Is a 1.8 cm placental venous lake (placental lake) on anatomy ultrasound in pregnancy a concerning finding with normal fetal anatomy and maternal vital signs?

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From the Research

A placental venous lake measuring 1.8 cm on anatomy ultrasound during pregnancy is generally not a concerning finding if everything else appears normal. Placental venous lakes (also called subchorionic lakes or placental lakes) are common variations in placental structure representing areas of maternal blood within the placental tissue. These lakes typically appear as sonolucent (dark) areas on ultrasound. A measurement of 1.8 cm falls within the range of what is considered normal, as studies have shown that placental lakes are usually benign and do not affect pregnancy outcomes when isolated findings are less than 4 cm 1.

The presence of venous lakes is thought to represent normal variations in maternal blood flow within the intervillous spaces of the placenta. No specific treatment or additional monitoring is needed solely for this finding if the remainder of the ultrasound is normal, including normal fetal growth, amniotic fluid levels, and placental position. However, if you notice any concerning symptoms such as vaginal bleeding or decreased fetal movement, you should contact your healthcare provider regardless of this ultrasound finding. It's essential to consider the overall clinical context and other potential risk factors that may impact pregnancy outcomes, as discussed in studies on placental dysfunction and fetal growth restriction 2, 3.

Key points to consider:

  • Placental venous lakes are common and usually benign
  • A measurement of 1.8 cm is within the normal range
  • No additional monitoring is needed if the rest of the ultrasound is normal
  • Concerning symptoms such as vaginal bleeding or decreased fetal movement should be reported to a healthcare provider
  • The presence of venous lakes may represent normal variations in maternal blood flow within the placenta, but other risk factors should be considered in the overall clinical context 1, 2, 3.

References

Research

Presence and Size of Placental Lakes on 20-Week Fetal Anatomy Ultrasound and Obstetrical Outcomes.

Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC, 2024

Research

The Placental Basis of Fetal Growth Restriction.

Obstetrics and gynecology clinics of North America, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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