The placenta is the powerhouse of pregnancy. This amazing organ is exclusively created by the body to nourish and sustain the developing baby.
Placenta previa is the blocking of the internal cervical opening by the placenta.
Placenta previa pregnancies require a cesarean section to ensure safe delivery.
Placenta previa greatly increases the risk of hemorrhage, preterm delivery, and placenta accreta.
There is no cure for placenta previa, only medical management to ensure the safest delivery for the mother and baby.
Unfortunately, in a small percentage of pregnancies, the placenta can become the cause of complications that can be dangerous for the mother and baby.
Types of placenta previa
Placenta previa is a condition where the placenta partially or completely covers the cervical opening. This occlusion prevents a safe path for a vaginal birth and increases the risk of dangerous bleeding during pregnancy. It affects approximately 0.3-2% of pregnancies, with increasing rates that can be attributed to the rising rate of cesarean sections.
Placenta previa can be diagnosed early in pregnancy by ultrasound. It may also be discovered if complaints of painless vaginal bleeding occur during the second or third trimester of pregnancy.
There are three types of placenta previa:
- Marginal (low-lying) placenta previa. The placenta lies within two centimeters of the internal cervical opening. Up to 90% of these placentas will resolve or migrate by delivery as the uterus and placenta grow.
- Partial placenta previa. The placenta partially blocks the internal cervical opening.
- Total (complete) placenta previa. The placenta completely blocks the internal cervical opening.
The causes of placenta previa are not fully understood, but several risk factors have been associated with the condition, including the following:
- Being 35 years old or older.
- Having had multiple pregnancies.
- Cocaine use.
- History of curettage, for example, during a surgical abortion.
- History of cesarean sections, endometrial damage, or uterine scarring.
Complications of placenta previa
There are certain complications associated with placenta previa that can impact both, the mother and the developing baby.
For the mother
Placenta previa can increase the risk of the placenta accreta spectrum (PAS). The Placenta accreta spectrum is when the placenta grows into the myometrium — the inner lining of the uterus. The spectrum of placenta accreta describes the depth to which the placenta has invaded the myometrium. As a result, PAS greatly increases the pregnant parent’s risk for life-threatening hemorrhage, hysterectomy, and death. Pregnancies complicated by placenta previa and a history of cesarean have a greatly increased risk of PAS with each additional cesarean section.
Vaginal bleeding due to placenta previa can lead to hemorrhaging and be life-threatening. One study found the rate of postpartum hemorrhage to be 59.7% in placenta previa pregnancies. Maternal hemorrhage can lead to:
- Blood transfusion.
- ICU admission.
- Septicemia (bacterial blood infection).
For the developing baby
Placenta previa greatly increases the risk of preterm delivery. A retrospective study of numerous births found that 3.5% of delivered babies arrived before 28 weeks, 11.7% were delivered before 32 weeks, and 16.1% were delivered before 34 weeks. Preterm deliveries can have several complications for a baby, depending on the gestational age. Unfortunately, placenta previa pregnancies are associated with a three to fourfold increase in infant death. This rate is largely due to the increased risk of early preterm delivery. Thankfully, placenta previa has not been found to impact infant growth. Other risks for the newborn include:
- Low birth rate.
- Low APGAR score (indicating infant well-being).
- Respiratory distress syndrome.
Placenta previa – what to expect during delivery
You will be scheduled for a cesarean section between 36 and 37 weeks if you have placenta previa. However, complications may arise sooner that require an urgent cesarean section regardless of your baby’s gestational age.
Sometimes you could experience vaginal bleeding that, after assessment, may subside. This situation may require continuous fetal monitoring and bed rest in the hospital. In addition, a steroid injection may be given to assist with your baby’s lung maturity should it need to be delivered early.
During your cesarean delivery, your providers and nurses will be prepared for the worst-case scenario. Placenta previa carries a high risk of bleeding or hemorrhage. You will require at least two IVs. The room will be prepped with all the necessary equipment if a blood transfusion is necessary. Additionally, spinal-epidural anesthesia is the recommendation.
Your ability to bond with your newborn baby will depend on your condition and that of your newborn. Your baby’s delivery status depends on the gestational age, the urgency of the cesarean, and the bleeding status.
Placenta previa prevention and treatment
Unfortunately, there is no sure way to prevent placenta previa. While certain risk factors increase your chances of developing placenta previa, they do not guarantee its development. There are a few things that you can do to decrease your risk of bleeding with placenta previa, including:
- Limited activity.
- Intercourse abstinence.
- Avoiding digital examinations.
- No uterine manipulation.
Bleeding during pregnancy can be a common, benign complaint, but sometimes it can mean potentially serious complications for the pregnant parent and baby. It is vital that you report any vaginal bleeding to your healthcare provider so that you can be fully evaluated for any pregnancy-related issues.