Placenta previa or low-lying placenta is a complication in pregnancy in which the placenta develops in the lower part of the uterus. The placenta may partially (partial placenta previa) or completely (major placenta previa) cover the opening of cervix. This condition is usually noted around 20 weeks of pregnancy. In some pregnant women, this low-lying placenta may be pulled upwards as the fetus grows. It is seen in one out of 200 pregnancies during the third trimester.
The actual cause of placenta previa is not known. A number of risk factors are found to influence the attachment of fetus lower in the uterus.
The major risk factors that increase the chances of low-lying placenta include
- History of Cesarean section
- Age above 35 years
Painless bleeding in the third trimester is the most common symptom of placenta previa. Premature contractions, breech position of the baby, and a uterus larger for the gestational age may also indicate placenta previa. It is usually identified during one of the mid-pregnancy ultrasound scans.
In most of the cases, watchful waiting is the best option available for this condition. In many cases, the placenta may be pulled upward during the later stages of pregnancy. If bleeding was mild, you may be allowed to monitor the condition from home. Do have some help a home and to take you to the hospital, if needed. You may be suggested a planned cesarean section sometime in between 37–38 weeks of pregnancy. If you had a substantial amount of bleeding during the earlier stages, you may be recommended a cesarean section much before the normal time. If you have heavy bleeding and premature labor, emergency cesarean section may be suggested.
Those who are diagnosed with placenta previa may be asked to avoid intercourse and pelvic exams for the rest of pregnancy. One should also limit travel during this period.