How is it managed?
Further bleeding
In most pregnancies, the placenta implants high in the top of the uterus (called the upper segment or 'fundus'). Occasionally, (in 0.5% of pregnancies) part of the placenta (or all of it) will implant in the lower segment of the uterus. The lower segment is the part of the uterus that absorbs the cervix as it dilates during labour.
Image 1-05 and Image 4-40 show the positions of the placenta lying in a normal position and low lying.
This is known as placenta previa, meaning 'placenta first' and depending on the severity (or 'grading'), the placenta can be situated close to, or actually cover the cervix. More severe cases of placenta previa are prone to bleed heavily during labour, and if the placenta fully covers the cervix, will prevent the baby from being able to be born. Placenta previa is covered in more depth in
bleeding during late pregnancy.
Most placenta previa's are known to be present before the labour begins, because the woman has experienced some bright, painless, bleeding in the last 3 months of her pregnancy. This bleeding is normally investigated with an ultrasound, showing the placenta to be low. In this case, the woman and her caregiver are well aware that heavy bleeding could be a problem if planning a vaginal birth.
Occasionally, you may not be aware that you have placenta previa before the labour, especially if the baby is premature, have not experienced any bleeding late in the pregnancy. In this case, your caregiver will suspect it if you start to bleed more heavily than normal during labour.