Potentially Preventable Primary Cesarean Sections in Future Placenta Accreta Spectrum

Background Prior cesarean delivery is a well-known risk factor for placenta accreta spectrum disorders. While primary cesarean section is unavoidable in some patients, in others it may not be clearly indicated. Objective The aim of the study is to determine the proportion of patients with placenta accreta spectrum who had a potentially preventable primary cesarean section and to identify factors associated with preventable placenta accreta spectrum. Study Design This was a single-center retrospective cohort study of women with pathology-confirmed placenta accreta spectrum from 2007 to 2019. Primary cesarean sections were categorized as potentially preventable or unpreventable based on practice consistent with the American College of Obstetricians and Gynecologists and the Society for Maternal–Fetal Medicine “Safe Prevention of the Primary Cesarean Delivery” recommendations. Fisher's exact test and Mann-Whitney U-test were used for comparison with p <0.05 considered statistically significant. Results Seventy-two patients had pathology-confirmed placenta accreta spectrum over the course of the study period, 15 (20.8%) of whom required a cesarean hysterectomy at the time of primary cesarean section. Fifty-seven patients had placenta accreta spectrum in a pregnancy following their primary cesarean section. Of these, 29 (50.9%) were considered potentially preventable. Most were performed without clear medical indication (37.9%) or for fetal malpresentation without attempted external cephalic version (37.9%). The remainder were due to arrest of labor not meeting criteria (17.2%) and abnormal or indeterminate fetal heart patterns with documented recovery (6.9%). Of the 11 patients without clear medical indication for primary cesarean section, eight (72.7%) were patient-choice cesarean sections and three (27.3%) were for suspected fetal macrosomia with estimated fetal weights not meeting criteria for cesarean delivery. There was no difference in the incidence of potentially preventable primary cesarean sections before and after the ACOG-SMFM “Safe Prevention of the Primary Cesarean Delivery” publication (48.8 vs. 57.1%, p = 0.59). Privately insured patients were more likely to have a potentially preventable primary cesarean section than those with Medicaid (62.5 vs. 23.5%, p = 0.008) and were more likely to have a primary cesarean section without clear medical indication (81.8 vs. 18.2%, p = 0.004). Conclusion Many patients with placenta accreta spectrum had a potentially preventable primary cesarean section. Most were performed without clear medical indication or for malpresentation without attempted external cephalic version, suggesting that at least a subset of placenta accreta spectrum cases may be preventable. This was particularly true for privately insured patients. These findings call for continued investigation of potentially preventable primary cesarean sections with initiatives to address concerns at the patient, provider, and hospital level. Key Points

Predictive Factors for Successful Vaginal Delivery after a Trial of External Cephalic Version: A Retrospective Cohort Study of 946 Women

Objective Our aim was to find the factors which predict a vertex presentation of vaginal delivery (VD) in women who are admitted for a trial of external cephalic version (ECV). Study Design This is a retrospective cohort study of women who underwent a trial of ECV and delivered between November 2011 and December 2018 in a single tertiary center. The main outcome measure was successful VD of a fetus in the vertex presentation. Women who achieved VD in the vertex presentation or underwent cesarean delivery were compared on the basis of variety of predictive factors. Adverse neonatal and maternal outcomes were reported. Logistic regression was used for the multivariate analysis. Results A total of 946 women were included; 717 (75.8%) women had a successful ECV and 663 (70.1%) women had a VD in the vertex presentation. Parous women had 79.3% VD rate (570/719) and nulliparous women had 41.0% VD rate (93/227). Women with an amniotic fluid index (AFI) of 50 to 79, 80 to 200, and >200 mm had 34.8, 71.0, and 83.1% VD rate, respectively. Parous versus nulliparous women had an adjusted odds ratio (aOR) of 5.42 (95% confidence interval [CI] 3.90–7.52, p < 0.001), women with AFI 50 to 79 mm compared with AFI 80 to 200 mm had an aOR of 0.21 (95% CI 0.12–0.37, p < 0.001), and women with an AFI >200 mm compared with AFI 80 to 200 mm had an aOR of 1.74 (95% CI 1.03–2.92, p = 0.037) to achieve VD. The final prediction model for the chances of a VD based on data on admission for ECV was reported. The Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model (p = 0.836). Conclusion Being parous and having an AFI >200 mm are positive independent predictive factors for achieving VD of a vertex presenting fetus after ECV. Whereas AFI 50 to 79 mm is a negative independent predictive factor. Key Points

External cephalic version in the outpatient clinic

The continuous increase in the rates of cesarean section worldwide is concerning. Breech presentation is one of the major indications for cesarean section in most countries. External cephalic version (ECV) can reduce cesarean rates by approximately two-thirds in term breech pregnancies. After introduction of ultrasonography and cardiotocography before and after the procedure, ECV has become much safer. As a result, over-night fasting, intravenous access, and preoperative laboratory tests are no longer recommended as the patient’s risk of requiring emergency cesarean section is very low. We have been running the largest ECV clinic in South Korea since 2008, and ECV trials in the outpatient clinic were started in 2015. We want to share our experiences running the ECV clinic for 15 years managing more than 2000 patients.