Effect of urinary bladder fullness on fundal height measurements

Measurements of fundal height were obtained on 117 obstetric patients with a full and with an empty bladder. Statistical testing demonstrated a significant difference between the two measurements. A full urinary bladder can change fundal height measurements and thus be a source of false positive variations in the progression of fundal height. There is a need to establish a baseline (with the bladder empty) before measuring fundal height.