Appendicitis in pregnancy: new information that contradicts long-held clinical beliefs

Our purpose was to elicit a better understanding of the presentation of acute appendicitis in pregnancy and to clarify diagnostic dilemmas reported in the literature.

We retrospectively reviewed 66,993 consecutive deliveries from 1986 to 1995 by a computer program. Selected records were reviewed for gestational age; signs and symptoms at presentation; complications including preterm contractions, preterm labor, and appendiceal rupture; and histologic diagnosis of appendicitis.

Of 66, 993 deliveries, 67 (0.1%) were complicated by a preoperative diagnosis of probable appendicitis. Acute appendicitis was confirmed histologically in 45 (67%) of the 67 cases, for an incidence of 1 in 1493 pregnancies in this population. Distribution of suspected appendicitis in pregnancy was as follows: first trimester, 17 cases (25%); second trimester, 27 (40%); and third trimester, 23 (34%). Right-lower-quadrant pain was the most common presenting symptom regardless of gestational age (first trimester, 12 [86%] of 14 cases; second trimester, 15 [83%] of 18 cases; and third trimester, 10 [78%] of 13 cases). The mean maximal temperature for proven appendicitis was 37.6 degrees C (35.5 degrees C-39.4 degrees C), in comparison with 37.8 degrees C (36.7 degrees C-38.9 degrees C; not significant) for those with normal histologic findings. The mean leukocyte count in patients with proven appendicitis was 16.4 x 10(9)/L (8.2-27.0 x 10(9)/L), in comparison with 14.0 x 10(9)/L (5. 9-25.0 x 10(9)/L) for patients with normal histologic findings. At the time of surgery, perforation had occurred in 8 cases. Of 23 patients at > or =24 weeks' gestational age, 19 (83%) had contractions and an additional 3 patients (13%) had preterm labor with documented cervical change. One patient was delivered in the immediate postoperative period because of abruptio placentae.

Pain in the right lower quadrant of the abdomen is the most common presenting symptom of appendicitis in pregnancy regardless of gestational age. Fever and leukocytosis are not clear indicators of appendicitis in pregnancy and preterm labor is a problem after appendectomy, but preterm delivery is rare.