Placenta Accreta Spectrum Disorders: A National Survey

OBJECTIVES

Describe the current practice of Canadian obstetricians-gynaecologists in managing placenta accreta spectrum (PAS) disorders from suspicion of diagnosis to delivery planning and explore the impact of the latest national practice guidelines on this topic.

METHODS

We distributed a cross-sectional bilingual electronic survey to Canadian obstetricians-gynaecologists in March-April 2021. Demographic data and information on screening, diagnosis, and management were collected using a 39-item questionnaire. The survey was validated and pretested among a sample population. Descriptive statistics were used to present the results.

RESULTS

We received 142 responses. Almost 60% of respondents said they had read the latest Society of Obstetricians and Gynaecologists of Canada clinical practice guideline on PAS disorders, published in July 2019. Nearly 1 in 3 respondents changed their practice following this guideline. Respondents highlighted the importance of 4 key points: (1) limiting travel to thereby remain close to a regional care centre, (2) preoperative anemia optimization, (3) performance of cesarean-hysterectomy leaving the placenta in situ (83%), (4) access via midline laparotomy (65%). Most respondents recognized the importance of perioperative blood loss reduction strategies such as tranexamic acid and perioperative thromboprophylaxis via sequential compression devices and low-molecular-weight heparin until full mobilization.

CONCLUSIONS

This study demonstrates the impact of the Society of Obstetricians and Gynaecologists of Canada's PAS clinical practice guideline on management choices made by Canadian clinicians. Our study highlights the value of a multidisciplinary approach to reducing maternal morbidity in individuals facing surgery for a PAS disorder and the importance of regionalized care that is resourced to provide maternal-fetal medicine and surgical expertise, transfusion medicine, and critical care support.

Measurement of Lower Uterine Segment Thickness to Detect Uterine Scar Defect: Comparison of Transabdominal and Transvaginal Ultrasound

OBJECTIVES

Lower uterine segment (LUS) thickness measurement using transabdominal ultrasound (TA-US), transvaginal ultrasound (TV-US), or the combination of both methods can detect scar defect in women with prior cesarean. We aimed to compare the sensitivity of three approaches.

METHODS

Women with prior cesarean underwent LUS thickness measurement at 34-38 weeks' gestation. Among those who underwent repeat cesarean before labor, we compared the accuracy of TA-US, TV-US, and the thinner of the two measurements (the "combined measurement") for uterine scar dehiscence using the area under the curve (AUC) of receiver operating curves with their 95% confidence intervals (CI). We calculated the sensitivity and specificity of the three approaches using a cut-off of 2.3 mm based on prior literature.

RESULTS

We included 747 participants. The mean LUS thickness was greater with TA-US (3.8 ± 1.6 mm) compared with TV-US (3.5 ± 1.9 mm) or the combined measurement (3.2 ± 1.5 mm; P < .001). The AUC was 78% (95% CI: 69%-87%), 85% (95% CI: 79%-91%), and 88% (95% CI: 82%-93%), respectively (all with P < .001). The AUC difference between TA-US and the combined measurement was not significant (P = .057). A LUS below 2.3 mm would have predicted 9 (45%) of the 20 cases of uterine scar dehiscence using TA-US, 17 (85%) using TV-US, and 18 (90%) using the combined measurement (P < .01).

CONCLUSION

The choice of ultrasound approach influences the measurement of the LUS thickness. The combination of the TA-US and TV-US seems to be superior for the detection of uterine dehiscence.

Virtual Laparoscopy Simulation: a Promising Pedagogic Tool in Gynecology

Background and Objectives:

Virtual simulators have played a vital role in preparing surgeons for laparoscopic and robotic procedures in gynecologic surgery. The efficacy of the simulator was evaluated to improve basic (trainee) laparoscopic skills and assess training levels.

Methods:

This prospective, comparative study was conducted in volunteer residents in the obstetrics and gynecology training program of Université Laval. Study participants performed 9 laparoscopic simulator tasks on 2 different occasions. Skills improvement between sessions and differences between junior and senior residents were examined.

Results:

Thirteen junior and 11 senior residents participated in the study. Junior trainees significantly improved their speed of execution, accuracy, and maintenance of horizontal view. Senior trainees mainly accelerated their rapidity in completing different tasks. They performed better than junior trainees, with economy of movements, and tended toward greater precision, speed of execution, and safe retraction in various tasks.

Conclusion:

Virtual simulators are useful pedagogic tools that could benefit both junior and senior residents. Integration into the residency curricula should be considered.

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

BACKGROUND

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.

OBJECTIVE

To estimate the impact of previous uterine closure on lower uterine segment thickness.

STUDY DESIGN

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.

RESULTS

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.

CONCLUSION

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.

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

BACKGROUND

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.

OBJECTIVE

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.

STUDY DESIGN

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%.

RESULTS

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).

CONCLUSION

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.

Could High Volume of Physical Activities in Early Pregnancy Interfere with Deep Placentation?

Background The impact of physical activity (PA) during pregnancy on obstetrical outcomes remains controversial. We followed pregnant women who reported more than 3 hours of sustained PA per week during the first trimester of pregnancy. Cases Total five eligible women were followed. We observed small placenta from the first trimester (median: 0.68; interquartile [IQ]: 0.62-0.97 multiples of median [MoM]) to delivery (median: 0.82; IQ: 0.71-0.94 MoM), high uterine artery pulsatility index in the first (median: 1.82; IQ: 1.68-1.99 MoM) and second trimesters (median: 1.33; IQ: 1.11-1.56 MoM) of pregnancy. Placenta pathology revealed deep vasculopathy in three (60%) cases. However, all participants delivered at term and none of them experienced preeclampsia. Conclusion This small case series suggest that high PA volume in first trimester could interfere with deep placentation.

Labor Dystocia and the Risk of Uterine Rupture in Women with Prior Cesarean

Objective The objective of this study was to evaluate the association between labor dystocia and uterine rupture. Methods We performed a secondary analysis of a multicenter case-control study that included women with single, prior, low-transverse cesarean section who experienced complete uterine rupture during a trial of labor (TOL). For each case, three women who underwent a TOL without uterine rupture were selected as controls. Data were collected on cervical dilatations from admission to delivery. We evaluated the relationship between uterine rupture and labor dystocia according to several criteria, including the World Health Organization's (WHO's) partogram. Results Data were available for 90 cases and 260 controls. Compared with the controls, uterine rupture was associated with less cervical dilatation on admission, slower cervical dilatation in the first stage of labor and longer second stage of labor (all with p < 0.05). Performing cesarean when the labor curve crossed the ACTION line of WHO's partogram or when the second stage was greater than 2 hours could have (1) prevented up to 56% of uterine rupture and (2) reduced the duration of labor in 57% of women with failed TOL. Conclusion Labor dystocia is a significant risk factor for uterine rupture. Labor progression should be assessed regularly in women with prior cesarean.