Transverse technique: complementary approach to measurement of first-trimester uterine artery Doppler.

OBJECTIVES: To define a protocol for the first-trimester assessment of uterine artery pulsatility index (UtA-PI) using the new transverse technique, to evaluate UtA-PI measured using the transverse approach vs that obtained using the conventional sagittal approach and to determine if accelerated onsite training (in both methods) of inexperienced sonographers can achieve reproducible UtA-PI measurements comparable with those obtained by an experienced sonographer. METHODS: This was a prospective observational study of women with a singleton pregnancy attending for routine combined first-trimester screening at 11 to 13 + 6 weeks' gestation. The study consisted of two parts, each conducted at a different center (Part 1 in Calgary, Canada and Part 2 in Hong Kong). In Part 1, UtA-PI measurements were performed using the transverse and sagittal techniques by four sonographers trained in both methods, in 10 cases each, and measurement indices (PI), time required and subjective difficulty in obtaining satisfactory measurements were compared. The one sample t-test and Wilcoxon signed rank test were used when appropriate. Bland-Altman plots were used to assess measurement agreement, and intraclass correlation coefficient (ICC) was used to evaluate measurement reliability. A target plot was used to assess measures of central tendency and dispersion. In Part 2, one experienced and three inexperienced sonographers prospectively measured UtA-PI using both approaches in 42 and 35 women, respectively. Inexperienced sonographers underwent accelerated onsite training by the experienced sonographer. Measurement approach and sonographer order were on a random basis. ICC, Bland-Altman and Passing-Bablok analyses were performed to assess measurement agreement and reliability and effect of accelerated training. RESULTS: In Part 1, no difference was observed between the two techniques in mean time to acquire the measurements (118 s for sagittal vs 106 s for transverse; P = 0.38). The four sonographers reported that the transverse technique was subjectively easier to perform (P = 0.04). Bias and ICC for mean UtA-PI between sagittal and transverse measurements were -0.05 (95% limits of agreement, -0.48 to 0.37) and 0.94, respectively. Measurements obtained using the transverse technique after correcting for gestational age were significantly closer to the expected distribution than those obtained using the sagittal technique. In Part 2, there were no significant differences in median UtA-PI measured using the different approaches for both experienced and inexperienced sonographers (P > 0.05 for all sonographers). Mean UtA-PI measurement reliability between approaches was high for the experienced (ICC = 0.92) and inexperienced (ICC > 0.80) sonographers. UtA-PI measurement approaches did not deviate from linearity, while bias ranged from -0.10 to 0.07. The median time required was similar between the techniques (56.1 s for sagittal vs 49.3 s for transverse; P = 0.054). CONCLUSIONS: This novel transverse approach for the measurement of UtA-PI in the first trimester appears to be comparable with the sagittal approach in terms of reliability, reproducibility and time required, and may be easier to perform. Providing accelerated onsite training can be helpful for improving the reliability of UtA-PI measurements and could potentially facilitate the broad implementation of first-trimester pre-eclampsia screening. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Maternal and perinatal outcomes associated with a trial of labour after previous caesarean section in sub-Saharan countries.

OBJECTIVE: To assess the risks of uterine rupture, maternal and perinatal outcomes associated with a trial of labour (TOL) after one previous caesarean were compared with having an elective repeated caesarean section (ERCS) without labour in low-resource settings. DESIGN: A prospective 4-year observational study. SETTING: Senegal and Mali. SAMPLE: A cohort of 9712 women with one previous caesarean delivery. METHODS: Maternal and perinatal outcomes were compared between 8083 women who underwent a TOL and 1629 women who had an ERCS. Perinatal and maternal outcomes were then stratified according to the presence or absence of risk factors associated with vaginal birth after caesarean section. These outcomes were adjusted on maternal, perinatal and institutional characteristics. MAIN OUTCOME MEASURES: The risks of uterine rupture, maternal complication and perinatal mortality associated with TOL after one previous caesarean as compared with ERCS, RESULTS: The risks of hospital-based maternal complication [adjusted odds ratio (OR) 1.52; 95% CI 1.09-2.13; P = 0.013] and perinatal mortality (adjusted OR 4.53; 95% CI 2.30-9.92; P < 0.001) were significantly higher in women with a TOL compared with women who had an ERCS. However, when restricted to low-risk women, these differences were not significant (adjusted OR 0.90, 95% CI 0.55-1.46, P = 0.68, and adjusted OR 1.13; 95% CI 0.75-1.86; P = 0.53, for each outcome, respectively). Uterine rupture occurred in 25 (0.64%) of 3885 low-risk women compared with 70 (1.66%) of 4198 women with unfavourable risk factors. CONCLUSION: Low-risk women have no increased risk of maternal complications or perinatal mortality compared with women with one or more unfavourable factors. TWEETABLE ABSTRACT: Low-risk women have a lower risk of maternal complications or perinatal mortality compared with high-risk women.

Prevention of pre-eclampsia by low-molecular-weight heparin in addition to aspirin: a meta-analysis.

OBJECTIVE: To estimate the impact of adding low-molecular-weight heparin (LMWH) or unfractionated heparin to low-dose aspirin started ≤ 16 weeks' gestation on the prevalence of pre-eclampsia (PE) and the delivery of a small-for-gestational-age (SGA) neonate. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) was performed by searching the medical databases PubMed, EMBASE, Web of Science and Cochrane Central. Pregnant women randomized to receive LMWH or unfractionated heparin in addition to low-dose aspirin were compared with those who received low-dose aspirin alone. Outcome measures were PE, severe PE, early-onset PE and SGA. Pooled relative risks (RRs) with 95% CI were calculated using a random-effects model. RESULTS: Eight RCTs met the inclusion criteria; the indication for recruitment was previous recurrent miscarriage in five studies (three included women with thrombophilia) and a history of severe or early-onset PE in three studies (including women with thrombophilia in one). LMWH was administered in seven studies and unfractionated heparin in one. In women with a history of PE, treatment with LMWH and aspirin, compared with aspirin alone, was associated with a significant reduction in development of PE (three trials (n = 379); RR, 0.54 (95% CI, 0.31-0.92); P = 0.03) and in delivery of SGA neonates (two trials (n = 363); RR, 0.54 (95% CI, 0.32-0.91); P = 0.02). These outcomes were not significantly reduced in women with recurrent miscarriage who received LMWH and aspirin, compared with aspirin alone. The small number of studies precluded sensitivity analyses and the evaluation of publication biases. Blinding to the allocation treatment was absent in all RCTs. CONCLUSIONS: Based on limited evidence, the addition of LMWH to low-dose aspirin could reduce the prevalence of PE and SGA in women with a history of PE. This observation should be the basis of a well-conducted future trial rather than a recommendation for immediate clinical application. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Screening for pre-eclampsia early in pregnancy: performance of a multivariable model combining clinical characteristics and biochemical markers.

OBJECTIVE: To investigate the performance of a multivariable model combining a priori clinical characteristics and biomarkers to detect, early in pregnancy, women at higher risk of developing pre-eclampsia (PE). DESIGN: Nested case-control study. SETTING: University medical centre, Quebec, Canada (CHU de Québec). POPULATION: A total of 7929 pregnant women recruited between 10 and 18 weeks of gestation. In all, 350 developed hypertensive disorders of pregnancy (HDP)-of which 139 had PE, comprising 68 with severe PE and 47 with preterm PE-and were matched with two women with a normal pregnancy. METHODS: We selected a priori clinical characteristics and promising markers to create multivariable logistic regression models: body mass index (BMI), mean arterial pressure (MAP), placental growth factor, soluble Fms-like tyrosine kinase-1, pregnancy-associated plasma protein A and inhibin A. MAIN OUTCOME MEASURES: PE, severe PE, preterm PE, HDP. RESULTS: At false-positive rates of 5 and 10%, the estimated detection rates were between 15% (5-29%) and 32% (25-39%), and between 39% (19-59%) and 50% (34-66%), respectively. Considering the low prevalence of PE in this population, the positive predictive values were 7% (5-9%) to 10% (7-13%) for PE and 2% (1-4%) to 4% (3-6%) in the preterm and severe PE subgroups. The multivariable model yielded areas under the receiver operating characteristics curves (AUC) between 0.72 (0.61-0.81) and 0.78 (0.68-0.88). When only BMI and MAP were included in the model, the AUC were similar to those of the a priori model. CONCLUSIONS: In a population with a low prevalence of preterm PE, a multivariable risk algorithm using an a priori combination of clinical characteristics and biochemical markers did not reach a performance justifying clinical implementation as screening test early in pregnancy.

Hysterosalpingosonography for diagnosing tubal occlusion in subfertile women: a systematic review with meta-analysis.

STUDY QUESTION: Is hysterosalpingosonography (sono-HSG) an accurate test for diagnosing tubal occlusion in subfertile women and how does it perform compared with hysterosalpingography (HSG)? SUMMARY ANSWER: sono-HSG is an accurate test for diagnosing tubal occlusion and performs similarly to HSG. WHAT IS KNOWN ALREADY: sono-HSG and HSG are both short, well-tolerated outpatient procedures. However, sono-HSG has the advantage over HSG of obviating ionizing radiation and the risk of iodine allergy, being associated with a greater sensitivity and specificity in detecting anomalies of the uterine cavity and permitting concomitant visualization of the ovaries and myometrium. STUDY DESIGN, SIZE, DURATION: A systematic review and meta-analysis of studies published in any language before 14 November 2012 were performed. All studies assessing the accuracy of sono-HSG for diagnosing tubal occlusion in a subfertile female population were considered. PARTICIPANTS/MATERIALS, SETTING, METHODS: We searched Medline, Embase, Cochrane Library, Web of Science and Biosis as well as related articles, citations and reference lists. Diagnostic studies were eligible if they compared sono-HSG (±HSG) to laparoscopy with chromotubation in women suffering from subfertility. Two authors independently screened for eligibility, extracted data and assessed the quality of included studies. Risk of bias and applicability concerns were investigated according to the Quality Assessment of Diagnostic Accuracy Study (QUADAS-2). Bivariate random-effects models were used to estimate pooled sensitivity and specificity with their 95% confidence intervals (95% CIs), to generate summary receiver operating characteristic curves and to evaluate sources of heterogeneity. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 4221 citations identified, 30 studies were eligible. Of the latter, 28 reported results per individual tube and were included in the meta-analysis, representing a total of 1551 women and 2740 tubes. In nine studies, all participants underwent HSG in addition to sono-HSG and laparoscopy, allowing direct comparison of the accuracy of sono-HSG and HSG. Pooled estimates of sensitivity and specificity of sono-HSG were 0.92 (95% CI: 0.82-0.96) and 0.95 (95% CI: 0.90-0.97), respectively. In nine studies (582 women, 1055 tubes), sono-HSG and HSG were both compared with laparoscopy, giving pooled estimates of sensitivity and specificity of 0.95 (95% CI: 0.78-0.99) and 0.93 (95% CI: 0.89-0.96) for sono-HSG, and 0.94 (95% CI: 0.74-0.99) and 0.92 (95% CI: 0.87-0.95) for HSG, respectively. Doppler sonography was associated with significantly greater sensitivity and specificity of sono-HSG compared with its non-use (0.93 and 0.95 versus 0.86 and 0.89, respectively, P = 0.0497). Sensitivity analysis regarding methodological quality of studies was consistent with these findings. We also found no benefit of the commercially available contrast media over saline solution in regard to the diagnostic accuracy of sono-HSG. LIMITATIONS, REASONS FOR CAUTION: Methodological quality varied greatly between studies. However, sensitivity analysis, taking methodological quality of studies into account, did not modify the results. This systematic review did not allow the distinction between distal and proximal occlusion. This could be interesting to take into account in further studies, as the performance of the test may differ for each localization. WIDER IMPLICATIONS OF THE FINDINGS: Given our findings and the known benefits of sono-HSG over HSG in the context of subfertility, sono-HSG should replace HSG in the initial workup of subfertile couples. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by personal funds. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: This review has been registered at PROSPERO: Registration number #CRD42013003829.

Prevention of perinatal death and adverse perinatal outcome using low-dose aspirin: a meta-analysis.

OBJECTIVE: To compare early vs late administration of low-dose aspirin on the risk of perinatal death and adverse perinatal outcome. METHODS: Databases were searched for keywords related to aspirin and pregnancy. Only randomized controlled trials that evaluated the prophylactic use of low-dose aspirin (50-150 mg/day) during pregnancy were included. The primary outcome combined fetal and neonatal death. Pooled relative risks (RR) with their 95% CIs were compared according to gestational age at initiation of low-dose aspirin (≤ 16 vs > 16 weeks of gestation). RESULTS: Out of 8377 citations, 42 studies (27 222 women) were included. Inclusion criteria were risk factors for pre-eclampsia, including: nulliparity, multiple pregnancy, chronic hypertension, cardiovascular or endocrine disease, prior gestational hypertension or fetal growth restriction, and/or abnormal uterine artery Doppler. When compared with controls, low-dose aspirin started at ≤ 16 weeks' gestation compared with low-dose aspirin started at >16 weeks' gestation was associated with a greater reduction of perinatal death (RR = 0.41 (95% CI, 0.19-0.92) vs 0.93 (95% CI, 0.73-1.19), P = 0.02), pre-eclampsia (RR = 0.47 (95% CI, 0.36-0.62) vs 0.78 (95% CI, 0.61-0.99), P < 0.01), severe pre-eclampsia (RR = 0.18 (95% CI, 0.08-0.41) vs 0.65 (95% CI, 0.40-1.07), P < 0.01), fetal growth restriction (RR = 0.46 (95% CI, 0.33-0.64) vs 0.98 (95% CI, 0.88-1.08), P < 0.001) and preterm birth (RR = 0.35 (95% CI, 0.22-0.57) vs 0.90 (95% CI, 0.83-0.97), P < 0.001). CONCLUSION: Low-dose aspirin initiated at ≤ 16 weeks of gestation is associated with a greater reduction of perinatal death and other adverse perinatal outcomes than when initiated at >16 weeks.

Comparison of two different sites of measurement for transabdominal uterine artery Doppler velocimetry at 11-13 weeks.

OBJECTIVES: To compare the feasibility of two transabdominal approaches for performing first-trimester uterine artery (UtA) Doppler and to evaluate the correlation with pulsatility index (PI) in the second trimester. METHODS: This was a prospective longitudinal Doppler study of the uterine arteries at 11-13 and 21-22 weeks' gestation. Transabdominal ultrasound and color Doppler were used to measure the UtA-PI of the ascending branch of the uterine artery at the level of the internal cervical os (Site A) and at the level of the apparent crossover with the external iliac artery (Site B) at 11-13 weeks, and at Site B only at 21-22 weeks. In all cases the measured left and right PI were converted to a multiple of the median (MoM) for gestational age, and the intercorrelation between the measurements at different sites and gestational ages was calculated using non-parametric analysis (Spearman's rank correlation). RESULTS: Satisfactory measurements were obtained at 11-13 weeks from both uterine arteries in all 81 women at Site A and in 50 (62%; 95% CI, 50-72%) at Site B (P < 0.01). Measurements were obtained at Site B at 21-22 weeks in all cases. In the 50 cases with measurements from both sites at 11-13 weeks, the correlation of PI-MoMs between Sites A and B at 11-13 weeks was only moderate (ρ = 0.61). The correlation between first-trimester UtA-PI MoMs at Site A and second-trimester UtA-PI MoMs was stronger than that between first-trimester UtA-PI MoMs at Site B and second-trimester UtA-PI MoMs (ρ = 0.73 vs ρ = 0.47, P < 0.01). CONCLUSION: Evaluation of UtA-PI at 11-13 weeks can be achieved at the level of the internal cervical os in a greater proportion of women than at the level of the apparent crossover with the external iliac vessels, and the measurements obtained correlate better with second-trimester UtA-PI.

A cluster-randomized trial to reduce major perinatal morbidity among women with one prior cesarean delivery in Québec (PRISMA trial): study protocol for a randomized controlled trial.

BACKGROUND: Rates of cesarean delivery are continuously increasing in industrialized countries, with repeated cesarean accounting for about a third of all cesareans. Women who have undergone a first cesarean are facing a difficult choice for their next pregnancy, i.e.: (1) to plan for a second cesarean delivery, associated with higher risk of maternal complications than vaginal delivery; or (b) to have a trial of labor (TOL) with the aim to achieve a vaginal birth after cesarean (VBAC) and to accept a significant, but rare, risk of uterine rupture and its related maternal and neonatal complications. The objective of this trial is to assess whether a multifaceted intervention would reduce the rate of major perinatal morbidity among women with one prior cesarean. METHODS/DESIGN: The study is a stratified, non-blinded, cluster-randomized, parallel-group trial of a multifaceted intervention. Hospitals in Quebec are the units of randomization and women are the units of analysis. As depicted in Figure 1, the study includes a 1-year pre-intervention period (baseline), a 5-month implementation period, and a 2-year intervention period. At the end of the baseline period, 20 hospitals will be allocated to the intervention group and 20 to the control group, using a randomization stratified by level of care. Medical records will be used to collect data before and during the intervention period. Primary outcome is the rate of a composite of major perinatal morbidities measured during the intervention period. Secondary outcomes include major and minor maternal morbidity; minor perinatal morbidity; and TOL and VBAC rate. The effect of the intervention will be assessed using the multivariable generalized-estimating-equations extension of logistic regression. The evaluation will include subgroup analyses for preterm and term birth, and a cost-effectiveness analysis. DISCUSSION: The intervention is designed to facilitate: (1) women's decision-making process, using a decision analysis tool (DAT), (2) an estimate of uterine rupture risk during TOL using ultrasound evaluation of low-uterine segment thickness, (3) an estimate of chance of TOL success, using a validated prediction tool, and (4) the implementation of best practices for intrapartum management. TRIAL REGISTRATION: Current Controlled Trials, ID: ISRCTN15346559 . Registered on 20 August 2015.

What factors are associated with neonatal injury following shoulder dystocia?

OBJECTIVE: To identify factors associated with the development of neonatal injury in the setting of shoulder dystocia. STUDY DESIGN: Medical record ICD-9 codes and a computerized perinatal database were reviewed to identify cases of shoulder dystocia from January 1996 to January 2001 in a tertiary care center. For confirmation of the diagnosis and collection of data, both maternal and neonatal charts were then reviewed and neonatal injuries categorized as either neurological (brachial plexus injury) or skeletal (clavicular fracture, humeral fracture). Shoulder dystocia cases were divided into groups based on the presence of neonatal injury at delivery or at discharge (with or without Erb's palsy). The group with neonatal injury was compared for demographic and obstetrical factors to the group without injury (control). chi (2) test, Mann-Whitney test and logistic regression were used as appropriate. RESULTS: During this 5-year period, there were 25,995 deliveries and 206 (0.8%) confirmed cases of shoulder dystocia. Of these cases, 36 (17.5%) had neonatal injury diagnosed at delivery and 25 (12%) remained with significant residual injury at discharge. Of these there were 19 cases of Erb's palsy and six cases of clavicular fracture. No association was found between neonatal injury and maternal age, ethnicity, diabetes, operative vaginal delivery or number of obstetrical maneuvers. However, maternal body mass index >30 kg/m2, a second stage of labor >20 min and a birth weight >4500 g were all associated with an increased risk of neonatal injury at delivery and at discharge, including Erb's palsy. After logistic regression analysis, only a second stage of delivery >20 min remained significantly associated with neonatal injury at discharge. CONCLUSION: In our population, maternal obesity was associated with an increased risk of neonatal injury after shoulder dystocia. In addition, a short second stage of labor (<20 min) was associated with a lower rate of neonatal injury.

Should we allow a trial of labor after a previous cesarean for dystocia in the second stage of labor?

OBJECTIVE: To estimate the rate of successful vaginal birth including operative vaginal delivery in patients with a previous cesarean for cephalopelvic disproportion in the second stage of labor. METHODS: Data from all patients who underwent trial of labor after a previous cesarean between 1990 and 2000 at our tertiary care institution were analyzed. Medical records were reviewed and data collected for the following variables: indication for the previous cesarean, birth weight and cervical dilatation at previous cesarean delivery, as well as the mode of delivery (spontaneous, vacuum, forceps, cesarean) and the birth weight for the subsequent pregnancy. Pearson's chi(2) test and one-way analysis of variance were used for statistical analyses. RESULTS: There were 2002 patients included in the study. Two hundred fourteen (11%) had their previous cesarean for dystocia in the second stage of labor, 654 (33%) for dystocia in the first stage of labor, and 1134 (57%) for other indications. The vaginal birth after cesarean success rate was 75.2% (P = .015 vs other indications), 65.6% (P < .001 vs other indications), and 82.5%, respectively. The rate of operative vaginal delivery was 15%, 12%, and 10% (P = .109). CONCLUSION: A trial of labor is reasonable in women whose previous cesarean was for dystocia in the second stage of labor. In this series, patients who underwent a trial of labor after a previous cesarean for dystocia in the second stage had 75.2% (95% confidence interval 69.5, 81.0) chance of achieving vaginal delivery.

The effect of gestational age on trial of labor after Cesarean section.

OBJECTIVES: To evaluate the effect of gestational age on the rate of successful vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior Cesarean delivery. STUDY DESIGN: This was a cohort study including patients with a live singleton fetus undergoing a TOL after a previous low transverse Cesarean delivery between 1988 and 2002. Patients were divided into three groups according to gestational age: 24-36 weeks 6 days, 37-40 weeks 6 days and > or = 41 weeks. Obstetric outcomes, including the rates of successful vaginal delivery and symptomatic uterine rupture, were compared between the groups. Multivariate logistic regression analysis was performed to adjust for potential confounding factors. RESULTS: There were 253, 1911 and 329 patients in each group, respectively. In patients with advanced gestational age (> or = 41 weeks) the rate of uterine rupture was significantly higher (0% vs. 1.0% vs. 2.7%, p = 0.006) and the rate of successful vaginal deliveries was significantly lower (83% vs. 76.9% vs. 62.6%, p < 0.001). After adjusting for confounding variables, advanced gestational age was associated with a lower rate of successful vaginal delivery (odds ratio 0.68, 95% CI 0.51-0.89), and a higher rate of uterine rupture (odds ratio 2.85, 95% CI 1.27-6.42) when compared to 37-40 weeks 6 days. CONCLUSION: Advanced gestational age is associated with higher rates of failed TOL and uterine rupture.