Succenturiate lobe (SL): 1 or more accessory placental lobes connected by submembranous fetal vessels

2 or more separate placentas

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  Color Doppler shows connecting vessels

Find placental cord insertion

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  Might be on small placenta

  
  
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  Might be velamentous or marginal

Risk for vasa previa if placental tissue in lower uterus

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  Crossing fetal vessels within 2 cm of internal cervical os

Acute placental abruption

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  Isoechoic blood mimics smaller placenta

Focal myometrial contraction

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  Contracted focus of muscle is echogenic

Seen in 5-6% of all pregnancies

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  More common with twins and with in vitro fertilization

↑ risk for retained placenta after delivery

SL with velamentous cord insertion has more complications

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  ↑ risk of growth restriction, ↑ risk for cord trauma

Scan entire uterus before assigning placental location

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  Look for additional placental lobes

  
  
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  If 1 additional lobe seen, look for more

  
  
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  Look for vascular connections between lobes

  
  
  
  
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    Color Doppler to show connections

  
  

Perform TVUS for any case in which any placental tissue or connecting vessels are suspected in lower uterus

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  Rule out vasa previa, low-lying placenta, and placenta previa of SL

  
  
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  Move fetal head to see internal os well