Placenta previa is a pregnancy problem in which placenta grows in the lower part of the cervix causing a complete or partial obstruction of its opening.
The main symptom is sudden painless vaginal bleeding. It is detected by ultrasound, which shows the position of the placenta.
It is convenient to have an exhaustive ultrasound control in these cases in order to avoid premature birth.
Sometimes it may be necessary to perform an emergency caesarean section.