Vacuum-assisted delivery outcomes: is advanced maternal age a factor?

PURPOSE: This study evaluated age-related maternal outcomes of vacuum-assisted vaginal deliveries (VAD). METHODS: This retrospective cohort study included all nulliparous women with singleton VAD in one academic institution. Study group parturients were maternal age ≥ 35 years and controls < 35. Power analysis revealed that 225 women/group would be sufficient to detect a difference in the rate of third- and fourth-degree perineal tears (primary maternal outcome) and umbilical cord pH < 7.15 (primary neonatal outcome). Secondary outcomes were maternal blood loss, Apgar scores, cup detachment, and subgaleal hematoma. Outcomes were compared between groups. RESULTS: From 2014 to 2019, 13,967 nulliparas delivered at our institution. Overall, 8810 (63.1%) underwent normal vaginal delivery, 2432 (17.4%) instrumental, and 2725 (19.5%) cesarean. Among 11,242 vaginal deliveries, 10,116 (90%) involved women < 35, including 2067 (20.5%) successful VAD vs. 1126 (10%) women ≥ 35 years with 348 (30.9%) successful VAD (p < 0.001). Rates of third- and fourth-degree perineal lacerations were 6 (1.7%) with advanced maternal age and 57 (2.8%) among controls (p = 0.259). Cord pH < 7.15 was similar: 23 (6.6%) study group and 156 (7.5%) controls (p = 0.739). CONCLUSION: Advanced maternal age and VAD are not associated with higher risk for adverse outcomes. Older, nulliparous women are more likely to undergo vacuum delivery than younger parturients.

Traction force profile in children with severe perinatal outcomes delivered with a digital vacuum extraction handle: A case-control study.

INTRODUCTION: During the second stage of labor, vacuum-assisted delivery is an alternative to forceps delivery and emergency cesarean section. Extensive research concerning perinatal outcomes has indicated that the risk of complications, although rare, is higher than with a spontaneous vaginal delivery. An important factor related to perinatal outcomes is the traction force applied. Our research group previously developed a digital extraction handle, the Vacuum Intelligent Handle-3 (VIH3), that measures and records traction force. The objective of this study was to compare traction force profiles in children with and without severe perinatal outcomes delivered with the digital handle. A secondary aim was to establish a safe force limit. MATERIAL AND METHODS: This was an observational case-control study at the delivery ward at Karolinska University Hospital, Sweden. In total, 573 children delivered with the digital handle between 2012 and 2018 were included. Cases were defined as a composite of severe perinatal outcomes, including subgaleal hematoma, intracranial hemorrhage, hypoxic ischemic encephalopathy 1-3, seizures or death. The cases in the cohort were matched 1:3 based on five matching variables. Traction profiles were analyzed using the MATLAB® software and conditional logistic regression. RESULTS: The incidence of severe perinatal outcomes was 2.3%. The 13 cases were matched with three controls each (n = 39). A statistically significant increased odds for higher total traction forces was seen in the case group (odds ratio [OR] 1.004; 95% confidence interval [CI] 1.001-1.007) and for the peak force (OR 1.022; 95% CI 1.004-1.041). Several procedure-related parameters were significantly increased in the case group. As expected, some neonatal characteristics also differed significantly. An upper force limit of 343 Newton minutes (Nmin) revealed an 86% reduction in severe perinatal outcomes (adjusted OR 0.14; 95% CI 0.04-0.5). CONCLUSIONS: Children with severe perinatal outcomes had traction force profiles with significantly higher forces. The odds for severe perinatal outcomes increased for every increase in Nmin and Newton used during the extraction procedure. A calculated total force level of 343 Nmin is suggested as an upper safety limit, but this must be tested prospectively to provide validity.

Adverse outcomes in vacuum-assisted delivery after detachment of non-metal cup: a retrospective cohort study.

PURPOSE: To evaluate neonatal and maternal outcomes associated with detachment of non-metal vacuum cup during delivery and to identify risk factors for these detachments. METHODS: This retrospective cohort study included women with singleton pregnancy, who underwent vacuum-assisted vaginal delivery with a non-metal vacuum cup in a single academic institution, January 2014-August 2019. Failed vacuum deliveries were excluded. Primary outcomes were defined as subgaleal hematoma (SGH) and cord blood pH < 7.15. Secondary outcome included other neonatal complications and adverse maternal outcomes. Outcomes were compared between vacuum-assisted deliveries with and without cup detachment during the procedure. RESULTS: A total of 3246 women had successful VAD and met the inclusion criteria. During the procedure, the cup detached at least once in 665 (20.5%) deliveries and did not detach in 2581 (79.5%). The cup detachment group experienced higher rates of SGH (8.9% vs. 3.5%, p = 0.001) and cord blood pH < 7.15 (9.8% vs. 7.1%, p = 0.03). There were also more neonatal intensive care unit admissions (NICU) (4.4% vs. 2.7%, p = 0.03) and more fetuses with occiput posterior position (70.8% vs. 79.4%, p = 0.001), the vacuum duration was slightly longer (6 ± 3.7 vs. 5 ± 2.9 min) and more neonates had birth weights > 3700 g (14.1% vs, 10.3%, p = 0.006). Interestingly, there were more males in that group (60.6 vs. 54.6, p = 0.005). All these factors remained significant after controlling for potential confounders. CONCLUSIONS: Vacuum cup detachment has several predictive characteristics and is associated with adverse neonatal outcomes that should be incorporated into decisions made during the procedure.

Comparison of a practice-based versus theory-based training program for conducting vacuum-assisted deliveries: a randomized-controlled trial.

PURPOSE: Vacuum-assisted deliveries (VAD) are complex procedures that require training and experience to be performed proficiently. We aimed to evaluate if a more resource intensive practice-based training program for conducting VAD is more efficient compared to a purely theory-based training program, with respect to immediate training effects and persistence of skills 4-8 weeks after the initial training. METHODS: In this randomized-controlled study conducted in maternity staff, participants performed a simulated low-cavity non-rotational vacuum delivery before (baseline test) and immediately after the training (first post-training test) as well as 4-8 weeks thereafter (second post-training test). The study's primary endpoint was to compare training effectiveness between the two study groups using a validated objective structured assessment of technical skills (OSATS) rating scale. RESULTS: Sixty-two participants were randomized to either the theory-based group (n = 31) or the practice-based group (n = 31). Total global and specific OSATS scores, as well as distance of cup application to the flexion point improved significantly from baseline test to the first post-training test in both groups (pall < 0.007). Skill deterioration after 4-8 weeks was only found in the theory-based group, whereas skills remained stable in the practice-based group. CONCLUSION: A practice-based training program for conducting VAD results in comparable immediate improvement of skills compared to a theory-based training program, but the retention of skills 4-8 weeks after training is superior in a practice-based program. Future studies need to evaluate, whether VAD simulation training improves maternal and neonatal outcome after VAD.

Risk of anal sphincter injury in trial of labor post cesarean section.

INTRODUCTION: We wanted to evaluate whether secundiparas who achieved vaginal birth after cesarean (VBAC) were at an increased risk for obstetric anal sphincter injury (OASI) compared to primiparas who delivered vaginally, with a stratification by the mode of delivery-spontaneous or operative vaginal delivery. MATERIAL AND METHODS: We conducted a retrospective cohort study of primiparous women who delivered by vacuum-assisted delivery between March 2011 and June 2019. Primiparas delivering vaginally and secundiparas undergoing VBAC were compared. The cohort was further stratified into two categories: spontaneous vaginal delivery and operative vaginal delivery. RESULTS: Overall, 23 822 primiparas who delivered vaginally and 1596 secundiparas who underwent VBAC were analyzed. Operative vaginal delivery was performed in 4561 deliveries. OASI rate did not differ between the VBAC and primipara groups (1.3% vs 1.8%, P = .142). A total of 20 857 women delivered by spontaneous vaginal delivery, among them 1180 (5.7%) women were secundiparas and 19 677 (94.3%) were primiparas. OASI rate was comparable between the secundiparas undergoing VBAC and primiparas delivering vaginally (17 [1.4%] vs 338 [1.7%], P = .436). A total of 4561 women delivered by operative vaginal delivery, among them 416 (9.1%) were secundiparas and 4145 (90.9%) were primiparas. The rate of operative vaginal deliveries was higher among the VBAC group compared with the primipara group (6.1% vs 17.4%, P < .001). However, women undergoing successful VBAC had lower rates of OASI compared with primiparas (3 [0.7%] vs 96 [2.3%]; odds ratio [OR] 0.30, 95% CI 0.09-0.97, P = .032). After multivariate logistic regression including all statistically significant factors, OASI was not associated with VBAC in spontaneous or operative vaginal deliveries (adjusted OR 0.85, 95% CI 0.51-1.40 and 0.39, 95% CI 0.12-1.28, respectively). CONCLUSIONS: Secundiparas undergoing VBAC were not at a higher risk of OASI when compared with primiparas delivering vaginally, either in spontaneous or operative vaginal deliveries. This information might aid when counseling women contemplating a trial of labor after cesarean--to address their concerns regarding the risks and benefits of VBAC.

Perinatal outcome after vacuum assisted delivery with digital feedback on traction force; a randomised controlled study.

BACKGROUND: Low and mid station vacuum assisted deliveries (VAD) are delicate manual procedures that entail a high degree of subjectivity from the operator and are associated with adverse neonatal outcome. Little has been done to improve the procedure, including the technical development, traction force and the possibility of objective documentation. We aimed to explore if a digital handle with instant haptic feedback on traction force would reduce the neonatal risk during low or mid station VAD. METHODS: A two centre, randomised superiority trial at Karolinska University Hospital, Sweden, 2016-2018. Cases were randomised bedside to either a conventional or a digital handle attached to a Bird metal cup (50 mm, 80 kPa). The digital handle measured applied force including an instant notification by vibration when high levels of traction force were predicted according to a predefined algorithm. Primary outcome was a composite of hypoxic ischaemic encephalopathy, intracranial haemorrhage, seizures, death and/or subgaleal hematoma. Three hundred eighty low and mid VAD in each group were estimated to decrease primary outcome from six to 2 %. RESULTS: After 2 years, an interim analyse was undertaken. Meeting the inclusion criteria, 567 vacuum extractions were randomized to the use of a digital handle (n = 296) or a conventional handle (n = 271). Primary outcome did not differ between the two groups: (2.7% digital handle vs 2.6% conventional handle). The incidence of primary outcome differed significantly between the two delivery wards (4% vs 0.9%, p < 0.05). A recalculation of power revealed that 800 cases would be needed in each group to show a decrease in primary outcome from three to 1 %. This was not feasible, and the study therefore closed. CONCLUSIONS: The incidence of primary outcome was lower than estimated and the study was underpowered. However, the difference between the two delivery wards might reflect varying degree of experience of the technical equipment. An objective documentation of the extraction procedure is an attractive alternative in respect to safety and clinical training. To demonstrate improved safety, a multicentre study is required to reach an adequate cohort. This was beyond the scope of the study. TRIAL REGISTRATION: ClinicalTrials.gov NCT03071783 , March 1, 2017, retrospectively registered.

Risk factors for obstetric anal sphincter injury among parous women.

PURPOSE: Nulliparity and operative vaginal delivery are established risk factor for obstetric anal sphincter injury (OASI). However, risk factors for OASIS occurrence among parous women delivering vaginally are not well-established. We aimed to study the risk factors for OASI occurrence among parous women. METHODS: A retrospective study including all parous women who delivered vaginally at term during 2011-2019 at a university hospital. Deliveries of parous women with OASI were compared to deliveries without OASI. The risk factors associated with OASI were investigated. RESULTS: Overall, 35,397 women were included in the study with an OASI rate of 0.4% (n = 144). A higher rate of only one previous vaginal delivery was noted in the OASI group (78.5% vs. 46.4%, OR [95% CI] 4.20, 2.82-6.25, p < 0.001). The rate of vacuum-assisted deliveries was comparable between the study groups. The median birth weight was higher among the OASI group (3566 vs. 3300 g, p < 0.001), as was the rate of macrosomic neonates (19.4% vs. 5.5%, OR [95% CI] 4.15, 2.74-6.29, p < 0.001). On multivariate logistic regression analysis, only two factors were independently positively associated with the occurrence of OASI: a history of only one previous vaginal delivery (adjusted OR [95% CI] 4.34, 2.90-6.49, p = 0.001), and neonatal birth-weight (for each 500 g increment) (adjusted OR [95% CI] 2.51, 1.84-3.44, p < 0.001). CONCLUSIONS: Among parous women, the only factors found to be independently positively associated with OASI were the order of parity and neonatal birth-weight. Vacuum-assisted delivery was not associated with an increased risk of OASI among parous women.

Vacuum extraction delivery at first vaginal birth following cesarean: maternal and neonatal outcome.

OBJECTIVE: To evaluate the maternal and neonatal morbidity outcome associated with vacuum assisted (VA) vaginal delivery at first vaginal birth following a previous cesarean delivery (CD). STUDY DESIGN: This is a retrospective computerized study conducted at a single tertiary center, between 2005 and 2018. The study compared the morbidity outcome of VA vaginal delivery between two groups of parturients at their first vaginal birth; primigravid and those in second delivery with a prior cesarean. The primary outcome was the maternal adverse outcome: postpartum hemorrhage (PPH), anal sphincter injuries, retained placenta, shoulder dystocia, uterine rupture, and intensive care unit (ICU) admissions. Secondary outcome was the neonatal adverse outcome: Apgar score, NICU admission, meconium aspiration, jaundice, sepsis, birth trauma, and death. Univariate analysis was followed by a multiple logistic regression model controlling for potential confounders, adjusted odds ratios (95% confidence interval). RESULTS: During the study period, we identified 3695 parturients that engaged in Trial of labor after cesarean with no previous vaginal birth, among which 679 (18.4%) delivered by Vacuum (VA-VBAC). These were compared to 6544/43,083 (15.2%) primigravid delivered by Vacuum. The VA-VBAC group had higher risk of PPH (10.5% vs. 7.2%, p < 0.01), blood transfusions (5.6% vs. 3.5%, p < 0.01), retained placenta (10.2% vs. 4.7%, p < 0.01), and uterine rupture (0.4% vs. 0%, p < 0.01). The adverse neonatal outcomes were comparable among groups. CONCLUSION: The VA-VBAC has a higher risk of maternal postpartum hemorrhagic complications; preventive measures should be directed to this selected group of operative vaginal deliveries.

Does birthweight have a role in the effect of episiotomy on anal sphincter injury?

PURPOSE: Most professional guidelines advise against routine episiotomy during vaginal delivery, although mounting evidence supports its protective role regarding obstetric anal sphincter injury (OASI). We aimed to study the effect of lateral and mediolateral episiotomies on the rate of OASI in relation to birthweight among nulliparous women undergoing vaginal delivery. METHODS: A historical cohort study was conducted of all nulliparous women who delivered vaginally at term between 2011 and 2019 at a tertiary university hospital. Women were allocated into two groups: (1) with OASI and (2) without OASI. Episiotomy performance and birthweight groups were analyzed. RESULTS: Overall, 22,250 deliveries were analyzed for inclusion: 18,533 (83.3%) spontaneous vaginal deliveries (SVD), 3222 (14.5%) vacuum-assisted deliveries (VAD) and 495 (2.2%) forceps deliveries. Total episiotomy and OASI rate was 48.2% and 1.7%, respectively. Episiotomy rate was lower in the OASI group as compared to the no OASI group (158 (41.3%) vs. 10,568 (48.3%), OR 0.75, 0.61-0.92, p = 0.006). Median birthweight was higher for OASI group neonates (3355 vs. 3160, p < 0.001). In SVDs, episiotomy decreased the rate of OASI in neonatal birthweight groups of 3000-3499, 3500-3999 and > 4000 g (OR 0.56, 0.38-0.82, p = 0.003; 0.66, 0.45-0.99, p = 0.04 and 0.24, 0.07-0.78, p = 0.01, respectively). In VADs, episiotomy decreased the rate of OASI in the neonatal weight groups of 2500-2999 and 3000-3499 g (OR 0.36, 0.14-0.89, p = 0.02 and OR 0.38, 0.19-0.75, p = 0.004, respectively). CONCLUSIONS: Lateral and mediolateral episiotomies are independent modifiable predictors of OASI, protective against OASI in SVDs when neonates weigh > 3000 g and 2500-3499 g in VADs.

Risk factors associated with subgaleal hemorrhage in neonates exposed to vacuum extraction.

INTRODUCTION: Subgaleal hemorrhage (SGH) is a life-threatening neonatal condition that is strongly associated with vacuum assisted delivery (VAD). The factors associated with the development of SGH following VAD are not well-established. We aimed to evaluate the factors associated with the development of SGH following attempted VAD. MATERIAL AND METHODS: A retrospective case-control study of women who delivered at a tertiary university-affiliated medical center in Jerusalem, Israel, during 2009-2018. Cases comprised all parturients with singleton pregnancies for whom attempted VAD resulted in neonatal SGH. A control group of VAD attempts was established by matching one-to-one according to gestational age at delivery, parity and year of delivery. Fetal, intrapartum and vacuum procedure characteristics were compared between the groups. RESULTS: In all, 313 (89.5%) of the 350 attempted VAD were nulliparous. Baseline maternal and fetal characteristics were similar between the groups except for higher neonatal birthweight in the SGH group. In multivariate logistic regression analysis, only six independent risk factors were significantly associated with the development of SGH: second-stage duration (for each 30-minute increase, adjusted odds ratio [OR] 1.13; 95% confidence intervals [CI] 1.04-1.25; P = .006), presence of meconium-stained amniotic fluid (adjusted OR 2.61; 95% CI 1.52-4.48; P = .001), presence of caput succedaneum (adjusted OR 1.79; 95% CI 1.11-2.88; P = .01), duration of VAD (for each 3-minute increase, adjusted OR 2.04; 95% CI 1.72, 2.38; P < .001), number of dislodgments (adjusted OR 2.38; 95% CI 1.66-3.44; P < .001), and fetal head station (adjusted OR 3.57; 95% CI 1.42-8.33; P = .006). Receiver operating characteristic curves showed that VAD duration of ≥15 minutes had a 96.7% sensitivity and 75.0% specificity in predicting SGH formation, with an area under the curve equal to .849. CONCLUSIONS: Vacuum duration, the number of dislodgments, the duration of second stage of delivery, fetal head station, the presence of caput succedaneum and the presence of meconium were found to be independently associated with SGH formation.

Operative vaginal deliveries and their impact on maternal and neonatal outcomes - prospective analysis.

OBJECTIVE: Evaluation of maternal and neonatal outcomes in operative vaginal deliveries in prospective study analysis. DESIGN: Prospective case-control study analysis. SETTING: Prospective analysis of 292 operative vaginal deliveries (VEX, forceps) for the period June 2016 - August 2017 from overall 6056 vaginal deliveries. Type and frequency of maternal and neonatal trauma occurence was observed in connection with using vacuum-assisted delivery and forceps delivery, mainly the cephalohematomas and their complications. Collected data were statistically analysed. RESULTS: In the reported period from overall 6056 deliveries there were 216 vacuumextractions (3.6%) and 72 forceps deliveries (1.2%) performed. Both methods were used in four patients (VEX and forceps). The most frequent trauma in newborns were cephalohematomas. Remarkable cephalohematoma, requiring further observation has occured in 40 newborns (18.5%) after vacuum-assisted delivery and in 5 newborns (6.9%), (p = 0,017) after forceps delivery. Consequential punction of cephalohematoma occured only after vacuumextraction delivery and in 6 newborns (15.0 %). The third degree perineal rupture occured after vacuumextraction in 20 patients (9.3%) and after forceps delivery in 12 patients (16.7%), (p = 0,091). The fourth degree perineal rupture occured only after vacuumextraction and in 1 case (0.5%). CONCLUSION: The vacuumextraction compared with forceps is more likely to be associated with the statistically significant incidence of cephalohematomas and their further treatment. Forceps deliveries compared with vacuumextraction are more likely to be associated with the maternal perineal trauma, but the diference was not statistically significant.

Non-progressive labor in the second stage leading to vacuum extraction is a risk factor for recurrent non-progressive labor.

OBJECTIVE: To address risk factors and perinatal outcomes after vacuum-assisted delivery (VAD) due to non-progressive labor (NPL) 2nd stage, and to assess its impact on the subsequent delivery. METHODS: A retrospective, population-based cohort study was conducted in a tertiary medical center. Maternal characteristics, and maternal and neonatal outcomes of singleton pregnancies that resulted in VAD due to NPL 2nd stage were compared to those that resulted in VAD due to other indications. Multiple logistic regression models were constructed. RESULTS: Out of 202,462 singleton deliveries, 3.4% were delivered using VAD. Of these, 1928 VAD due to NPL 2nd stage and 4985 VAD due to other indications were identified. Independent risk factors for VAD due to NPL 2nd stage were identified: advanced gestational age, pre-eclampsia, and labor induction. VAD due to NPL 2nd stage in the index pregnancy was noted as an independent risk factor for NPL 1st stage and NPL 2nd stage during the subsequent pregnancy. CONCLUSION: VAD due to NPL 2nd stage results in adverse perinatal outcome in the index and subsequent pregnancies. VAD due to NPL 2nd stage in the index pregnancy is an independent risk factor for NPL 1st stage and NPL 2nd stage during the subsequent pregnancy.

Is vaginal birth after cesarean section a risk factor for obstetric anal sphincter injury?

OBJECTIVE: To investigate whether women undergoing their first vaginal delivery after a previous cesarean section (secundiparous) are at increased risk for obstetric anal sphincter injury (OASI) compared with primiparous women. METHODS: A retrospective cohort study of 85 428 women who delivered vaginally over a 10-year period in a single tertiary medical center. Incidence of OASI, risk factors, and clinical characteristics were compared between primiparous women who delivered vaginally and secundiparous women who underwent their first vaginal birth after cesarean section (VBAC). A multivariable logistic regression analysis was used to study the association between VBAC and OASI. RESULTS: Overall, 36 250 primiparous and 1602 secundiparous women were enrolled, 309 of whom had OASI. The rates of OASI were similar among secundiparous women who had VBAC and primiparous women who underwent vaginal delivery (15 [0.94%] vs 294 [0.81%], P = 0.58). The proportions of third- and fourth-degree tears were also similar among secundiparous and primiparous women who experienced OASI (87% vs 91.5%, and 13% vs 8.5%, respectively, P = 0.68). Furthermore, the rates of OASI were similar in both study groups, although secundiparous women who underwent VBAC had higher rates of birth weights exceeding 3500 g (414 [25.8%] vs 8284 [22.8%], P = 0.016), and higher rates of vacuum-assisted deliveries (338 [21%] vs 6224 [17.2%], P < 0.001). A multivariate logistic regression analysis failed to establish a statistically significant association between VBAC and OASI (odds ratio 0.672, 95% confidence interval 0.281-1.61, P = 0.37). CONCLUSIONS: No increased risk for OASI was found in secundiparous women who underwent VBAC compared with primiparous women at their first vaginal birth.

Does delayed vacuum-assisted delivery harbor greater maternal or neonatal complications?

OBJECTIVE: To compare maternal and fetal outcomes between early (<2 h) and delayed (>2 h) vacuum extraction (VE) deliveries. METHODS: We performed a retrospective cohort study in a single, university-affiliated medical center (2014-2021). We included term singleton pregnancies delivered by VE, allocated into one of two groups according to second stage duration: <2 h or >2 h. Primary outcome was maternal composite adverse outcome (included chorioamnionitis, 3-4 degree lacerations, and postpartum hemorrhage [PPH]). RESULTS: We included 2521 deliveries: 2261 (89.6%) with early VE and 260 (10.4%) with delayed VE. Study groups' characteristics were not different, except of parity. Maternal composite outcome almost reached a significance (P = 0.054) comparing between the groups. Comparing second stage length up to 2 h versus more, there was similar rate of advance maternal lacerations. However, extending the second stage to more than 3 h was associated with third degree lacerations compared to 2-3 h (9.8% vs 3%, P = 0.011). There were significantly more PPH events in the later VE group (P = 0.004), but the need for blood transfusions was similar. The rates of 5 min Apgar score ≤7 (P = 0.001) and umbilical artery pH <7.0 were significantly higher in group 2 compared with group 1. The effect was much more pronounced when second stage was >3 h. After conducting multiregression analysis, the results became insignificant. CONCLUSION: Our study suggests that VE performed in the late second stage of labor, up to 3 h, is safe as VE performed in the early stages regarding maternal and neonatal outcomes. Extra caution is needed with extended second stage to more than 3 h.

A preliminary quantification of the clinical gesture during vacuum assisted delivery on a training dummy.

BACKGROUND: The vacuum assisted delivery represents, in France, the most used operative vaginal delivery technique. The purpose was to provide a preliminar quantification of the operator's hand kinematics while performing a vacuum assisted delivery. METHODS: A group of 21 participants composed of 12 trainees and 9 obstetricians were recorded performing a vacuum assisted delivery on a training dummy, the matching fetal presentation was a left occiput anterior position. FINDINGS: The mean movement was composed of a first phase corresponding to a descendant pull, followed by an ascendant finish of the gesture. No significative difference were found between the trainees and the obstetricians' mean gesture. INTERPRETATION: This is the first quantification of the clinical gesture associated with the vacuum assisted delivery.

Can Intrapartum Ultrasonography Improve the Placement of the Vacuum Cup in Operative Vaginal Deliveries?

Although the fetal head position has traditionally been evaluated by digital examination (DE), it has a failure rate ranging between 20 and 70%; hence, intrapartum transabdominal ultrasonography (TUS) has become relevant. We aimed to evaluate the utility of the TUS to identify the fetal head positions in vacuum-assisted deliveries. We performed a prospective observational study including 101 pregnant patients in active labor who required a vacuum-assisted delivery. The fetal head position was assessed by a DE and a TUS prior to vacuum cup placement. After delivery, the optimal vacuum cup placement was evaluated as the distance between the chignon and the flexion point ≤2 cm. The general concordance rate between the DE and TUS was 72.2%, with the poorest concordance rate for occiput posterior positions at 46.1%. In five cases (4.9%), it was not possible to determine the fetal head position through the DE. The correlation was higher in low and medium planes, with 77% and 68.1% concordance rates, respectively, while it was lower in high planes (60%). In 90.1% of cases, the vacuum cup placement was optimal. Our findings show that intrapartum transabdominal ultrasonography is a useful technique to identify the fetal head position allowing optimal placement of the vacuum cup necessary for correct vacuum-assisted delivery.

Head position and vacuum-assisted delivery using the Kiwi Omnicup.

OBJECTIVE: To evaluate the association between fetal head position during prevacuum assessment and adverse outcomes. METHOD: This retrospective cohort study included all vacuum-assisted deliveries using the Kiwi Omnicup over 5 years. Primary outcomes were third- or fourth-degree perineal tear, pH < 7.1, and subgaleal hematoma (SGH). AGAR, neonatal intensive care unit admission, cephalohematoma, Erb's palsy, third-stage duration, and postpartum hemorrhage were secondary. Outcomes were compared between the occiput posterior (OP) and occiput anterior (OA) positions. RESULTS: The study included 1960 patients. OP position was more likely to involve epidural analgesia (311 [82.5%] vs. 1216 [77%], P = 0.020), higher fetal head station (P = 0.001), higher percentage of cup detachments (121 cases [32.1%] vs. 307 [19.4%], P = 0.001), and longer procedure (5.5 ± 3.7 min vs. 4.7 ± 2.8 min, P = 0.001). OP was associated with umbilical cord pH < 7.1 (21 [5.5%] vs. 52 [3.9%], P = 0.032), NICU admissions (16 [4.2%] vs. 38 [2.4%], P = 0.049), SGH (18 [4.8%] vs. 38 [2.4%], P = 0.013), and high-degree perineal tears (12 [3.2%] vs. 26 [1.7%], with borderline significance, P = 0.051). SGH and high-grade tears remained significantly associated with OP position (P = 0.008 and P = 0.016, respectively) after adjusting for maternal age, nulliparity, diabetes, epidural anesthesia, preprocedure head station, and birth weight. CONCLUSION: OP position is an independent risk-factor for anal sphincter injury and SGH during vacuum-assisted delivery.

Head Injuries Related to Birth Trauma in Low Birthweight Neonates During Vacuum Extraction.

Introduction Preterm delivery (gestational age < 34 w) is a relative contraindication to vacuum extraction. Current data do not differentiate clearly between preterm delivery and low birthweight. We aimed to evaluate the impact of non-metal vacuum cup extraction on neonatal head injuries related to birth trauma in newborns with low birthweights (< 2500 g). Materials and Methods A retrospective cohort of 3377 singleton pregnancies delivered by vacuum extraction from 2014 to 2019. All were gestational age ≥ 34 w. We compared 206 (6.1%) neonates with low birthweights < 2500 g to 3171 (93.9%) neonates with higher birthweights, divided into 3 subgroups (2500-2999 g, 3000-3499 g, and ≥ 3500 g). A primary composite outcome of neonatal head injuries related to birth trauma was defined. Results The lowest rates of subgaleal hematoma occurred in neonates < 2500 g (0.5%); the rate increased with every additional 500 g of neonatal birthweight (3.5%, 4.4% and 8.0% in the 2500-2999 g, 3000-3499 g, and ≥ 3500 g groups, respectively; p = 0.001). Fewer cephalohematomas occurred in low birthweight neonates (0.5% in < 2500 g), although the percentage increased with every additional 500 g of birthweight (2.6%, 3.3% and 3.7% in the 2500-2999 g, 3000-3499 g, and ≥ 3500 g groups, respectively, p = 0.020). Logistic regression found increasing birthweight to be a significant risk factor for head injuries during vacuum extraction, with adjusted odds ratios of 8.12, 10.88, and 13.5 for 2500-2999 g, 3000-3499 g, and ≥ 3500 g, respectively (p = 0.016). NICU hospitalization rates were highest for neonates weighing < 2500 g (10.2%) compared to the other groups (3.1%, 1.7% and 3.3% in 2500-2999 g, 3000-3499 g, ≥ 3500 respectively, p < 0.001). Conclusions Vacuum extraction of neonates weighing < 2500 g at 34 w and beyond seems to be a safe mode of delivery when indicated, with lower rates of head injury related to birth trauma, compared to neonates with higher birthweights.

Is There an Added Neonatal Risk in Vacuum-Assisted Deliveries with Nuchal Cord?

This retrospective cohort study assessed the association between nuchal cord and adverse outcomes during vacuum-assisted delivery (VAD). Women with singleton pregnancies, 34−41-weeks gestation, who underwent VAD, from 2014 to 2020 were included. The primary outcome was umbilical cord pH ≤ 7.1. Secondary outcomes were neonatal intensive care unit admission, Apgar scores, pH < 7.15, subgaleal hematoma, shoulder dystocia and third/fourth-degree perineal tear. Outcomes were compared between neonates with (1059/3754, 28.2%) or without (71.8%) nuchal cord after VAD. No difference in cord pH ≤ 7.1 was found between groups. The nuchal cord group had a lower rate of nulliparity (729 (68.8%) vs. 2004 (74.4%), p = 0.001) and higher maternal BMI (23.6 ± 4.3 vs. 23.1 ± 5, p = 0.017). Nuchal cord was associated with higher rates of induction (207 (19.5%) vs. 431 (16%), p = 0.009) and lower birthweights (3185 ± 413 vs. 3223 ± 436 g, p = 0.013). The main indication for VAD in 830 (80.7%) of the nuchal cord group was non-reassuring fetal heart rate (NRFHR) vs. 1989 (75.6%) controls (p = 0.004). The second stage was shorter in the nuchal cord group (128 ± 81 vs. 141 ± 80 min, p < 0.001). Multivariate regression found nulliparity, induction and birthweight as independent risk factors for nuchal cord VAD. Although induction and NRFHR rates were higher in VAD with nuchal cord, the rate of umbilical cord acidemia was not.

Vacuum-Assisted Delivery Complication Rates Based on Ultrasound-Estimated Fetal Weight.

This retrospective cohort study investigated the association between ultrasonographic estimated fetal weight (EFW) and adverse maternal and neonatal outcomes after vacuum-assisted delivery (VAD). It included women with singleton pregnancies at 34−41 weeks gestation, who underwent ultrasonographic pre-labor EFW and VAD in an academic institution, over 6 years. Adverse neonatal and maternal outcomes included shoulder dystocia, clavicular fracture, or third- and fourth-degree perineal tears. A receiver−operator characteristic curve was used to identify the optimal weight cut-off value to predict adverse outcomes. Fetuses above and below this point were compared. Multivariate analysis was used to control for factors that could lead to adverse outcomes. Eight-hundred and fifty women met the inclusion criteria and had sonographic EFW within two-weeks before delivery. Receiver−operator characteristic curve analysis found that ultrasonographic EFW 3666 g is the optimal threshold for adverse outcomes. Based on these results, outcomes were compared using EFW 3700 g. The average EFW in the ≥3700 g group (n = 220, 25.9%) was 3898 ± 154 g (average birthweight 3710 ± 324 g). In the group <3700 g (n = 630, 74.1%), average EFW was 3064 ± 411 g (birthweight 3120 ± 464 g). Shoulder dystocia and clavicular fractures were more frequent in the higher EFW group (6.4% and 2.3% vs. 1.6% and 0.5%, respectively; p < 0.05). Women in the ≥3700 g group experienced more third- and fourth-degree perineal tears (3.2% vs. 1%, p = 0.02). Multivariate logistic regression analysis found maternal age, diabetes and sonographic EFW ≥ 3700 g as independent risk-factors for adverse outcomes. Sonographic EFW ≥ 3700 g is an independent risk-factor for adverse outcomes in VAD. This should be considered when choosing the optimal mode of delivery.