Do placental lakes increase the risk of postpartum hemorrhage (PPH) at the time of delivery?

From the Guidelines

Placental lakes are associated with an increased risk of postpartum hemorrhage (PPH) at the time of delivery.

Key Risk Factors

• The risk of severe and even life-threatening hemorrhage is greatest at the time of delivery when a portion of the placenta does not separate in the usual fashion 1.
• Placenta accreta spectrum disorder (PASD) is a significant risk factor for PPH, and placental lakes may be a sign of underlying PASD 1.
• Other risk factors for PPH include prior cesarean delivery, placenta previa, advanced maternal age, and high gravidity or parity 1.

Management Strategies

• As a precautionary measure, it is recommended to have blood products readily available and to consider administering uterotonic medications, such as oxytocin 10-20 units intravenously, to help minimize the risk of excessive bleeding.
• Close monitoring of the patient's vital signs and bleeding is essential during and after delivery.
• Accurate antenatal diagnosis and planning for an appropriate delivery strategy at an experienced center can help reduce maternal morbidity 1.

Delivery Planning

• The American Congress of Obstetricians and Gynecologists (ACOG) and FIGO recommend planned cesarean delivery with or without hysterectomy depending on the suspected severity of PASD around 34 to 38 weeks 1.
• A contingency plan for emergent delivery should be in place, and obtaining radiologic and clinical data when PASD is first suspected can play a significant role in formulating an appropriate delivery strategy and contingency plan 1.

From the Research

Placental Lakes and Postpartum Hemorrhage

• There is no direct evidence in the provided studies that specifically addresses the relationship between placental lakes and the risk of postpartum hemorrhage (PPH) at the time of delivery.
• However, the studies do discuss the risk of PPH in relation to other placental conditions, such as placenta previa, low-lying placenta, and placenta accreta spectrum 2, 3, 4, 5, 6.
• Placenta previa and low-lying placenta have been associated with an increased risk of PPH, with one study finding that women with resolved previa or low-lying placenta were 2.5 times more likely to experience PPH 3.
• Placenta accreta spectrum, which includes conditions such as placenta increta and percreta, has also been identified as a key independent risk factor for severe postpartum hemorrhage (SPPH) in women with placenta previa or low-lying placenta 5, 6.

Risk Factors for Postpartum Hemorrhage

• The studies identify several risk factors for PPH and SPPH, including:
  • Placenta accreta spectrum, particularly placenta increta and percreta 5, 6
  • Lower hemoglobin levels 6
  • Higher D-dimer levels 6
  • Anterior placental location 4
  • Previous cesarean section delivery 4
  • Increta or percreta placenta 5

Implications for Clinical Practice

• The findings of these studies suggest that women with placental conditions such as placenta previa, low-lying placenta, and placenta accreta spectrum are at an increased risk of PPH and SPPH, and may require closer monitoring and management during pregnancy and delivery 2, 3, 4, 5, 6.
• Clinicians should consider these risk factors when counseling patients and performing hemorrhage risk stratification 3.