Placenta previa and baby
one in 200 pregnancies at term are complicated by placenta previa where the placenta is implanted in the lower segment of the uterus and lies in front of the presenting part of the baby. If the placenta is completely covers the internal part of the cervix, the cervical os, the only option for delivery is C-section. In minor degrees of previa where the baby's head is able to descent past the lower edge of the placenta, a vaginal birth may be possible.
It is common for the placenta to be low-lying at the 20 week scan. However, by 32 weeks, the lower segment of the uterus has started to extend downward and previously low-lying placentas now appear to be placed higher in the uterus.
Placenta previa is responsible for 20 percent of cases of antepartum hemorrhage and is more common in multiparous women. The bleeding is painless, usually recurrent, and can be very severe.
The exact cause of placenta previa is unknown. However, the following can increase your risk:
If over the age of 35
Had more than four pregnancies
Have a history of uterine surgery (regardless of incision type)
Once diagnosed, placenta previa will usually require bed rest for the mother and frequent hospital visits. Depending on the gestational age, steroid shots may be given to help mature the baby’s lungs. If the bleeding cannot be controlled, an immediate cesarean delivery is usually done regardless of the length of the pregnancy.