Trends, characteristics, and outcomes of placenta accreta spectrum: a national study in the United States

Published:April 20, 2021DOI:


      Although an infrequent occurrence, the placenta can adhere abnormally to the gravid uterus leading to significantly high maternal morbidity and mortality during cesarean delivery. Contemporary national statistics related to a morbidly adherent placenta, referred to as placenta accreta spectrum, are needed.


      This study aimed to examine national trends, characteristics, and perioperative outcomes of women who underwent cesarean delivery for placenta accreta spectrum in the United States.

      Study Design

      This is a population-based retrospective, observational study querying the National Inpatient Sample. The study cohort included women who underwent cesarean delivery from October 2015 to December 2017 and had a diagnosis of placenta accreta spectrum. The main outcome measures were patient characteristics and surgical outcomes related to placenta accreta spectrum assessed by the generalized estimating equation on multivariable analysis. The temporal trend of placenta accreta spectrum was also assessed by linear segmented regression with log transformation.


      Of 2,727,477 cases who underwent cesarean delivery during the study period, 8030 (0.29%) had the diagnosis of placenta accreta spectrum. Placenta accreta was the most common diagnosis (n=6205, 0.23%), followed by percreta (n=1060, 0.04%) and increta (n=765, 0.03%). The number of placenta accreta spectrum cases increased by 2.1% every quarter year from 0.27% to 0.32% (P=.004). On multivariable analysis, (1) patient demographics (older age, tobacco use, recent diagnosis, higher comorbidity, and use of assisted reproductive technology), (2) pregnancy characteristics (placenta previa, previous cesarean delivery, breech presentation, and grand multiparity), and (3) hospital factors (urban teaching center and large bed capacity hospital) represented the independent characteristics related to placenta accreta spectrum (all, P<.05). The median gestational age at cesarean delivery was 36 weeks for placenta accreta and 34 weeks for both placenta increta and percreta vs 39 weeks for non–placenta accreta spectrum cases (P<.001). On multivariable analysis, cesarean delivery complicated by placenta accreta spectrum was associated with increased risk of any surgical morbidities (78.3% vs 10.6%), Centers for Disease Control and Prevention–defined severe maternal morbidity (60.3% vs 3.1%), hemorrhage (54.1% vs 3.9%), coagulopathy (5.3% vs 0.3%), shock (5.0% vs 0.1%), urinary tract injury (8.3% vs 0.2%), and death (0.25% vs 0.01%) compared with cesarean delivery without placenta accreta spectrum. When further analyzed by subtype, cesarean delivery for placenta increta and percreta was associated with higher likelihood of hysterectomy (0.4% for non–placenta accreta spectrum, 45.8% for accreta, 82.4% for increta, 78.3% for percreta; P<.001) and urinary tract injury (0.2% for non–placenta accreta spectrum, 5.2% for accreta, 11.8% for increta, 24.5% for percreta; P<.001). Moreover, women in the placenta increta and percreta groups had markedly increased risks of surgical mortality compared with those without placenta accreta spectrum (increta, odds ratio, 19.9; and percreta, odds ratio, 32.1).


      Patient characteristics and outcomes differ across the placenta accreta spectrum subtypes, and women with placenta increta and percreta have considerably high surgical morbidity and mortality risks. Notably, 1 in 313 women undergoing cesarean delivery had a diagnosis of placenta accreta spectrum by the end of 2017, and the incidence seems to be higher than reported in previous studies.

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        • Burton G.J.
        • Jauniaux E.
        What is the placenta?.
        Am J Obstet Gynecol. 2015; 213 (S6.e1, S6–8)
        • Silver R.M.
        • Branch D.W.
        Placenta accreta spectrum.
        N Engl J Med. 2018; 378: 1529-1536
        • Cahill A.G.
        • et al.
        • Society of Gynecologic Oncology, American College of Obstetricians and Gynecologists and the Society for Maternal–Fetal Medicine
        Placenta accreta spectrum.
        Am J Obstet Gynecol. 2018; 219: B2-B16
        • Jauniaux E.
        • Hussein A.M.
        • Zosmer N.
        • et al.
        A new methodologic approach for clinico-pathologic correlations in invasive placenta previa accreta.
        Am J Obstet Gynecol. 2020; 222: 379.e1-379.e11
        • Matsuzaki S.
        • Yoshino K.
        • Endo M.
        • Kakigano A.
        • Takiuchi T.
        • Kimura T.
        Conservative management of placenta percreta.
        Int J Gynaecol Obstet. 2018; 140: 299-306
        • Sentilhes L.
        • Goffinet F.
        • Kayem G.
        Management of placenta accreta.
        Acta Obstet Gynecol Scand. 2013; 92: 1125-1134
        • Licon E.
        • Matsuzaki S.
        • Opara K.N.
        • et al.
        Implementation of multidisciplinary practice change to improve outcomes for women with placenta accreta spectrum.
        Eur J Obstet Gynecol Reprod Biol. 2020; 246: 194-196
        • American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine
        Obstetric Care Consensus No. 7: placenta accreta spectrum.
        Obstet Gynecol. 2018; 132: e259-e275
        • Jauniaux E.
        • Alfirevic Z.
        • Bhide A.G.
        • et al.
        Placenta praevia and placenta accreta: diagnosis and management: Green-Top Guideline No. 27a.
        BJOG. 2019; 126: e1-e48
        • O’Brien J.M.
        • Barton J.R.
        • Donaldson E.S.
        The management of placenta percreta: conservative and operative strategies.
        Am J Obstet Gynecol. 1996; 175: 1632-1638
        • Read J.A.
        • Cotton D.B.
        • Miller F.C.
        Placenta accreta: changing clinical aspects and outcome.
        Obstet Gynecol. 1980; 56: 31-34
        • Miller D.A.
        • Chollet J.A.
        • Goodwin T.M.
        Clinical risk factors for placenta previa-placenta accreta.
        Am J Obstet Gynecol. 1997; 177: 210-214
        • Wu S.
        • Kocherginsky M.
        • Hibbard J.U.
        Abnormal placentation: twenty-year analysis.
        Am J Obstet Gynecol. 2005; 192: 1458-1461
        • Bailit J.L.
        • Grobman W.A.
        • Rice M.M.
        • et al.
        Morbidly adherent placenta treatments and outcomes.
        Obstet Gynecol. 2015; 125: 683-689
        • Creanga A.A.
        • Bateman B.T.
        • Butwick A.J.
        • et al.
        Morbidity associated with cesarean delivery in the United States: is placenta accreta an increasingly important contributor?.
        Am J Obstet Gynecol. 2015; 213: 384.e1-384.e11
        • Thurn L.
        • Lindqvist P.G.
        • Jakobsson M.
        • 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
        • Klar M.
        • Michels K.B.
        Cesarean section and placental disorders in subsequent pregnancies--a meta-analysis.
        J Perinat Med. 2014; 42: 571-583
        • Thurn L.
        • Wikman A.
        • Westgren M.
        • Lindqvist P.G.
        Massive blood transfusion in relation to delivery: incidence, trends and risk factors: a population-based cohort study.
        BJOG. 2019; 126: 1577-1586
        • Marcellin L.
        • Delorme P.
        • Bonnet M.P.
        • et al.
        Placenta percreta is associated with more frequent severe maternal morbidity than placenta accreta.
        Am J Obstet Gynecol. 2018; 219: 193.e1-193.e9
        • Agency for Healthcare Research and Quality
        Overview of the National (Nationwide) impatient sample (NIS). 2001–2015.
        (Available at:)
        Date accessed: December 27, 2020
        • Soni A.F.
        • Fingar K.R.
        • Reid L.D.
        Obstetric delivery inpatient stays involving substance use disorders and related clinical outcomes, 2016.
        (Available at:) (Accessed December 27, 2020)
        • Charlson M.E.
        • Pompei P.
        • Ales K.L.
        • MacKenzie C.R.
        A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
        J Chronic Dis. 1987; 40: 373-383
        • Centers for Disease Control and Prevention
        Defining adult overweight and obesity.
        (Available at:)
        Date accessed: December 27, 2020
        • Agency for Healthcare Research and Quality
        NIS description of data elements. Healthcare Cost and Utilization Project.
        (Available at:)
        • Mandelbaum R.S.
        • Smith M.B.
        • Violette C.J.
        • et al.
        Conservative surgery for ovarian torsion in young women: perioperative complications and national trends.
        BJOG. 2020; 127: 957-965
        • Matsuo K.
        • Mandelbaum R.S.
        • Nusbaum D.J.
        • et al.
        National trends and outcomes of morbidly obese women who underwent inpatient hysterectomy for benign gynecological disease in the USA.
        Acta Obstet Gynecol Scand. 2021; 100: 459-470
        • Centers for Disease Control and Prevention
        How does CDC identify severe maternal morbidity?.
        (Available at:)
        • National Cancer Institute
        Joinpoint trend analysis software.
        (Available at:)
        Date: 2000
        Date accessed: December 27, 2020
        • Kim H.J.
        • Fay M.P.
        • Feuer E.J.
        • Midthune D.N.
        Permutation tests for joinpoint regression with applications to cancer rates.
        Stat Med. 2000; 19: 335-351
        • Zeger S.L.
        • Liang K.Y.
        • Albert P.S.
        Models for longitudinal data: a generalized estimating equation approach.
        Biometrics. 1988; 44: 1049-1060
        • Greenland S.
        • Daniel R.
        • Pearce N.
        Outcome modelling strategies in epidemiology: traditional methods and basic alternatives.
        Int J Epidemiol. 2016; 45: 565-575
        • Pavlou M.
        • Ambler G.
        • Seaman S.
        • De Iorio M.
        • Omar R.Z.
        Review and evaluation of penalised regression methods for risk prediction in low-dimensional data with few events.
        Stat Med. 2016; 35: 1159-1177
        • Mandelbaum R.S.
        • Adams C.L.
        • Yoshihara K.
        • et al.
        The rapid adoption of opportunistic salpingectomy at the time of hysterectomy for benign gynecologic disease in the United States.
        Am J Obstet Gynecol. 2020; 223: 721.e1-721.e18
        • von Elm E.
        • Altman D.G.
        • Egger M.
        • et al.
        Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies.
        BMJ. 2007; 335: 806-808
        • Baldwin H.J.
        • Patterson J.A.
        • Nippita T.A.
        • et al.
        Maternal and neonatal outcomes following abnormally invasive placenta: a population-based record linkage study.
        Acta Obstet Gynecol Scand. 2017; 96: 1373-1381
        • Martin J.A.
        • Hamilton B.E.
        • Osterman M.J.K.
        • Driscoll A.K.
        Births: final data for 2018.
        Natl Vital Stat Rep. 2019; 68: 1-47
        • Jauniaux E.
        • Ayres-de-Campos D.
        • Langhoff-Roos J.
        • Fox K.A.
        • Collins S.
        • FIGO Placenta Accreta Diagnosis and Management Expert Consensus Panel
        FIGO classification for the clinical diagnosis of placenta accreta spectrum disorders.
        Int J Gynaecol Obstet. 2019; 146: 20-24
        • Einerson B.D.
        • Comstock J.
        • Silver R.M.
        • Branch D.W.
        • Woodward P.J.
        • Kennedy A.
        Placenta accreta spectrum disorder: uterine dehiscence, not placental invasion.
        Obstet Gynecol. 2020; 135: 1104-1111
        • Kyozuka H.
        • Yamaguchi A.
        • Suzuki D.
        • et al.
        Risk factors for placenta accreta spectrum: findings from the Japan environment and children’s study.
        BMC Pregnancy Childbirth. 2019; 19: 447
        • Belfort M.A.
        • Publications Committee, Society for Maternal-Fetal Medicine
        Placenta accreta.
        Am J Obstet Gynecol. 2010; 203: 430-439
        • Kaser D.J.
        • Melamed A.
        • Bormann C.L.
        • et al.
        Cryopreserved embryo transfer is an independent risk factor for placenta accreta.
        Fertil Steril. 2015; 103: 1176-1184.e2
        • Iacovelli A.
        • Liberati M.
        • Khalil A.
        • et al.
        Risk factors for abnormally invasive placenta: a systematic review and meta-analysis.
        J Matern Fetal Neonatal Med. 2020; 33: 471-481
        • Sunderam S.
        • Kissin D.M.
        • Crawford S.B.
        • et al.
        Assisted reproductive technology surveillance—United States, 2015.
        (Available at:)
        Date: 2018
        Date accessed: December 27, 2020
        • Miller H.E.
        • Leonard S.A.
        • Fox K.A.
        • Carusi D.A.
        • Lyell D.J.
        Placenta accreta spectrum among women with twin gestations.
        Obstet Gynecol. 2021; 137: 132-138
        • 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
        • 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
        • Clark S.L.
        • Belfort M.A.
        • Dildy G.A.
        • Herbst M.A.
        • Meyers J.A.
        • Hankins G.D.
        Maternal death in the 21st century: causes, prevention, and relationship to cesarean delivery.
        Am J Obstet Gynecol. 2008; 199: 36.e1-36.e5
        • US Department of Health & Human Services, National Institutes of Health
        NIH Consensus Development Conference on vaginal birth after cesarean: new insights.
        (Available at:)
        Date: 2010
        Date accessed: January 1, 2021
        • Kingdom J.C.
        • Hobson S.R.
        • Murji A.
        • et al.
        Minimizing surgical blood loss at cesarean hysterectomy for placenta previa with evidence of placenta increta or placenta percreta: the state of play in 2020.
        Am J Obstet Gynecol. 2020; 223: 322-329
        • Carusi D.A.
        • Fox K.A.
        • Lyell D.J.
        • et al.
        Placenta accreta spectrum without placenta previa.
        Obstet Gynecol. 2020; 136: 458-465
        • Buca D.
        • Liberati M.
        • Calì G.
        • et al.
        Influence of prenatal diagnosis of abnormally invasive placenta on maternal outcome: systematic review and meta-analysis.
        Ultrasound Obstet Gynecol. 2018; 52: 304-309
        • Jotwani A.R.
        • Leonard S.A.
        • Butwick A.
        • Lyell D.J.
        Positive predictive value of ICD-10 codes for placenta accreta syndrome: a single center validation study.
        Am J Obstet Gynecol. 2021; 224: S523-S524
        • Couret M.
        • Huang Y.
        • Khoury-Collado F.
        • et al.
        Patterns of care for women with placenta accreta spectrum.
        J Matern Fetal Neonatal Med. 2019; ([Epub ahead of print])
        • Tong V.T.
        • Dietz P.M.
        • Morrow B.
        • et al.
        Trends in smoking before, during, and after pregnancy—pregnancy risk assessment monitoring system, United States, 40 sites, 2000–2010.
        (Available at:)
        Date: 2013
        Date accessed: January 6, 2021
        • Erfani H.
        • Fox K.A.
        • Clark S.L.
        • et al.
        Maternal outcomes in unexpected placenta accreta spectrum disorders: single-center experience with a multidisciplinary team.
        Am J Obstet Gynecol. 2019; 221: 337.e1-337.e5
        • Silver R.M.
        • Fox K.A.
        • Barton J.R.
        • et al.
        Center of excellence for placenta accreta.
        Am J Obstet Gynecol. 2015; 212: 561-568