Sana Usman1,2, Birgitte Kahrs3,4, Helen Barton1, Kjell Salvesen3,4, Torbjorn Moe Eggebo3,4, Christoph Lees1,2,5. 1. Department of Cancer and Surgery Institute of Reproductive Developmental Biology Hammersmith Campus Du Cane Road London W12 ONN UK. 2. Centre for Fetal Care Imperial College Healthcare NHS Trust Du Cane Road London W12 0HS UK. 3. National Center for Fetal Medicine St Olavs Hospital Trondheim University Hospital Prinsesse Kristinas Gate 3, 7030 Trondheim Norway. 4. Department of Clinical and Molecular Medicine Norwegian University of Science and Technology NO-7491 Trondheim Norway. 5. KU Leuven Oude Markt 13 3000 Leuven Belgium.
Abstract
INTRODUCTION: To compare the duration of vacuum and forceps delivery in relation to ultrasound assessment of fetal head position and station. METHODS: A prospective single-centre cohort study in nulliparous women at term with prolonged second stage of labour. Fetal head position was determined using transabdominal ultrasound and station as head-perineum distance (HPD) from transperineal ultrasound prior to an instrument. The primary outcome was duration of vacuum and forceps to vaginal delivery and was analysed as survival expressed by hazard ratio (HR). Secondary outcomes were delivery mode and immediate neonatal outcome. RESULTS: In the study population of 54 women, the primary instrument was vacuum for 36 and forceps for 18. Four women were delivered by Caesarean section. Estimated median duration for forceps deliveries was 5 min (95% CI 4.0-6.0) vs. 9 min (95% CI 7.3-10.6) for vacuum deliveries (P = 0.17; Log-rank test). The HR for vaginal delivery was 2.02 (95% CI 1.04-3.91, P = 0.038) after adjusting for HPD, maternal age and BMI. OP position had minor influence on the primary outcome (HR changed from 2.02 to 2.08). The first instrument failed in 11/31 (35.5%) where HPD > 35 mm vs. 2/21 (9.5%) where HPD ≤ 35 mm (P < 0.05). There were no cases of Apgar score <7 at 5 min or umbilical artery pH < 7.1. CONCLUSION: In prolonged second stage, delivery with forceps was achieved more quickly than by vacuum when matched for ultrasound determined head station. Irrespective of which was the primary instrument, the failure rate was greater at higher head stations.
INTRODUCTION: To compare the duration of vacuum and forceps delivery in relation to ultrasound assessment of fetal head position and station. METHODS: A prospective single-centre cohort study in nulliparous women at term with prolonged second stage of labour. Fetal head position was determined using transabdominal ultrasound and station as head-perineum distance (HPD) from transperineal ultrasound prior to an instrument. The primary outcome was duration of vacuum and forceps to vaginal delivery and was analysed as survival expressed by hazard ratio (HR). Secondary outcomes were delivery mode and immediate neonatal outcome. RESULTS: In the study population of 54 women, the primary instrument was vacuum for 36 and forceps for 18. Four women were delivered by Caesarean section. Estimated median duration for forceps deliveries was 5 min (95% CI 4.0-6.0) vs. 9 min (95% CI 7.3-10.6) for vacuum deliveries (P = 0.17; Log-rank test). The HR for vaginal delivery was 2.02 (95% CI 1.04-3.91, P = 0.038) after adjusting for HPD, maternal age and BMI. OP position had minor influence on the primary outcome (HR changed from 2.02 to 2.08). The first instrument failed in 11/31 (35.5%) where HPD > 35 mm vs. 2/21 (9.5%) where HPD ≤ 35 mm (P < 0.05). There were no cases of Apgar score <7 at 5 min or umbilical artery pH < 7.1. CONCLUSION: In prolonged second stage, delivery with forceps was achieved more quickly than by vacuum when matched for ultrasound determined head station. Irrespective of which was the primary instrument, the failure rate was greater at higher head stations.
Authors: T M Eggebø; L K Gjessing; C Heien; E Smedvig; I Økland; P Romundstad; K A Salvesen Journal: Ultrasound Obstet Gynecol Date: 2006-04 Impact factor: 7.299