The impact of a trial of instrumental delivery in theatre on neonatal outcome

Determinants of fetomaternal complication of instrumental vaginal delivery among women who gave childbirth in Southern Ethiopia: a facility-based cross-sectional study

BACKGROUND

In Ethiopia, one in five instrumental deliveries among women giving birth resulted in an unfavourable outcome. This study aimed to assess the determinants of feto-maternal complications of instrumental delivery in selected public hospitals of Gamo and Gofa zones, Southern Ethiopia.

METHODS

An institution-based cross-sectional study was conducted among 399 women attending selected public hospitals in the Gamo and Gofa zones. Data were collected using data extraction tools using a systematic random sampling technique. The collected data was entered into Epi-data version 3.1 and then analyzed using SPSS version 25. Logistic regression analysis was conducted to determine an association.

RESULTS

One hundred eighty-three (45.9%, n = 183/399) instrumental deliveries were found to be complicated. Primigravida women (AOR: 95% CI: 2.21 (1.35, 3.63), infant birth weight (AOR: 95% CI: 2.56 (1.37, 4.77), post-term pregnancy (AOR: 95% CI: 12.77 (2.92, 55.78), and maternal age (AOR: 95% CI: 7.00 (2.16, 22.64) were associated with fetomaternal complications in instrumental delivery among women who gave birth.

CONCLUSIONS AND RECOMMENDATION

A high proportion of women developed fetomaternal complications when compared to local studies. Promotion of antenatal care services, increasing women's education and empowerment as well as working on capacity building of health care professionals through education and training is cost-effective to reduce the occurrence of fetomaternal complications.

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.

Novel artificial intelligence approach for automatic differentiation of fetal occiput anterior and non-occiput anterior positions during labor

OBJECTIVES

To describe a newly developed machine-learning (ML) algorithm for the automatic recognition of fetal head position using transperineal ultrasound (TPU) during the second stage of labor and to describe its performance in differentiating between occiput anterior (OA) and non-OA positions.

METHODS

This was a prospective cohort study including singleton term (> 37 weeks of gestation) pregnancies in the second stage of labor, with a non-anomalous fetus in cephalic presentation. Transabdominal ultrasound was performed to determine whether the fetal head position was OA or non-OA. For each case, one sonographic image of the fetal head was then acquired in an axial plane using TPU and saved for later offline analysis. Using the transabdominal sonographic diagnosis as the gold standard, a ML algorithm based on a pattern-recognition feed-forward neural network was trained on the TPU images to discriminate between OA and non-OA positions. In the training phase, the model tuned its parameters to approximate the training data (i.e. the training dataset) such that it would identify correctly the fetal head position, by exploiting geometric, morphological and intensity-based features of the images. In the testing phase, the algorithm was blinded to the occiput position as determined by transabdominal ultrasound. Using the test dataset, the ability of the ML algorithm to differentiate OA from non-OA fetal positions was assessed in terms of diagnostic accuracy. The F₁ -score and precision-recall area under the curve (PR-AUC) were calculated to assess the algorithm's performance. Cohen's kappa (κ) was calculated to evaluate the agreement between the algorithm and the gold standard.

RESULTS

Over a period of 24 months (February 2018 to January 2020), at 15 maternity hospitals affiliated to the International Study group on Labor ANd Delivery Sonography (ISLANDS), we enrolled into the study 1219 women in the second stage of labor. On the basis of transabdominal ultrasound, they were classified as OA (n = 801 (65.7%)) or non-OA (n = 418 (34.3%)). From the entire cohort (OA and non-OA), approximately 70% (n = 824) of the patients were assigned randomly to the training dataset and the rest (n = 395) were used as the test dataset. The ML-based algorithm correctly classified the fetal occiput position in 90.4% (357/395) of the test dataset, including 224/246 with OA (91.1%) and 133/149 with non-OA (89.3%) fetal head position. Evaluation of the algorithm's performance gave an F₁ -score of 88.7% and a PR-AUC of 85.4%. The algorithm showed a balanced performance in the recognition of both OA and non-OA positions. The robustness of the algorithm was confirmed by high agreement with the gold standard (κ = 0.81; P < 0.0001).

CONCLUSIONS

This newly developed ML-based algorithm for the automatic assessment of fetal head position using TPU can differentiate accurately, in most cases, between OA and non-OA positions in the second stage of labor. This algorithm has the potential to support not only obstetricians but also midwives and accoucheurs in the clinical use of TPU to determine fetal occiput position in the labor ward. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Outcomes of the novel Odon Device in indicated operative vaginal birth

BACKGROUND

No new method of assisting vaginal birth has been introduced into clinical practice since the development of the vacuum extractor in the 1950s. The Odon Device is a new device that employs a circumferential air cuff over the fetal head to assist birth. In this study, the Odon Device has been used to assist vaginal birth for standard clinical indications.

OBJECTIVE

This study aimed to investigate the clinical impact, safety, and acceptability of the Odon Device to women, their babies, and clinicians and to assess the feasibility of recruiting women to an interventional intrapartum research study.

STUDY DESIGN

This is a nonrandomized, single-arm interventional feasibility study of the Odon Device for operative vaginal birth undertaken in a single maternity unit: Southmead Hospital, Bristol, United Kingdom. The Odon Device was used to assist birth in 40 women who required the birth to be assisted for suspected fetal compromise and/or prolonged second stage of labor. The primary clinical outcome was the proportion of births successfully assisted with the Odon Device, and the primary feasibility outcome was the proportion of eligible women who were approached and who agreed to participate. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90.

RESULTS

Between October 2018 and January 2019, 298 of 384 approached, eligible women (77.6%) consented to participate. Of these women, 40 received the intervention-the use of the Odon Device. Birth was assisted in all cephalic (occiput anterior, occiput transverse, and occiput posterior) fetal positions, at all stations at or below the ischial spine and with or without regional analgesia. The Odon Device was effective in 19 of 40 cases (48%). Of the 40 births, 21 (52.5%) required additional assistance: 18 of 40 births (45%) were completed using nonrotational forceps, 1 of 40 births (3%) required rotational forceps, and 2 of 40 births (5%) required an emergency cesarean delivery. There was no serious maternal or neonatal adverse event related to the use of the device, and there was no serious adverse device effect. There were 4 devices (10%) that were ineffective because of a manufacturing fault. Furthermore, 39 of 40 women (98%) reported a high birth perception score. All practitioners were able to use the device as intended, although some steps in using the device were reported to be easier to perform (setup and deflation of air chamber) than others (application of the device and withdrawal of the applicator).

CONCLUSION

Recruitment to an interventional study of a new device for operative vaginal birth was feasible; 78% of eligible women were willing to participate, often expressing an aspiration for an alternative to forceps and vacuum. The success rate of the Odon Device was lower than reported success rates of vacuum and forceps; however, in this study, the device had been used to assist birth for standard clinical indications. There was no significant maternal or neonatal safety concern associated with the use of the device, although the number of births studied was small. Further feasibility study to establish iterative changes to the device, technique, and clinical indications is necessary.

Transperineal ultrasound of fetal head progression in prolonged labor: women’s acceptance and ability to predict the mode of delivery

Background

Digital transvaginal examination of fetal head progression is subjective evaluation with many limitations. Using ultrasound (US) in the assessment of labor progression in prolonged labor is the current trend to predict the mode of delivery. The study intends to evaluate the women’s acceptance to the transperineal ultrasound (TPUS) compared with digital transvaginal examination, and its ability to predict the mode of delivery in prolonged labor. We included 28 pregnant ladies in a prolonged active phase of first or second stages of labor and followed them till delivery. TPUS was used to measure the fetal head–perineum distance (FHPD) and the angle of fetal head descent.

Results

Of the 28 participants, 53.5% of them delivered vaginally and 46.5% by Cesarean section (CS). All pregnant ladies described the TPUS as more convenient and less painful than digital vaginal examination. Cervical dilatation was negatively correlated with FHPD, and positively correlated with angle of fetal head descent. Both FHPD and angle of fetal head descent had a strong significant negative correlation. Using a cutoff value of 115° for the angle of fetal head descent, the positive predictive value (PPV) of vaginal delivery was 87%; using a cutoff value of 4.2 cm for FHPD, the PPV for vaginal delivery was 85%.

Conclusion

TPUS is more convenient, more accepted, and less painful than digital vaginal examination. Angle of head descent and FHPD are reliable predictors of the mode of delivery in prolonged labor.

Impact of ultrasound guided training in the diagnosis of the fetal head position during labor: A prospective observational study

OBJECTIVES

To assess whether the additional training with transabdominal ultrasound may improve the accuracy of the transvaginal digital examination in the assessment of the fetal head position during the active stage of labor.

METHODS

Prospective observational study involving 2 residents in their 1 st year of training in Obstetrics with no prior experience in neither transvaginal digital examination nor ultrasound. Women with term, cephalic presenting fetus and active labor with cervical dilation ≥ 8 cm and ruptured membranes were included. In the preliminary phase of the study, the resident A ("blinded") was assigned to assess the fetal head position by transvaginal digital examination, while the resident B ("unmasked") performed transvaginal digital examination following transabdominal ultrasound, which was considered to be the gold standard to determine the fetal head position. After 50 examinations independently performed by each resident in the training phase, a post-training phase of the study was carried out to compare the accuracy of each resident in the diagnosis of fetal head position by digital assessment. The occiput position was eventually confirmed by ultrasound performed by the main investigator.

RESULTS

Over a 6 months period, 90 post-training vaginal examinations were performed by each resident. The number of incorrect diagnoses of head position was higher for the "blinded" resident compared with the "unmasked" resident subjected to the ultrasound training (28/90 or 31.1 % vs 15/90 or 16.7 % p = 0.02). For both residents a wrong diagnosis was more likely with non-OA vs OA fetuses but this difference was statistically significant for the "blinded" Resident (10/20 or 50 % vs 18/70 or 25.7 % p = 0.039) but not for the "unmasked" Resident (5/18 or 27.9 % vs 10/72 or 13.9 % p = 0.16).

CONCLUSION

The addition of transabdominal ultrasound as a training tool in the determination of the fetal head position during labor seems to improve the accuracy of the transvaginal digital examination in unexperienced residents.

Operative vaginal delivery: a review of four national guidelines

There is a broad range in the rates of operative vaginal deliveries (OVD) worldwide, which reflects the variety of local practice patterns, the number of trained clinicians and the lack of international evidence-based guidelines. The aim of this study was to review and compare the recommendations from published guidelines on OVD. Thus, a descriptive review of guidelines from the Royal College of Obstetricians and Gynaecologists (RCOG), the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), the Society of Obstetricians and Gynaecologists of Canada (SOGC) and the American College of Obstetricians and Gynecologists (ACOG) on instrumental vaginal birth was conducted. All the guidelines point out that the use of any instrument should be based on the clinical circumstances and the experience of the operator. The indications, the contraindications, the prerequisites and the classification for OVD are overall very similar in the reviewed guidelines. Further, they all agree that episiotomy should not be performed routinely. The RCOG, the RANZCOG and the SOGC describe some interventions which may promote spontaneous vaginal birth and therefore reduce the need for OVD. They also highlight the importance of adequate postnatal care and counseling. There is no consensus on the actual technique that should be used, including the type of forceps or vacuum cup, the force and duration of traction or the number of detachments allowed. Hence, there is need for international practice protocols, so as to encourage the clinicians to use OVD when indicated, minimize the complications and reduce rates of cesarean delivery.

Prediction of spontaneous vaginal delivery in nulliparous women with a prolonged second stage of labor: the value of intrapartum ultrasound

BACKGROUND

A limited number of studies have addressed the role of intrapartum ultrasound in the prediction of the mode of delivery in women with prolonged second stage of labor.

OBJECTIVE

The objective of the study was to evaluate the role of transabdominal and transperineal sonographic findings in the prediction of spontaneous vaginal delivery among nulliparous women with prolonged second stage of labor.

STUDY DESIGN

This was a 2-center prospective study conducted at 2 tertiary maternity units. Nulliparous women with a prolonged active second stage of labor, as defined by active pushing lasting more than 120 minutes, were eligible for inclusion. Transabdominal ultrasound to evaluate the fetal head position and transperineal ultrasound for the measurement of the midline angle, the head-perineum distance, and the head-symphysis distance were performed in between uterine contractions and maternal pushes. At transperineal ultrasound the angle of progression was measured at rest and at the peak of maternal pushing effort. The delta angle of progression was defined as the difference between the angle of progression measured during active pushing at the peak of maternal effort and the angle of progression at rest. The sonographic findings of women who had spontaneous vaginal delivery vs those who required obstetric intervention, either vacuum extraction or cesarean delivery, were evaluated and compared.

RESULTS

Overall, 109 were women included. Spontaneous vaginal delivery and obstetric intervention were recorded in 40 (36.7%) and 69 (63.3%) patients, respectively. Spontaneous vaginal delivery was associated with a higher rate of occiput anterior position (90% vs 53.2%, P < .0001), lower head-perineum distance and head-symphysis distance (33.2 ± 7.8 mm vs 40.1 ± 9.5 mm, P = .001, and 13.1 ± 4.6 mm vs 19.5 ± 8.4 mm, P < .001, respectively), narrower midline angle (29.6° ± 15.3° vs 54.2° ± 23.6°, P < .001) and wider angle of progression at the acme of the pushing effort (153.3° ± 19.8° vs 141.8° ± 25.7°, P = .02) and delta-angle of progression (17.3° ± 12.9° vs 12.5° ± 11.0°, P = .04). At logistic regression analysis, only the midline angle and the head-symphysis distance proved to be independent predictors of spontaneous vaginal delivery. More specifically, the area under the curve for the prediction of spontaneous vaginal delivery was 0.80, 95% confidence interval (0.69-0.92), P < .001, and 0.74, 95% confidence interval (0.65-0.83), P = .002, for the midline angle and for the head-symphysis distance, respectively.

CONCLUSION

Transabdominal and transperineal intrapartum ultrasound parameters can predict the likelihood of spontaneous vaginal delivery in nulliparous women with prolonged second stage of labor.

A simple sonographic finding is associated with a successful vacuum application: the fetal occiput or forehead sign

BACKGROUND

Intrapartum ultrasound scanning has been proposed as an ancillary tool in the decision-making process of instrumental vaginal delivery.

OBJECTIVE

The purpose of this study was to evaluate the correlation between the sonographic visualization with a transperineal scan of the fetal occiput or forehead distal to the pubic symphysis with anterior or posterior presentation, respectively (fetal occiput or forehead sign), and the outcome of a vacuum delivery.

STUDY DESIGN

We conducted a retrospective cohort study of patients who underwent a vacuum application in our hospital from 2011-2017, excluding outlet applications. In each case, a preliminary transperineal scan was performed to confirm fetal presentation and position and to demonstrate the presence or absence of the fetal occiput or forehead sign. The head direction, angle of progression, and the head perineum distance were also noted. The primary outcome measure was the success of the vacuum. The secondary outcome measures included fetal complications and perineal lacerations.

RESULTS

A total of 196 consecutive patients were enrolled in the study. The occiput or forehead sign was present in 150 and was associated with a successful vaginal extraction in all cases. Of the 46 cases without the sign, 5 babies (10.8%) were delivered by cesarean section after a failed vacuum (P=.0006). The occiput or forehead sign was also associated with fewer grade 3-4 perineal lacerations (10.7% vs 35.7%; P=.0005) and cephalohematomas, although the difference was not statistically significant (1.4% vs 4.3%). There was a good correlation between the occiput or forehead sign and the other sonographic methods that previously had been proposed to predict a successful vacuum extraction, such as head direction, angle of progression, and head perineum distance.

CONCLUSION

In our hands, the fetal occiput or forehead sign was associated strongly with successful vacuum application and with a very low rate of maternal and fetal complications.

Randomised Italian Sonography for occiput POSition Trial Ante vacuum (R.I.S.POS.T.A.)

OBJECTIVE

To assess whether sonographic diagnosis of fetal head position before instrumental vaginal delivery can reduce the risk of failed vacuum extraction and improve delivery outcome.

METHODS

Randomised Italian Sonography for occiput POSition Trial Ante vacuum (R.I.S.POS.T.A.) is a randomized controlled trial of term (37 + 0 to 41 + 6 weeks' gestation) singleton pregnancies with cephalic presentation requiring instrumental delivery by vacuum extraction, which was conducted between April 2014 and June 2017 and involved 13 Italian maternity hospitals. Patients were randomized to assessment of fetal head position before attempted instrumental delivery by either vaginal examination (VE) alone or VE plus transabdominal sonography (TAS). Primary outcome was incidence of emergency Cesarean section due to failed vacuum extraction. A sample size of 653 women per group was planned to compare the primary outcome between the two groups. The sample size estimation was based on the hypothesis that the risk of failed vacuum delivery in the VE group would be 5% and that ultrasound assessment of fetal position prior to vacuum extraction would decrease this risk to 2%.

RESULTS

On interim analysis, the trial was stopped for futility. During this period, 222 women were randomized and 221 were included in the final data analysis, of whom 132 (59.7%) were randomized to evaluation of fetal head position by VE only and 89 (40.3%) to assessment by VE plus TAS prior to vacuum extraction. No significant differences were observed between the two groups with respect to incidence of emergency Cesarean section due to failed instrumental delivery and other maternal and fetal outcomes. Women randomized to assessment by VE plus TAS showed higher incidence of non-occiput anterior position of the fetal head at randomization and lower incidence of incorrect diagnosis of occiput position compared with women undergoing assessment by VE alone. A higher rate of episiotomy was noted in the women undergoing both VE and TAS compared with those in the VE-only group.

CONCLUSIONS

Our prematurely discontinued randomized controlled trial did not demonstrate any benefit in terms of reduced risk of failed instrumental delivery or maternal and fetal morbidity in women undergoing sonographic assessment of fetal head position prior to vacuum extraction. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

ISUOG Practice Guidelines: intrapartum ultrasound

The purpose of these Guidelines is to review the published techniques of ultrasound in labor and their practical applications, to summarize the level of evidence regarding the use of ultrasound in labor and to provide guidance to practitioners on when ultrasound in labor is clinically indicated and how the sonographic findings may affect labor management. We do not imply or suggest that ultrasound in labor is a necessary standard of care.

Comparison of Caesarean sections and instrumental deliveries at full cervical dilatation: a retrospective review

INTRODUCTION

This study aimed to compare instrumental vaginal deliveries (IDs) and Caesarean sections (CSs) performed at full cervical dilatation, including factors influencing delivery and differences in maternal and neonatal outcomes.

METHODS

A retrospective review was conducted of patients who experienced a prolonged second stage of labour at Singapore General Hospital from 2010 to 2012. A comparison between CS and ID was made through analysis of maternal/neonatal characteristics and peripartum outcomes.

RESULTS

Of 253 patients who required intervention for a prolonged second stage of labour, 71 (28.1%) underwent CS and 182 (71.9%) underwent ID. 5 (2.0%) of the patients who underwent CS had failed ID. Of the maternal characteristics considered, ethnicity was significantly different. Induction of labour and intrapartum epidural did not influence delivery type. 70.4% of CSs occurred outside office hours, compared with 52.7% of IDs (p = 0.011). CS patients experienced a longer second stage of labour (p < 0.001). Babies born via CS were heavier (p < 0.001), while the ID group had a higher proportion of occipitoanterior presentations (p < 0.001). Estimated maternal blood loss was higher with CSs (p < 0.001), but neonatal outcomes were similar.

CONCLUSION

More than one in four parturients requiring intervention for a prolonged second stage of labour underwent emergency CS. Low failed instrumentation rates and larger babies in the CS group suggest accurate diagnoses of cephalopelvic disproportion. The higher incidence of CS after hours suggests trainee reluctance to attempt ID. There were no clinically significant differences in maternal and neonatal morbidity.

An international assessment of trainee experience, confidence, and comfort in operative vaginal delivery

AIM

The aim of this study was to assess Irish and Canadian obstetricians in training ("trainees") experience, confidence, and comfort in performing operative vaginal delivery (OVD).

STUDY DESIGN

Trainees in Obstetrics and Gynaecology in the University of Toronto and the Royal College of Physicians of Ireland (RCPI) were invited to participate in an anonymous online survey reviewing experience as primary operator of OVD. Trainee confidence and comfort was self-assessed based upon their last few OVDs.

RESULTS

The response rate was 55% amongst Canadian trainees (31/56) and 44% amongst Irish trainees (21/48). When comparing Irish with Canadian trainee experience, the median numbers of vacuum and forceps deliveries performed by Irish trainees as primary operator were reported to be higher [125 (range 10-150) vs 20 (range 5-40); p < 0.0001 (ventouse), 45 (range 10-150) vs 6 (range 1-12); p = 0.0001 (forceps)]. Despite this, trainee confidence between the groups did not differ [confidence score: 18.7 (SD 3.2) vs 17.8 (SD 3.5), p = 0.3]. There were some differences regarding comfort in certain aspects of OVD, most notably increased comfort in Irish trainees in pre-procedure assessment skills of OVD.

CONCLUSION

With falling OVD rates worldwide, training experience is declining. Despite higher numbers of OVD within the Irish trainee group, there was no difference in trainee confidence between the two groups. These results suggest that a high number of cases as primary operator may not be required to establish operator confidence in performing a procedure. Irish trainees self-reported more comfort in non-technical skills of OVD, suggesting a step-wise effect of experience on first technical and then non-technical skills.

Trial of instrumental delivery in theatre versus immediate caesarean section for anticipated difficult assisted births

BACKGROUND

The majority of women have spontaneous vaginal births, but some women need assistance in the second stage with delivery of the baby, using either the obstetric forceps or vacuum extraction. Rates of instrumental vaginal delivery range from 5% to 20% of all births in industrialised countries. The majority of instrumental vaginal deliveries are conducted in the delivery room, but in a small proportion (2% to 5%), a trial of instrumental vaginal delivery is conducted in theatre with preparations made for proceeding to caesarean section.

OBJECTIVES

To determine differences in maternal and neonatal morbidity between women who, due to anticipated difficulty, have trial of instrumental vaginal delivery in theatre and those who have immediate caesarean section for failure to progress in the second stage.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 June 2012).

SELECTION CRITERIA

Randomised controlled trials comparing trial of instrumental vaginal delivery (vacuum extraction or forceps) in operating theatre to immediate caesarean section for women with failure to progress in the second stage (active second stage more than 60 minutes in primigravidae).

DATA COLLECTION AND ANALYSIS

We identified no studies meeting our inclusion criteria.

MAIN RESULTS

No studies were included.

AUTHORS' CONCLUSIONS

There is no current evidence from randomised trials to influence practice.

Prevention of the first cesarean delivery: the role of operative vaginal delivery

While the cesarean delivery (CD) rates have increased worldwide, operative vaginal delivery (OVD) rates continue to decline, with the United States having some of the lower rates amongst developed countries. It is clear that the use of forceps or vacuum can safely assist in accomplishing a vaginal delivery and prevent a cesarean during the IInd stage of labor performed for a variety of maternal or fetal indications. In the absence of randomized trials between OVD's and immediate CD's for anticipated difficult births the question of the balance of risks between the two interventions remains unanswered. Properly performed OVD's are associated with lower maternal morbidity compared with cesarean, without an increase in significant neonatal morbidity. In order to reverse the current trends and for these skills to continue active training in OVD's is clearly needed during and after residency. The availability of clinicians with expertise in OVD's should aid in decreasing the rates of CD and the training of newer generations of practitioners. The professional endorsement of OVD's is also fundamental not only to frame the practice for physicians but to promote and improve the general acceptance of assisted deliveries and facilitate the societal discourse to reduce CD rates.

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.

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.

Teaching forceps: the impact of proactive faculty

OBJECTIVE

The objective of the study was to evaluate the impact on resident forceps experience by a single proactive teacher.

STUDY DESIGN

A study was performed to assess the impact on delivery statistics and outcome following the assignment of a single attending to teach forceps to residents. A 2 year period immediately preceding and 2 years following the study was compared using χ(2) and Student t tests.

RESULTS

After appointment of the specific teaching attending, forceps deliveries increased by 59% (8% of all births), whereas vacuum procedures decreased to 3% of births (P < .0001) compared with the prior 2 years. The overall percentage of operative vaginal deliveries remained unchanged (11%). Cesarean section rates were unchanged during the study period at 27% of all births. Perineal laceration, 5 minute Apgar less than 7, and birth injuries were also not statistically different. There were fewer fetal pH events less than 7.1 in the teaching period (P = .003).

CONCLUSION

In the population studied, there was an association between increasing resident forceps use and a positive impact on birth outcomes from the designation of a full-time, experienced, and proactive faculty member to obstetrics teaching duty.

Diagnosis of station and rotation of the fetal head in the second stage of labor with intrapartum translabial ultrasound

OBJECTIVE

To investigate the ability of intrapartum translabial sonography to diagnose fetal station in the second stage of labor.

METHODS

Patients with uncomplicated pregnancies at term gestation with fetuses in vertex presentation in the second stage of labor underwent serial translabial sonography and digital examinations. In a sagittal section of the maternal pelvis, the direction of the head was noted and categorized as downward, horizontal or upward. By rotating the transducer in the transverse plane the cerebral midline echo was also visualized and the rotation of the head was noted. Clinical and ultrasound data were compared using Somer's d-test.

RESULTS

Sixty patients underwent a total of 168 clinical and sonographic examinations. When on the sonogram the fetal head was directed downward, the station assessed clinically was most frequently <or= + 1 cm from the ischial spines (44/57 (77.2%) cases); when the direction was horizontal, the station was most frequently <or= + 2 cm (53/59 (89.8%) cases); when the fetal head was directed upward, the station was usually >or= + 3 cm (46/52 (88.5%) cases). Failure to visualize the cerebral midline or a rotation >or= 45 degrees were associated with a station of + 2 cm or less in 98/103 (95.1%) examinations. Conversely, a rotation of < 45 degrees was associated with a station of + 3 cm or more in 45/65 (69.2%) examinations. All comparisons between clinical and sonographic findings demonstrated a statistically significant relationship (P < 0.0001). The probability of a station + 3 cm or more was particularly high when an upward direction of the head was seen in combination with a rotation of < 45 degrees (40/42 (95.2%) examinations). The interobserver variability (Cohen's kappa 0.795 and 0.727 for station and rotation, respectively; P < 0.001) and intraobserver variability (0.845 for both station and rotation, P < 0.001) suggested good reproducibility of the method.

CONCLUSIONS

Translabial sonography allows a diagnosis of fetal station with an accuracy comparable to that of digital examination and may provide useful information for diagnosing obstructed labor in the second stage as well as assisting in the choice of instrumental delivery.

Trial of instrumental delivery in theatre versus immediate caesarean section for anticipated difficult assisted births

BACKGROUND

The majority of women have spontaneous vaginal births, but some women need assistance in the second stage with delivery of the baby, using either the obstetric forceps or vacuum extraction. Rates of instrumental vaginal delivery range from 5% to 20% of all births in industrialised countries. The majority of instrumental vaginal deliveries are conducted in the delivery room, but in a small proportion (2% to 5%), a trial of instrumental vaginal delivery is conducted in theatre with preparations made for proceeding to caesarean section.

OBJECTIVES

To determine differences in maternal and neonatal morbidity between women who, due to anticipated difficulty, have trial of instrumental vaginal delivery in theatre and those who have immediate caesarean section for failure to progress in the second stage.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2008).

SELECTION CRITERIA

Randomised controlled trials comparing trial of instrumental vaginal delivery (vacuum extraction or forceps) in operating theatre to immediate caesarean section for women with failure to progress in the second stage (active second stage more than 60 minutes in primigravidae).

DATA COLLECTION AND ANALYSIS

We identified no studies meeting our inclusion criteria.

MAIN RESULTS

No studies were included.

AUTHORS' CONCLUSIONS

There is no current evidence from randomised trials to influence practice.

Impact of the severity of fetal distress on decision-to-delivery intervals for assisted vaginal delivery

To correlate the severity of fetal distress assessed retrospectively using the Dublin intrapartum fetal monitoring classification, with decision-to-delivery intervals (DDI) and neonatal outcome, a prospective 3-month study of 78 consecutive instrumental deliveries was conducted. There were 66 cardiotocographs (CTGs) with an 83% majority agreement on classification: it was agreed 95% of deliveries should be expedited for the 58 interpretable CTGs. Although the more abnormal CTG patterns resulted in shorter DDIs and greater neonatal acidaemia, there were no significant correlations. Acidosis was present in 14% with a suspicious, or 22% an ominous CTG pattern. Delivery as a trial in theatre doubled the DDI at 41.5 +/- 22.7 (mean +/- SD) min, compared with 18.1 +/- 8.1 min in the labour room (p < 0.0001), with one case of severe acidosis in the former group. The prolonged DDI with a trial of delivery in theatre could adversely compromise the already 'distressed' fetus and should be used only when clearly indicated.