The Maternal-Fetal Medicine Units Cesarean Registry: safety and efficacy of a trial of labor in preterm pregnancy after a prior cesarean delivery

Trial of labor after 2 previous cesareans: a multicenter study

BACKGROUND

Trial of labor after cesarean after 2 cesarean deliveries is linked to a lower success rate of vaginal delivery and higher rates of adverse obstetrical outcomes than trial of labor after cesarean after 1 previous cesarean delivery.

OBJECTIVE

This study aimed to investigate the factors associated with failed trial of labor after cesarean among women with 2 previous cesarean deliveries.

STUDY DESIGN

This was a multicenter retrospective cohort study, which included all women with singleton pregnancies attempting trial of labor after cesarean after 2 previous cesarean deliveries between 2003 and 2021. This study compared labor, maternal, and neonatal characteristics between women with failed trial of labor after cesarean and those with successful trial of labor after cesarean. Univariate analysis was initially performed, followed by multivariable analysis (adjusted odds ratios with 95% confidence intervals).

RESULTS

The study included a total of 1181 women attempting trial of labor after cesarean after 2 previous cesarean deliveries. Among these cases, vaginal birth after cesarean was achieved in 973 women (82.4%). Women with failed trial of labor after cesarean had higher rates of maternal and neonatal morbidities. Several factors were found to be associated with failed trial of labor after cesarean, including longer interpregnancy and interdelivery intervals, lower gravidity and parity, lower rates of previous successful vaginal delivery, smoking, earlier gestational age at delivery (38.3±2.1 vs 39.5±1.3 weeks), late preterm delivery (34-37 weeks of gestation), lower cervical dilation on admission, no use of epidural, and smaller neonatal birthweight. Our multivariable model revealed that late preterm delivery (adjusted odds ratio, 3.79; 95% confidence interval, 1.37-10.47) and cervical dilation on admission for labor <3 cm (adjusted odds ratio, 2.58; 95% confidence interval, 1.47-4.54) were associated with higher odds of failed trial of labor after cesarean.

CONCLUSION

In the investigated population of women with 2 previous cesarean deliveries undergoing trial of labor after cesarean, admission at the late preterm period with a cervical dilation of <3 cm, which reflects the latent phase, may elevate the risk of failed trial of labor after cesarean and a repeated intrapartum cesarean delivery.

Trial of labor after cesarean, vaginal birth after cesarean, and the risk of uterine rupture: an expert review

The decision to pursue a trial of labor after cesarean delivery is complex and depends on patient preference, the likelihood of successful vaginal birth after cesarean delivery, assessment of the risks vs benefits of trial of labor after cesarean delivery, and available resources to support safe trial of labor after cesarean delivery at the planned birthing center. The most feared complication of trial of labor after cesarean delivery is uterine rupture, which can have catastrophic consequences, including substantial maternal and perinatal morbidity and mortality. Although the absolute risk of uterine rupture is low, several clinical, historical, obstetrical, and intrapartum factors have been associated with increased risk. It is therefore critical for clinicians managing patients during trial of labor after cesarean delivery to be aware of these risk factors to appropriately select candidates for trial of labor after cesarean delivery and maximize the safety and benefits while minimizing the risks. Caution is advised when considering labor augmentation and induction in patients with a previous cesarean delivery. With established hospital safety protocols that dictate close maternal and fetal monitoring, avoidance of prostaglandins, and careful titration of oxytocin infusion when induction agents are needed, spontaneous and induced trial of labor after cesarean delivery are safe and should be offered to most patients with 1 previous low transverse, low vertical, or unknown uterine incision after appropriate evaluation, counseling, planning, and shared decision-making. Future research should focus on clarifying true risk factors and identifying the optimal approach to intrapartum and induction management, tools for antenatal prediction, and strategies for prevention of uterine rupture during trial of labor after cesarean delivery. A better understanding will facilitate patient counseling, support efforts to improve trial of labor after cesarean delivery and vaginal birth after cesarean delivery rates, and reduce the morbidity and mortality associated with uterine rupture during trial of labor after cesarean delivery.

Second stage duration and delivery outcomes among women laboring after cesarean with no prior vaginal delivery

BACKGROUND

We aimed to evaluate the association of the duration of the second stage with labor after cesarean (LAC) success and other outcomes among women with one prior cesarean delivery (CD) and no prior vaginal births.

METHODS

All women undergoing LAC that reached the second stage of labor from March 2011 to March 2020 were included in this retrospective cohort study. The primary outcome was the mode of delivery by second stage duration. The secondary outcomes included adverse maternal and neonatal outcomes. We allocated the study cohort into five groups of second stage duration. Further analysis compared <3 to ≥3 h of second stage based on prior studies. LAC success rates were compared. Composite maternal outcome was defined as the presence of uterine rupture/dehiscence, postpartum hemorrhage, or intrapartum/postpartum fever.

RESULTS

One thousand three hundred ninety seven deliveries were included. Vaginal birth after cesarean (VBAC) rates decreased as the second stage length time interval increased: 96.4% at <1 h, 94.9% at 1 to <2 h, 94.6% at 2 to <3 h, 92.1% at 3 to <4 h and 79.5% at ≥4 h (p < 0.001). Operative vaginal and CDs were significantly more likely as second stage duration time interval increased (p < 0.001). The composite maternal outcome was comparable among groups (p = 0.226). When comparing the outcomes of deliveries at <3 h versus ≥3 h, the composite maternal outcome and neonatal seizure rates were lower in the <3 h group (p = 0.041 and p = 0.047, respectively).

CONCLUSION

Vaginal birth after cesarean rates decreased as second stage time interval length increased. Even with prolonged second stage, VBAC rates remained relatively high. Increased risk of composite adverse maternal outcomes and neonatal seizures were observed when the second stage lasted 3 h or more.

Prenatal immobility stress: Relationship with oxidative stress, inflammation, apoptosis, and intrauterine growth restriction in rats

BACKGROUND

Prenatal stress is a significant risk factor affecting pregnant women and fetal health. In the present study, we aimed to investigate the effect of immobility stress at different periods of pregnancy on oxidative stress, inflammation, placental apoptosis and intrauterine growth retardation in rats.

METHODS

Fifty adult virgin female Wistar albino rats were used. Pregnant rats were exposed to 6 h/day immobilization stress in a wire cage at different stages of pregnancy. Groups I and II (Day 1-10 stress group) were sacrificed on the 10th day of pregnancy, and Group III, Group IV (10-19th-day stress group), and Group V (1-19th-day stress group) were sacrificed on the 19th day of pregnancy. Inflammatory cytokines, including interleukin-6 (IL-6) and interleukin-10 (IL-10), serum corticotropin-releasing hormone (CRH), and corticosterone levels were measured by enzyme-linked immunosorbent assay. Malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels in the placenta were spectrophotometrically measured. Histopathological analyses of the placenta were evaluated by hematoxylin and eosin staining. Tumor necrosis factor-alpha (TNF-α) and caspase-3 immunoreactivity in placenta tissues were determined by the indirect immunohistochemical method. Placental apoptosis was determined by the TUNEL staining method.

RESULTS

We found that the immobility stress during pregnancy significantly increased serum corticosterone levels. Our results showed that the immobility stress diminished the number and weight of fetuses in rats compared to the non-stress group. The immobility stress caused significant histopathological changes in the connection zone and labyrinth zone and increased placental TNF-α and caspase-3 immunoreactivity and placental apoptosis. In addition, immobility stress significantly increased the levels of pro-inflammatory IL-6 and MDA and caused a significant decrease in the levels of antioxidant enzymes such as SOD, CAT, and anti-inflammatory IL-10.

CONCLUSIONS

Our data suggest that immobility stress causes intrauterine growth retardation by activating the hypothalamic-pituitary-adrenal axis and deteriorating placental histomorphology and deregulating inflammatory and oxidative processes.

Birth trauma in preterm spontaneous vaginal and cesarean section deliveries: A 10-years retrospective study

OBJECTIVE

We compared birth injuries for spontaneous vaginal (VD) and caesarean section (CS) deliveries in preterm and term pregnancies.

METHODS

A retrospective cohort study was conducted in a single tertiary center, between January 1st, 2007, and December 31st, 2017. The study included 62330 singleton pregnancies delivered after 24 0/7 weeks gestation. Multivariable analyses compared trauma at birth, birth hypoxia and birth asphyxia in term and preterm deliveries, stratified by mode of birth, VD versus CS. Main outcome measure was trauma at birth including intracranial laceration and haemorrhage, injuries to scalp, injuries to central and peripheral nervous system, fractures to skeleton, facial and eye injury.

RESULTS

The incidence of preterm deliveries was 10.9%. Delivery of preterm babies by CS increased from 37.0% in 2007 to 60.0% in 2017. The overall incidence of all birth trauma was 16.2%. When stratified by mode of delivery, birth trauma was recorded in 23.4% of spontaneous vaginal deliveries and 7.5% of CS deliveries (aOR 3.3, 95%CI 3.1-3.5). When considered all types of birth trauma, incidence of trauma at birth was higher after 28 weeks gestation in VD compared to CS (28-31 weeks, aOR 1.7, 95% CI 1.3-2.3; 32-36 weeks, aOR 4.2, 95% CI 3.6-4.9; >37 weeks, aOR 3.3, 95% CI 3.1-3.5). There was no difference in the incidence of birth trauma before 28 weeks gestation between VD and CS (aOR 0.8, 95% CI 0.5-1.2). Regarding overall life-threatening birth trauma or injuries at birth with severe consequences such as cerebral and intraventricular haemorrhage, cranial and brachial nerve injury, fractures of long bones and clavicle, eye and facial injury, there was no difference in vaginal preterm deliveries compared to CS deliveries (p > 0.05 for all).

CONCLUSION

CS is not protective of injury at birth. When all types of birth trauma are considered, these are more common in spontaneous VD, thus favoring CS as preferred method of delivery to avoid trauma at birth. However, when stratified by severity of birth trauma, preterm babies delivered vaginally are not at higher risk of major birth trauma than those delivered by CS.

Trial of labor following cesarean in preterm deliveries: success rates and maternal and neonatal outcomes: a multicenter retrospective study

PURPOSE

To evaluate the rates of vaginal birth after cesarean (VBAC) among parturients attempting preterm trial of labor following a cesarean delivery (TOLAC) vs. term TOLAC.

METHODS

A multicenter historic cohort study was conducted at two university-affiliated centers between August 2005 and March 2021. Parturients in their second delivery, attempting TOLAC after a single low segment transverse cesarean delivery were included. We retrospectively examined computerized medical records of all preterm (< 37 weeks) and term (37-42 weeks) births. Multifetal gestations and postterm deliveries (≥ 42 weeks) were excluded. A univariate analysis was conducted, followed by a multivariate analysis.

RESULTS

4865 second deliveries following previous cesarean were identified: 212 (4.4%) preterm and 4653 (95.6%) term. Hypertensive disorders, diabetes and fertility treatments were significantly more prevalent in the preterm group. VBAC rate was significantly lower in preterm group (57.5 vs 79.7%., p < 0.01), including both spontaneous and vaginal-assisted deliveries. In multivariate analysis, preterm TOLAC was independently associated with TOLAC failure [adjusted odds ratio 2.24, [95% confidence interval 1.62-3.09]. Overall, maternal outcomes were favorable. Rates of uterine rupture, re-laparotomy and postpartum hemorrhage were comparable between groups. Neonatal outcomes were less favorable among the preterm group; however, preterm vs. term TOLAC was not associated with low 5 min Apgar score (aOR 1.76, 95% CI 0.92-3.40).

CONCLUSION

In our study, VBAC rates were lower in preterm compared to term deliveries. Maternal outcomes were comparable. Neonatal outcomes were less favorable in the preterm group, more likely due to prematurity than delivery mode.

Neonatal outcomes in trial of vaginal birth versus repeat caesarean delivery in preterm pregnancies: A prospective cohort study

OBJECTIVE

To characterise neonatal morbidity following preterm trial of labour (TOL) in comparison with elective repeat caesarean section (eRCS) specifically among patients without a previous vaginal delivery who may have a lower success rate of vaginal birth after caesarean.

DESIGN

This is a secondary analysis of a multicentre prospective database.

SETTING/POPULATION

Maternal and Fetal Medicine Unit Cesarean Section Registry.

POPULATION

Singleton pregnancies in women without a previous vaginal delivery who delivered at 24⁺⁰  weeks to 36⁺⁶  weeks gestation.

METHODS

Neonatal outcomes were compared between those with a TOL and those undergoing eRCS. Logistic regression was used to control for confounders, including gestational age at delivery.

MAIN OUTCOME MEASURES

Composite neonatal morbidity.

RESULTS

A total of 1906 patients were included, 985 with TOL and 921 with no TOL. The TOL success rate was 63.1%. The rate of uterine rupture was low, at 0.10% in the TOL group and 0.11% in the eRCS group (p = 0.32). After adjustment, neonates born to women undergoing a TOL had no statistically significant difference in outcomes including composite neonatal outcome (adjusted odds ratio 0.86, 95% CI 0.68-1.09), neonatal intensive care unit admission, respiratory distress syndrome, necrotising enterocolitis, hypoxic ischaemic encephalopathy, seizures, transient tachypnoea of the newborn, compared with patients who underwent eRCS, with the exception of decreased risk of proven/suspected sepsis (adjusted odds ratio 0.68, 95% CI 0.52-0.87) CONCLUSION: A TOL in preterm patients without a previous vaginal delivery was not found to have a statistically significant association with increased neonatal morbidity.

Mode of delivery and pregnancy outcomes in preterm birth: a secondary analysis of the WHO Global and Multi-country Surveys

Many studies have been conducted to examine whether Caesarean Section (CS) or vaginal birth (VB) was optimal for better maternal and neonatal outcomes in preterm births. However, findings remain unclear. Therefore, this secondary analysis of World Health Organization Global Survey (GS) and Multi-country Survey (MCS) databases was conducted to investigate outcomes of preterm birth by mode of delivery. Our sample were women with singleton neonates (15,471 of 237 facilities from 21 countries in GS; and 15,053 of 239 facilities from 21 countries in MCS) delivered between 22 and <37 weeks of gestation. We assessed association between mode of delivery and pregnancy outcomes in singleton preterm births by multilevel logistic regression adjusted for hierarchical data. The prevalences of women with preterm birth delivered by CS were 31.0% and 36.7% in GS and MCS, respectively. Compared with VB, CS was associated with significantly increased odds of maternal intensive care unit admission, maternal near miss, and neonatal intensive care unit admission but significantly decreased odds of fresh stillbirth, and perinatal death. However, since the information on justification for mode of delivery (MOD) were not available, our results of the potential benefits and harms of CS should be carefully considered when deciding MOD in preterm births.

Second-Stage Duration and Outcomes Among Women Who Labored After a Prior Cesarean Delivery

OBJECTIVE

To characterize probabilities of vaginal delivery based on second-stage duration along with maternal and neonatal risks for women undergoing labor after cesarean delivery.

METHODS

This unplanned secondary analysis of the Maternal-Fetal Medicine Units Cesarean Registry, a prospective observational cohort, assessed outcomes in women with a prior uterine scar and included women with a previous cesarean delivery without prior vaginal delivery who reached the second stage of labor. The primary outcome was mode of delivery by second-stage duration. Secondary outcomes included assessment of individual adverse maternal (chorioamnionitis, atony, endometritis, hysterectomy, uterine rupture or dehiscence, and red cell transfusion) and neonatal (cord pH less than 7.10, Apgar score less than 6 at 5 minutes, neonatal intensive care unit admission, and ventilatory support) outcomes.

RESULTS

Of 4,579 women with a previous cesarean delivery who reached the second stage of labor, 4,147 (90.6%) delivered vaginally. As second stage increased, successful vaginal delivery rates decreased: 97.3% at less than 1 hour (95% CI 96.6-97.9%), 91.5% at 1 to less than 2 hours (95% CI 89.8-93.1%), 78.5% at 2 to less than 3 hours (95% CI 74.5-82.1%), 62.3% at 3 to less than 4 hours (95% CI 55.2-69.1%), and 45.6% at 4 hours or greater (95% CI 37.7-53.7%). Risk of all adverse maternal outcomes increased with the length of the second stage. Specifically, risk of uterine rupture or dehiscence increased with second-stage length from less than 1 hour (0.7%), 1 to less than 2 hours (1.4%), 2 to less than 3 hours (1.5%), to 3 hours or greater (3.1%) (P<.001 for differential risk across the second stage). Risk of neonatal outcomes did not differ significantly by second-stage length.

CONCLUSION

Although many women with a longer second stage (greater than 3 hours) will achieve successful vaginal delivery, these patients may be at increased risk for adverse maternal outcomes and should have close observation of fetal heart rate monitoring, maternal vital signs, and symptoms suggestive of uterine rupture or dehiscence.

Balloon catheter for induction of labor in women with one previous cesarean and an unfavorable cervix

Introduction

When women with a previous cesarean section and an unfavorable cervix have an indication for delivery, the choice is to induce labor or to perform a cesarean section. This study aims to assess the effectiveness and safety of a balloon catheter as a method of induction of labor in women with one previous cesarean section and an unfavorable cervix compared with an elective repeat cesarean section.

Material and methods

We performed a prospective cohort study in 51 hospitals in the Netherlands on term women with one previous cesarean section, a live singleton fetus in cephalic position, an unfavorable cervix and an indication for delivery. We recorded obstetric, maternal and neonatal characteristics. We compared the outcome of women who were induced with a balloon catheter with the outcome of women who delivered by elective repeat cesarean section. Main outcomes were maternal and neonatal morbidity. Mode of delivery was a secondary outcome for women who were induced. Adjusted odds ratios (aOR) were calculated using logistic regression, adjusted for potential confounders.

Results

Analysis was performed on 993 women who were induced and 321 women who had a repeat cesarean section (August 2011 until September 2012). Among the women who were induced, 560 (56.4%) delivered vaginally and 11 (1.1%) sustained a uterine rupture. Composite adverse maternal outcome (uterine rupture, severe postpartum hemorrhage or postpartum infection) occurred in 73 (7.4%) in the balloon and 14 (4.5%) women in the repeat cesarean section group (aOR 1.58, 95% confidence interval [CI] 0.85‐2.96). Composite adverse neonatal outcome (Apgar score <7 at 5 minutes or umbilical pH <7.10) occurred in 57 (5.7%) and 10 (3.2%) neonates, respectively (aOR 1.40, 95% CI 0.87‐3.48). Women who were induced had a shorter postpartum admission time (2.0 vs 3.0 days (P < 0.0001)).

Conclusions

In women with a previous cesarean section and a need for delivery, induction of labor with a balloon catheter does not result in a significant increase in adverse maternal and neonatal outcomes as compared with planned cesarean section.

Vaginal Birth After Previous Cesarean Birth: A Comparison of 3 National Guidelines

Importance

Vaginal birth after previous cesarean birth (VBAC) is a reasonable option for many women with previous cesarean delivery.

Objective

The aim of this study was to summarize evidence and compare recommendations from national guidelines regarding VBAC.

Evidence Acquisition

A descriptive review of 3 national guidelines on VBAC was conducted: Royal College of Obstetricians and Gynaecologists on "Birth After Previous Caesarean Birth," American College of Obstetricians and Gynecologists on "Vaginal Birth After Cesarean Delivery," and Society of Obstetricians and Gynaecologists of Canada on "Guidelines for Vaginal Birth After Previous Caesarean Birth." These guidelines were summarized and compared in terms of the recommended antenatal and intrapartum care of women. Recommendations and strength of evidence were also reviewed based on method of reporting.

Results

The variations mentioned on the different guidelines reflect the heterogeneity of the published data on the management of VBAC during the antenatal and intrapartum care.

Conclusions

Evidence-based medicine could support the conception of international recommendations for VBAC, which may improve both safety and efficacy of this procedure.

A prediction model of vaginal birth after cesarean in the preterm period

BACKGROUND

A validated model exists that predicts the probability of vaginal birth after cesarean delivery in patients at term who are undergoing a trial of labor after cesarean delivery. However, a model that predicts the success of a vaginal birth after cesarean delivery in the preterm period has not been developed.

OBJECTIVE

We sought to develop and validate a predictive model for vaginal birth after cesarean delivery for women undergoing a trial of labor after cesarean delivery during the preterm period.

STUDY DESIGN

We performed a secondary analysis of a prospective cohort study designed to evaluate perinatal outcomes in women with a prior cesarean scar. We included women with 1 prior low transverse cesarean delivery undergoing a trial of labor after cesarean delivery with a vertex singleton pregnancy in the preterm period (26-36 weeks). Using multivariable logistic regression modeling, we constructed a predictive model for vaginal birth after cesarean delivery with information known at admission for preterm delivery. Using a 70% to 30% random split of the data, the model was developed in the training data and subsequently confirmed in the validation data. Predictions and area under the curve were based on a 10-fold cross-validated jackknife estimation and based on 1000 bootstrap resampling methods. The adequacy of all models was evaluated based on the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

One thousand two hundred ninety-five women met our criteria for analysis. The significant predictors of vaginal birth after cesarean delivery success were chronic hypertension, hypertensive disease of pregnancy (gestational hypertension or preeclampsia), prior vaginal delivery, dilation on cervical examination at admission, prior vaginal birth after cesarean delivery, a recurring indication in a prior cesarean delivery, and induction of labor as well as a 2-way interactions between dilation and hypertensive disease of pregnancy, dilation and diabetes mellitus (pregestational or gestational), and induction of labor and hypertensive disease of pregnancy. The area under the curve from the prediction model was 0.80 (95% confidence interval, 0.77-0.83) and the model fit the data well (Hosmer-Lemeshow P = .367). The bootstrap and 10-fold cross-validated jackknife estimates of the corrected area under the curve of the model were 0.78 (95% confidence interval, 0.74-0.82) and 0.77 (95% confidence interval, 0.73-0.82), respectively, following incorporation of regression shrinkage.

CONCLUSION

A cross-validated predictive model was created for patients undergoing a trial of labor after cesarean delivery in the preterm period using 8 variables known on admission. These factors were notably different from factors used in the model for term patients. This new model can be used to counsel patients in the preterm period who want to undergo a trial of labor after cesarean delivery on their predicted vaginal birth after cesarean delivery success.

Delivery after prior cesarean: success rate and factors

Cesarean delivery rates in the United States have reached an all-time high. The current rate of 31% is 6 times higher than the 1970s rate. Many factors including physician preference and hospital accessibility account for this trend. A decreased vaginal birth after cesarean (VBAC) rate and an increased repeat cesarean rate have important consequences for women in future pregnancies. Because of these considerations, VBAC has been an important issue within the obstetric community for over 3 decades. Identifying the best candidates for VBAC using factors available to the obstetrician can increase the VBAC success rate while minimizing maternal morbidity.

Uterine rupture during a trial of labor after previous cesarean delivery

Uterine rupture, which involves complete separation of the uterine wall, occurs in about 1% of those attempting vaginal birth after cesarean. Because uterine rupture is one of the most significant complications of a trial of labor (TOL) after previous cesarean, identifying those at increased risk of uterine rupture is paramount to the safety of a TOL after previous cesarean birth. It seems that both antepartum demographic characteristics and intrapartum factors modify the risk of uterine rupture. The ability to reliably predict an individual's a priori risk for intrapartum uterine rupture remains a major area of investigation.

Trends and patterns of vaginal birth after cesarean availability in the United States

A review of the literature and analysis of the National Inpatient Sample Database was performed to describe the trends in vaginal birth after cesarean availability in the United States and the factors associated with changing use. Vaginal birth after cesarean increased after the first National Institutes of Health Consensus Conference on Cesarean Childbirth in 1981. It increased from 3% to a maximum rate of 28.3% in 1996. Despite studies reporting stable success rates of approximately 70% and low complication rates (<1%), concerns about patient safety and physician liability have led to more restrictive policies and a decrease in vaginal birth after cesarean use. The current rate is approximately 8.5%, and decreased rates have been noted for all age and ethnic groups. There is decreased use of vaginal birth after cesarean as the result of concerns about patient safety and physician liability, which has resulted in decreased availability.

Birth after previous cesarean delivery: short-term maternal outcomes

An estimated 40% of the 1.3 million cesarean deliveries performed each year in the United States are repeat procedures. The appropriate clinical management approach for women with previous cesarean delivery remains challenging because options are limited. The risks and benefits of clinical management choices in the woman's health need to be quantified. Thus, we discuss the available published scientific data on (1) the short-term maternal outcomes of trial of labor after cesarean and elective repeat cesarean delivery, (2) the differences between outcomes for both, (3) the important factors that influence these outcomes, and (4) successful vs. unsuccessful vaginal birth after cesarean. For women with a previous cesarean delivery, a successful trial of labor offers several distinct, consistently reproducible advantages compared with elective repeat cesarean delivery, including fewer hysterectomies, fewer thromboembolic events, lower blood transfusion rates, and shorter hospital stay. However, when trial of labor after cesarean fails, emergency cesarean is associated with increased uterine rupture, hysterectomy, operative injury, blood transfusion, endometritis, and longer hospital stay. Care of women with a history of previous cesarean delivery involves a confluence of interactions between medical and nonmedical factors; however, the most important determinants of the short-term outcomes among these women are likely individualized counseling, accurate clinical diagnoses, and careful management during a trial of labor. We recommend a randomized controlled trial among women undergoing a TOLAC and a longitudinal cohort study among women with previous cesarean to evaluate adverse outcomes, with focused attention on both mother and the infant.

Comparison of viscoelastic coagulation analysis and standard coagulation profiles in critically ill neonatal foals to outcome

OBJECTIVE

To determine if changes in viscoelastic variables are associated with abnormalities observed in the standard coagulation profile and patient outcome in foals with suspected septicemia.

DESIGN

Prospective clinical trial during 2003 and 2004 foal season.

SETTING

Neonatal intensive care unit at a veterinary teaching hospital.

ANIMALS

Thirty critically ill foals <72-hour-old admitted sequentially meeting criteria for systemic inflammatory response associated with infection.

INTERVENTIONS

Hemostatic evaluation, using standard coagulation testing and viscoelastic analysis, was performed at admission, 24 hours following admission, and 48 hours following admission in critically ill foals. Standard coagulation tests included platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin(ogen) degradation products, and antithrombin. Data collected from viscoelastic analysis included time to initial clot formation (ACT), clot rate, and platelet function. Signalment, blood culture results, clinicopathologic data, and outcome were collected from medical records. Equality of populations test was used to determine associations between coagulation tests and blood culture status/outcome, as well as between viscoelastic parameters and coagulopathy, blood culture status, and outcome. Logistic regression was used to quantify associations. A significance level of P<0.05 was used.

MEASUREMENTS AND MAIN RESULTS

Foals with decreasing clot rate (CR) over the sample period were more likely to be euthanized or die (P=0.02). Foals with prolonged ACT (P=0.03), and decreased CR at admission (P=0.047), were more commonly coagulopathic. Identification of coagulopathy on admission (P=0.02), or persistence of hemostatic dysfunction 48 hours later (P=0.04), was associated with death.

CONCLUSIONS

Viscoelastic coagulation evaluation could be used in a neonatal intensive care unit setting to further characterize coagulopathy, and identify foals at higher risk for poor outcome.

External cephalic version among women with a previous cesarean delivery: report on 36 cases and review of the literature

AIMS

Whether or not women with a previous cesarean section should be considered for an external cephalic version remains unclear. In our study, we sought to examine the relationship between a history of previous cesarean section and outcomes of external cephalic version for pregnancies at 36 completed weeks of gestation or more.

METHODS

Data on obstetrical history and on external cephalic version outcomes was obtained from the C.H.U. Sainte-Justine External Cephalic Version Database. Baseline clinical characteristics were compared among women with and without a history of previous cesarean section. We used logistic regression analysis to evaluate the effect of previous cesarean section on success of external cephalic version while adjusting for parity, maternal body mass index, gestational age, estimated fetal weight, and amniotic fluid index.

RESULTS

Over a 15-year period, 1425 external cephalic versions were attempted of which 36 (2.5%) were performed on women with a previous cesarean section. Although women with a history of previous cesarean section were more likely to be older and para >2 (38.93% vs. 15.0%), there were no difference in gestational age, estimated fetal weight, and amniotic fluid index. Women with a prior cesarean section had a success rate similar to women without [50.0% vs. 51.6%, adjusted OR: 1.31 (0.48-3.59)].

CONCLUSION

Women with a previous cesarean section who undergo an external cephalic version have similar success rates than do women without. Concern about procedural success in women with a previous cesarean section is unwarranted and should not deter attempting an external cephalic version.

Identifying risk factors for uterine rupture

Uterine rupture, whether in the setting of a prior uterine incision or in an unscarred uterus, is an obstetric emergency with potentially catastrophic consequences for both mother and child. Numerous studies have been published regarding various risk factors associated with uterine rupture. Despite the mounting data regarding both antepartum and intrapartum factors, it currently is impossible to predict in whom a uterine rupture will occur. This article reviews the data regarding these antepartum and intrapartum predictors for uterine rupture. The author hopes that the information presented in this article will help clinicians assess an individual's risk for uterine rupture.