In this kind of an ailment, issues occur when the placenta previa should have moved itself away from the uterus as the level pregnancy has increased
. However, sometimes, this movement does not happen and the placenta continues to exist near the uterus. Most of the women in their 10-20 weeks gestation term have placenta near uterus but it goes away as the time period elapses. However, the existence of this placenta after 20 weeks indicates an anomaly. Some factors also require females to have a larger placenta size because of its increased functions. For example, the female may reside at greater heights due to which the availability of oxygen for the fetus is low. Therefore, there is an increase in size of placenta.