An observational study of gastric content in women scheduled for cesarean section or operative hysteroscopy

The estimation of gastric content in third trimester pregnant women has already been studied, conclusions remain contradictory. The aim of this study was to compare gastric content in pregnant and non-pregnant women using gastric ultrasound. We performed an observational two-center study of women scheduled for a cesarean section (CS group) and of non-pregnant women scheduled for hysteroscopy (HS group).

Ultrasound evaluation was performed before surgery with measurement of antral cross-sectional area (CSA) in the semi-recumbent position (SRP), primary outcome, and in the right lateral position (RLD). Gastric fluid volume (GFV) was calculated. Results are expressed as medians (25^th and 75^th percentiles). Perlas Score was evaluated and expressed as number (percentage).

Sixty patients in the CS group and 64 in the HS group were analyzed. Antral CSA (SRP) was greater in the CS group (350 mm² [236-415] vs. 247 mm² [180-318]; P=0.001). Antral CSA (RLD) was also significantly greater in the CS group (P=0.027). GFV was not different between groups whether expressed in absolute value (P=0.516) or relative to weight (P=0.946) mL.kg^-1. Perlas Score repartition was similar in both groups (P=0.860). Kappa coefficients of concordance between CSA, GFV and Perlas Score were slight or at best fair.

Our study confirmed that antral CSA is increased among pregnant women and outlined that antral CSA should not be used alone in the decision-making process especially when the results of indicators (antral CSA, GFV, and Perlas Grading Score) are discordant.