Tomography (Jan 2023)
Can Intrapartum Ultrasonography Improve the Placement of the Vacuum Cup in Operative Vaginal Deliveries?
Abstract
Although the fetal head position has traditionally been evaluated by digital examination (DE), it has a failure rate ranging between 20 and 70%; hence, intrapartum transabdominal ultrasonography (TUS) has become relevant. We aimed to evaluate the utility of the TUS to identify the fetal head positions in vacuum-assisted deliveries. We performed a prospective observational study including 101 pregnant patients in active labor who required a vacuum-assisted delivery. The fetal head position was assessed by a DE and a TUS prior to vacuum cup placement. After delivery, the optimal vacuum cup placement was evaluated as the distance between the chignon and the flexion point ≤2 cm. The general concordance rate between the DE and TUS was 72.2%, with the poorest concordance rate for occiput posterior positions at 46.1%. In five cases (4.9%), it was not possible to determine the fetal head position through the DE. The correlation was higher in low and medium planes, with 77% and 68.1% concordance rates, respectively, while it was lower in high planes (60%). In 90.1% of cases, the vacuum cup placement was optimal. Our findings show that intrapartum transabdominal ultrasonography is a useful technique to identify the fetal head position allowing optimal placement of the vacuum cup necessary for correct vacuum-assisted delivery.
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