Risk factors associated with subaponeurotic haemorrhage in full-term infants exposed to vacuum extraction
Article first published online: 17 MAR 2006
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 113, Issue 4, page 491, April 2006
How to Cite
Vacca, A. (2006), Risk factors associated with subaponeurotic haemorrhage in full-term infants exposed to vacuum extraction. BJOG: An International Journal of Obstetrics & Gynaecology, 113: 491. doi: 10.1111/j.1471-0528.2006.00910.x
- Issue published online: 5 MAY 2006
- Article first published online: 17 MAR 2006
- Accepted 1 February 2006.
The report by Boo et al.1 makes for disturbing yet compelling reading. To my knowledge, an incidence of 21% for severe subaponeurotic haemorrhage (SAH) in infants exposed to vacuum extraction is the highest ever reported. Nevertheless, this carefully designed study has produced a number of notable findings, namely, that SAH occurred more frequently with the use of soft vacuum extractor cups (56%) and that it was not associated with the number of pulls or a prolonged duration of the procedure. From the data, the authors concluded that independent risk factors associated with SAH were
- • maternal nulliparity
- • failed vacuum extraction
- • deflexing vacuum extractor cup application.
The juxtaposition of this report with the article by Attilakos et al.2 in the same issue of BJOG should produce an interesting dilemma for obstetric policy makers and risk managers. Whereas one in five of the 338 infants exposed to vacuum extraction in the Kuala Lumpur study developed severe SAH, not one case was reported in the 194 infants delivered in the Bristol study despite a 28% failed procedure rate and a 72% multiple instrumental delivery rate in the failed extractions. Furthermore, Boo et al. asserted that nulliparity was a risk factor for SAH; yet, 88% of the mothers in the study by Attilakos et al. were nulliparae. The latter authors suggested that a possible explanation for the 28% vacuum delivery failure in their study was the number of rotational (30%) and midpelvic (70%) procedures. On the other hand, Boo et al. recorded a 4% failure rate in their vacuum extractions, of which 52% were rotational deliveries.
Such contrasting adverse outcomes may be due to factors inherent to the vacuum extractor but are more likely to result from the way the device is used and by whom. The authors state that formal training programmes and competency checks were not in place at both institutions and reported that only 7% of the vacuum deliveries in Bristol and 14% in Kuala Lumpur were performed by specialist obstetricians. While this may be a more accurate reflection of the ‘real-life’ situation especially in most UK hospitals, unless these conditions are changed, reports of suboptimal outcomes associated with vacuum extraction will persist.