Measurement of intra-abdominal pressure in term pregnancy: a pilot study

This study was conducted to assess the feasibility of measuring intra-abdominal pressure in term parturients under spinal anesthesia.

Intra-abdominal pressure was measured in 20 term parturients after spinal anesthesia for elective caesarean section. Pressure was measured in the supine and 10° left lateral tilt positions with a constant reference point throughout.

Intra-abdominal pressure measurement was feasible and safe to perform. Pressure was significantly lower in the left lateral tilt position than supine (10.9 mmHg ± 4.67 vs. 8.9 mmHg ± 4.87, P=0.0004). The range of intra-abdominal pressure in pregnancy was wide, from 2 to 20 mmHg, with >25% of patients resting with pressures above 12 mmHg in both positions.

Under spinal anesthesia, intra-abdominal pressure in >25% of healthy term parturients was > 12 mmHg, which has conventionally been defined as intra-abdominal hypertension. The intra-abdominal pressure in term pregnancy should be performed in the left lateral tilt position to avoid falsely elevated pressure measurements.