[Trial vacuum extractor for cephalic engagement. 50 cases in French Guiana]

[Instrumental delivery with perineum-fetal head distance >55 MM on ultrasound]

OBJECTIVE

Compare the issue of an operative vaginal delivery associated to the fetal presentation diagnosed by transperineal ultrasound. Three groups were formed: ≥55 mm, between 45 and 55 mm, and <45 mm.

METHODS

A monocentric prospective study on 108 patients has been conducted between April 2011 and August 2014. The distance between perinea and skull has been analyzed to compare the success of operative vaginal delivery considering the level of the fetal presentation in the pelvic cavity.

RESULTS

The failed operative vaginal deliveries are more frequent while the fetal head is above 55 mm (16.7%) or while the fetal head is between 45 and 55 mm (9.1%) than while the fetal skull is under 45 mm (1.8%) (P=0.04). However there is no significant difference for the fetal shoulder dystocia (5.6% vs 3.0% vs 3.5%, P=0.5), nor for the newborn outcomes (16.7 vs 15.2 vs 14; P=0.9).

CONCLUSION

Despite the high rate of failed operative vaginal delivery above 55 mm, it should be considered not to prohibit but send free to the obstetrician appreciation.

[Failure of vacuum extractions: risk factors, maternal and fetal issues]

OBJECTIVES

Determine cases which are at risk of vacuum extraction failure as well as maternal and foetal issues depending on the delivery outcome.

MATERIAL AND METHODS

It was a retrospective study comparing 147 vacuum failures, from January 2002 to December 2010, with a control group randomly composed of 526 successful vacuum extractions. The outcomes were high risk situations of vacuum failure, maternal and neonatal morbidity depending on the delivery method (caesarean section or other instrumental extraction).

RESULTS

The global vacuum failure rate was 3.3 %. During labour, we identified several situations at risk of vacuum extraction failure: cephalhematomas prior to extraction (P<0.001), deflexion attitude (P<0.001), posterior variety (P<0.001), entering above the inlet strait (P<0.001), occiput posterior delivery (P<0.001), fœtal weight greater than 3500g (P=0.023). Neonatals consequency were more Apgar score below 7 at five minutes life (P=0.007), fœtal acidosis (pH<7,20) (P=0.032), neonatal resuscitation (P<0.001), and craniofacial damages (P<0.001).

CONCLUSION

Many dystocic situations occurring during labour require intense care when practicing vacuum extraction since they more frequently result in failure. In case of vacuum extraction failure, immediate adaptation to extra-uterine life seems to be more difficult for new-born babies.

Césarienne pour échec d'extraction par ventouse obstétricale : facteurs de risque et conséquences maternelles et néonatales

OBJECTIVE

To evaluate risk factors associated with failed attempts of vacuum extraction and their outcomes.

PATIENTS AND METHODS

All trial vacuum extractions (metal Minicup) from 1992 to 2000 in Besançon University Hospital Center were retrospectively analysed, namely 2447 cases. Univariate and multivariate analyses of failed vacuum extraction risk factors and descriptive analyse of outcomes were performed.

RESULTS

The rate of failed vacuum extractions was 3.47% (85/2447). A multivariate analysis showed the following independent risks factors in failed extraction: extraction above pelvic level + 2 (OR = 1.8; CI 95%: 1.1-3), newborn weight (OR = 2.9; CI 95%: 1.8-4.9), parity >2 (OR = 0.08; CI 95%: 0.01-0.6). In case of failed vacuum extraction, newborns had a significantly higher rate of Apgar score <7 at 1 min (P = 0.0002), but not at 5 min. These newborns were most regularly admitted in pediatric care units (P = 0.01).

CONCLUSION

The failed trial attempt vacuum extraction rate stays low. These failed instrumental extractions are more common in an extraction above pelvic + 2, a high fetal weight and an arrest during the second stage of labor. There is an increased adverse neonatal outcome. Clinical fetal weight estimation and diagnosis of presentation level in mother pelvis must be performed before vacuum extraction.