Placenta Accreta

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Key points

  • Placenta accreta is thought to be becoming more common due to a number of factors including rising maternal age at delivery and an increasing proportion of deliveries by caesarean section.
  • There is a debate about the optimal diagnostic and management techniques.
  • This study will describe the current management of placenta accreta in the UK and associated outcomes for women and their infants. In addition, this study will estimate the national incidence of placenta accreta in the UK and identify the extent to which previous caesarean section and older maternal age are risk factors in this population.

Surveillance Period

May 2010 – April 2011

Background

The presence of placenta accreta/increta/percreta is associated with major pregnancy complications, including life-threatening maternal haemorrhage, uterine rupture[1], peripartum hysterectomy[2] and maternal death[3], as well as complications associated with surgical removal including damage to bladder, ureters and other organs[1]. Placenta accreta is thought to be becoming more common[4][5], due to a number of factors including rising maternal age at delivery and an increasing proportion of deliveries by caesarean section[6][7]. However, the risk associated with these factors has not been quantified on a population basis in the UK.

There is also a debate about the optimal diagnostic and management techniques for placenta accreta. This study will describe the current management of placenta accreta in the UK and associated outcomes for women and their infants. In addition, this study will estimate the national incidence of placenta accreta in the UK and identify the extent to which previous caesarean section and older maternal age are risk factors in this population. This will enable appropriate future service planning, provide accurate information which can be used when counselling women about the risks associated with caesarean section and developing management guidelines, and provide a baseline incidence against which future trends can be monitored if caesarean delivery rates continue to rise nationally.

Objectives

  • To use the UK Obstetric Surveillance System to describe the epidemiology of placenta accreta/percreta/increta in the UK.
  • To quantify the risks attributable to prior delivery by caesarean section.

Research questions

  • What is the current incidence of placenta accreta/increta/percreta in the UK?
  • How is the condition managed in the UK?
  • What proportion of cases are diagnosed antenatally by ultrasound or MRI? What ultrasonographic features are most commonly present and do any of these predict poor outcome?
  • What is the role of previous caesarean section delivery (and number of previous caesarean deliveries) in relation to a) risk of the condition and b) outcome from the condition?
  • What are the outcomes of the condition for women and their babies?
  • Do any factors, including antenatal diagnosis, timing of diagnosis and seniority of operator impact on outcomes?

Case definition

Any pregnant woman in the UK identified as having placenta accreta using the following definition:

EITHER Placenta accreta/increta/percreta diagnosed histologically following hysterectomy or postmortem

OR An abnormally adherent placenta, requiring active management, including conservative approaches where the placenta is left in situ.

EXCLUDED Women who have had a manual placental removal with minimal or moderate difficulty but required no additional active management.

Funding

This study has been funded by the National Institute for Health Research as part of the new UK National Maternal Near-miss Surveillance Programme (UKNeS).

Ethics committee approval

The study has been approved by the North London REC (study ref 10/H0717/20).

Investigators

Marian Knight, Jenny Kurinczuk, Peter Brocklehurst, Maria Quigley, NPEU;

Sue Sellers, United Bristol Hospitals NHS Trust; Mervi Jokinnen, RCM;

Shona Golightly, CMACE; Gwyneth Lewis, Department of Health;

James Walker, NPSA; Alison Burton, Oxfordshire PCT; Jenny Furniss, Lay representative.

Download the Data Collection Form (DCF)

UKOSS Placenta Accreta CASE Form

References

  1. a, b Oyelese Y, Smulian JC. Placenta previa, placenta accreta, and vasa previa. Obstet Gynecol 2006;107(4):927-41.
  2. ^ Knight M. Peripartum hysterectomy in the UK: management and outcomes of the associated haemorrhage. BJOG 2007;114(11):1380-7
  3. ^ Lewis GE, editor. The Confidential Enquiry into Maternal and Child Health (CEMACH). Saving Mothers Lives: reviewing maternal deaths to make childhood safer - 2003-2005. London: CEMACH, 2007.
  4. ^ Khong TY. The pathology of placenta accreta, a worldwide epidemic. J Clin Pathol 2008;61(12):1243-6.
  5. ^ Timmermans S, van Hof AC, Duvekot JJ. Conservative management of abnormally invasive placentation. Obstet Gynecol Surv 2007;62(8):529-39.
  6. ^ Usta IM, Hobeika EM, Musa AA, Gabriel GE, Nassar AH. Placenta previa-accreta: risk factors and complications. Am J Obstet Gynecol 2005;193(3 Pt 2):1045-9.
  7. ^ Angstmann T, Gard G, Harrington T, Ward E, Thomson A, Giles W. Surgical management of placenta accreta: a cohort series and suggested approach. Am J Obstet Gynecol 2009.

Updated: Wednesday, 08 May 2019 14:11 (v4)