Informed consent to midwifery practices and interventions during the second stage of labor-An observational study within the Oneplus trial.

OBJECTIVES: To study informed consent to midwifery practices and interventions during the second stage of labor and to investigate the association between informed consent and experiences of these practices and interventions and women's experiences of the second stage of labor. METHODS: This study uses an observational design with data from a follow-up questionnaire sent to women one month after giving birth spontaneously in the Oneplus trial, a study aimed at evaluating collegial midwifery assistance to reduce severe perineal trauma. The trial was conducted between 2018-2020 at five Swedish maternity wards and trial registered at clinicaltrials.gov, no NCT03770962. The follow-up questionnaire contained questions about experiences of the second stage of labor, practices and interventions used and whether the women had provided informed consent. Evaluated practices and interventions were the use of warm compresses held at the perineum, manual perineal protection, vaginal examinations, perineal massage, levator pressure, intermittent catheterization of the bladder, fundal pressure, and episiotomy. Associations between informed consent and women's experiences were assessed by univariate and multivariable logistic regression. FINDINGS: Of the 3049 women participating in the trial, 2849 consented to receive the questionnaire. Informed consent was reported by less than one in five women and was associated with feelings of being safe, strong, and in control. Informed consent was further associated with more positive experiences of clinical practices and interventions, and with less discomfort and pain from interventions involving physical penetration of the genital area. CONCLUSION: The findings indicate that informed consent during the second stage is associated with feelings of safety and of being in control. With less than one in five women reporting informed consent to all practices and interventions performed by midwives, the results emphasize the need for further action to enhance midwives' knowledge and motivation in obtaining informed consent prior to performance of interventions.

Effects of perineal massage at different stages on perineal and postpartum pelvic floor function in primiparous women: a systematic review and meta-analysis.

BACKGROUND: Perineal massage, as a preventive intervention, has been shown to reduce the risk of perineal injuries and may have a positive impact on pelvic floor function in the early postpartum period. However, there is still debate concerning the best period to apply perineal massage, which is either antenatal or in the second stage of labor, as well as its safety and effectiveness. Meta-analysis was used to evaluate the effect of implementing perineal massage in antenatal versus the second stage of labor on the prevention of perineal injuries during labor and early postpartum pelvic floor function in primiparous women. METHODS: We searched nine different electronic databases from inception to April 16, 2024. The randomized controlled trials (RCTs) we included assessed the effects of antenatal and second-stage labor perineal massage in primiparous women. All data were analyzed with Revman 5.3, Stata Statistical Software, and Risk of Bias 2 was used to assess the risk of bias. Subgroup analyses were performed based on the different periods of perineal massage. The primary outcomes were the incidence of perineal integrity and perineal injury. Secondary outcomes were perineal pain, duration of the second stage of labor, postpartum hemorrhage, urinary incontinence, fecal incontinence, and flatus incontinence. RESULTS: This review comprised a total of 10 studies that covered 1057 primigravid women. The results of the analysis showed that perineal massage during the second stage of labor reduced the perineal pain of primigravid women in the immediate postpartum period compared to the antenatal period, with a statistical value of (MD = -2.29, 95% CI [-2.53, -2.05], P < 0.001). Additionally, only the antenatal stage reported that perineal massage reduced fecal incontinence (P = 0.04) and flatus incontinence (P = 0.01) in primiparous women at three months postpartum, but had no significant effect on urinary incontinence in primiparous women at three months postpartum (P = 0.80). CONCLUSIONS: Reducing perineal injuries in primiparous women can be achieved by providing perineal massage both antenatally and during the second stage of labor. Pelvic floor function is improved in the postnatal phase by perineal massage during the antenatal stage. TRIAL REGISTRATION: CRD42023415996 (PROSPERO).

Improving management of first and second stages of labour in low- and middle-income countries.

Labour care must balance aspirations of parents with vigilance for unanticipated calamities. The 'on-site midwife-led primary care birth unit' facilitates this. The World Health Organization have replaced the traditional partograph with the 'Labour Care Guide'. An implementation project in Botswana included the mnemonic COPE: Companion, Oral fluids, Pain relief and Eliminate the supine position. The Parto-Ma project in Tanzania used guidelines, training and support to improve childbirth outcomes. We list labour practices supported by recent evidence, and highlight new developments. Foetal macrosomia increases risk but mistaken diagnosis increases caesarean births. Obstructed labour is a complex clinical diagnosis, and is difficult to predict. For shoulder dystocia prioritise delivery of the posterior shoulder, facilitated if needed by posterior axilla sling traction. 'Extended balloon labour induction' with two or three Foley catheters side by side, may reduce risks associated with uterine stimulants. Bedside ultrasound may facilitate the diagnosis of cephalic malpositions and malpresentations.

Factors Associated with Obstetric Anal Sphincter Injury During Vacuum-Assisted Vaginal Delivery.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injury (OASI) is a major complication associated with vacuum-assisted vaginal delivery (VAVD). The aim of this study was to evaluate risk factors related to vacuum extraction that are associated with OASI. METHODS: This was a case-control study performed at a tertiary university teaching hospital. Included were patients aged 18-45 years who had a singleton pregnancy resulting in a live, term, VAVD. The study group consisted of women diagnosed with OASI following vacuum extraction. The control group included women following VAVD without OASI. Matching at a ratio of 1:2 was performed. Groups were compared regarding demographic, obstetric. and labor-related parameters, specifically focusing on variables related to the vacuum procedure itself. RESULTS: One hundred and ten patients within the study group and 212 within the control group were included in the final analysis. Patients in the OASI group were more likely to undergo induction of labor, use of oxytocin during labor, increased second stage of labor, higher likelihood of the operator being a resident, increased number of pulls, procedure lasting under 10 min, occipito-posterior head position at vacuum initiation, episiotomy, increased neonatal head circumference, and birthweight. Multivariate logistic regression analysis revealed that increased week of gestation (OR 1.67, 95% CI 1.25-2.22, p < 0.001), unsupervised resident performing the procedure (OR 4.63, 95% CI 2.17-9.90), p < 0.001), indication of VAVD being fetal distress (OR 2.72, 95% CI 1.04-7.10, p = 0.041), and length of procedure under 10 min (OR 4.75, 95% CI 1.53-14.68, p = 0.007) were associated with OASI. Increased maternal age was associated with lower risk of OASI (OR 0.9, 95% CI 0.84-0.98, p = 0.012). CONCLUSIONS: When performing VAVD, increased week of gestation, unsupervised resident performing the procedure, fetal distress as vacuum indication, and vacuum procedure under 10 min were associated with OASI. In contrast, increased maternal age was shown to be a protective factor.

Effects of Fetal Position on the Loading of the Fetal Brain During the Onset of the Second Stage of Labor.

During vaginal delivery, the delivery requires the fetal head to mold to accommodate the geometric constraints of the birth canal. Excessive molding can produce brain injuries and long-term sequelae. Understanding the loading of the fetal brain during the second stage of labor (fully dilated cervix, active pushing, and expulsion of fetus) could thus help predict the safety of the newborn during vaginal delivery. To this end, this study proposes a finite element model of the fetal head and maternal canal environment that is capable of predicting the stresses experienced by the fetal brain at the onset of the second phase of labor. Both fetal and maternal models were adapted from existing studies to represent the geometry of full-term pregnancy. Two fetal positions were compared: left-occiput-anterior and left-occiput-posterior. The results demonstrate that left-occiput-anterior position reduces the maternal tissue deformation, at the cost of higher stress in the fetal brain. In both cases, stress is concentrated underneath the sutures, though the location varies depending on the presentation. In summary, this study provides a patient-specific simulation platform for the study of vaginal delivery and its effect on both the fetal brain and maternal anatomy. Finally, it is suggested that such an approach has the potential to be used by obstetricians to support their decision-making processes through the simulation of various delivery scenarios.

Duration of labor in consecutive deliveries: a retrospective data analysis.

PURPOSE: Labor is shorter in multiparous women. However, there are no individualized data on differences in duration of labor for consecutive deliveries in the same parturient. METHODS: We conducted a retrospective data analysis from 2004 to 2021 at the University Hospital of Zurich and included all women with 2 or more vaginal deliveries of a singleton child in cephalic position, between 22 and 42 weeks of gestation. Descriptive statistics were performed with SPSS version 25.0 (IBM, SPSS Inc., USA). The primary endpoint was the ratio between durations of labor stages in consecutive deliveries of the same parturient. RESULTS: A total of 3344 women with 7066 births (2601 first [P0], 2987 s [P1], 1176 third [P2], and 302 fourth [P3]) were included. The ratio of duration of the active first stage of labor between P1 and P0 was 0.49 (95% CI 0.47-0.51, p < 0.001) meaning that the active first stage of labor was 51% shorter. The second stage of labor with a ratio of 0.26 (95% CI 0.24-0.27, p < 0.001) was 74% shorter in P1 compared to P0. Higher birthweight of the first child led to an even greater decrease in duration of the second stage of labor in P1 compared to P0 (p = 0.003). Neuraxial anesthesia was an independent risk factor for a longer duration of labor, irrespective of parity (p < 0.001). Birthweight and HC of the neonates did not significantly differ between the children born by the same women. However, higher birthweight in of the first child significantly augmented the rate of second stage of labor between P0 and P1 (p = 0.003). DISCUSSION: Up to the third delivery, duration of labor decreased with each consecutive delivery of the same parturient. An individualized assessment of the expected duration of labor in multiparous women should be encouraged.

Novel hybrid rigid-deformable fetal modeling for simulating the vaginal delivery within the second stage of labor.

BACKGROUND AND OBJECTIVE: The fetal representation as a 3D articulated body plays an essential role to describe a realistic vaginal delivery simulation. However, the current computational solutions have been oversimplified. The objective of the present work was to develop and evaluate a novel hybrid rigid-deformable modeling approach for the fetal body and then simulate its interaction with surrounding fetal soft tissues and with other maternal pelvis soft tissues during the second stage of labor. METHODS: CT scan data was used for 3D fetal skeleton reconstruction. Then, a novel hybrid rigid-deformable model of the fetal body was developed. This model was integrated into a maternal 3D pelvis model to simulate the vaginal delivery. Soft tissue deformation was simulated using our novel HyperMSM formulation. Magnetic resonance imaging during the second stage of labor was used to impose the trajectory of the fetus during the delivery. RESULTS: Our hybrid rigid-deformable fetal model showed a potential capacity for simulating the movements of the fetus along with the deformation of the fetal soft tissues during the vaginal delivery. The deformation energy density observed in the simulation for the fetal head fell within the strain range of 3 % to 5 %, which is in good agreement with the literature data. CONCLUSIONS: This study developed, for the first time, a hybrid rigid-deformation modeling of the fetal body and then performed a vaginal delivery simulation using MRI-driven kinematic data. This opens new avenues for describing more realistic behavior of the fetal body kinematics and deformation during the second stage of labor. As perspectives, the integration of the full skeleton body, especially the upper and lower limbs will be investigated. Then, the completed model will be integrated into our developed next-generation childbirth training simulator for vaginal delivery simulation and associated complication scenarios.

Midwives' experiences of professional learning when practicing collegial midwifery assistance during the active second stage of labour: data from the oneplus trial.

BACKGROUND: Learning is a lifelong process and the workplace is an essential arena for professional learning. Workplace learning is particularly relevant for midwives as essential knowledge and skills are gained through clinical work. A clinical practice known as 'Collegial Midwifery Assistance' (CMA), which involves two midwives being present during the active second stage of labour, was found to reduce severe perineal trauma by 30% in the Oneplus trial. Research regarding learning associated with CMA, however, is lacking. The aim was to investigate learning experiences of primary and second midwives with varying levels of work experience when practicing CMA, and to further explore possible factors that influence their learning. METHODS: The study uses an observational design to analyse data from the Oneplus trial. Descriptive statistics and proportions were calculated with 95% confidence intervals. Stratified univariable and multivariable logistic regression analysis were performed. RESULTS: A total of 1430 births performed with CMA were included in the study. Less experienced primary midwives reported professional learning to a higher degree (< 2 years, 76%) than the more experienced (> 20 years, 22%). A similar but less pronounced pattern was seen for the second midwives. Duration of the intervention ≥ 15 min improved learning across groups, especially for the least experienced primary midwives. The colleague's level of experience was found to be of importance for primary midwives with less than five years' work experience, whereas for second midwives it was also important in their mid to late career. Reciprocal feedback had more impact on learning for the primary midwife than the second midwife. CONCLUSIONS: The study provides evidence that CMA has the potential to contribute with professional learning both for primary and second midwives, for all levels of work experience. We found that factors such as the colleague's work experience, the duration of CMA and reciprocal feedback influenced learning, but the importance of these factors were different for the primary and second midwife and varied depending on the level of work experience. The findings may have implications for future implementation of CMA and can be used to guide the practice.

On the uncertainty quantification of the active uterine contraction during the second stage of labor simulation.

Uterine contractions in the myometrium occur at multiple scales, spanning both organ and cellular levels. This complex biological process plays an essential role in the fetus delivery during the second stage of labor. Several finite element models of active uterine contractions have already been developed to simulate the descent of the fetus through the birth canal. However, the developed models suffer severe reliability issues due to the uncertain parameters. In this context, the present study aimed to perform the uncertainty quantification (UQ) of the active uterine contraction simulation to advance our understanding of pregnancy mechanisms with more reliable indicators. A uterus model with and without fetus was developed integrating a transversely isotropic Mooney-Rivlin material with two distinct fiber orientation architectures. Different contraction patterns with complex boundary conditions were designed and applied. A global sensitivity study was performed to select the most valuable parameters for the uncertainty quantification (UQ) process using a copula-based Monte Carlo method. As results, four critical material parameters ( C 1 , C 2 , K , Ca 0 ) of the active uterine contraction model were identified and used for the UQ process. The stress distribution on the uterus during the fetus descent, considering first and second fiber orientation families, ranged from 0.144 to 1.234 MPa and 0.044 to 1.619 MPa, respectively. The simulation outcomes revealed also the segment-specific contraction pattern of the uterus tissue. The present study quantified, for the first time, the effect of uncertain parameters of the complex constitutive model of the active uterine contraction on the fetus descent process. As perspectives, a full maternal pelvis model will be coupled with reinforcement learning to automatically identify the delivery mechanism behind the cardinal movements of the fetus during the active expulsion process.

First and Second Stage Risk Factors Associated with Perineal Lacerations.

OBJECTIVE: To determine intrapartum factors associated with perineal laceration at delivery. METHODS: This was a planned secondary analysis of a multicenter randomized clinical trial of delayed versus immediate pushing among term nulliparous women in labor with neuraxial analgesia conducted in the United States. Intrapartum characteristics were extracted from the medical charts. The primary outcome was perineal laceration, defined as second degree or above, characterized at delivery in women participating in longer term pelvic floor assessments post-delivery. Multivariable logistic regression was used to refine risk estimates while adjusting for randomization group, birth weight, and maternal age. RESULTS: Among the 941 women participating in the pelvic floor follow-up, 40.6% experienced a perineal laceration. No first stage labor characteristics were associated with perineal laceration, including type of labor or length of first stage. Receiving an amnioinfusion appeared protective of perineal laceration (adjusted odds ratio, 0.48; 95% confidence interval 0.26-0.91; P = 0.01). Second stage labor characteristics associated with injury were length of stage (2.01 h vs. 1.50 h; adjusted odds ratio, 1.36; 95% confidence interval 1.18-1.57; P < 0.01) and a prolonged second stage (adjusted odds ratio, 1.64; 95% confidence interval 1.06-2.56; P < 0.01). Operative vaginal delivery was strongly associated with perineal laceration (adjusted odds ratio, 3.57; 95% confidence interval 1.85-6.90; P < 0.01). CONCLUSION: Operative vaginal delivery is a modifiable risk factor associated with an increased risk of perineal laceration. Amnioinfusion appeared protective against injury, which could reflect a spurious finding, but may also represent true risk reduction similar to the mechanism of warm perineal compress.

Impact of the Duration of the Second Stage of Labor on Postpartum Pelvic Floor Symptoms.

IMPORTANCE: The associated effect of duration of the second stage of labor (SSL) on pelvic floor symptoms development is not well studied. OBJECTIVE: This study aimed to examine the association between duration of SSL and pelvic floor symptoms at 6 months postpartum among primiparous women. STUDY DESIGN: A planned secondary analysis of a multicenter randomized trial evaluating the impact of immediate versus delayed pushing on vaginal delivery rates, maternal morbidity, and neonatal outcomes was conducted between 2014 and 2018. For pelvic floor arm participants, demographic, pelvic examination, and validated questionnaire data were collected postpartum. Primary outcome was change in Pelvic Floor Distress Inventory 20 (PFDI-20) score from immediate to 6 months postpartum. Secondary outcomes included changes in the Pelvic Floor Impact Questionnaire, Fecal Incontinence Severity Index, Modified Manchester Health Questionnaire scores, and Pelvic Organ Prolapse Quantification measurements at 6 months postpartum. Participants were analyzed by SSL duration ≤60 minutes or >60 minutes. RESULTS: Of the 2,414 trial participants, 767 (32%) completed pelvic floor assessments at 6 months. Pelvic Floor Distress Inventory 20 scores significantly improved at 6 months in the ≤60 minutes SSL group compared with >60 minutes SSL (-14.3 ± 48.0 and -3.2 ± 45.3, respectively; P = 0.04). Changes from immediate postpartum in total and subscale scores for other questionnaires at 6 months did not differ between groups. Prolapse stage did not differ between groups. Perineal body was significantly shorter in the >60 minutes SSL group (3.7 ± 0.7, 3.5 ± 0.8; P = 0.03). CONCLUSIONS: Women with SSL >60 minutes experience less improvement in PFDI-20 scores at 6 months. Greater tissue and innervation trauma in those with SSL >60 minutes may explain persistently less improvement in PFDI-20 scores.

The second stage of labor.

The second stage of labor extends from complete cervical dilatation to delivery. During this stage, descent and rotation of the presenting part occur as the fetus passively negotiates its passage through the birth canal. Generally, descent begins during the deceleration phase of dilatation as the cervix is drawn upward around the fetal presenting part. The most common means of assessing the normality of the second stage of labor is to measure its duration, but progress can be more meaningfully gauged by measuring the change in fetal station as a function of time. Accurate clinical identification and evaluation of differences in patterns of fetal descent are necessary to assess second stage of labor progress and to make reasoned judgments about the need for intervention. Three distinct graphic abnormalities of the second stage of labor can be identified: protracted descent, arrest of descent, and failure of descent. All abnormalities have a strong association with cephalopelvic disproportion but may also occur in the presence of maternal obesity, uterine infection, excessive sedation, and fetal malpositions. Interpretation of the progress of fetal descent must be made in the context of other clinically discernable events and observations. These include fetal size, position, attitude, and degree of cranial molding and related evaluations of pelvic architecture and capacity to accommodate the fetus, uterine contractility, and fetal well-being. Oxytocin infusion can often resolve an arrest or failure of descent or a protracted descent caused by an inhibitory factor, such as a dense neuraxial block. It should be used only if thorough assessment of fetopelvic relationships reveals a low probability of cephalopelvic disproportion. The value of forced Valsalva pushing, fundal pressure, and routine episiotomy has been questioned. They should be used selectively and where indicated.

Optimizing the length of the second stage and management of pushing.

Although the optimal length of the second stage of labor to minimize maternal and neonatal morbidities and optimize spontaneous vaginal delivery is not known, available evidence suggests that increasing length of the second stage is associated with increasing maternal and neonatal morbidity. Thus, evidence-based strategies to safely shorten the second stage, such as initiating pushing when complete dilation is reached among those with neuraxial anesthesia, is prudent. Many aspects of optimal management of the second stage of labor require future study to continue to guide clinical second-stage management.

Pelvic floor dysfunction after intervention, compared with expectant management, in prolonged second stage of labour: A population-based questionnaire and cohort study.

OBJECTIVE: To investigate the effect of vacuum extraction (VE) or caesarean section (CS), compared with expectant management, on pelvic floor dysfunction (PFD) 1-2 years postpartum in primiparous women with a prolonged second stage of labour. DESIGN: A population-based questionnaire and cohort study. SETTING: Stockholm, Sweden. POPULATION: A cohort of 1302 primiparous women with a second stage duration of ≥3 h, delivering from December 2017 to November 2018. METHODS: The 1-year follow-up questionnaire from the Swedish National Perineal Laceration Register was distributed 12-24 months postpartum. Exposure was VE or CS at 3-4 h or 4-5 h, compared with expectant management. MAIN OUTCOME MEASURES: Pelvic floor dysfunction was defined as at least weekly symptoms of urinary incontinence, pelvic organ prolapse or a Wexner score of ≥4. The risk of PFD was calculated using Poisson regression with robust variance estimation, presented as crude and adjusted relative risks (RRs and aRRs) with 95% confidence intervals (95% CIs). The implication of obstetric anal sphincter injury (OASI) on pelvic floor disorders was investigated through mediation analysis. RESULTS: In total, 35.1% of women reported PFD. Compared with expectant management, the risk of PFD was increased after VE at 3-4 h (aRR 1.33, 95% CI 1.06-1.65) and 4-5 h (aRR 1.34, 95% CI 1.05-1.70), but remained unchanged after CS. The increased risk after VE was not mediated by OASI. CONCLUSIONS: Pelvic floor dysfunction was common in primiparous women after a prolonged second stage, and the risk of PFD increased after VE but was unaffected by CS, compared with expectant management. If a spontaneous vaginal delivery eventually occurred, allowing an extended duration of labour did not increase the risk of PFD.

Meta-analysis of the effect of duration of labour on postpartum haemorrhage.

OBJECTIVES: To evaluate the relationship between stages of labour and the risk of postpartum haemorrhage (PPH) and provide evidence for clinical application. MATERIAL AND METHODS: Manual searches were undertaken, and computer searches of PubMed, MEDLINE, Web of Science, CNKI, Wanfang and Wipu databases with a search window from database creation to April 2022 were conducted to procure relevant studies on the relationship between labour phase and PPH. The articles included in this study were evaluated for quality, and RevMan 5.3 software was used for meta-analysis. RESULTS: Meta-analysis showed that the incidence of PPH in women with weak uterine contractions was 27.5%, compared with 18.1% in women with normal contractions [relative risk (RR) = 1.60; 95% confidence interval (CI) 1.38, 1.85; p < 0.01]. There was a statistically significant difference in the incidence of PPH in pregnant women with a prolonged second stage of labour (≥ 2 h) (34.5%) compared with those whose second stage of labour was normal in duration (15.9%) (RR = 0.20; 95% CI 0.15, 0.25; p < 0.01). The incidence of PPH was 52.1% in pregnant women with a prolonged third stage of labour (≥ 15 min) compared with 20.9% in those whose third stage of labour was of normal duration (RR = 3.53; 95% CI 2.75, 4.52; p < 0.01). The difference in the incidence of a prolonged third stage of labour in pregnant women with weak contractions compared with those with normal contractions was statistically significant (72.3% vs 15.5%) (RR = 0.47; 95% CI 0.35, 0.60; p < 0.01). CONCLUSIONS: Duration of labour is associated with the development of PPH, and the risk of PPH is increased in women with weak contractions or with a prolonged second or third stage of labour.

Exploring the Optimal Intertwin Delivery Interval for Vaginal Delivery.

The effect of prolonged intertwin delivery interval (IDI) is not well studied. This work aimed to assess the inflection point for Cesarean delivery (CD) and associated adverse maternal and neonatal outcomes. This was a retrospective cohort study at a single tertiary care center. The study included women with twin pregnancies in 2010-2019 who reached the second stage of labor, and assessed the most predictive cutoff for CD using Youden J statistic and compared adverse maternal and neonatal outcomes between short and prolonged intertwin delivery intervals. A total of 461 gravidas reached the second stage of labor and were included in the study. Using the ROC curve and Youden J statistic, the IDI cutoff was set at 15 min (80% sensitivity, 75% specificity, p < 0.001), with 312 women in the short and 149 in the prolonged IDI groups. Women in the prolonged IDI group were less likely to deliver the second twin vaginally (75.8% vs. 93.3%, p < 0.001). Postpartum hemorrhage (PPH) (39.1% vs. 24.7%, p = 0.01), and placental abruption (4% vs. 1%, p = 0.03) were more likely to occur in the prolonged IDI group. An increased rate of neonatal acidemia and low 5-min Apgar score were also found in the prolonged IDI group (15.7% vs. 4.3%, P = 0.01, 9.7% vs. 3.5%, p = 0.008; respectively). IDIs of more than 15 min are associated with increased risk of adverse maternal and neonatal outcomes. These findings should be used for counseling and managing twin pregnancies attempting vaginal delivery.

Impacted fetal head extraction methods at second stage cesarean and subsequent preterm delivery: A multicenter study.

OBJECTIVE: Second-stage cesarean delivery (CD) is associated with subsequent preterm birth (PTB). It has been suggested that an increased risk of PTB after second-stage cesarean delivery could be linked to a higher chance of cervical injury due to the extension of the uterine incision. Previous studies have shown that reverse breech extraction is associated with lower rates of uterine incision extensions compared to the "push" method. We aimed to investigate the association between the method of fetal extraction during second-stage CD and the rate of spontaneous PTB (sPTB), as well as other maternal and neonatal outcomes during the subsequent pregnancy. METHODS: This was a multicenter retrospective cohort study. The study population included women in their first subsequent singleton delivery following a second-stage CD between 2004 and 2021. The main exposure of interest was the method of fetal extraction in the index CD ("push" method vs. reverse breech extraction). The primary outcome of this study was sPTB <37 weeks in the subsequent pregnancy. Secondary outcomes were overall PTB, trial of labor, and other adverse maternal and neonatal outcomes. Univariate analysis was followed by multiple logistic regression modeling. RESULTS: During the study period, 2969 index CD during second stage were performed, of those 583 met the inclusion criteria, of whom 234 (40.1%) had fetal extraction using the reverse breech extraction method, while 349 (59.9%) had the "push" method for extraction. In univariate analysis, women in those two groups had statistically similar rates of sPTB (3.7% vs. 3.0%; odds ratio [OR] 1.25, 95% CI: 0.49-3.19) and overall PTB (<37, <34 and <32 weeks), as well as other maternal, neonatal, and trial of labor outcomes. This was confirmed by multivariate analyses with an adjusted OR of 1.27 (95% CI: 0.43-3.71) for sPTB. CONCLUSION: Among women with a previous second-stage CD, no significant difference was observed in PTB rates in the subsequent pregnancies following the "push" method compared to the reverse breech extraction method.

The optimal cutoff for intertwin delivery interval: A retrospective cohort study.

OBJECTIVE: To determine the cutoff of intertwin delivery intervals (IDIs) as a predictor for neonatal acidemia. METHOD: This retrospective cohort study was conducted at a single tertiary care center. Women attempting vaginal delivery of twins between 2010 and 2019 and who reached the second stage of labor were included. The cutoff point for prolonged IDI was established using a receiver operating characteristic (ROC) curve and Youden's J statistic. Maternal and neonatal outcomes were compared between short and prolonged IDI cohorts. RESULTS: A total of 461 women were included in the study. A cutoff time of 10 min was found to be the best predictor for neonatal acidemia (arterial cord pH ≤ 7.1), with a sensitivity of 90% and a specificity of 59%. Second twins delivered more than 10 min after the first twin were more likely to be acidemic and to have a 5-min Apgar score of 7 or less (13.5% vs 3.3%, P = 0.01, and 8.4% vs 3.2%, P = 0.02, respectively). An IDI of more than 10 min was also associated with increased rate of cesarean delivery and placental abruption (13.5% vs 0.8%, P < 0.001, and 3.4% vs 0.8%, P = 0.047, respectively). No other adverse maternal or neonatal outcomes were statistically significant between cohorts. CONCLUSION: An IDI of more than 10 min is associated with a higher risk for neonatal academia, with a low 5-min Apgar score, and higher cesarean delivery and placental abruption rates. These findings provide insights that are valuable when counseling and managing twin pregnancies attempting vaginal delivery. Interventions aimed at shortening the IDI should be considered to prevent adverse neonatal outcomes.

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.

Optimizing Management of the Second Stage of Labor: A Multicenter Randomized Controlled Trial.

To review the findings of the Optimizing Management of the Second Stage of Labor randomized controlled trial in the context of prior and subsequent obstetric literature. A multi-database search was performed in addition to a review of the parent trial and secondary studies. Nulliparous patients with neuraxial anesthesia randomized to either immediate or delayed pushing showed no difference in vaginal delivery rates. However, delayed pushing is associated with an increased duration of the second stage and perinatal morbidity. Patients should be appropriately counseled on the timing of second-stage pushing and the risks of prolonged second-stage labor.