Negative appendectomy in pregnant women is associated with a substantial risk of fetal loss

The preoperative diagnosis of acute appendicitis is often inaccurate in pregnant women, and complicated appendicitis is associated with a high rate of fetal loss. The study objective was to evaluate rates of fetal loss and early delivery in pregnant patients undergoing appendectomy, using a large population-based database.

Using the California Inpatient File, we retrospectively analyzed all women undergoing appendectomy between 1995 and 2002 for pregnancy, diagnosis, operative technique, fetal loss, and early delivery during the same hospitalization as appendectomy.

Of 94,789 women who underwent appendectomy, 3,133 were pregnant. Complicated appendicitis was found in 30% of pregnant women and 29% of nonpregnant women (p=NS). The rate of negative appendectomy was considerably higher in pregnant compared with nonpregnant women (23% versus 18%, p < 0.05). Rates of fetal loss and early delivery were considerably higher in women with complex appendicitis (6% and 11% respectively; p < 0.05) in comparison with negative (4% and 10%) and simple (2% and 4%) appendicitis. Using multivariate logistic regression, complicated and negative appendicitis (odds ratio [OR] 2.69 and 1.88 respectively, compared with simple) remained major positive predictors of fetal loss. Also, laparoscopy was associated with a higher rate of fetal loss compared with open appendectomy (odds ratio=2.31).

The current approach to possible acute appendicitis in pregnant women puts 23% at risk for fetal loss, even though they have a normal appendix. These data indicate that reducing fetal loss in pregnant women suspected of having acute appendicitis will require more accurate diagnosis to avoid unnecessary operation.