Predictors for failure of vacuum-assisted vaginal delivery: a case-control study § Corine J. Verhoeven a,b, *, Chelly Nuij c , Christel R.M. Janssen-Rolf a , Ewoud Schuit d,e , Joke M.J. Bais c , S. Guid Oei a , Ben Willem J. Mol e,f a Department of Obstetrics & Gynecology, Maxima Medical Center, Veldhoven, The Netherlands b Department of Midwifery Science, AVAG/EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands c Department of Obstetrics & Gynecology, Medical Center Alkmaar, The Netherlands d Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands e Department of Obstetrics & Gynecology, Academic Medical Center, Amsterdam, The Netherlands f Department of Obstetrics & Gynecology, the Robinson Institute, School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia Introduction Vacuum-assisted operative vaginal delivery is used to facilitate childbirth and to avoid cesarean delivery and its associated morbidities in case of non-progression of the second stage of labor or fetal distress. Cesarean delivery rates increase, affecting 33% of all births in the United States (US) in 2011, while rates of operative assisted vaginal deliveries have been declining since the mid-1990s. In the US use of operative delivery with forceps or vacuum extraction was 3.5% in 2011 [1]. In literature, failure rates for vacuum-assisted delivery vary between 5% and 8% [2,3]. There is however a wide range of operative delivery rates (1–23%), both across and within geographic regions in the US [4]. A failed vacuum extraction is associated with adverse maternal and fetal outcomes [5–7], and may be a negative experience for the mother [8]. The guidelines of the British and American Colleges emphasize the importance of adequate training and operator experience but do not specify criteria for the attempt or abandonment of a trial of operative delivery [9,10]. Four or more pulls at attempted vaginal operative delivery has been associated with increased neonatal trauma and admission to special-care baby-unit [8]. European Journal of Obstetrics & Gynecology and Reproductive Biology 200 (2016) 29–34 A R T I C L E I N F O Article history: Received 9 April 2015 Received in revised form 9 February 2016 Accepted 11 February 2016 Keywords: Cesarean section Operative vaginal delivery Prediction Vacuum extraction A B S T R A C T Objective: To identify potential predictors for failed vacuum-assisted delivery. Study design: Retrospective case-control study conducted in two perinatal centers in the Netherlands. Cases were women who underwent a failed vacuum-assisted delivery between 1997 and 2011. A failed vacuum extraction was defined as a delivery that was started as vacuum extraction but was converted to a cesarean section because of failure to progress. As controls we studied two successful vacuum extractions that were performed before the failed one. We used multivariable logistic regression to assess the risk for failed vacuum extraction. Results: Between 1997 and 2011, 6734 trials of vacuum extraction were performed of which 309 failed (4.6%). These 309 cases were compared to the data of 618 women who underwent a successful vacuum extraction. Predictors for failed vacuum-assisted vaginal delivery were increasing gestational age (OR 1.2 per week), maternal height (OR 0.97 per cm), previous vaginal birth as compared to nulliparae (OR 0.32), estimated fetal weight 3750 g as compared to <3250 g (OR 5.7), epidural analgesia (OR 3.0), augmentation (OR 1.4), failure to progress as indication for trial of vacuum delivery (OR 1.7), station of descent of the fetal head (OR 0.31 per station more descended), and occiput posterior position (OR 2.6). The area under the receiver-operating characteristic curve of a prediction model integrating these indicators was 0.83. Conclusion: Failed vacuum extraction can be predicted accurately using both ante- and intrapartum characteristics. There is a strong need for prospective studies on the subject. ß 2016 Elsevier Ireland Ltd. All rights reserved. § This study was conducted in Veldhoven and Alkmaar, the Netherlands. * Corresponding author at: Maxima Medical Center, De Run 4600, P.O. Box 7777, 5500 MB Veldhoven, The Netherlands. Tel.: +31 040 8888385; fax: +31 040 8888387; mobile: +31 6 51853746. E-mail address: corineverhoeven@mmc.nl (Corine J. Verhoeven). Contents lists available at ScienceDirect European Journal of Obstetrics & Gynecology and Reproductive Biology jou r nal h o mep ag e: w ww .elsevier .co m /loc ate/ejo g rb http://dx.doi.org/10.1016/j.ejogrb.2016.02.008 0301-2115/ß 2016 Elsevier Ireland Ltd. All rights reserved.