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Female Reproductive System ORGAN SYSTEMS

Morbidly adherent placenta (MAP)

Abnormal plantation or abnormal implantation of the placenta into the uterine wall.

Abnormal plantation or abnormal implantation of the placenta into the uterine wall.

  • M/C extrauterine organ involved: Urinary bladder (associated with a substantial morbidity and mortality of up to 10%)

Classification

  • Placenta accreta: Chorionic villi in contact with myometrium
  • Placenta increta: Chorionic villi invade myometrium
  • Placenta percreta: Chorionic villi penetrate uterine serosa

Aetiology

Risk factors:

Myometrial tissue trauma and scarring are the main predisposing factors resulting in both placenta previa and morbidly adherent placenta
  • Placenta previa (#1 risk factor)
  • Previous caesarean section (#2 risk factor)
  • Multiparity
  • Advanced maternal age
  • Other uterine procedures: Curettage, surgery, etc

Pathophysiology

  • Absent Nitabuch’s layer
  • Absent decidua basalis

Diagnosis

Ultrasonography (USG):

Sonographic markers of placenta accreta can be present as early as the first trimester
  • Low uterine implantation of gestational sac
  • Multiple intraplacental vascular lacunae
  • Loss of normal hypoechoic retroplacental zone
  • Hypervascularity of uterine serosa–bladder interface
Gray‐scale and color Doppler images showing sonographic diagnostic criteria for morbidly adherent placenta. (a) Clear space: loss/irregularity of echolucent area located between uterus and placenta (arrows). (b) Bladder line: thinning or interruption of hyperechoic interface between uterine serosa and bladder wall (arrows). (c,d) Placental lacunae with turbulent high‐velocity flow. | Calì, G., Giambanco, L., Puccio, G. and Forlani, F. (2013), Morbidly adherent placenta: evaluation of ultrasound diagnostic criteria and differentiation of placenta accreta from percreta. Ultrasound Obstet Gynecol, 41: 406-412. doi:10.1002/uog.12385

Colour doppler:

  • Turbulent blood flow extending from the placenta into the surrounding tissues
Three‐dimensional power Doppler used to map intraplacental vascularization and vascularization of uterine serosa–bladder interface. Sagittal sections show neovascularization limited to basal layer in a case of morbidly adherent placenta (MAP) without percreta (a), and extended to entire placental parenchyma in a case of placenta percreta (b). Coronal sections show extent of serosa–bladder wall interface neovascularization involving whole area (d) in placenta percreta, or only a portion (c) in MAP without percreta. | Calì, G., Giambanco, L., Puccio, G. and Forlani, F. (2013), Morbidly adherent placenta: evaluation of ultrasound diagnostic criteria and differentiation of placenta accreta from percreta. Ultrasound Obstet Gynecol, 41: 406-412. doi:10.1002/uog.12385

Management

Elective cesarean section + hysterectomy

Laparotomic image showing anarchic vascularization over the uterine serosa. Placenta percreta was confirmed after pathological examination. | Calì, G., Giambanco, L., Puccio, G. and Forlani, F. (2013), Morbidly adherent placenta: evaluation of ultrasound diagnostic criteria and differentiation of placenta accreta from percreta. Ultrasound Obstet Gynecol, 41: 406-412. doi:10.1002/uog.12385

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