Transperineal ultrasound assessment of fetal head elevation by maneuvers used for managing umbilical cord prolapse

Abstract

OBJECTIVE To objectively assess the degree of fetal head elevation by different maneuvers, including wedging the maternal buttocks, knee chest position, Trendelenburg position and filling up the maternal urinary bladder. METHODS This was a prospective observational study on 20 pregnant women at term before elective Cesarean delivery. A baseline assessment of fetal head station was made when they were in supine position using transperineal ultrasound scanning by measuring psAoP, HSD and HPD. The ultrasonographic measurements of fetal head station were repeated when different maneuvers were applied, and then compared with the baseline. RESULTS When compared to baseline (median psAOP 103.6), knee‐chest position gave the strongest elevation effect, with the greatest reduction in psAOP (80.7; p<0.001), followed by filling the bladder with 500ml (89.9; p=<0.001) and 300ml normal saline (94.4; p<0.001). Filling with 100ml normal saline (96.1; p=0.001), Trendelenburg position (96.8; p=0.014) and wedging the maternal buttocks (98.3; p=0.033) gave modest elevation effect. Similar findings were reported using HSD and HPD. The elevation effect of knee‐chest position was independent of the initial fetal head station, but that of bladder filling was greater when the initial head station was low. CONCLUSIONS To elevate the fetal presentation, knee‐chest position provides the best effect, followed by filling the maternal urinary bladder with 500ml and 300ml fluid respectively. Filling the bladder with 100ml, Trendelenburg position and wedging the maternal buttocks have modest effect. Based on this, we formulate an algorithm for acute management of cord prolapse.