Placenta is a disc shaped lobe that develops inside the uterus of a pregnant woman. One side of placenta is attached to the inner wall of uterus. The other surface is attached to the fetus through a tube like structure called umbilical cord. The umbilical cord has two arteries and one vein. Main function of placenta is to provide nutrition and oxygen to the growing fetus from the maternal blood circulation.
An accessory lobe of placenta is an addition separate lobe of placenta. It is a small lobe connected to the main lobe through blood vessels.There can be second or even third accessory lobe attached with the main larger placental lobe. Accessory placenta lobe is detected during routine sonography examination during pregnancy.
As such the additional lobe does not pose any risk to fetal anomaly but there is high risk of post partum hemorrhage. Prenatal monitoring and proper management during labor will help to reduce the risk of hemorrhage.
What Causes Accessory Placental Lobe?
Normally there is one placental lobe attached to the uterine wall during pregnancy. But sometimes an additional or accessory lobe may develop. Chorionic villi are product of conception.They are fine finger like structures that help in development of placenta and provide better surface area for maternal blood circulation to the fetus.
Sometimes few chorionic villi still stay on the uterine surface. This may result in development of another smaller placental lobe. The disc shape of placenta is because few chorionic villi disappear. The disc shape also helps in providing enough space inside the uterus for growing fetus.
Till now researchers are not able to pinpoint any risk factors for developing accessory placenta. This condition is not common and out of 1000 pregnancy only 2 pregnant women are known to develop accessory placenta.
Symptoms Of Accessory Lobe Of Placenta
Accessory placenta is connected to the larger placenta with blood vessels. It does not produce any signs and symptoms. Accessory placenta is detected during routine sonogram examination of pregnancy. It does not pose any risk for development of fetal growth. However, it can increase possibilities of certain complications such as post partum hemorrhage or excessive bleeding from uterus after delivery. This may occur as a result of retention of placenta.
Rupture of vessels that connect main and smaller placenta may cause fetal distress or even bleeding. There is also an increased risk of vasa previa. In vasa previa the blood vessel of fetus can get ruptured. At least 50 percent of vasa previa are due to accessory placenta. Possibility of vasa previa increases in older woman who underwent in-vitro fertilization.
Treatment For Accessory Lobe Of Placenta
Accessory lobe of placenta is also called succenturiate placenta. Its meaning in Latin is to ‘substitute’. Accessory lobe of placenta as such does not need any treatment as it functions normally as the main placental lobe. However, there is an increased risk of retained placenta and post partum hemorrhage.
This may be detrimental for the fetus as well as for the mother. Hence antenatal detection is important as the vessels connecting the two lobes may rupture during delivery. Once detected careful monitoring is required continuously especially during the time of labor.