Placentomegaly
Updates to Article Attributes
Body
was changed:
Placentomegaly is a term applied to an abnormally enlarged placenta.
Pathology
Associations
It can be associated with a number of maternal and fetal disorders which include:
- maternal
- maternal anaemia(s)
- maternal diabetes
- chronic intrauterine infections
- alpha-thalassemia
- fetal
- umbilical vein obstruction
- fetal high output failure
- fetal malformation
- Beckwith-Wiedemann syndrome 1,5
- sacrococcygeal teratoma
- hydrops fetalis and causative underlying conditions
-
chromosomal anomalies
- triploid: with an extra set from paternal origin
- in utero infection 8
- Finnish type congenital nephrotic syndrome 6
- fetomaternal haemorrhage
- placental abnormalities
Radiographic features
Antenatal ultrasound
May show an increase in placental thickness and/or placental extent. The increase in size may be homo or heterogeneous dependent on the cause. The maximum thickness considered normal at any stage in pregnancy is often taken at 4 cm.
Differential diagnosis
The differential for an apparent increased in placental size on ultrasound includes:
- retroplacental haematoma: especially when it is isoechoic, e.g. from a placental abruption
- +<li><a title="Placental mesenchymal dysplasia" href="/articles/placental-mesenchymal-dysplasia">placental mesenchymal dysplasia</a></li>