A pregnancy is considered high-risk if either you or your baby has a higher risk of health issues. High-risk pregnancies will require special care from healthcare providers due to a variety of reasons. In high-risk pregnancies, prenatal care becomes crucial as it helps to ensure the pregnancy progresses to term and that both you and the baby are healthy. While having a high-risk pregnancy may sound scary, it is just a way for your healthcare team to ensure you get more attention throughout your pregnancy. Some of the conditions that are considered high-risk include preeclampsia (a condition where the pregnant woman has high blood pressure that leads to damage to organs, protein in urine, and swelling in hands, legs, and feet), obesity, multiple births, pre-existing health issues (underlying heart problems, human immunodeficiency virus (HIV) positive, placental problems, and more.)
What Is Placenta Abruption?
This is a serious issue where part of the placenta is separated from the wall of the uterus. There can be pain, vaginal bleeding, and contractions. It increases the risk of stillbirth, growth problems, and premature birth. Some of the causes of placental abruption are trauma to the abdomen, high blood pressure, smoking, and cocaine use. If you are near term, the baby is usually delivered and a caesarean section (surgery) is recommended. If the baby is not mature enough, you may be kept in the hospital under observation.
What Is Placenta Previa?
Placenta previa is also known as a low-lying placenta. It occurs when the placenta covers part or all of the cervix during pregnancy and can cause bleeding before or during labor. The placenta is like a sac that functions to nourish and nurture the developing baby with the necessary nutrition and oxygen. As the baby grows and stretches the uterus, the placenta moves as well. In normal cases, the placenta attaches at the lower part of the uterus during early pregnancy and by the third trimester, it moves to the top of the uterus allowing a clear path for delivery. In placenta previa, the placenta covers part or all of the cervix during the last few months of pregnancy. Below is a diagram that can hep you visualize better:
The Epidemiology Of Placenta Previa
Placenta previa is seen in 0.5% of all pregnancies in the United States. A population study revealed that it occurs in 2.8 out of every 1000 live births with a 1.5 to 5 times increased risk if there is a history of caesarean delivery. An analysisfound that there is a 1% rate after 1 caesarean delivery, 2.8% after 3 caesarean deliveries, and 3.7% after 5 caesarean deliveries..
What Are The Causes Of Placenta Previa?
The exact cause of placenta previa is unknown. Experts believe that it may be due to multiple factors with contribution from the following risk factors:
- Advance maternal age (more than 35 years old)
- Multiple babies (twins or more)
- Fertility treatment
- Short interval between pregnancies
- Previous injury to the uterus (either surgery, procedures, or injury)
- History of Caesarean delivery
- >History of placenta previa
- Ethnicity (non-white, some experts believe that there is a higher risk of placenta previa in Asian and black women)
- Cocaine use
- Low socioeconomic status
Common Signs And Symptoms Of Placenta Previa
Most patients present with painless vaginal bleeding that resolves spontaneously and occurs again. The bleeding usually occurs in the third trimester and can lead to preterm delivery. If you have vaginal bleeding at any time during your pregnancy, seek medical attention as soon as possible.
Diagnosis Of Placenta Previa
The best way to see if you have a placenta previa is to use an ultrasound to visualize the placenta. An abdominal examination is also useful to rule out other causes of vaginal bleeding such as uterine rupture or placenta abruption. In ideal cases, your doctor would have located the placenta during your routine 18 to 20 weeks ultrasound scan. Women who has placenta previa will require another ultrasonographic evaluation at 32 weeks to plan the best method for delivery.
There are three types of placenta previa:
- Marginal – the placenta touches only the edge of the cervix
- Partial – the placenta partially covers the cervix
- Complete – the cervix is completely covered by the placenta
How To Treat And Manage Placenta Previa
Any episode of bleeding in placenta previa requires a minimum of 48 hours observation in the hospital. If there is vaginal bleeding in the third trimester, your healthcare team will closely monitor both you and your baby’s vital signs. Preparations such as matching your blood type to ensure there is extra blood ready, lab tests to determine your current condition, and starting an intravenous access is done to prepare for emergency delivery and complications. Once you and your baby has been stabilized, they will assess the cause of the vaginal bleeding using an ultrasound and speculum examination. If the baby is less than 36 weeks of gestation, the team will wait and observe your condition. If the baby is less than 34 weeks, betamethasone is given to ensure your baby’s lungs are ready for the outside world should delivery become inevitable. In cases of extreme prematurity and minimal bleeding, tocolytics can be used to delay premature birth. In cases where there is more than one episode of bleeding after 24 weeks, hospitalization may be necessary until delivery as there is a higher risk of placental abruption and demise of the baby. Emergency caesarean delivery is indicated if there is severe bleeding or if the baby is not doing well.
Prognosis Of Placenta Previa
Some of the complications that are associated with placenta previa are:
- Preterm delivery – 16.9% of women deliver their baby less than 34 weeks, 27.5% deliver between weeks 24 to 37.
- Increased likelihood of needing a hysterectomy (surgical removal of the uterus)
- Increased likelihood of needing blood transfusion
- Placental abruption
- Postpartum endometritis
- Increased mortality rate of mother
- Congenital malformations
- Low birth weight
- Neonatal respiratory distress syndrome
- Admission into neonatal intensive care unit (NICU)
- Higher risk of infant neurodevelopmental delay
- Higher risk of sudden infant death syndrome
- Increased neonatal mortality rate
What Do I Do If I Have Placenta Previa?
If you have placenta previa, you should avoid activity to lower the likelihood of bleeding. You should also avoid pelvic examinations and intercourse. Patients who have had a history of placenta previa has a higher likelihood of having it again in future pregnancies and it is important that you inform your doctor about it. It is also beneficial for you to continue your iron and folic acid supplements just in case you have bleeding as it can help maintain your body’s reserve to replenish the blood. You can also reduce your risk by not using cocaine and not smoking. Lower your risk of placenta previa by only having a caesarean section only if necessary. For more information, you can read these articles on “Bleeding During Pregnancy” and “Vaginal Bleeding”.