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.

      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.


      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.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Belfort M.A.
        Placenta accreta.
        Am J Obstet Gynecol. 2010; 203: 430-439
        • Solheim K.N.
        • Esakoff T.F.
        • Little S.E.
        • Cheng Y.W.
        • Sparks T.N.
        • Caughey A.B.
        The effect of cesarean delivery rates on the future incidence of placenta previa, placenta accreta, and maternal mortality.
        J Matern Fetal Neonat Med. 2011; 24: 1341-1346
        • Fitzpatrick K.E.
        • Sellers S.
        • Spark P.
        • Kurinczuk J.J.
        • Brocklehurst P.
        • Knight M.
        The management and outcomes of placenta accreta, increta, and percreta in the UK: a population-based descriptive study.
        BJOG. 2014; 121 (discussion 70-1): 62-70
        • Thurn L.
        • Lindqvist P.G.
        • Jakobsson M.
        • Colmorn L.B.
        • Klungsoyr K.
        • Bjarnadottir R.I.
        • et al.
        Abnormally invasive placenta-prevalence, risk factors and antenatal suspicion: results from a large population-based pregnancy cohort study in the Nordic countries.
        BJOG. 2016; 123: 1348-1355
        • Bowman Z.S.
        • Eller A.G.
        • Kennedy A.M.
        • et al.
        Accuracy of ultrasound for the prediction of placenta accreta.
        Am J Obstet Gynecol. 2014; 211: 177.e1-177.e7
        • Eller A.G.
        • Bennett M.A.
        • Sharshiner M.
        • et al.
        Maternal morbidity in cases of placenta accreta managed by a multidisciplinary care team compared with standard obstetric care.
        Obstet Gynecol. 2011; 117: 331-337
        • Shamshirsaz A.A.
        • Fox K.A.
        • Erfani H.
        • et al.
        Multidisciplinary team learning in the management of the morbidly adherent placenta: outcome improvements over time.
        Am J Obstet Gynecol. 2017; 216: 612.e1-612.e5
        • Shamshirsaz A.A.
        • Fox K.A.
        • Erfani H.
        • et al.
        Outcomes of planned compared with urgent deliveries using a multidisciplinary team approach for morbidly adherent placenta.
        Obstet Gynecol. 2018; 131: 234-241
        • Shamshirsaz A.A.
        • Fox K.A.
        • Erfani H.
        • Belfort M.A.
        The role of centers of excellence with multidisciplinary teams in the management of abnormal invasive placenta.
        Clin Obstet Gynecol. 2018; 61: 841-850
        • Bailit J.L.
        • Grobman W.A.
        • Rice M.M.
        • et al.
        Morbidly adherent placenta treatments and outcomes.
        Obstet Gynecol. 2015; 125: 683-689
        • Shamshirsaz A.A.
        • Fox K.A.
        • Salmanian B.
        • et al.
        Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach.
        Am J Obstet Gynecol. 2015; 212: 218.e1-218.e9
        • Belfort M.A.
        • Shamshirsaz A.A.
        • Fox K.
        Minimizing blood loss at cesarean-hysterectomy for placenta previa percreta.
        Am J Obstet Gynecol. 2017; 216: 78.e1-78.e2
        • Warshak C.R.
        • Ramos G.A.
        • Eskander R.
        • et al.
        Effect of predelivery diagnosis in 99 consecutive cases of placenta accreta.
        Obstetr Gynecol. 2010; 115: 65-69