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 ... -  《-》

Comparison of maternal outcomes and clinical characteristics of prenatally vs nonprenatally diagnosed placenta accreta spectrum: a systematic review and meta-analysis.

This study aimed to compare maternal outcomes of prenatally and nonprenatally diagnosed placenta accreta spectrum. A systematic literature search was performed in PubMed, the Cochrane database, and Web of Science until November 28, 2022. Studies comparing the clinical presentation of prenatally and nonprenatally diagnosed placenta accreta spectrum were included. The primary outcomes were emergent cesarean delivery, hysterectomy, blood loss volume, number of transfused blood product units, urological injury, coagulopathy, reoperation, intensive care unit admission, and maternal death. In addition, the pooled mean values for blood loss volume and the number of transfused blood product units were calculated. The secondary outcomes included maternal age, gestational age at birth, nulliparity, previous cesarean delivery, previous uterine procedure, assisted reproductive technology, placenta increta and percreta, and placenta previa. Study screening was performed after duplicates were identified and removed. The quality of each study and the publication bias were assessed. Forest plots and I2 statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis. Overall, 415 abstracts and 157 full-text studies were evaluated. Moreover, 31 studies were analyzed. Prenatally diagnosed placenta accreta spectrum was associated with a significantly lower rate of emergency cesarean delivery (odds ratio, 0.37; 95% confidence interval, 0.21-0.67), higher hysterectomy rate (odds ratio, 1.98; 95% confidence interval, 1.02-3.83), lower blood loss volume (mean difference, -0.65; 95% confidence interval, -1.17 to -0.13), and lower number of transfused red blood cell units (mean difference, -1.96; 95% confidence interval, -3.25 to -0.68) compared with nonprenatally diagnosed placenta accreta spectrum. The pooled mean values for blood loss volume and the number of transfused blood product units tended to be lower in the prenatally diagnosed placenta accreta spectrum groups than in the nonprenatally diagnosed placenta accreta spectrum groups. Nulliparity (odds ratio, 0.14; 95% confidence interval, 0.10-0.20), previous cesarean delivery (odds ratio, 6.81; 95% confidence interval, 4.12-11.25), assisted reproductive technology (odds ratio, 0.19; 95% confidence interval, 0.06-0.61), placenta increta and percreta (odds ratio, 3.97; 95% confidence interval, 2.24-7.03), and placenta previa (odds ratio, 6.81; 95% confidence interval, 4.12-11.25) showed statistical significance. No significant difference was found for the other outcomes. Despite its severity, the positive effect of prenatally diagnosed placenta accreta spectrum on outcomes underscores the necessity of a prenatal diagnosis. In addition, the pooled mean values provide a preoperative preparation guideline.

Sugai S ，Yamawaki K ，Sekizuka T ，Haino K ，Yoshihara K ，Nishijima K ... -  《-》

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 ... -  《-》

Placenta Accreta Spectrum Without Placenta Previa.

Carusi DA ，Fox KA ，Lyell DJ ，Perlman NC ，Aalipour S ，Einerson BD ，Belfort MA ，Silver RM ，Shamshirsaz AA ... -  《-》

Clinical Correlates of Placenta Accreta Spectrum Disorder Depending on the Presence or Absence of Placenta Previa: A Systematic Review and Meta-analysis.

To evaluate whether there are differences in risk factors and maternal outcomes of pregnancies complicated by placenta accreta spectrum depending on the presence or absence of placenta previa. We performed a systematic search in Medline, EMBASE, ClinicalTrials.gov , and Web of Science from inception through April 25, 2022, without language or date restrictions. Search strategy included the key words "placenta accreta," "placenta increta," "placenta percreta," "adherent placenta," "invasive placenta," "abnormal placent*," "placenta previa," and "marginal placent*." Of the 1,122 articles screened, seven studies were included in the final review. Studies were included if they compared the risk factors and maternal outcomes of pregnancies complicated by placenta accreta spectrum depending on the presence or absence of placenta previa. A random-effects model was used to pool the mean differences or odds ratios (OR) and the corresponding 95% CIs using RevMan software. A total of 3,342 pregnancies complicated by placenta accreta spectrum were included in the meta-analysis (2,365 without previa and 977 with previa). Pregnancies complicated by placenta accreta spectrum without previa were more likely to have been conceived by in vitro fertilization (IVF) (OR 3.11, 95% CI 1.93-5.02, P <.001, I 2 =52.0%) and to be associated with prior dilation and curettage (D&C) (OR 1.60, 95% CI 1.15-2.22, P =.005, I 2 =0.0%) and myomectomy (OR 2.47, 95% CI 1.31-4.66, P =.005, I 2 =0.0%), but they were less likely to be associated with prior cesarean delivery (OR 0.15, 95% CI 0.06-0.37, P <.001, I 2 =87.0%). Placenta accreta spectrum without previa was less likely to be diagnosed antenatally (OR 0.07, 95% CI 0.04-0.11, P <.001, I 2 =38.0%). Also, women with pregnancies without previa had lower rates of red blood cell transfusion, intensive care unit admission, risk of hysterectomy, unscheduled delivery, and intraoperative bowel or bladder injuries. Pregnancies complicated by placenta accreta spectrum without previa had a more prominent association with IVF and prior D&C and myomectomy but were much less likely to be associated with prior cesarean delivery. Further, placenta accreta spectrum without previa was less likely to be diagnosed antenatally, although it had better maternal outcomes as compared with placenta accreta spectrum with previa. PROSPERO, CRD42022307637.

Hessami K ，Salmanian B ，Einerson BD ，Carusi DA ，Shamshirsaz AA ，Shainker SA ，Subramaniam A ，Shrivastava VK ，Nieto-Calvache AJ ，Gilner JB ，Khandelwal M ，Backer-Meurke S ，Cimic A ，Aalipour S ，Grace MR ，Fox KA ，Lyell DJ ，Belfort MA ，Silver RM ，Shamshirsaz AA ... -  《-》