Maternal outcomes in unexpected placenta accreta spectrum disorders: single-center experience with a multidisciplinary team. Erfani Hadi,Fox Karin A,Clark Steven L,Rac Martha,Rocky Hui Shiu-Ki,Rezaei Atefeh,Aalipour Soroush,Shamshirsaz Amir A,Nassr Ahmed A,Salmanian Bahram,Stewart Kelsey A,Kravitz Elizabeth S,Eppes Catherine,Coburn Michael,Espinoza Jimmy,Teruya Jun,Belfort Michael A,Shamshirsaz Alireza A American journal of obstetrics and gynecology OBJECTIVE: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. STUDY DESIGN: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. RESULTS: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). CONCLUSION: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. 10.1016/j.ajog.2019.05.035

The effect of placental location in cases of placenta accreta spectrum. Morgan Elizabeth A,Sidebottom Abbey,Vacquier Marc,Wunderlich Whitney,Loichinger Matthew American journal of obstetrics and gynecology BACKGROUND:Placenta accreta spectrum affects approximately 3 in 1000 pregnancies. There is a paucity of data evaluating the effect of placental location on diagnosis, risk factors, and resultant outcomes in cases of placenta accreta spectrum. OBJECTIVE:We analyzed placenta accreta spectrum cases to assess whether risk factors or maternal outcomes varied based on placental location. MATERIALS AND METHODS:We performed a retrospective chart review of pathology-confirmed cases of placenta accreta spectrum from patients delivering at 2 large urban hospitals in the same healthcare system from 2007 to 2017. Placental location was defined by ultrasound images and confirmed by pathology reports. Location was categorized as anterior, posterior, or anterior/posterior for those with placental location at both sites. Fisher exact tests and analysis of variance were used to examine associations with measures of diagnosis, risk factors, and maternal outcomes. RESULTS:A total of 86 pathology-confirmed placenta accreta spectrum cases were reviewed. The distribution of placental location on ultrasound was as follows: 19% posterior, 59% anterior, and 22% anterior/posterior. We found that prior cesarean delivery was lower with posterior placenta accreta spectrum (63% vs 94% vs 84% in the anterior and anterior/posterior groups respectively; (P = .007); however, in vitro fertilization rates were significantly higher (38% vs 2% vs 5% in the anterior and anterior/posterior groups respectively; P = .001). There was also lower incidence of percreta with posterior placenta accreta spectrum compared to the anterior and anterior/posterior groups (19% vs 47% vs 58% respectively; P = .055). Posterior cases were less likely to have placenta accreta spectrum suspected prenatally (50%) compared to anterior (80%) and anterior/posterior (89%) cases (P = .019). Despite late diagnosis, ureteral injury was the only surgical complication that was more common in patients with posterior placenta accreta spectrum (13% vs 0% vs 5% for anterior and anterior/posterior groups respectively; P = .037). CONCLUSION:Placenta accreta spectrum with posterior placental location is associated with delayed diagnosis, surgical complications, assisted reproductive technology, and lower numbers of prior cesarean deliveries relative to anterior location. These differences in outcomes and risk factors based on placental location may allow for heightened clinical awareness, and improved diagnosis and management. 10.1016/j.ajog.2019.07.028

Placenta Accreta Spectrum. , ,Cahill Alison G,Beigi Richard,Heine R Phillips,Silver Robert M,Wax Joseph R American journal of obstetrics and gynecology Placenta accreta spectrum, formerly known as morbidly adherent placenta, refers to the range of pathologic adherence of the placenta, including placenta increta, placenta percreta, and placenta accreta. The most favored hypothesis regarding the etiology of placenta accreta spectrum is that a defect of the endometrial-myometrial interface leads to a failure of normal decidualization in the area of a uterine scar, which allows abnormally deep placental anchoring villi and trophoblast infiltration. Maternal morbidity and mortality can occur because of severe and sometimes life-threatening hemorrhage, which often requires blood transfusion. Although ultrasound evaluation is important, the absence of ultrasound findings does not preclude a diagnosis of placenta accreta spectrum; thus, clinical risk factors remain equally important as predictors of placenta accreta spectrum by ultrasound findings. There are several risk factors for placenta accreta spectrum. The most common is a previous cesarean delivery, with the incidence of placenta accreta spectrum increasing with the number of prior cesarean deliveries. Antenatal diagnosis of placenta accreta spectrum is highly desirable because outcomes are optimized when delivery occurs at a level III or IV maternal care facility before the onset of labor or bleeding and with avoidance of placental disruption. The most generally accepted approach to placenta accreta spectrum is cesarean hysterectomy with the placenta left in situ after delivery of the fetus (attempts at placental removal are associated with significant risk of hemorrhage). Optimal management involves a standardized approach with a comprehensive multidisciplinary care team accustomed to management of placenta accreta spectrum. In addition, established infrastructure and strong nursing leadership accustomed to managing high-level postpartum hemorrhage should be in place, and access to a blood bank capable of employing massive transfusion protocols should help guide decisions about delivery location. 10.1016/j.ajog.2018.09.042

The management and outcomes of placenta accreta, increta, and percreta in the UK: a population-based descriptive study. Fitzpatrick K E,Sellers S,Spark P,Kurinczuk J J,Brocklehurst P,Knight M BJOG : an international journal of obstetrics and gynaecology OBJECTIVE:To describe the management and outcomes of placenta accreta, increta, and percreta in the UK. DESIGN:A population-based descriptive study using the UK Obstetric Surveillance System (UKOSS). SETTING:All 221 UK hospitals with obstetrician-led maternity units. POPULATION:All women diagnosed with placenta accreta, increta, and percreta in the UK between May 2010 and April 2011. METHODS:Prospective case identification through the monthly mailing of UKOSS. MAIN OUTCOME MEASURES:Median estimated blood loss, transfusion requirements. RESULTS:A cohort of 134 women were identified with placenta accreta, increta, or percreta: 50% (66/133) were suspected to have this condition antenatally. In women with a final diagnosis of placenta increta or percreta, antenatal diagnosis was associated with reduced levels of haemorrhage (median estimated blood loss 2750 versus 6100 ml, P = 0.008) and a reduced need for blood transfusion (59 versus 94%, P = 0.014), possibly because antenatally diagnosed women were more likely to have preventative therapies for haemorrhage (74 versus 52%, P = 0.007), and were less likely to have an attempt made to remove their placenta (59 versus 93%, P < 0.001). Making no attempt to remove any of the placenta, in an attempt to conserve the uterus or prior to hysterectomy, was associated with reduced levels of haemorrhage (median estimated blood loss 1750 versus 3700 ml, P = 0.001) and a reduced need for blood transfusion (57 versus 86%, P < 0.001). CONCLUSIONS:Women with placenta accreta, increta, or percreta who have no attempt to remove any of their placenta, with the aim of conserving their uterus, or prior to hysterectomy, have reduced levels of haemorrhage and a reduced need for blood transfusion, supporting the recommendation of this practice. 10.1111/1471-0528.12405

Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging. Jauniaux Eric,Collins Sally,Burton Graham J American journal of obstetrics and gynecology Placenta accreta spectrum is a complex obstetric complication associated with high maternal morbidity. It is a relatively new disorder of placentation, and is the consequence of damage to the endometrium-myometrial interface of the uterine wall. When first described 80 years ago, it mainly occurred after manual removal of the placenta, uterine curettage, or endometritis. Superficial damage leads primarily to an abnormally adherent placenta, and is diagnosed as the complete or partial absence of the decidua on histology. Today, the main cause of placenta accreta spectrum is uterine surgery and, in particular, uterine scar secondary to cesarean delivery. In the absence of endometrial reepithelialization of the scar area the trophoblast and villous tissue can invade deeply within the myometrium, including its circulation, and reach the surrounding pelvic organs. The cellular changes in the trophoblast observed in placenta accreta spectrum are probably secondary to the unusual myometrial environment in which it develops, and not a primary defect of trophoblast biology leading to excessive invasion of the myometrium. Placenta accreta spectrum was separated by pathologists into 3 categories: placenta creta when the villi simply adhere to the myometrium, placenta increta when the villi invade the myometrium, and placenta percreta where the villi invade the full thickness of the myometrium. Several prenatal ultrasound signs of placenta accreta spectrum were reported over the last 35 years, principally the disappearance of the normal uteroplacental interface (clear zone), extreme thinning of the underlying myometrium, and vascular changes within the placenta (lacunae) and placental bed (hypervascularity). The pathophysiological basis of these signs is due to permanent damage of the uterine wall as far as the serosa, with placental tissue reaching the deep uterine circulation. Adherent and invasive placentation may coexist in the same placental bed and evolve with advancing gestation. This may explain why no single, or set combination of, ultrasound sign(s) was found to be specific for the depth of abnormal placentation, and accurate for the differential diagnosis between adherent and invasive placentation. Correlation of pathological and clinical findings with prenatal imaging is essential to improve screening, diagnosis, and management of placenta accreta spectrum, and standardized protocols need to be developed. 10.1016/j.ajog.2017.05.067