A randomised prospective study comparing the new vacuum extractor policy with forceps delivery

Instruments for assisted vaginal birth

BACKGROUND

Assisted vaginal births are carried out to expedite birth for the benefit of mothers and babies but are sometimes associated with significant morbidity for both. Various instruments are available, broadly divided into forceps and vacuum cups, and choice may be influenced by clinical circumstances, operator preference, experience and availability.  OBJECTIVES: To evaluate the different instruments in terms of success in achieving a vaginal birth, and the risk of morbidity for mother and baby.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (14 May 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We selected randomised controlled trials of assisted vaginal birth using different instruments. The review did not include quasi-randomised trials, cluster-randomised trials or cross-over designs. The review included trials for which abstracts alone were available as long as there was sufficient information to assess eligibility.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We used the GRADE approach to assess the certainty of evidence.  The main outcomes assessed included failed delivery with allocated instrument, any maternal trauma, third- and fourth-degree tears, postpartum haemorrhage, any neonatal trauma, low Apgar and low umbilical artery pH.  MAIN RESULTS: We included 31 studies involving a total of 5754 women.  Risk of bias criteria were largely assessed as 'unclear', due to a lack of detail in trial reports. Blinding would have been challenging for all trials due to their inability to conceal the type of instrument used from either the woman or the operator, which is reflected in the risk of bias assessment. Any type of forceps versus any type of vacuum cup (12 studies, 3129 women) Forceps may be less likely to fail in achieving vaginal birth: risk ratio (RR) 0.58, 95% confidence interval (CI) 0.39 to 0.88; 11 studies, 3080 women; low certainty. 'Any maternal trauma' may be slightly more likely with forceps: odds ratio (OR) 1.53, 95% CI 0.98 to 2.40; 5 studies, 1356 women; low certainty; and third- or fourth-degree tears may also be more likely with forceps: RR 1.83, 95% CI 1.32 to 2.55; 9 studies, 2493 women; low certainty. There is no evidence of a difference in the incidence of postpartum haemorrhage (PPH) between the two groups: RR 1.71, 95% CI 0.59 to 4.95; 2 studies, 523 women; low certainty, because the evidence is very imprecise due to a very wide CI.  More women in the forceps group reported requiring pain relief. There is probably no evidence of difference in rates of low Apgar: RR 0.83, 95% CI 0.46 to 1.51; 7 studies, 1644 women; moderate certainty; or low umbilical artery pH in the forceps group compared to any vacuum: RR 1.33, 95% CI 0.91 to 1.93; 2 studies, 789 women; low certainty; both of these outcomes are imprecise and have wide CIs that include both benefit and harm. There were also lower rates of fetal trauma with 'any forceps' (cephalhematoma, retinal haemorrhage and jaundice). The composite outcome of 'any neonatal trauma' was not reported. Low-cavity forceps versus any vacuum cup (2 studies, 218 women) We included two small studies with 218 participants in this comparison, but we judged most of the evidence as very low certainty, hence it was not feasible to make judgements on the difference in the rates of failed delivery, any maternal trauma or third- and fourth- degree tears. PPH and low umbilical artery pH were not reported. Soft vacuum cup versus any rigid cup (9 studies, 1148 women) Failed delivery may be more likely in the soft vacuum cup group: RR 1.62, 95% CI 1.21 to 2.17; 9 studies, 1148 women; low certainty. There may be no difference in the rates of 'any maternal trauma': OR 0.63, 95% CI 0.24 to 1.67; 2 studies, 348 women; low certainty, but the confidence interval is wide, indicating possible benefit or harm. There may be no difference in the rates of third- or fourth-degree tears: RR 0.93, 95% CI 0.35 to 2.44; 4 studies, 619 women; low certainty. There is probably no difference in the rates of PPH: RR 0.89, 95% CI 0.49 to 1.61; 5 studies, 737 women; moderate certainty between the soft and rigid cup groups.   There may be little or no difference in the incidence of low Apgar scores: RR 0.82, 95% CI 0.49 to 1.37; 9 studies, 1148; low certainty; or low umbilical artery pH: RR 0.80, 95% CI 0.47 to 1.36; 1 study, 100 women; low certainty. Handheld vacuum versus any vacuum cup (4 studies, 968 women) There may be no difference in the rates of failures with allocated instrument: RR 1.35, 95% CI 0.81 to 2.25; 4 studies, 962 women; low certainty, any maternal trauma: OR 1.16, 95% CI 0.71 to 1.88; 2 studies; 394 women; low certainty, PPH: RR 0.31, 95% CI 0.03 to 2.92; 1 study, 164 women; low certainty, low umbilical artery pH: RR 1.06, 95% CI 0.71 to 1.59; 1 study, 164 women; low certainty, or low Apgar scores: RR 1.25, 95% CI 0.34 to 4.61; 3 studies, 784 women; low certainty) between the two groups. There is probably no difference in the rates of third- or fourth-degree tears between the 'handheld vacuum' and 'any vacuum cup' groups: RR 1.15, 95% CI 0.62 to 2.12; 4 studies, 962 women; moderate certainty.

AUTHORS' CONCLUSIONS

This review provides low-certainty evidence that forceps may be more likely to achieve vaginal birth and have lower rates of fetal trauma, but at a greater risk of perineal trauma and higher pain relief requirements compared with vacuum cups. There was low-certainty evidence that rigid vacuum cups may be more likely to achieve a vaginal birth than soft cups but with more fetal trauma, whilst handheld vacuum cups had similar success rates compared to other cups. There was no evidence of a difference in the rates of third- or fourth-degree tears or postpartum haemorrhages between types of cups, but wide confidence intervals around the estimates indicate further research is needed in this area.

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 (p_all < 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.

Neonatal morbidity in a low volume forceps practice

BACKGROUND

Currently, the use of FE is decreasing and neonatal adverse outcomes following FE are underreported. We aimed to evaluate the rate of neonatal adverse outcomes in current obstetric practice at two university hospitals with a low FE volume.

METHODS

A multicentre retrospective study. All singleton pregnancies delivered by forceps extraction between 2011 and 2020 were analyzed. The characteristics of the deliveries with a composite neonatal adverse outcome (CNAO) were analyzed and compared with those without.

RESULTS

The study cohort included 861 neonates delivered by FE. The CNAO was recorded in 131 (15.2%). Women in the CNAO group gained less weight during pregnancy (mean 13 kg vs. 15 kg, p = .014). Factors found to be associated with CNAO were preterm delivery (gestational age < 37°^/7) (26 (19.8%) vs. 44 (6.0%), OR [95% CI]: 3.86 (2.28-6.52), p < .001), low birth weight (23 (17.6%) vs. 44 (6.0%), OR [95% CI] 3.32 (1.92-5.71), p < .001), and smaller head circumference (329 vs. 331 mm, OR [95% CI] 0.79 (0.67-0.93), p = .035). In a multivariate analysis, gestational age (adjusted OR [95% CI] 0.672 (0.546-0.826), p < .001) and maternal weight gain during pregnancy (adjusted OR [95% CI]: 0.950 (0.904-0.998), p = .042), were both negatively associated with CNAO. Among term deliveries, the only factor found to be independently associated with CNAO was maternal weight gain during pregnancy (adjusted OR [95% CI]: 0.951 (0.910-0.994), p = .025).

CONCLUSIONS

In the setting of low volume FE, this mode of delivery is associated with a relatively low rate of neonatal morbidity.

SYNOPSIS

Performance of forceps extraction in the setting of low volume practice is associated with a relatively low rate of neonatal morbidity.

Exploring the reporting standards of RCTs involving invasive procedures for assisted vaginal birth: A systematic review

OBJECTIVE

Assisted vaginal birth (AVB) is a complex intervention involving medical devices, comprising multiple components. This complexity creates difficulties when designing and conducting randomised controlled trials (RCTs), in terms of describing, standardising and monitoring the intervention, and accounting for differing clinician expertise. This review examines the reporting standards of complex interventions involving a medical device, in the context of AVB RCTs.

STUDY DESIGN

Searches were undertaken from the start of indexing to March 2021, and limited to RCTs, feasibility and pilot studies including at least one device for AVB. RCTs were selected if they included participants having an AVB with any device, with or without a comparator group. Reporting details were assessed according to the Consolidating Standards of Reporting Trials extension for non-pharmacological treatments (CONSORT-NPT), focusing on intervention descriptions, standardization, adherence and clinician expertise. Screening of abstracts, full-text articles and data extraction was performed by two independent reviewers.

RESULTS

Of 4098 abstracts and 83 full-text articles, 39 papers were included, investigating 80 interventions. Twenty-seven different named devices were identified. Intervention descriptions were provided in 20 (55%) papers with varying levels of detail and with only one covering the entire procedure. Standardization of interventions was mentioned in 25 papers (64%). Only eight (21%) papers reported any form of adherence to the intended procedure. Some data regarding expertise were reported in 25 (64%) papers.

CONCLUSIONS

Despite some compliance with reporting standards, there is a lack of detail regarding intervention description, standardization, adherence and expertise in RCTs of AVB. This creates difficulties in understanding how intervention delivery was intended and what actually occurred. Clearer guidelines for the reporting of invasive procedures and devices are required.

Operator experience affects the risk of obstetric anal sphincter injury in vacuum extraction deliveries

INTRODUCTION

Delivery by vacuum extraction is a major risk factor for obstetric anal sphincter injury. The aim of this study was to assess risk factors for obstetric anal sphincter injury in vacuum extraction in nulliparous women, specifically operator-related factors. A secondary aim was to assess other complications of vacuum extraction that are dependent on operator experience.

MATERIAL AND METHODS

A historical cohort study of nulliparous women with a live single fetus ≥34 weeks, delivered by vacuum extraction at a teaching hospital in Sweden in 1 year (2013), using data from medical records. Risk of obstetric anal sphincter injury was assessed for obstetricians (reference), gynecologists, and residents, and adjusted for maternal, fetal, procedure-related, and operator-related covariates using unconditional logistic regression. Results are presented as prevalence and crude and adjusted odds ratio (aOR) with 95% CI.

RESULTS

In total, 323 nulliparous women delivered by vacuum extraction were included. Obstetric anal sphincter injury occurred in 57 (17.6%) women. Fifteen (11.5%) obstetric anal sphincter injuries occurred in vacuum extractions performed by obstetricians, 10 (13.5%) by gynecologists (aOR 1.84, 95% CI 0.72-4.70), and 32 (26.9%) by residents (aOR 5.13, 95% CI 2.20-11.95). Maternal height ≤155 cm (aOR 4.63, 95% CI 1.35-15.9) and conversion to forceps (aOR 19.4, 95% CI 1.50-252) increased the risk of obstetric anal sphincter injury. Operator gender, night shift work, or being a frequent operator did not affect the risk of obstetric anal sphincter injury. Postpartum hemorrhage and fetal complications did not differ between operator categories.

CONCLUSIONS

The adjusted risk of obstetric anal sphincter injury in nulliparous women was five times higher in vacuum extractions performed by residents compared with those performed by obstetricians. Vacuum extractions performed by gynecologists did not carry an increased risk of obstetric anal sphincter injury. Experience in years of training, rather than frequency of the procedure, seemed to have the highest impact on reducing obstetric anal sphincter injury in vacuum extractions, which indicates a need for increased training and supervision.

Evaluation of delivery options for second-stage events

BACKGROUND

Cesarean delivery in the second stage of labor is common, whereas the frequency of operative vaginal delivery has been declining. However, data comparing outcomes for attempted operative vaginal delivery vs cesarean in the second stage are scant. Previous studies that examine operative vaginal delivery have compared it to a baseline risk of complications from a spontaneous vaginal delivery and cesarean delivery. However, when a woman has a need for intervention in the second stage, spontaneous vaginal delivery is not an option she or the provider can choose. Thus, the appropriate clinical comparison is cesarean vs operative vaginal delivery.

OBJECTIVE

Our objective was to compare outcomes by the first attempted operative delivery (vacuum, forceps vs cesarean delivery) in patients needing second-stage assistance at a fetal station of +2 or below.

STUDY DESIGN

We conducted secondary analysis of an observational obstetric cohort in 25 academically affiliated US hospitals over a 3-year period. A subset of ≥37 weeks, nonanomalous, vertex, singletons, with no prior vaginal delivery who reached a station of +2 or below and underwent an attempt at an operative delivery were included. Indications included for operative delivery were: failure to descend, nonreassuring fetal status, labor dystocia, or maternal exhaustion. The primary outcomes included a composite neonatal outcome (death, fracture, length of stay ≥3 days beyond mother's, low Apgar, subgaleal hemorrhage, ventilator support, hypoxic encephalopathy, brachial plexus injury, facial nerve palsy) and individual maternal outcomes (postpartum hemorrhage, third- and fourth-degree tears [severe lacerations], and postpartum infection). Outcomes were examined by the 3 attempted modes of delivery. Odds ratios (OR) were calculated for primary outcomes adjusting for confounders. Final mode of delivery was quantified.

RESULTS

In all, 2531 women met inclusion criteria. No difference in the neonatal composite outcome was observed between groups. Vacuum attempt was associated with the lowest frequency of maternal complications (postpartum infection 0.2% vs 0.9% forceps vs 5.3% cesarean, postpartum hemorrhage 1.4% vs 2.8% forceps vs 3.8% cesarean), except for severe lacerations (19.1% vs 33.8% forceps vs 0% cesarean). When confounders were taken into account, both forceps (OR, 0.16; 95% confidence interval, 0.05-0.49) and vacuum (OR, 0.04; 95% confidence interval, 0.01-0.17) were associated with a significantly lower odds of postpartum infection. The neonatal composite and postpartum hemorrhage were not significantly different between modes of attempted delivery. Cesarean occurred in 6.4% and 4.4% of attempted vacuum and forceps groups (P = .04).

CONCLUSION

In patients needing second-stage delivery assistance with a station of +2 or below, attempted operative vaginal delivery was associated with a lower frequency of postpartum infection, but higher frequency of severe lacerations.

Obstetric anal sphincter injuries: review of anatomical factors and modifiable second stage interventions

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injuries (OASIs) are the leading cause of anal incontinence in women. Modification of various risk factors and anatomical considerations have been reported to reduce the rate of OASI.

METHODS

A PubMed search (1989-2014) of studies and systematic reviews on risk factors for OASI.

RESULTS

Perineal distension (stretching) of 170 % in the transverse direction and 40 % in the vertical direction occurs at crowning, leading to significant differences (15-30°) between episiotomy incision angles and suture angles. Episiotomies incised at 60° achieve suture angles of 43-50°; those incised at 40° result in a suture angle of 22°. Episiotomies with suture angles too acute (<30°) and too lateral (>60°) are associated with an increased risk of OASI. Suture angles of 40-60° are in the safe zone. Clinicians are poor at correctly estimating episiotomy angles on paper and in patients. Sutured episiotomies originating 10 mm away from the midline are associated with a lower rate of OASIs. Compared to spontaneous tears, episiotomies appear to be associated with a reduction in OASI risk by 40-50 %, whereas shorter perineal lengths, perineal oedema and instrumental deliveries are associated with a higher risk. Instrumental deliveries with mediolateral episiotomies are associated with a significantly lower OASI risk. Other preventative measures include warm perineal compresses and controlled delivery of the head.

CONCLUSIONS

Relieving pressure on the central posterior perineum by an episiotomy and/or controlled delivery of the head should be important considerations in reducing the risk of OASI. Episiotomies should be performed 60° from the midline. Prospective studies should evaluate elective episiotomies in women with a short perineal length and application of standardised digital perineal support.

Neonatal scalp haematoma and necrosis

Birth trauma after prolonged deliveries and instrument-assisted extractions can result in skin lesions and reduced viability of the scalp. In these instances, scalp swellings and haematomas are often also seen. The classification and inter-relationship between these conditions might not, however, always be clear. This report describes three cases of neonates with scalp swellings and necrosis. Nomenclature, underlying causes, work up, treatment options, and outcomes are presented and discussed. The first case consisted of a newborn with a subgaleal haematoma and occipital pressure necrosis that healed by secondary intention. In the second case, an infected scalp haematoma led to scarring and alopecia that required secondary reconstruction with tissue expansion. The third neonate suffered from a subgaleal haematoma and a scalp lesion that required split skin grafting and secondary reconstruction with tissue expansion.

A prospective randomized study comparing maternal and fetal effects of forceps delivery and vacuum extraction

OBJECTIVE

To compare maternal and neonatal effects of assisted vaginal delivery by forceps and vacuum extraction.

METHODS

A prospective randomized study. One hundred eligible women requiring assisted vaginal delivery in the second stage of labor were randomized to deliver by forceps or vacuum extraction.

RESULTS

All of those allocated to forceps delivery actually delivered with the allocated instrument (100 % delivery rate in forceps vs. 90 % in VE); however, maternal trauma (40 % in forceps vs. 10 % in VE, p < 0.001), use of analgesia (p < 0.001), and blood loss at delivery (234 ml in VE vs. 337 ml in forceps group, p < 0.05) were significantly less in the group allocated to deliver by vacuum extraction. Vacuum extraction, however, appears to predispose to an increase in neonatal jaundice and incidence of cephalhematoma. More serious neonatal morbidity was rare in both groups.

CONCLUSION

Extrapolation of the data from the study reveals that there is a significant reduction in maternal injuries. However, vacuum extraction has the potential to injure babies more.

KIELLAND'S FORCEPS: PAST, PRESENT AND FUTURE

Kielland's forceps have been in obstetric practice for over 80 years but their use causes a wide spectrum of reactions in obstetricians. Those that have been well tutored in their use argue that they are a very effective instrument to achieve vaginal delivery in the malpositioned fetus, avoiding the problems of full cervical dilation caesarean section, with low complications in their hands. These exponents of the instrument argue that the “art” of obstetrics is demonstrated in the use of Kielland's forceps. However, others claim that Kielland's forceps are dangerous with high complication rates and that they should be confined to the obstetric museum. This paper reviews the history of the instrument and its inventor, to consider evidence for its effectiveness and its safety, to briefly consider other methods for delivery of the malpositioned fetus at full cervical dilation and finally to complete the journey by considering the future with particular emphasis on training the new generation of obstetricians.

Grasping soft tissue by means of vacuum technique

INTRODUCTION

A notable characteristic of bariatric surgery is the frequent manipulation of the bowel. The bowel is large, delicate, flexible, and has a natural lubricant on the tissue surface. Therefore the bowel is difficult to grasp and manipulate. Vacuum technique is commonly used in industry for all types of grasping and manipulation. Two types of nozzles that differed slightly in geometry (NT1 and NT2), were reviewed in an experimental set up for pull tests on pig bowels.

MATERIALS AND METHODS

An experimental set-up was used to conduct a series of pull tests on pig bowel tissue. The basic principle of the measurements was a Newton's force balance; F(Pmax)=Δp×A. Student t-tests, two-way ANOVA and Wilcoxon signed rank tests were conducted for the statistical analysis of NT1 and NT2 with regard to the maximum pull force (F(Pmax)).

RESULTS

Concerning NT1 the Newton's force balance could not be confirmed. Concerning NT2 the Newton's force balance could partly be confirmed. For both nozzle types the effect of Δp on F(Pmax) was significant. F(Pmax) increases linear in proportion as Δp increases. This relation between F(Pmax) and Δp was confirmed by the Newton's force balance.

DISCUSSION

The results confirm that vacuum technique can be used as a grasp technique for soft organs, particularly the bowels. By means of a clever design of the nozzle a firm grip can be obtained on the bowel segments. Therefore vacuum technique should be studied for further development of instruments, graspers and retractors, to be used in the abdominal area.

Operative vaginal deliveries: practical aspects

Forceps, vacuum, and cesarean sections are relatively recent additions to the obstetrician's armamentarium. The art of modern obstetrics is one that mandates from obstetricians the attentive vigilance of the development of natural processes and an active intervention when such processes fall outside normally accepted standards. What constitutes the "normal process" and the "accepted standard" is subject to discussion, and international variations in obstetric practice are in part the reflection of such controversies. This article presents a practical approach to the contemporary issue of instrumental deliveries, outlining supporting evidence (when available) and the most current position of professional colleges in obstetrics and gynecology.

Risk factors for severe perineal injury during childbirth: a case-control study of 60 consecutive cases

AIM

The study aimed to evaluate the current risk factors for severe perineal tears in a single university-affiliated maternity hospital.

METHOD

An obstetric database of 31 784 consecutive women who delivered from January 2007 to December 2009 was screened for cases of third-degree or fourth-degree perineal tears. Four controls, matched by time of delivery, were selected for each case of third- or fourth-degree perineal tear. Maternal and obstetric parameters were analyzed and compared between the study and control groups.

RESULTS

Sixty women (0.25% of all vaginal deliveries) had a third-degree (53 women) or a fourth-degree (seven women) perineal tear. The control group comprised 240 matched vaginal deliveries without severe tears. Primiparity, younger maternal age, Asian ethnicity, longer duration of second stage of labour, vacuum-assisted delivery and heavier newborn birth weight were significantly more common among women who had third- or fourth-degree perineal tears. Of the variables that were found to be statistically significant in the univariate analysis, only primiparity (OR = 2.809, 95% CI: 1.336-5.905), vacuum delivery (OR = 10.104, 95% CI: 3.542-28.827) and heavier newborn birth weight (OR = 1.002, 95% CI: 1.001-1.003) were found to be statistically significant independent risk factors for severe perineal trauma.

CONCLUSION

Identification of women at risk may facilitate the use, or avoidance, of certain obstetric interventions to minimize the occurrence of childbirth-associated perineal trauma.

Third- and fourth-degree perineal tears: prevalence and risk factors in the third millennium

OBJECTIVE

We sought to assess the modern prevalence and risk factors for third- and fourth-degree perineal tears.

STUDY DESIGN

The study population comprised 38,252 women who delivered in one medical center, from January 2005 through December 2009, and met the following inclusion criteria: singleton pregnancy, vertex presentation, and vaginal delivery. Of these, 96 women (0.25%) sustained third- or fourth-degree perineal tears. Maternal and obstetric variables were compared between women with vs without severe perineal tears.

RESULTS

Five variables were found to be statistically significant independent risk factors: Asian ethnicity (odds ratio [OR], 8.9; 95% confidence interval [CI], 4.2-18.9), primiparity (OR, 2.4; 95% CI, 1.5-3.7), persistent occipito posterior (OR, 2.1; 95% CI, 1-4.5), vacuum delivery (OR, 2.7; 95% CI, 1.6-4.6), and heavier birthweight (OR, 1.001; 95% CI, 1-1.001).

CONCLUSION

Severe perineal tears are uncommon in modern obstetric practice. Significant risk factors are Asian ethnicity, primiparity, persistent occipito posterior, vacuum delivery, and heavier birthweight.

Prevalence of and Risk Factors for Urinary Incontinence During the Third Trimester and First Postpartum Year in Primiparous Women

OBJECTIVES: To identify the prevalence of and risk factors for urinary incontinence (UI) during the antenatal period and postpartum year in primiparous women.

DESIGN: A longitudinal, prospective, repeated measures and cohort study.

SETTING: Wirral University Teaching Hospital NHS Foundation Trust.

PARTICIPANTS: Primiparous women with no preexisting disease (N = 516) recruited after a normal 20-week obstetric ultrasound scan.

METHOD: Data were collected in the last trimester of pregnancy and at 6 weeks, at 6 months, and at 1 year postpartum using validated questionnaires. Obstetric data were extracted from case notes.

MAIN OUTCOME MEASURES: UI symptoms.

RESULTS: Stress incontinence during the third trimester was reported by 39.7% (n = 185) of the women participating in the study. At 6 weeks postpartum, 28.2% (n = 114); at 6 months postpartum, 31% (n = 123); and at 1 year postpartum, 26.5% (n = 89) of participants also reported stress incontinence.

Urge incontinence was reported by 23.5% (n = 110) of participants in the third trimester, 21.2% (n = 86) at 6 weeks postpartum, 21.4% (n = 85) at 6 months postpartum, and 16.4% (n = 55) at 1 year postpartum.

Women younger than 20 years old had higher rates of postpartum urge incontinence (p < .001) possibly associated with increased rates of infection. Body mass index (BMI) >30 was associated with higher rates of antenatal stress incontinence but was not significant in the postpartum period. BMI <20 was associated with an increase in postpartum urge incontinence. Prolonged periods in labor without bladder emptying was associated with increased rates of UI (odds ratio [OR] = 2.36). Forceps delivery was associated with postpartum stress incontinence (OR = 2.41). Although cesarean section appeared protective against UI initially, long-term data show a progressive increase in reported rates of UI even after elective cesarean section. Perineal trauma was associated with UI throughout the postpartum year with those women having anal sphincter disruption with the highest rates of stress incontinence (p < .005). Birth weight, duration of labor, feeding method, epidural anesthesia, and smoking were not significant. Overall, UI appears to be a regressive condition. Some participants had a progressive, deteriorating condition, which appears to be associated with a higher BMI or >6 hours from bladder emptying to delivery of the newborn.

CONCLUSION: There are several identifiable risk factors that increase the prevalence and/or severity of UI symptoms.

The relation between delivery type and tau protein levels in cord blood

BACKGROUND

The perinatal morbidity risk is higher in operative deliveries than normal vaginal deliveries. 'Tau protein' is a cytoskeletal component that is predominantly expressed in axons of neurons. The aim of this study was to investigate whether delivery type, particularly the forceps application, had any effect on cord blood tau levels.

METHODS

Ninety babies born in the Division of Maternal-Fetal Medicine of Ankara Etlik Maternity and Women's Health Teaching Hospital, Ankara, Turkey were involved in the study. The babies were divided into three groups according to delivery type: Group 1: normal vaginal delivery (NVD); Group 2: caesarean section; Group 3: forceps application. Cord blood samples were drawn from umbilical veins of the babies soon after the birth.

RESULTS

The cord blood tau protein levels in the caesarean section group (79 pg/mL [45-223]) were found to be significantly lower than those of NVD (135 pg/mL [44-627]) and forceps (175 pg/mL [17-418]) groups (P = 0.001 and P < 0.001, respectively).

CONCLUSION

We have shown that forceps applications uncomplicated with perinatal asphyxia did not affect the cord blood tau protein level significantly. Tau levels in caesarean section group were significantly lower than the other two groups. Caesarean section in this manner might be considered especially in conditions of risk of perinatal asphyxia to avoid hypoxia.

The relation between delivery type and cord blood levels of chitotriosidase and Troponin T

The operative deliveries can expose the fetus to acute and systemic hypoxia along with an increase in perinatal morbidity. The aim of this study was to reveal any relationship between delivery type and Chitotriosidase and Troponin T levels in cord blood. Ninety babies born in Ankara Etlik Maternity and Women’s Health Teaching Hospital were involved in the study. The babies were divided into three groups; Group 1: Normal vaginal; Group 2: Caesarean section; Group 3: Forceps application. Cord blood samples were drawn from umbilical arteries of the babies soon after the birth. Chitotriosidase enzyme activities in group 3 (141 nmol/ml/h (0–246)) were found higher than groups 1 (100 nmol/ml/h (0–208)) and 2 (91 nmol/ml/h (0–202)) (p<0.01 and p<0.03 respectively). Although cardiac Troponin T levels were higher in group 3, the difference among groups was not statistically significant (p=0.79). Acute or systemic hypoxic exposure of the organism gives rise to a microvascular response characterized by interactions between leukocytes and endothelium. We are hypothesizing that the high levels of chitotriosidase found in the forceps group were due to hypoxia, and that chitotriosidase level can be used as a marker of acute and systemic hypoxia.

WITHDRAWN: Soft versus rigid vacuum extractor cups for assisted vaginal delivery

BACKGROUND

The original cups used for vacuum extraction delivery of the fetus were rigid metal cups. Subsequently, soft cups of flexible materials such as silicone rubber or plastic were introduced. Soft cups are thought to have a poorer success rate than metal cups. However they are also thought to be less likely to be associated with scalp trauma and less likely to injure the mother.

OBJECTIVES

The objective of this review was to assess the effects of soft versus rigid vacuum extractor cups on perineal injury, fetal scalp injury and success rate.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register. Date of last search: February 2000.

SELECTION CRITERIA

Acceptably controlled comparisons of soft versus rigid vacuum extractor cups.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Nine trials involving 1375 women were included. The trials were of average quality. Soft cups are significantly more likely to fail to achieve vaginal delivery (odds ratio 1.65, 95% confidence interval 1.19 to 2.29). However, they were associated with less scalp injury (odds ratio 0.45, 95% confidence interval 0.15 to 0.60). There was no difference between the two groups in terms of maternal injury.

AUTHORS' CONCLUSIONS

Metal cups appear to be more suitable for 'occipito-posterior', transverse and difficult 'occipito-anterior' position deliveries. The soft cups seem to be appropriate for straightforward deliveries.

WITHDRAWN: Vacuum extraction versus forceps for assisted vaginal delivery

BACKGROUND

Proponents of vacuum delivery argue that it should be chosen first for assisted vaginal delivery, because it is less likely to injure the mother.

OBJECTIVES

The objective of this review was to assess the effects of vacuum extraction compared to forceps, on failure to achieve delivery and maternal and neonatal morbidity.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register. Date of last search: February 1999.

SELECTION CRITERIA

Acceptably controlled comparisons of vacuum extraction and forceps delivery.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Ten trials were included. The trials were of reasonable quality. Use of the vacuum extractor for assisted vaginal delivery when compared to forceps delivery was associated with significantly less maternal trauma (odds ratio 0.41, 95% confidence interval 0.33 to 0.50) and with less general and regional anaesthesia. There were more deliveries with vacuum extraction (odds ratio 1.69, 95% confidence interval 1.31 to 2.19). Fewer caesarean sections were carried out in the vacuum extractor group. However the vacuum extractor was associated with an increase in neonatal cephalhaematomata and retinal haemorrhages. Serious neonatal injury was uncommon with either instrument.

AUTHORS' CONCLUSIONS

Use of the vacuum extractor rather than forceps for assisted delivery appears to reduce maternal morbidity. The reduction in cephalhaematoma and retinal haemorrhages seen with forceps may be a compensatory benefit.

Choice of instruments for assisted vaginal delivery

BACKGROUND

Instrumental or assisted vaginal birth is commonly used to expedite birth for the benefit of either mother or baby or both. It is sometimes associated with significant complications for both mother and baby. The choice of instrument may be influenced by clinical circumstances, operator choice and availability of specific instruments.

OBJECTIVES

To evaluate different instruments in terms of achieving a vaginal birth and avoiding significant morbidity for mother and baby.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2010).

SELECTION CRITERIA

Randomised controlled trials of assisted vaginal delivery using different instruments.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality, extracted the data, and checked them for accuracy.

MAIN RESULTS

We included 32 studies (6597 women) in this review. Forceps were less likely than the ventouse to fail to achieve a vaginal birth with the allocated instrument (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.45 to 0.94). However, with forceps there was a trend to more caesarean sections, and significantly more third- or fourth-degree tears (with or without episiotomy), vaginal trauma, use of general anaesthesia, and flatus incontinence or altered continence. Facial injury was more likely with forceps (RR 5.10, 95% CI 1.12 to 23.25). Using a random-effects model because of heterogeneity between studies, there was a trend towards fewer cases of cephalhaematoma with forceps (average RR 0.64, 95% CI 0.37 to 1.11).Among different types of ventouse, the metal cup was more likely to result in a successful vaginal birth than the soft cup, with more cases of scalp injury and cephalhaematoma. The hand-held ventouse was associated with more failures than the metal ventouse, and a trend to fewer than the soft ventouse.Overall forceps or the metal cup appear to be most effective at achieving a vaginal birth, but with increased risk of maternal trauma with forceps and neonatal trauma with the metal cup.

AUTHORS' CONCLUSIONS

There is a recognised place for forceps and all types of ventouse in clinical practice. The role of operator training with any choice of instrument must be emphasised. The increasing risks of failed delivery with the chosen instrument from forceps to metal cup to hand-held to soft cup vacuum, and trade-offs between risks of maternal and neonatal trauma identified in this review need to be considered when choosing an instrument.

Obstetric risk factors and pelvic floor dysfunction 20 years after first delivery

INTRODUCTION AND HYPOTHESIS

Intrapartum events at first delivery and subsequent childbearing are associated with long-term pelvic floor dysfunction (PFD).

METHODS

Primigravidae delivered between 1983-1986 were identified; current addresses traced through the UK National Health Service database (N = 3002). Women completed screening and Sheffield Pelvic Floor Questionnaires (Sheffield-PAQ). Maternity data were obtained from Standard Maternity Information System. Primary outcomes were urinary incontinence (UI), anal incontinence (AI), and prolapse (POP).

RESULTS

Primary response was 62.1%; 53.8% (n = 985) had >or=1 PFD symptom and in 71.5% symptoms were bothersome. UI (OR 0.47 95% CI 0.28, 0.81) and fecal incontinence (FI; OR 0.32 95% CI 0.13, 0.77) risks were lower after first delivery by cesarean section (CS). However, 25% had UI and 12% had FI after delivering exclusively by CS. Obesity was a risk factor independent of obstetric history.

CONCLUSIONS

CS provides incomplete or poorly sustained pelvic floor protection by middle age. Obese women were at highest risk and had the most severe symptoms.

Operative vaginal delivery: current trends in obstetrics

After centuries of use in obstetrics, have forceps and vacuum deliveries become a dying art? Contemporary trends in operative vaginal delivery show increasing numbers of vacuum deliveries and decreasing numbers of forceps deliveries worldwide. Primary drivers of such trends include concerns over neonatal and maternal safety as well as fewer clinicians skilled in forcep use. Current literature reports a comparable efficacy rate for the two instruments, as well as a decrease in maternal morbidity compared with cesarean section. It has also been suggested that the neonatal morbidity once associated with operative vaginal delivery may actually be a function of an abnormal labor process itself, rather than a consequence of an operative vaginal intervention. Both the American College and the Royal College of Obstetricians and Gynecologists continue to support the use of both vacuum and forceps and strongly encourage residency programs to incorporate the teaching of these skills into their curricula.

Diagnosis and management of obstetric anal sphincter injury

PURPOSE OF REVIEW

The purpose of this review is to outline optimum practice in diagnosis and management of obstetric anal sphincter injury. The review focuses briefly on prevention of the problem before outlining diagnosis of sphincter injury as well as immediate and long-term management of patients who have sustained such injuries.

RECENT FINDINGS

Increasing vigilance is vital in order that sphincter injury is not overlooked; immediate radiological assessment may play a role in diagnosis. Optimum anal sphincter repair should be followed by oral laxative administration to maintain sphincter integrity. Biofeedback physiotherapy and sacral nerve stimulation show great promise in treatment of persistent symptoms. Optimum mode of delivery in future pregnancies is not clearly defined, and decisions should be individualized.

SUMMARY

Because obstetric injury to the anal sphincter mechanism cannot always be prevented, efforts must focus on limiting its occurrence, documenting its severity and providing optimum therapy to women who have sustained it. Management includes routine postnatal review of at-risk women and antenatal assessment in future pregnancies to limit deterioration in continence after future deliveries.

Obstetric anal sphincter injury: incidence, risk factors, and management

BACKGROUND AND AIMS

Obstetric sphincter damage is the most common cause of fecal incontinence in women. This review aimed to survey the literature, and reach a consensus, on its incidence, risk factors, and management.

METHOD

This systematic review identified relevant studies from the following sources: Medline, Cochrane database, cross referencing from identified articles, conference abstracts and proceedings, and guidelines published by the National Institute of Clinical Excellence (United Kingdom), Royal College of Obstetricians and Gynaecologists (United Kingdom), and American College of Obstetricians and Gynecologists.

RESULTS

A total of 451 articles and abstracts were reviewed. There was a wide variation in the reported incidence of anal sphincter muscle injury from childbirth, with the true incidence likely to be approximately 11% of postpartum women. Risk factors for injury included instrumental delivery, prolonged second stage of labor, birth weight greater than 4 kg, fetal occipitoposterior presentation, and episiotomy. First vaginal delivery, induction of labor, epidural anesthesia, early pushing, and active restraint of the fetal head during delivery may be associated with an increased risk of sphincter trauma. The majority of sphincter tears can be identified clinically by a suitably trained clinician. In those with recognized tears at the time of delivery repair should be performed using long-term absorbable sutures. Patients presenting later with fecal incontinence may be managed successfully using antidiarrheal drugs and biofeedback. In those who fail conservative treatment, and who have a substantial sphincter disruption, elective repair may be attempted. The results of primary and elective repair may deteriorate with time. Sacral nerve stimulation may be an appropriate alternative treatment modality.

CONCLUSIONS

Obstetric anal sphincter damage, and related fecal incontinence, are common. Risk factors for such trauma are well recognized, and should allow for reduction of injury by proactive management. Improved classification, recognition, and follow-up of at-risk patients should facilitate improved outcome. Further studies are required to determine optimal long-term management.

Alopecia Associated With Birth Injury

BACKGROUND

Alopecia after birth-related caput succedaneum is an extremely rare complication.

CASE

The case of a child with permanent alopecia due to birth-related caput succedaneum is presented. After delivery with vacuum extraction, caput succedaneum at the left occipitoparietal region of the neonate's head was noted, which subsided within a week, leaving a circular necrotic crust and finally a circular bald area. At age 4, the child was referred at a tertiary center for the management of alopecia. Treatment initially consisted of the expansion of the hair-bearing skin adjacent to the bald area, which was excised at a second stage and covered with the expanded skin. A pleasing esthetic result was achieved.

CONCLUSION

Neonatal alopecia is a rare birth-associated complication. Premature rupture of the membranes, prolonged second stage of the labor, and prolonged vacuum extraction time may be important features in the pathogenesis of this complication. In case of permanent alopecia, excellent esthetic results can be achieved with the use of reconstructive plastic surgery techniques.

The outcome of preterm neonates with intraventricular hemorrhage delivered with intravenous meperidine or epidural analgesia

We aimed to study, retrospectively, the neonatal outcome of 45 preterm neonates with intraventricular hemorrhage (IVH) who were delivered vaginally with intravenous meperidine (n = 23) or epidural analgesia (n = 22). Neonates in the epidural group had a better outcome in terms of a first-minute Apgar score of 7 or less, in 31% vs 69% (P = 0.001); 5-min Apgar score of 7 or less, in 18% vs 82% (P = 0.003); a lower incidence of respiratory distress syndrome (RDS; 23% vs 30%; P = 0.03); a lower dopamine requirement during the first neonatal week (13% vs 72%; P = 0.01); and a higher survival rate (91% vs 58%, respectively; P = 0.008). It is concluded that preterm neonates with IVH had a better outcome when delivered to mothers receiving epidural analgesia as compared to those receiving intravenous meperidine.

Chart Documentation of Informed Consent for Operative Vaginal Delivery: Is It Adequate?

OBJECTIVES

To determine the documentation frequency of informed consent for women undergoing a trial of nonemergent instrumental delivery.

STUDY DESIGN

A retrospective chart review of instrumented vaginal deliveries from 1992 to 2005 was performed. Cases were identified from a Labor and Delivery database and hospital records were reviewed for documentation of associated risks, general consent for the procedure, indication, and option of cesarean delivery (CD).

RESULTS

Three hundred forty six charts were reviewed: 246 were excluded for an emergency delivery (19%), misclassification (25%), or lost notes (27%). In the remaining 100 cases, 61% had a general consent for instrumented vaginal delivery. Documentation of any maternal or neonatal risks was found in 3% and 0%, respectively. The option of a cesarean delivery was documented in 22% of the cases. When comparing 5-year time intervals before and after 2000, there was no increased frequency in documentation of maternal or neonatal risks.

CONCLUSIONS

Documentation of informed consent for instrumented vaginal delivery is inconsistent and should be improved.

A prospective randomised controlled trial of the Kiwi Omnicup versus conventional ventouse cups for vacuum-assisted vaginal delivery

OBJECTIVE

To evaluate the performance and safety of the Kiwi Omnicup and compare it to conventional vacuum cups in routine clinical practice.

DESIGN

A randomised controlled trial of the Kiwi Omnicup versus conventional vacuum cups.

SETTING

Queen Charlotte's and Chelsea Hospital, a tertiary referral hospital in London from April 2001 to March 2004.

POPULATION

Women requiring assisted vaginal delivery by ventouse.

METHODS

Women were randomised to the Kiwi Omnicup (n=206) or conventional vacuum cups (n=198). Data regarding maternal demographics, labour, mode of delivery and maternal and neonatal outcome were collected.

MAIN OUTCOME MEASURES

Failure of delivery with instrument of first choice.

RESULTS

The Kiwi Omnicup was less successful at delivery with instrument of first choice than the conventional ventouse, failure rate 30.1 versus 19.2% (RR 1.58; 95% CI 1.10-2.24). It was associated with a greater number of cup detachments (mean 0.68 compared with 0.28, with 44% compared with 18% having at least one detachment [P<0.0001]). There was no difference in the incidence of severe maternal trauma, and there were no cases of serious neonatal injury.

CONCLUSIONS

The Kiwi Omnicup is less successful than conventional ventouse in achieving vaginal delivery, but its safety profile is comparable.

Is it possible to predict or prevent third degree tears?

OBJECTIVES

This paper reviews the causes anal sphincter injury during vaginal delivery. It emphasises that they are not usually the result of poor obstetric care. The role of the colorectal surgeon in their management is discussed.

METHODS

Medline was searched using the key words third degree tears, pregnancy, risk factors, prevention and recurrence risk. A hand search of journals and located articles was made. Two hundred and twenty three papers were identified, 84 are referenced.

RESULTS

The reported incidence of anal sphincter tears is usually between 0.5% and 2.5% of vaginal deliveries. Maternal factors such as parity and age and obstetric factors such as mode of presentation, the use of forceps and the size of the baby all influence the incidence of sphincter tears. Predicting tears in individual women is inaccurate and midwifery practices can do little to prevent them. Reducing pelvic floor morbidity by increasing the caesarean section rate would require that a large number of caesarean sections be done to prevent a small number of tears. The recognition of perineal trauma is improved by training. Accurate apposition of the sphincters with antibiotic cover and post-operative laxatives are the important technical aspects of the repair. Colorectal follow up helps to identify those women with symptoms and allows advice about the advisability of subsequent vaginal deliveries. A previous third degree tears increases the risk of a subsequent one, although the overall risk remains low. A second vaginal delivery after a third degree tear that has resulted in a functional deficit predisposes to worsening function. When there is no residual anatomical defect and no functional loss, there is no evidence of increased risk of incontinence following another vaginal delivery.

CONCLUSION

Vaginal delivery will continue to be the main method of delivery and will continue to generate a low incidence of pelvic floor morbidity. The management of injury to the anal sphincter is facilitated by close co-operation between obstetricians and colorectal surgeons.

Maternal and perinatal morbidity of caesarean delivery at full cervical dilatation compared with caesarean delivery in the first stage of labour

To estimate maternal and perinatal morbidity associated with caesarean delivery at full cervical dilatation, a population-based cohort study from 1997 to 2002 was used, which included 1623 nullipara with singleton pregnancies at 37-42 weeks of gestation requiring caesarean delivery in labour. Compared to caesarean delivery at less than full dilatation, women undergoing caesarean delivery at full dilatation were more likely to have complications of intraoperative trauma (RR 2.6, P < 0.001) and infants with perinatal asphyxia (RR 1.5, P < 0.05). There was no difference in maternal or perinatal morbidity when duration of the second stage of labour or when failed assisted vaginal delivery was considered.