Fetal rotation during vacuum extractions for prolonged labor: a prospective cohort study.

INTRODUCTION: The aim of the study was to investigate fetal head rotation during vacuum extraction. MATERIAL AND METHODS: We conducted a prospective cohort study from November 2013 to July 2016 in seven European hospitals. Fetal head position was determined with transabdominal or transperineal ultrasound and categorized as occiput anterior (OA), occiput transverse (OT) or occiput posterior (OP) position. Main outcome was the proportion of fetuses rotating during vacuum extraction. Secondary outcomes were conversion of delivery method, duration of vacuum extraction, umbilical artery pH <7.10 and agreement between clinical and ultrasound assessments. RESULTS: The study population comprised 165 women. During vacuum extraction 117/119 (98%) remained in OA and two fetuses rotated to OP position. Rotation from OT to OA position occurred in 14/19 (74%) and to OP position in 5/19 (26%). Rotation from OP to OA position occurred in 15/25 (60%), and 10/25 (40%) fetuses remained in OP position. Delivery information was missing in two cases. The conversion rate from vacuum extraction to cesarean section or forceps was 10% in the OA group vs. 23% in the non-OA group; p < 0.05. The estimated duration of vacuum extraction was significantly shorter in OA fetuses, 7 min vs. 10 min (log rank test p < 0.01). There was no significant difference in umbilical artery pH < 7.10 between OA and non-OA position. Cohens Kappa of agreement between clinical and ultrasound assessments was 0.42 (95% CI 0.26-0.57). CONCLUSION: Most fetuses in OP or OT positions rotated to OA position during vacuum extraction, but the proportion of failed vacuum extractions remained high.

Sonographic prediction of outcome of vacuum deliveries: a multicenter, prospective cohort study.

BACKGROUND: Safe management of the second stage of labor is of great importance. Unnecessary interventions should be avoided and correct timing of interventions should be focused. Ultrasound assessment of fetal position and station has a potential to improve the precision in diagnosing and managing prolonged or arrested labors. The decision to perform vacuum delivery is traditionally based on subjective assessment by digital vaginal examination and clinical expertise and there is currently no method of objectively quantifying the likelihood of successful delivery. Prolonged attempts at vacuum delivery are associated with neonatal morbidity and maternal trauma, especially so if the procedure is unsuccessful and a cesarean is performed. OBJECTIVE: The aim of the study was to assess if ultrasound measurements of fetal position and station can predict duration of vacuum extractions, mode of delivery, and fetal outcome in nulliparous women with prolonged second stage of labor. STUDY DESIGN: We performed a prospective cohort study in nulliparous women at term with prolonged second stage of labor in 7 European maternity units from 2013 through 2016. Fetal head position and station were determined using transabdominal and transperineal ultrasound, respectively. Our preliminary clinical experience assessing head-perineum distance prior to vacuum delivery suggested that we should set 25 mm for the power calculation, a level corresponding roughly to +2 below the ischial spines. The main outcome was duration of vacuum extraction in relation to ultrasound measured head-perineum distance with a predefined cut-off of 25 mm, and 220 women were needed to discriminate between groups using a hazard ratio of 1.5 with 80% power and alpha 5%. Secondary outcomes were delivery mode and umbilical artery cord blood samples after birth. The time interval was evaluated using survival analyses, and the outcomes of delivery were evaluated using receiver operating characteristic curves and descriptive statistics. Results were analyzed according to intention to treat. RESULTS: The study population comprised 222 women. The duration of vacuum extraction was shorter in women with head-perineum distance ≤25 mm (log rank test <0.01). The estimated median duration in women with head-perineum distance ≤25 mm was 6.0 (95% confidence interval, 5.2-6.8) minutes vs 8.0 (95% confidence interval, 7.1-8.9) minutes in women with head-perineum distance >25 mm. The head-perineum distance was associated with spontaneous delivery with area under the curve 83% (95% confidence interval, 77-89%) and associated with cesarean with area under the curve 83% (95% confidence interval, 74-92%). In women with head-perineum distance ≤35 mm, 7/181 (3.9%) were delivered by cesarean vs 9/41 (22.0%) in women with head-perineum distance >35 mm (P <.01). Ultrasound-assessed position was occiput anterior in 73%. Only 3/138 (2.2%) fetuses in occiput anterior position and head-perineum distance ≤35 mm vs 6/17 (35.3%) with nonocciput anterior position and head-perineum distance >35 mm were delivered by cesarean. Umbilical cord arterial pH <7.10 occurred in 2/144 (1.4%) women with head-perineum distance ≤35 mm compared to 8/40 (20.0%) with head-perineum distance >35 mm (P < .01). CONCLUSION: Ultrasound has the potential to predict labor outcome in women with prolonged second stage of labor. The information obtained could guide whether vacuum delivery should be attempted or if cesarean is preferable, whether senior staff should be in attendance, and if the vacuum attempt should be performed in the operating theater.

Estimation of fetal weight in pregnancies past term.

INTRODUCTION: The aim of the study was to investigate the accuracy of estimating fetal weight with ultrasound in pregnancies past term, using the eSnurra algorithm. MATERIAL AND METHODS: In all, 419 women with pregnancy length of 290 days, attending a specialist consultation at Stavanger University Hospital, Norway, were included in a prospective observational study. Fetal weight was estimated using biparietal diameter (BPD) and abdominal circumference (AC). The algorithm implemented in an electronic calculation (eSnurra) was used to compute estimated fetal weight (EFW). Results were compared with birthweight (BW). RESULTS: The mean interval between the ultrasound examination and birth was 2 days (SD 1.4). The median difference between BW and EFW was -6 g (CI -40 to +25 g) and the median percentage error was -0.1% (95% CI -1.0 to 0.6%). The median absolute difference was 190 g (95% CI 170-207 g). The BW was within 10% of EFW in 83% (95% CI 79-87%) of cases and within 15% of EFW in 94% (95% CI 92-96%) of cases. Limits of agreement (95%) were from -553 g to +556 g. Using 5% false-positive rates, the sensitivity in detecting macrosomic and small for gestational age fetuses was 54% (95% CI 35-72%) and 49% (95% CI 35-63%), respectively. CONCLUSION: The accuracy of fetal weight estimation was good. Clinicians should be aware of limitations related to prediction at the upper and lower end, and the importance of choosing appropriate cut-off levels.

Judicious use of oxytocin augmentation for the management of prolonged labor.

INTRODUCTION: A protocol including judicious use of oxytocin augmentation was investigated to determine whether it would change how oxytocin was used and eventually influence labor and fetal outcomes. MATERIAL AND METHODS: The population of this cohort study comprised 20 227 delivering women with singleton pregnancies ≥37 weeks, cephalic presentation, spontaneous or induced onset of labor, without previous cesarean section. Women delivering from 2009 to 2013 at Stavanger University Hospital, Norway, were included. Data were collected prospectively. Before implementing the protocol in 2010, oxytocin augmentation was used if progression of labor was perceived as slow. After implementation, oxytocin could only be started when the cervical dilation had crossed the 4-h action line in the partograph. RESULTS: The overall use of oxytocin augmentation was significantly reduced from 34.9% to 23.1% (p < 0.01). The overall frequency of emergency cesarean sections decreased from 6.9% to 5.3% (p < 0.05) and the frequency of emergency cesarean sections performed due to fetal distress was reduced from 3.2% to 2.0% (p = 0.01). The rate of women with duration of labor over 12 h increased from 4.4% to 8.5% (p < 0.01) and more women experienced severe estimated postpartum hemorrhage (2.6% vs. 3.7%; p = 0.01). The frequency of children with pH <7.1 in the umbilical artery was reduced from 4.7% to 3.2% (p < 0.01). CONCLUSIONS: The frequency of emergency cesarean section was reduced after implementing judicious use of oxytocin augmentation. Our findings may be of interest in the ongoing discussion of how the balanced use of oxytocin for labor augmentation can best be achieved.

Intrapartum assessment of caput succedaneum by transperineal ultrasound: a two-centre pilot study.

Digital assessments of caput succedaneum are subjective; however, caput succedaneum can also be expressed as ultrasound measured skin-skull distance (SSD). In this study, we aimed to compare the clinical and ultrasound assessment of caput succedaneum (caput) in nulliparous women in the first stage of labour. Furthermore, we aimed to investigate the repeatability of ultrasound measurements. We observed a significant but low correlation between clinical and ultrasound assessments (Kappa value 0.29; P < 0.01). Interobserver repeatability for SSD showed an intraclass correlation coefficient of 0.96 (95% CI, 0.93-0.98). The mean difference for the caput measurements was -0.4 mm (95% CI, -0.85 to 0.05), and limits of agreement were -3.44 to 2.64 mm. We conclude that ultrasound measured SSD is an objective expression of caput with significant correlation with clinical assessment.

A more liberal approach towards induction of labour in prolonged pregnancy does not result in an adverse labour outcome.

INTRODUCTION: Discussions among Norwegian obstetricians on how to handle prolonged pregnancies have been ongoing throughout the past decade. In 2011, the Norwegian Directorate of Health recommended a specialist care consultation one week after the estimated date of delivery, implying prompt induction of labour in women at risk. The aim of this study was to compare an expectant management with a more liberal approach towards induction of labour, and to assess how the women responded to these recommendations. MATERIAL AND METHODS: A quality assurance study was performed at Stavanger University Hospital in women with a pregnancy length ≥ 290 days. A total of 480 women who delivered prior to the introduction of the new guidelines (control period) were compared with 493 women treated according to the new recommendations (study period). RESULTS: A total of 421/493 (85%) women in the study period attended the consultation on day 290. Of these, 61% were recommended early induction of labour (within 24 hours) because their pregnancy was a risk pregnancy. Four percent of the women with risk factors awaited spontaneous labour until day 294, versus 20% of low-risk women. When comparing the two periods, we observed an increase in the frequency of induced labour from 38% to 65%, an insignificant elevation of Caesarean section rates from 11.5% to 13.8%, and no significant increase in other interventions or in adverse newborn outcomes. CONCLUSION: A more liberal approach towards induction of labour one week after the estimated date of delivery did not lead to an adverse labour outcome. FUNDING: none. TRIAL REGISTRATION: not relevant.