Incidence, risk factors and maternal outcomes of unsuspected placenta accreta spectrum disorders: a retrospective cohort study.

Zhao J ，Li Q ，Liao E ，Shi H ，Luo X ，Zhang L ，Qi H ，Zhang H ，Li J ... -  《BMC Pregnancy and Childbirth》

Association between Number of Prior Cesareans and Early Preterm Delivery in Women with Abnormal Placentation.

Delivery timing at 34 to 36 weeks is nationally recommended for pregnancies complicated by placenta accreta spectrum (PAS). However, it has recently been suggested that those with ≥2 prior cesarean deliveries (CD) and PAS should be delivered earlier than 34 weeks because of a higher risk of unscheduled delivery and complications. We sought to evaluate whether the number of prior CD in women with PAS is associated with early preterm delivery (PTD) (<34 weeks). We also evaluated the same relationship in women with placenta previa alone (without PAS). This is a secondary analysis of a multicenter and observational study that included women with prior CD (maternal-fetal medicine unit cesarean registry). Women with a diagnosis of PAS (regardless of placenta previa) were included for our primary analysis, and women with known placenta previa (without a component of PAS) were independently analyzed in a second analysis. Two groups of patients from the registry were studied: patients with PAS (regardless of placenta previa) and patients with placenta previa without PAS. The exposure of interest was the number of prior CD: ≥2 CD compared with <2 CD. The primary outcome was PTD <34 weeks. Secondary outcomes included preterm labor requiring hospitalization or tocolysis, transfusion of blood products, composites of maternal and neonatal morbidities, and NICU admission. Outcomes by prior CD number groups were compared in both cohorts. Backward selection was used to identify parsimonious logistic regression models. There were 194 women with PAS, 97 (50%) of whom had <2 prior CD and 97 (50%) of whom had ≥2 prior CD. The rate of PTD <34 weeks in women with ≥2 prior CD compared with <2 in the setting of PAS was 23.7 versus 29.9%, p = 0.27; preterm labor requiring hospitalization was 24.7 versus 13.5%; p = 0.05. The rates of plasma transfusion were increased with ≥2 prior CD (29.9 vs. 17.5%, p = 0.04), but there were no differences in transfusion of other products or in composite maternal or neonatal morbidities. After multivariable adjustments, having ≥2 CDs was not associated with PTD <34 weeks in women with PAS (adjusted odds ratio (aOR): 0.73, 95% confidence interval [CI]: 0.39-13.8) despite an association with preterm labor requiring hospitalization (aOR: 2.69; 95% CI: 1.15-6.32). In our second analysis, there were 687 women with placenta previa, 633 (92%) with <2 prior CD, and 54 (8%) with ≥2 prior CD. The rate of PTD <34 weeks with ≥2 CD in the setting of placenta previa was not significantly increased (27.8 vs. 22.1%, aOR: 1.49; 95% CI: 0.77-2.90, p = 0.08); the maternal composite outcome (aOR: 4.85; 95% CI: 2.43-9.67) and transfusion of blood products (aOR: 6.41; 95% CI: 2.30-17.82) were noted to be higher in the group with ≥2 prior CD. Women with PAS who have had ≥2 prior CD as compared with women with <2 prior CD did not appear to have a higher risk of complications leading to delivery prior to 34 weeks. As such, considering the associated morbidity with early preterm birth, we would not recommend scheduled delivery prior to 34 weeks in this population. · We do not recommend delivery prior to 34 weeks of gestational age in PAS.. · PTD was not significantly increased in PAS with ≥2 CDs.. · PTD < 34 weeks of gestational age was not increased in placenta previa with ≥2 prior CDs..

Oben A ，Ausbeck EB ，Gazi MN ，Subramaniam A ，Harper LM ，Szychowski JM ，Tita AT ... -  《-》

Unsuspected placenta accreta spectrum at vaginal delivery: assessment of incidence, characteristics, and maternal morbidity.

Placenta accreta spectrum refers to morbidly adherent trophoblastic tissue invading into the gravid uterus and is associated with significant maternal morbidity. Most cases of placenta accreta spectrum are suspected antenatally, and most patients undergo planned, late-preterm cesarean hysterectomy to reduce the risk of morbidity. Rarely, however, placenta accreta spectrum is incidentally diagnosed at vaginal delivery, but there is a scarcity of data regarding these events. This study aimed to examine the incidence, characteristics, and outcomes of pregnant individuals with incidentally diagnosed placenta accreta spectrum at term vaginal delivery. This was a retrospective cohort study investigating the Healthcare Cost and Utilization Project's National Inpatient Sample. The study population was 8,694,669 term vaginal deliveries from January 2016 to December 2019. Exclusion criteria included previous uterine scar, placenta previa, and preterm delivery. Exposure was assigned by the diagnosis of placenta accreta spectrum. The main outcomes were: (1) incidence rate, (2) clinical and pregnancy characteristics, and (3) maternal morbidity related to unsuspected placenta accreta spectrum at vaginal delivery. Multivariable binary logistic regression analysis and inverse probability of treatment weighting were fitted for statistical analysis. Unsuspected placenta accreta spectrum was reported in 1 in 3797 vaginal deliveries. In a multivariable analysis, the following were associated with increased likelihood of unsuspected placenta accreta spectrum (all, P<.05): (1) patient factor with older age, (2) uterine factors such as uterine anomaly and uterine myoma, (3) pregnancy factors including early-term delivery and previous recurrent pregnancy losses, and (4) fetal factors of in utero growth restriction and demise. Of those, uterine anomaly had the greatest association with unsuspected placenta accreta spectrum (adjusted odds ratio, 6.23; 95% confidence interval, 4.20-9.26). In a propensity score-weighted model, patients in the unsuspected placenta accreta spectrum group were more likely to have hemorrhage (65.2% vs 4.1%), blood product transfusion (21.3% vs 0.6%), hysterectomy (14.9% vs <0.1%), coagulopathy (2.9% vs 0.1%), and shock (2.9% vs <0.1%) compared with those without placenta accreta spectrum. Patients in the unsuspected placenta accreta spectrum group were also more likely to receive manual removal of the placenta compared with those in the non-placenta accreta spectrum group (25.1% vs 0.6%). This study suggests that although unsuspected placenta accreta spectrum among patients undergoing term vaginal delivery is rare, it is associated with significant morbidity. The observed association between uterine anomalies and placenta accreta spectrum warrants further investigation.

Rau AR ，Youssefzadeh AC ，Matsuzaki S ，Mandelbaum RS ，Ouzounian JG ，Matsuo K ... -  《-》

Focal-occult placenta accreta: a clandestine source of maternal morbidity.

Focal-occult placenta accreta spectrum is known to cause adverse obstetrical morbidity outcomes, however, direct comparisons with previa-associated placenta accreta spectrum morbidity are lacking. We sought to compare the baseline characteristics, surgical and obstetrical morbidity, and subsequent pregnancy outcomes of patients with focal-occult placenta accreta spectrum with those of patients with previa-associated accreta. A retrospective review was conducted of all pathologically confirmed placenta accreta spectrum cases from 2018 to 2022 at a tertiary care center. The baseline characteristics, surgical, obstetrical, and subsequent pregnancy outcomes were recorded. Cases of focal-occult placenta accreta spectrum was compared with cases of previa-associated placenta accreta spectrum across a range of morbidity characteristics including hemorrhagic factors, interventions, postdelivery reoperations, infections, and intensive care unit admission. Statistical comparison was performed using Kruskal-Wallis or chi-square tests, and a P value of <.05 was considered significant. A total of 74 cases were identified with 43 focal-occult and 31 previa-associated placenta accreta spectrum cases. Of those, 25.6% of the patients with focal-occult placenta accreta spectrum and 100% of the patients with previa-associated placenta accreta spectrum underwent a hysterectomy. One case of focal-occult placenta accreta spectrum and 29 cases of previa-associated placenta accreta spectrum were diagnosed antenatally. Patients with focal-occult placenta accreta spectrum did not differ from those with previa-associated placenta accreta spectrum in mean maternal age (33.0 vs 33.1 years), body mass index, or the incidence of previous dilation and curettage procedures (16.3% vs 25.8%). Patients with focal-occult placenta accreta spectrum were significantly more likely to have a lower mean parity (1.5 vs 3.6 gestations), higher gestational age at delivery (36.1 vs 33.9 weeks' gestation), and were less likely to have had a previous cesarean delivery (12/43, 27.9% vs 30/31, 96.8%). In addition, patients with focal-occult placenta accreta spectrum had less previous cesarean deliveries (mean, 0.5 vs 2.3), were more likely to have undergone in vitro fertilization (20.9% vs 3.2%), and less likely to have anterior placentation. When contrasting the clinical outcomes of patients with focal-occult placenta accreta spectrum with those with previa-associated placenta accreta spectrum, the postpartum hemorrhage rates (71.0% vs 67.4%), mean quantitative blood loss (2099 mL; range, 500-9516 mL vs 2119 mL; range 350-12,220 mL), mean units of red blood cells transfused (1.4 vs 1.7), massive transfusion rate (9.3% vs 3.2%), and intensive care unit admission rates (11.6% vs 6.5%) were not significantly different, but there was a nonsignificant trend toward higher morbidity among patients with focal-occult accreta. Patients with focal-occult accreta had a higher incidence of reoperations or return to the operating room (30.2 vs 6.5%; P=.01). When comparing focal-occult with previa-associated placenta accreta spectrum, the composite outcomes, including hemorrhagic morbidity (77.4% vs 74.4%), any maternal morbidity (83.9% vs 76.7%), and severe maternal morbidity (64.5% vs 65.1%), were not significantly different between the groups. Nine focal-occult placenta accreta spectrum patients had a subsequent pregnancy, and 3 of those had recurrent placenta accreta spectrum. Focal-occult placenta accreta spectrum presents with fewer identifiable risk factors than placenta previa-associated placenta accreta spectrum but may be associated with an in vitro fertilization pregnancy. Patients with focal-occult placenta accreta spectrum was observed to have a higher incidence of reoperation when compared with patients previa-associated placenta accreta spectrum, and no other statistically significant differences in morbidity outcomes were observed. The absence of differences in morbidity outcomes may be attributable to a lack of antenatal detection of focal-occult accreta and merits further investigation.

Larish A ，Horst K ，Brunton J ，Schenone M ，Branda M ，Mehta R ，Packard A ，VanBuren W ，Norgan A ，Shahi M ，Missert A ，Pompeian R ，Greenwood J ，Theiler R ... -  《-》

Maternal outcomes in unexpected placenta accreta spectrum disorders: single-center experience with a multidisciplinary team.

In a 2015 Maternal-Fetal Medicine Units Network study, only half of placenta accreta spectrum cases were suspected before delivery, and the outcomes in the anticipated cases were paradoxically poorer than in unanticipated placenta accreta spectrum cases. This was possibly because the antenatally suspected cases were of greater severity. We sought to compare the outcomes of expected vs unexpected placenta accreta spectrum in a single large US center with multidisciplinary management protocol. This was a retrospective cohort study carried out between Jan. 1, 2011, and June 30, 2018, of all histology-proven placenta accreta spectrum deliveries in an academic referral center. Patients diagnosed at the time of delivery were cases (unexpected placenta accreta spectrum), and those who were antentally diagnosed were controls (expected placenta accreta spectrume). The primary and secondary outcomes were the estimated blood loss and the number of red blood cell units transfused, respectively. Variables are reported as median and interquartile range or number (percentage). Analyses were made using appropriate parametric and nonparametric tests. Fifty-four of the 243 patients (22.2%) were in the unexpected placenta accreta spectrum group. Patients in the expected placenta accreta spectrum group had a higher rate of previous cesarean delivery (170 of 189 [89.9%] vs 35 of 54 [64.8%]; P < .001) and placenta previa (135 [74.6%] vs 19 [37.3%]; P < .001). There was a higher proportion of increta/percreta in expected placenta accreta spectrum vs unexpected placenta accreta spectrum (125 [66.1%] vs 9 [16.7%], P < .001). Both primary outcomes were higher in the unexpected placenta accreta spectrum group (estimated blood loss, 2.4 L [1.4-3] vs 1.7 L [1.2-3], P = .04; red blood cell units, 4 [1-6] vs 2 [0-5], P = .03). Our data contradict the Maternal-Fetal Medicine Units results and instead show better outcomes in the expected placenta accreta spectrum group, despite a high proportion of women with more severe placental invasion. We attribute this to our multidisciplinary approach and ongoing process improvement in the management of expected cases. The presence of an experienced team appears to be a more important determinant of maternal morbidity in placenta accreta spectrum than the depth of placental invasion.

Erfani H ，Fox KA ，Clark SL ，Rac M ，Rocky Hui SK ，Rezaei A ，Aalipour S ，Shamshirsaz AA ，Nassr AA ，Salmanian B ，Stewart KA ，Kravitz ES ，Eppes C ，Coburn M ，Espinoza J ，Teruya J ，Belfort MA ，Shamshirsaz AA ... -  《-》