What does it mean when you have placenta praevia?

It basically means that the site of the placenta within the womb is unusually low and is positioned over the ‘os’ (i.e. it covers the opening of the cervix). This situation definitely requires a C-section delivery, as the placenta is blocking the baby’s exit (he can’t enter into the birth canal). About 15 per cent of mid-pregnancy anatomy scans detect a low-lying placenta, but as the uterus wall enlarges, only about 1 in 200 pregnancies result in a true placenta praevia.