Low Transverse Cesarean Research Articles

810: Can we improve our ability to predict VBAC success in the contemporary labor management era

The Maternal Fetal Medicine-Units Network (MFMU) antenatal vaginal birth after cesarean (VBAC) prediction model has been used to aid clinicians in counseling patients but labor management has changed since its development. Secondary to the model’s suboptimal performance in our population, we aimed to identify factors predictive of success in the contemporary era of labor management. This is a retrospective cohort study of all women with one prior low transverse cesarean who underwent a trial of labor (TOLAC) at term with a non-anomalous singleton gestation between January 2011 and May 2018 at out academic tertiary care center. Regression analysis incorporated clinical factors available early in pregnancy. Data regarding antepartum factors that may influence TOLAC success and maternal and neonatal outcomes was also extracted from medical records for evaluation (Table 1). A receiver operating characteristic curve for our model was compared to the MFMU model to compare their performance. Of 1307 VBAC attempts, 1042 pregnancies met inclusion criteria with all of the variables necessary for calculation of predicted VBAC success using the MFMU model. The derived model includes seven antenatal factors: age, race, height, intake weight, number of prior vaginal deliveries, pregestational diabetes, and history of tobacco use (Table 2). The median predicted VBAC success rate was 76.6 % (IQR 64.8, 86.3) while the observed success rate was 74.2 % (difference 2.4 %, 95% CI -1.3-6.1 %). The median predicted probability of success was significantly higher for women who had a successful TOLAC (median 79.6 % (IQR 68.6, 88.1) than for those who had a repeat cesarean (66.1 % (IQR 54.8, 77.9, P < .0001). Area under the curve (AUC) for the model is 0.72 (95% confidence interval (CI) 0.68-0.75) which indicates better performance compared to the MFMU antenatal model which had a AUC of 0.69 (95% CI 0.65 – 0.72, P <.01). VBAC success is correlated with seven readily attainable antenatal clinical factors that, along with the predictive model that incorporates them warrant further investigation as they may improve our ability to predict VBAC success and counseling in the contemporary era of labor management.

Successful management of a spontaneous viable monochorionic diamniotic twin pregnancy on cesarean scar with systemic methotrexate

Rationale:Cesarean scar twin pregnancy is exceedingly rare and it remains to be a life-threatening condition even in the early weeks of gestation. Because of its rare occurrence, there is no consensus on the treatment modality of cesarean ectopic pregnancy.Patient concerns:A 41-year-old, woman, gravida 7, para 6, with a history of low transverse cesarean section 2 years back presented with an estimated 6 weeks gestational age and viable spontaneous twin, monochorionic diamniotic gestation. The patient presented to the Emergency Department with complaints of vaginal bleeding and mild lower abdominal pain for 5 days.Diagnoses:An ultrasound examination was performed demonstrating a single intrauterine gestational sac with 2 viable embryos (monochorionic diamniotic) implanted in the lower uterine segment at the level of the prior cesarean section scar. A diagnosis of viable cesarean scar twin pregnancy was made.Interventions:A 2 doses of 50 mg/m2 methotrexate (MTX) was given intramuscularly. The response to the treatment was monitored by serial beta-human chorionic gonadotropin (β-hCG) and ultrasound.Outcomes:Patient was followed up with β-hCG weekly levels which became 0 after 68 days of treatment. During the follow-up, the patient was asymptomatic, no side effects of MTX were noticed.Lessons:We reported a rare case of viable monochorionic diamniotic twin pregnancy on a cesarean scar that was successfully treated with systemic MTX without any additional therapy. Additionally, the decline of β-hCG in twin ectopic cesarean scar pregnancy appears to be similar to a singleton ectopic pregnancy.

Case 1: Late-Onset Hypoglycemia in an Extremely Low-Birthweight Infant

An 800-g extremely low-birthweight female (25 5/7 weeks) twin A of a dichorionic-diamniotic gestation is born via primary low transverse cesarean delivery to a 37-year-old gravida 5, para 0-4-0-0 woman. The mother of the child is group B Streptococcus positive, and received 1 dose of penicillin less than 4 hours before delivery. Results of other antenatal testing had been reassuring. Preterm delivery is indicated for prolonged rupture of membranes of twin B, and the mother had received 2 doses of betamethasone 24 hours apart at the estimated 24th week of gestation. The neonate has Apgar scores of 3 and 8 at 1 and 5 minutes, respectively. She is stabilized on continuous positive airway pressure and transferred to the NICU by 5 minutes after birth. In the NICU, she requires intubation and fraction of inspired oxygen greater than 60% to maintain oxygenation. An umbilical artery catheter and umbilical venous catheter are established and she is treated with ampicillin and gentamicin. She initially has hypotension requiring a 10-mL/kg bolus of normal saline without improvement, necessitating institution of a dopamine drip titrated from 2 to 5 μg/kg per minute to maintain mean arterial pressures above 25 mm Hg. She is started on intravenous fluids of 100 mL/kg per day with a glucose infusion rate (GIR) of 5 mg/kg per minute, which is reduced to 3.1 mg/kg per minute by 1 day after birth because of worsening hyperglycemia. Despite serial reduction of GIR, she persistently demonstrates capillary blood …

Dehiscence of a Low Transverse Cesarean Scar by a Submucous Myoma in a Nongravid Uterus

This is a case of a 32-year-old woman (G1P1001) with a history of uterine myomas who previously underwent surgeries for her myomas as well as a low transverse cesarean section for her delivery. The patient presented to our institution with vaginal bleeding and pelvic pressure symptoms. Magnetic resonance imaging found a 6-cm type 1 submucosal myoma that extended anteriorly through the myometrium and dehisced through the previous cesarean section scar, separating the scar by 2.5 cm (Figs. 1 and 2).

Endometrial Ablation—Current Evidence for Patient Optimization and Long-Term Outcomes

Endometrial ablation is a minimally invasive surgical option to treat abnormal uterine bleeding. Here, we summarize the evidence regarding patient optimization prior to endometrial ablation and the long-term outcomes of this procedure. Patient optimization includes preoperative planning, patient selection, and preoperative predictors of postoperative failure. Long-term outcomes include postoperative bleeding patterns, frequency of additional procedures for treatment failure, patient satisfaction, risk of endometrial cancer, and pregnancy outcomes. Endometrial ablation is a safe procedure to treat abnormal uterine bleeding in high- and low-risk surgical patients. A prior low transverse cesarean section is not a contraindication to the procedure. Young age at ablation (less than 30–45 years of age) is the most significant risk factor for treatment failure. Preoperative dysmenorrhea, large uterine size, fibroids, and prior tubal ligation may also be risk factors for failure. Reduction in menstrual bleeding and patient satisfaction achieved at 12 months usually persist for 5–10 years. There is a 17–25% risk of subsequent hysterectomy that usually occurs within the first 5 years. Endometrial ablation does not appear to increase the risk for developing endometrial cancer. Lastly, outcomes of post-ablation pregnancy are poor, and preoperative counseling should include a discussion about reliable post-ablation contraception. Endometrial ablation can effectively reduce menstrual blood loss and improve patient satisfaction with effects sustained for years after the procedure and is appropriate to use in high-risk surgical candidates. Younger women should be counseled preoperatively about the risk of treatment failure and need for additional procedures in the future.

Prédiction échographique du risque de rupture utérine après césarienne : LUSTrial, un essai randomisé pragmatique

BackgroundThe data from literature show that trial of labor and elective repeat cesarean delivery after a prior cesarean delivery both present significant risks and benefits, and these risks and benefits differ for the woman and her fetus. The benefits to the woman can be at the expense of her fetus and vice-versa. This uncertainty is compounded by the scarcity of high-level evidence that preclude accurate quantification of the risks and benefits that could help provide a fair counseling about a trial of labor and elective repeat cesarean delivery. An interesting way of research is to evaluate the potential benefits of a decision rule associated to the ultrasound measurement of the lower uterine segment (LUS). Indeed, ultrasonography may be helpful in determining a specific risk for a given patient by measuring the thickness of the LUS, i,e, the thickness of the cesarean delivery scar area. Although only small and often methodologically biased data have been published, they look promising as their results are concordant: ultrasonographic measurements of the LUS thickness is highly correlated with the intraoperative findings at cesarean delivery. Furthermore, the thinner the LUS becomes on ultrasound, the higher the likelihood of a defect in the LUS. Finally, ultrasound assessment of LUS has an excellent negative predictive value for the risk of uterine defect. Therefore, this exam associated with a rule of decision could help to reduce the rate of elective repeat cesarean delivery and especially to reduce the fetal and maternal mortality and morbidity related to trial of labor after a prior cesarean delivery. Methods/designThis is a pragmatic open multicenter randomized trial with two parallel arms. Randomization will be centralized and computerized. Since blindness is impossible, an adjudication committee will evaluate the components of the primary composite outcome in order to avoid evaluation bias. An interim analysis will be planned mid-strength of the trial. Ultrasound will be performed by expert sonographers after certification by the main investigator. Women aged 18 years or older are eligible for this trial if they have a singleton pregnancy in cephalic presentation at a gestational age from 36 to 38 weeks, a previous low transverse cesarean delivery and sign the informed consent sheet. Women will be asked to participate in this study when they reach a term of 36 to 38 weeks of gestation. After agreement, women will be randomized into two groups: in the study group, they will have the LUS measured by ultrasound and the patient will be informed that, based on a threshold value of 3.5mm for the ultrasound measurement of the LUS thickness, the patient with a higher measurement will be considered at low risk and will be encouraged to choose a trial of labor whereas the patient with a measurement is equal to or less than this threshold will be considered at risk and encouraged to choose an elective repeat cesarean; in the control group, ultrasound LUS measurement will not be performed. The mode of delivery will be decided according to standard practice at the center. The primary composite outcome will include: uterine rupture, uterine dehiscence, hysterectomy, thromboembolic complications, transfusion, endometritis, maternal mortality, fetal prenatal and intrapartum mortality, hypoxic-ischemic encephalopathy and neonatal mortality. DiscussionThis trial assesses the efficacy of ultrasound measurement of the lower uterine segment in women with a prior cesarean delivery in reducing fetal and maternal morbidity and mortality and it will provide evidence in order to establish clinical recommendations. Trial registrationClinicalTrials.gov identifier: NCT01916044 (date of registration: 5 August 2013).

Unintended hysterotomy extension during caesarean delivery: risk factors and maternal morbidity

We conducted an observational retrospective cohort study to evaluate the risk factors and the maternal morbidity associated with unintended extensions of the hysterotomy during caesarean delivery. We evaluated 2707 women who underwent low-transverse caesarean deliveries in 2011 at an academic, tertiary-care hospital. Hysterotomy extensions were identified through operative reports. Of the 2707 caesarean deliveries, 392 (14.5%) had an unintended hysterotomy extension. On the multivariable regression modelling, neonatal weight (OR 1.42; 95%CI 1.17–1.73), the arrest of labour [first-stage arrest (2.42; 1.73–3.38); second-stage arrest (5.54; 3.88–7.90)] and a non-reassuring foetal status (1.65; 1.20–2.25) were significantly associated with hysterotomy extensions. Hysterotomy extensions were significantly associated with an increased morbidity including an estimated blood loss >1200 millilitres (2.06; 1.41–3.02), a decline in postoperative haemoglobin ≥3.7 g/dL (2.07; 1.35–3.17), an evaluation for lower urinary tract injury (5.58; 3.17–9.81), and a longer operative time (8.11; 6.33–9.88). Based on these results, we conclude that unintended hysterotomy extensions significantly increase the maternal morbidity of caesarean deliveries.Impact statementWhat is already known on this subject? Maternal morbidity associated with caesarean delivery (CD) is significantly greater than that in vaginal delivery. Unintended extensions of the hysterotomy occur in approximately 4–8% of CDs and are more common after a prolonged second stage of labour. The morbidity associated with hysterotomy extensions has been incompletely evaluated.What do the results of this study add? We demonstrate a rate of hysterotomy extension in a general obstetric population of approximately 15%, which is higher than previously reported estimates, and represents a potential doubling of the rate of the unintended hysterotomy extensions in recent years. The most significant risk factor for a hysterotomy extension was a second-stage labour arrest with a fourfold increase in the frequency of extensions. A hysterotomy extension is a significant independent risk factor for an intraoperative haemorrhage, a drop in postoperative haemoglobin, an intraoperative evaluation for lower urinary tract injury, and longer CD operative times.What are the implications of these findings for clinical practice and/or further research? A second-stage arrest is a strong independent risk factor for a hysterotomy extension. Recent re-evaluations of the labour curve that extend the second stage of labour will likely increase the frequency of CDs performed after a prolonged second stage. In these scenarios, obstetricians should be prepared for an unintended hysterotomy extension and for the possibility of a longer procedure with the increased risks of blood loss and the need for evaluation of the lower urinary tract.

Validation of prediction model for successful vaginal birth after Cesarean delivery based on sonographic assessment of hysterotomy scar.

To validate a prediction model for successful vaginal birth after Cesarean delivery (VBAC) based on sonographic assessment of the hysterotomy scar, in a Swedish population. Data were collected from a prospective cohort study. We recruited non-pregnant women aged 18-35 years who had undergone one previous low-transverse Cesarean delivery at ≥ 37 gestational weeks and had had no other uterine surgery. Participants who subsequently became pregnant underwent transvaginal ultrasound examination of the Cesarean hysterotomy scar at 11 + 0 to 13 + 6 and at 19 + 0 to 21 + 6 gestational weeks. Thickness of the myometrium at the thinnest part of the scar area was measured. After delivery, information on pregnancy outcome was retrieved from hospital records. Individual probabilities of successful VBAC were calculated using a previously published model. Predicted individual probabilities were divided into deciles. For each decile, observed VBAC rates were calculated. To assess the accuracy of the prediction model, receiver-operating characteristics curves were constructed and the areas under the curves (AUC) were calculated. Complete sonographic data were available for 120 women. Eighty (67%) women underwent trial of labor after Cesarean delivery (TOLAC) with VBAC occurring in 70 (88%) cases. The scar was visible in all 80 women at the first-trimester scan and in 54 (68%) women at the second-trimester scan. AUC was 0.44 (95% CI, 0.28-0.60) among all women who underwent TOLAC and 0.51 (95% CI, 0.32-0.71) among those with the scar visible sonographically at both ultrasound examinations. The prediction model demonstrated poor accuracy for prediction of successful VBAC in our Swedish population. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Diagnosing and treating postpartum uterine artery pseudoaneurysm

ABSTRACTUterine artery pseudoaneurysm (UAP) is an uncommon cause of postpartum hemorrhage. We present a case of a 19-year-old woman 6 weeks postpartum after low transverse cesarean delivery with recurrent heavy vaginal bleeding requiring a blood transfusion. Transvaginal sonogram revealed a UAP. Embolization of the uterine artery was performed, with resolution of her symptoms.

Risk of Cesarean scar defect following single- vs double-layer uterine closure: systematic review and meta-analysis of randomized controlled trials.

There is a growing body of evidence that suggests that the surgical technique for uterine closure following Cesarean delivery influences the healing of the Cesarean scar, but there is still no consensus on the optimal technique. The aim of this systematic review and meta-analysis was to compare the effect of single- vs double-layer uterine closure on the risk of uterine scar defect. MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE and the Cochrane Central Register of Controlled Trials were searched from inception of each database until May 2016. All randomized controlled trials (RCTs) evaluating the effect of single- vs double-layer uterine closure following low transverse Cesarean section on the risk of uterine scar defect were included. The primary outcome was the incidence of uterine scar defects detected on ultrasound. Secondary outcomes were residual myometrial thickness evaluated by ultrasound and the incidence of uterine dehiscence and/or rupture in subsequent pregnancy. Summary measures were reported as relative risk (RR) or mean difference (MD), with 95%CIs. Quality of the evidence was assessed using the GRADE approach. Nine RCTs (3969 participants) were included in the meta-analysis. The overall risk of bias of the included trials was low. Statistical heterogeneity within the studies was low, with no inconsistency in the primary and secondary outcomes. Women who received single-layer uterine closure had a similar incidence of uterine scar defects as did women who received double-layer closure (25% vs 43%; RR, 0.77 (95% CI, 0.36-1.64); five trials; 350 participants; low quality of evidence). Compared with double-layer uterine closure, women who received single-layer closure had a significantly thinner residual myometrium on ultrasound (MD, -2.19 mm (95% CI, -2.80 to -1.57 mm); four trials; 374 participants; low quality of evidence). No difference was found in the incidence of uterine dehiscence (0.4% vs 0.2%; RR, 1.34 (95% CI, 0.24-4.82); three trials; 3421 participants; low quality of evidence) or uterine rupture (0.1% vs 0.1%; RR, 0.52 (95% CI, 0.05-5.53); one trial; 3234 participants; low quality of evidence) in a subsequent pregnancy. Single- and double-layer closure of the uterine incision following Cesarean delivery are associated with a similar incidence of Cesarean scar defects, as well as uterine dehiscence and rupture in a subsequent pregnancy. However, the quality level of summary estimates, as assessed by GRADE, was low, indicating that the true effect may be, or is even likely to be, substantially different from the estimate of the effect. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

P01.11: Comparison between first and third trimester evaluation of uterine scar: a prospective study

Third trimester evaluation of low-uterine segment (LUS) thickness can be used to predict uterine scar defect and uterine rupture during labour. We aim to estimate its correlation with remaining myometrium thickness (RMT) in the first-trimester. Women with a single previous low-transverse Caesarean were recruited at 11–14 weeks' gestation. Measurement of RMT at the site of uterine scar was obtained for each participant and they were invited to come back for a second evaluation at 34–36 weeks gestation, for measurement of the LUS thickness. Comparisons between the first trimester RMT and third trimester LUS thickness were performed using Pearson and Spearman's correlation tests. Data were available for 129 (70%) out of 184 participants recruited at a mean gestational age of 12.7±0.5 weeks and seen again at 36.3±0.7 weeks of gestation. The mean first trimester RMT 6.3±3.2 mm, and the mean third trimester LUS thickness was 4.0±1.8 mm. We observed no significant association between first trimester RMT and third trimester LUS thickness (cc: 0.05 and cc: 0.10, with p>0.05 for both analyses). Three participants had a first trimester RMT<2.0 mm, which could have predicted 10% (1/10) of those with third trimester LUS thickness <2.0 mm. There is a poor correlation between first and third trimester evaluation of low-uterine segment thickness in women with previous Caesarean. First trimester evaluation of low-uterine segment thickness should not be used to counsel women about the risk of uterine rupture during a trial of labour.

Labor after cesarean delivery managed without induction or augmentation of labor.

This study aimed to describe the perinatal outcomes of women opting for vaginal birth after cesarean delivery (VBAC) managed without induction or augmentation of labor. This was a retrospective cohort study of candidates for VBAC at a tertiary center in Japan from April 2003 to March 2012. Women with singleton gestations and one prior low-transverse cesarean delivery who intended VBAC at 36weeks of gestation were identified as candidates for VBAC and included in the study. Participants were managed without induction or augmentation of labor. Maternal characteristics and perinatal outcomes were obtained from medical records. Factors associated with successful VBAC were analyzed with a multivariable logistic regression model. Of 333 candidates for VBAC, 242 (72.7%) had vaginal birth, 49 (14.7%) had repeat cesarean delivery with spontaneous labor, and 42 (12.6%) had repeat cesarean delivery without spontaneous labor. The rate of uterine rupture was 0.3% (1/333). Prior vaginal delivery and nonrecurring indications for prior cesarean delivery were associated with successful VBAC. Management of candidates for VBAC without induction or augmentation of labor resulted in a high VBAC rate and favorable perinatal outcomes. Such restrictive VBAC policies may be an acceptable alternative to standard management or abandonment of VBAC.

Uterine rupture after previous low segment transverse cesarean is rarely catastrophic

Objective: The cornerstone of concerns over trial of labor after cesarean (TOLAC) is the risk of uterine rupture. The purpose of this study was to document the rate of uterine rupture during TOLAC and to delineate its severity and consequences.Materials and methods: We retrospectively collected the data on vaginal and cesarean deliveries after a previous cesarean section with specific emphasis on uterine rupture and dehiscence in our center from 2006 through 2013.Results: 22,670 deliveries were registered, with 18.2% rate of cesarean section. 2890 women had a single cesarean scar; of them 1206 delivered vaginally and 194 were re-operated during unsuccessful TOLAC. Seven cases of uterine rupture and 16 cases of dehiscence were recorded. There were no maternal, intrapartum or neonatal deaths, and no cesarean hysterectomy. There was one re-laparotomy, one ICU admission, and one blood transfusion; one neonate was admitted to NICU. TOLAC was successful in 86.1% of cases.Conclusions: Cautious selection and close monitoring of candidates are the cornerstones of successful management of TOLAC. Readily available facilities for emergency cesarean delivery and concerted obstetrical team can save the mother and child from catastrophic complications.

Single versus double-layer uterine closure at cesarean: impact on lower uterine segment thickness at next pregnancy

Uterine rupture is a potential life-threatening complication during a trial of labor after cesarean delivery. Single-layer closure of the uterus at cesarean delivery has been associated with an increased risk of uterine rupture compared with double-layer closure. Lower uterine segment thickness measurement by ultrasound has been used to evaluate the quality of the uterine scar after cesarean delivery and is associated with the risk of uterine rupture. To estimate the impact of previous uterine closure on lower uterine segment thickness. Women with a previous single low-transverse cesarean delivery were recruited at 34-38 weeks' gestation. Transabdominal and transvaginal ultrasound evaluation of the lower uterine segment thickness was performed by a sonographer blinded to clinical data. Previous operative reports were reviewed to obtain the type of previous uterine closure. Third-trimester lower uterine segment thickness at the next pregnancy was compared according to the number of layers sutured and according to the type of thread for uterine closure, using weighted mean differences and multivariate logistic regression analyses. Of 1613 women recruited, with operative reports available, 495 (31%) had a single-layer and 1118 (69%) had a double-layer closure. The mean third-trimester lower uterine segment thickness was 3.3 ± 1.3 mm and the proportion with lower uterine segment thickness <2.0 mm was 10.5%. Double-layer closure of the uterus was associated with a thicker lower uterine segment than single-layer closure (weighted mean difference: 0.11 mm; 95% confidence interval [CI], 0.02 to 0.21 mm). In multivariate logistic regression analyses, a double-layer closure also was associated with a reduced risk of lower uterine segment thickness <2.0 mm (odd ratio [OR], 0.68; 95% CI, 0.51 to 0.90). Compared with synthetic thread, the use of catgut for uterine closure had no significant impact on third-trimester lower uterine segment thickness (WMD:-0.10 mm; 95% CI,-0.22 to 0.02 mm) or on the risk of lower uterine segment thickness <2.0 mm (OR, 0.95; 95% CI, 0.67 to 1.33). Finally, double-layer closure was associated with a reduced risk of uterine scar defect (RR, 0.32; 95% CI, 0.17 to 0.61) at birth. Compared with single-layer closure, a double-layer closure of the uterus at previous cesarean delivery is associated with a thicker third-trimester lower uterine segment and a reduced risk of lower uterine segment thickness <2.0 mm in the next pregnancy. The type of thread for uterine closure has no significant impact on lower uterine segment thickness.

Economic Evaluations Comparing a Trial of Labor with an Elective Repeat Cesarean Delivery: A Systematic Review.

For women who have had a previous low transverse cesarean delivery, the decision to undergo a trial of labor after cesarean (TOLAC) or an elective repeat cesarean delivery (ERCD) has important clinical and economic ramifications. To evaluate the cost-effectiveness of the alternative choices of a TOLAC and an ERCD for women with low-risk, singleton gestation pregnancies. We searched EMBASE, MEDLINE, CINAHL, Cochrane Library, EconLit, and the Cost-Effectiveness Analysis Registry with no language, publication, or date restrictions up until October 2015. Studies were included if they were primary research, compared a TOLAC with an ERCD, and provided information on the relative cost of the alternatives. Abstracts and partial economic evaluations were excluded. Of 310 studies initially reviewed, 7 studies were included in the systematic review. In the base-case analyses, 4 studies concluded that TOLAC was dominant over ERCD, 1 study found ERCD to be dominant, and 2 studies found that although TOLAC was more costly, it offered more benefits and was thus cost-effective from a population perspective when considering societal willingness to pay for better outcomes. In sensitivity analyses, cost-effectiveness was found to be dependent on a high likelihood of TOLAC success, low risk of uterine rupture, and low relative cost of TOLAC compared with ERCD. For women who are likely to have a successful vaginal delivery, routine ERCD may result in excess morbidity and cost from a population perspective.

Maternal outcomes associated with early preterm cesarean delivery

Data on complications associated with classic cesarean delivery are conflicting. In extremely preterm cesarean delivery (22 0/7-27 6/7 weeks' gestation), the lower uterine segment is thicker. It is plausible that the rates of maternal complications may not differ between classic and low transverse cesarean. We sought to compare maternal outcomes associated with classic versus low transverse cesarean after stratifying by gestation (23 0/7-27 6/7 and 28 0/7-31 6/7 weeks' gestation). We conducted a multihospital retrospective cohort study of women undergoing cesarean delivery at 23 0/7 to 31 6/7 weeks' gestation from 2005 through 2014. Composite maternal outcome (postpartum hemorrhage, transfusion, endometritis, sepsis, wound infection, deep venous thrombosis/pulmonary embolism, hysterectomy, respiratory complications, and intensive care unit admission) was compared between classic and low transverse cesarean. Outcomes were calculated using multivariable logistic regression models yielding adjusted odds ratios with 95% confidence intervals and adjusted P values controlling for maternal characteristics, emergency cesarean delivery, and comorbidities. Analyses were stratified by gestational age categories (23 0/7-27 6/7 and 28 0/7-31 6/7 weeks' gestation). Of 902 women, 221 (64%) and 91 (16%) underwent classic cesarean between 23 0/7 and 27 6/7 and between 28 0/7 and 31 6/7 weeks' gestation, respectively. There was no increase in maternal complications for classic cesarean versus low transverse cesarean between 23 0/7 and 27 6/7 weeks' gestation. However, between 28 0/7 and 31 6/7 weeks' gestation, classic cesarean was associated with increased risks of the composite maternal outcome (adjusted odds ratio, 1.95; 95% confidence interval, 1.10-3.45), transfusion (adjusted odds ratio, 2.42; 95% confidence interval, 1.06-5.52), endometritis (adjusted odds ratio, 3.23; 95% confidence interval, 1.02-10.21), and intensive care unit admission (adjusted odds ratio, 5.05; 95% confidence interval, 1.37-18.52) compared to low transverse cesarean. Classic cesarean delivery compared with low transverse was associated with higher maternal complication rates between 280/7 and 31 6/7 weeks, but not between 23 0/7 and 27 6/7 weeks' gestation.

Obstetrician call schedule and obstetric outcomes among women eligible for a trial of labor after cesarean

Reducing cesarean deliveries is a major public health goal. The low rate of vaginal birth after cesarean has been attributed largely to a decrease in the likelihood of choosing a trial of labor after cesarean, despite evidence suggesting a majority of women with 1 prior low transverse cesarean are trial of labor after cesarean candidates. Although a number of reasons for this decrease have been explored, it remains unclear how systems issues such as physician call schedules influence delivery approach and mode in this context. The objective of the study was to investigate the relationship between obstetricians' call schedule and obstetric outcomes among women eligible for a trial of labor after cesarean. This is a retrospective cohort study of the likelihood of attempting a trial of labor after cesarean and achieving vaginal birth after cesarean among women with 1 prior low transverse cesarean delivery and a term, cephalic singleton gestation based on the delivering provider's call schedule. Attending obstetrician call schedules were classified as traditional or night float call. Night float call was defined as a schedule in which the provider had clinical responsibilities only for a day or night shift, without other clinical responsibilities before or after the period of responsibility for laboring patients. Call schedules are determined by individual provider groups. Bivariable analyses and random-effects logistic regression were used to examine the relationship between obstetricians' call schedule and the frequency of trial of labor after cesarean. Secondary outcomes including frequency of vaginal birth after cesarean and maternal and neonatal outcomes also were assessed. Of 1502 eligible patients, 556 (37%) were delivered by physicians in a night float call system. A total of 22.6% underwent a trial of labor after cesarean and 12.8% achieved vaginal birth after cesarean; the vaginal birth after cesarean rate for women attempting a trial of labor after cesarean was 56.5%. Women were more likely to undergo a trial of labor after cesarean (33.1% vs 16.5%, P < .001) and achieve vaginal birth after cesarean (18.7% vs 9.3%, P < .001) when cared for by physicians with a night float call schedule. Regression analyses demonstrated physicians with a night float call schedule remained significantly more likely to have patients undergo trial of labor after cesarean (adjusted odds ratio, 2.64, 95% confidence interval, 1.65-4.25) and experience vaginal birth after cesarean (adjusted odds ratio, 2.17, 95% confidence interval, 1.36-3.45) after adjusting for potential confounders. However, the likelihood of achieving vaginal birth after cesarean if a trial of labor after cesarean was attempted was not different based on provider call type (adjusted odds ratio, 0.96, 95% confidence interval, 0.57-1.62). Although women delivered by providers with a night float schedule were more likely to experience uterine rupture (1.8% vs 0.6%, P= .03), chorioamnionitis (4.3% vs 1.7%, P= .002), postpartum hemorrhage (7.6% vs 4.8%, P=.03), and neonates admitted to the neonatal intensive care unit (6.8%vs 3.9%, P= .01), these associations did not persist when the population was limited to women attempting trial of labor after cesarean. Although physicians working on a night float call system were significantly more likely to have patients with a prior cesarean undergo trial of labor after cesarean and achieve vaginal birth after cesarean, their patients also were more likely to experience maternal and neonatal morbidity. However, these differences did not persist when limiting analyses to women attempting a trial of labor after cesarean. Using a night float call schedule may be an effective measure to promote a trial of labor after cesarean and vaginal birth after cesarean.

Standardized ultrasonographic approach for the assessment of risk factors of incomplete healing of the cesarean section scar in the uterus

ObjectiveTo identify factors related to the healing of a Cesarean uterine incision using the standardized ultrasonographic approach of scar assessment in the non-pregnant uterus. Study designMeasurements of the uterine scar were taken from 409 women with a history of at least one low transverse cesarean section (CS) with a single layer uterine closure. Residual myometrial thickness (RMT), width (W) and depth (D) of the triangular hypoechoic scar niche, D/RMT ratio and clinical characteristics were analyzed. For statistical analysis, the Mann–Whitney U test, chi-square test, Spearman's rank correlation coefficient, ANOVA test, and logistic regression were used. Results268 women presented with a scar defect. RMT values were significantly correlated with the number of CSs (R=−0.17) and uterus retroflection (R=−0.15). The presence of a scar defect was significantly associated with lower RMT values (R=−0.33), greater gestational age (R=0.10), and younger maternal age (R=−0.11). The mean RMT value was significantly smaller in women with CSs performed in the second stage of labor (0.62) when compared to women with CSs in the first stage of labor (0.97) or without cervical dilatation (0.91). ConclusionA standardized approach of CS scar assessment in the non-pregnant uterus helps to identify women at risk of long-term complications of CS.

Uterine rupture during labor in women with twice successful vaginal births after cesarean delivery

Uterine rupture during labor is a serious complication resulting in maternal and neonatal morbidity and mortality. We present the extremely rare case of a 38-year-old gravid woman admitted with labor pain at term, about to experience a uterine rupture during labor. She had previously twice delivered vaginally, and during her third pregnancy had a low transverse Cesarean section. Prior to arriving at the hospital with labor pains, she had routine prenatal care with normal prenatal laboratory tests. One day the woman reported to having sudden epigastric pain, and 40 minutes after her admission a pelvic exam was completed. The unborn baby had a persistent fetal bradycardia of 60 beats/min and after 14 minutes, an emergency Cesarean section was performed. A complete uterine rupture was revealed, and a live neonate was promptly delivered with an Apgar score of 1 at one minute and 5 at five minutes. On the fifth postoperative day the woman and her baby were discharged home with no maternal and neonatal complications.

Lower uterine segment thickness to prevent uterine rupture and adverse perinatal outcomes: a multicenter prospective study

Choice of delivery route after previous cesarean delivery can be difficult because both trial of labor after cesarean delivery and elective repeat cesarean delivery are associated with risks. The major risk that is associated with trial of labor after cesarean delivery is uterine rupture that requires emergency laparotomy. This study aimed to estimate the occurrence of uterine rupture during trial of labor after cesarean delivery when lower uterine segment thickness measurement is included in the decision-making process about the route of delivery. In 4 tertiary-care centers, we prospectively recruited women between 34 and 38 weeks of gestation who were contemplating a vaginal birth after a previous single low-transverse cesarean delivery. Lower uterine segment thickness was measured by ultrasound imaging and integrated in the decision of delivery route. According to lower uterine segment thickness, women were classified in 3 risk categories for uterine rupture: high risk (<2.0 mm), intermediate risk (2.0-2.4 mm), and low risk (≥2.5 mm). Our primary outcome was symptomatic uterine rupture, which was defined as requiring urgent laparotomy. We calculated that 942 women who were undergoing a trial of labor after cesarean delivery should be included to be able to show a risk of uterine rupture <0.8%. We recruited 1856 women, of whom 1849 (99%) had a complete follow-up data. Lower uterine segment thickness was <2.0 mm in 194 women (11%), 2.0-2.4 mm in 217 women (12%), and ≥2.5 mm in 1438 women (78%). Rate of trial of labor was 9%, 42%, and 61% in the 3 categories, respectively (P<.0001). Of 984 trials of labor, there were no symptomatic uterine ruptures, which is a rate that was lower than the 0.8% expected rate (P=.0001). The inclusion of lower uterine segment thickness measurement in the decision of the route of delivery allows a low risk of uterine rupture during trial of labor after cesarean delivery.