8%) of patients who underwent a delayed repeat study. The remaining patients underwent empirical surgery. The pooled sensitivity and specificity of US for the cohort was 79.2% and 92.1%, respectively. There was no difference in proxies of maternal or fetal safety between the groups. Conclusion: US is a useful tool for diagnosing AA in pregnancy. In this cohort, performing a delayed repeat US during a period of observation in those patients who remained otherwise equivocal increased the diagnostic yield of the US. Delaying surgery in this specific group of patients does not affect maternal or fetal safety.