Characterization of ascites present at cesarean section.

Ascites has been reported at cesarean section delivery in pregnancies complicated by preeclampsia. The frequency and composition of peritoneal fluid collections in pregnancy have not previously been described. This descriptive study evaluated presence, composition, and characteristics of ascites present in 41 women undergoing cesarean delivery for a variety of indications. Twenty-six women had sufficient quantities of peritoneal fluid to be collected immediately after opening the parietal peritoneum. The protein content of the fluid was analyzed. The presence of fluid was not related to labor preceding delivery. All preeclamptic women in this study had fluid obtainable at cesarean section. Large volume ascites was noted in five preeclamptic women whose fluid had low total protein content, consistent with a transudate. Intrahepatic portal hypertension is one possible explanation of the large volume and low protein ascites in some preeclamptic patients. Ultrasonic measurements in preeclamptic patients and normotensive pregnant women showed uniform portal vein diameters and Doppler-derived portal vein flow velocities in all patients. The physiology of peritoneal fluid production in complicated and normal pregnancy remains unexplained.