The placenta is a vital organ that develops in the uterus during pregnancy. It nourishes and protects your baby. It is usually attached to the top or side of the uterus by the umbilical cord. But sometimes, it is attached to the lower part of the uterus, resulting in a pregnancy complication known as placenta previa or low-lying placenta.
Here, MomJunction tells you what placenta previa is, how it affects your pregnancy, and how to rectify or manage it for a healthy and safe delivery.
What Is Placenta Previa?
Placenta previa is a pregnancy complication that occurs when the placenta lies low in the uterus and covers a part, or the entire cervix, which is the opening to the birth canal (1).
Placenta previa occurs in one out of 200 pregnancies (2). The condition is not a concern if it happens in the early stages of pregnancy. But if it occurs during labor and delivery, it could lead to complications that can harm both the mom and the baby.
What Are The Types of Placenta Previa?
- Marginal previa, where the placenta borders the cervix
- Partial previa, where the placenta covers only a part of the cervical opening
- Complete previa, where the placenta covers the cervix entirely
The condition can be further classified into anterior and posterior placenta previa, which refers to the exact placental position within the uterus. It can be defined through an ultrasound scan (3) (4).
What Are The Causes Of Placenta Previa?
The actual cause of placenta previa is unknown. But some factors can increase the likelihood of this condition (5).
Risk factors that increase the chances of a low-lying placenta include:
- Previous surgeries of the uterus, such as a C-section, D&C (dilation and curettage) or uterine fibroid removal
- Second or subsequent pregnancy
- Advanced maternal age
- Carrying twins, triplets or more
However with most cases, sometimes there are no risk factors.
These risks cannot be controlled. Others that can be controlled to prevent placenta previa include:
- Cocaine consumption
Knowing the symptoms of this condition could help in an early diagnosis.
What Are The Symptoms and Signs Of Placenta Previa?
The signs and symptoms of placenta previa differ from one pregnant woman to another. While some do not experience any symptoms, others show warning signs such as (6):
- Sudden onset of painless, bright red vaginal bleeding that can range from light to heavy.
- Early labor symptoms such as regular contractions, pain in the belly, or lower back.
You must call your doctor immediately if you notice vaginal bleeding during your pregnancy, irrespective of the trimester.
If you do not experience any symptoms, your doctor may be able to identify a placenta previa during your regular prenatal ultrasound scans.
How Is Placenta Previa Diagnosed?
Placenta previa is diagnosed by ultrasound. Most cases are detected during the second-trimester checkup when you have a routine ultrasound test. The diagnostic tests include (7):
- Ultrasound scan
- A combination of abdominal and transvaginal ultrasounds, in some cases
If your doctor detects placenta previa, there will be activity restrictions placed.
Here are some questions your doctor may ask to confirm the diagnosis:
- When did you first notice vaginal bleeding?
- Was the bleeding only once, or was it recurring?
- Do you have any pain or contractions?
- Is the bleeding heavy?
- Did you undergo any surgeries such as fibroid removal, cesarean, D&C, or abortion?
- Is this your first pregnancy?
- How long does it take to reach the hospital in case of an emergency?
- Do you smoke?
- Is there anyone who can accompany you when required?
If the diagnosis is confirmed, you can ask your doctor these questions:
- Is there a chance of the condition resolving on its own?
- How do I take care of myself?
- How can I manage the bleeding?
- What symptoms should prompt me to go to the hospital?
- When should I revisit the hospital?
- Will a placenta previa increase the chances of complications in future pregnancies?
- Can I deliver vaginally?
In addition to this, your doctor may also give you care instructions and precautions to take when you have a placenta previa.
How Is Placenta Previa Treated?
Management and treatment depend on some factors:
- The health of the mother and the baby
- The position of the baby
- The location of the placenta
- The amount of blood loss
- The gestational age of the baby
- The type of placenta previa
If you are diagnosed with placenta previa before the 20th week of pregnancy, it is likely to resolve. The placental position can change with the growing uterus and can move away from the cervix.
If it does not resolve or placenta previa is diagnosed in the later stages of pregnancy, your doctor will most likely suggest a C-section. If a previa is detected on your 18-20 week ultrasound, a follow-up ultrasound is usually recommended around 28 weeks, and if still present, around 32-34 weeks.
What To Do When
You are not bleeding or bleeding lightly
- Be prepared to go to the hospital if bleeding turns heavy or resumes.
- If the placenta is placed low but is not covering the cervix, your doctor may suggest a vaginal delivery.
You are bleeding heavily
- Go to the doctor immediately as blood transfusion may be necessary in the case of severe bleeding.
- The doctor prescribes steroids if you are not nearing the due date, or haven’t reached the 37th week, to prepare the baby by speeding up the development of his or her lungs.
- The OB/GYN will plan a cesarean if you are past the 36th week.
Your bleeding does not stop
- Emergency cesarean, even if you are not nearing the due date.
These are situations when you need to visit the doctor immediately, to prevent any harm to you or your baby.
Precautions For Low-Lying Placenta
These precautions help you avoid further complications caused by a low-lying placenta (1).
- Avoid strenuous activities, such as intense cardio exercise or lifting weights
- Avoid sexual intercourse
- Take bed rest
Precautions are important because placenta previa can lead to some serious complications.
What Are The Complications Of Placenta Previa?
Some possible complications of placenta previa include (4):
- Hemorrhage (heavy bleeding)
- Fetal distress from lack of sufficient oxygen
- Premature birth that is before the 37th week of pregnancy
- Birth defects
- Slowed baby growth
- Health risks to the baby
- Emergency C-section
- Hysterectomy, when the placenta fails to deliver from the uterine lining
- Placenta accreta, where the placenta attaches deep into the uterine wall and mandates a hysterectomy at the time of delivery
While you cannot correct a low-lying placenta, you can manage the condition. Next, we’ll tell you how.
How To Cope With Placenta Previa?
Here is how you can do it:
- Learn everything about the condition: Having clarity about the condition eliminates unwanted doubts, fears, and anxiety. Talk to your doctor or connect with others (you can find in support groups) who have the same condition.
- Prepare for cesarean section: Placenta previa makes vaginal delivery impossible and dangerous. Therefore, a cesarean delivery will become necessary for your baby’s and your well-being.
- Rest: You may not like the idea of bed rest, but you need it at this time. Use the free time to pursue a hobby or read about baby care and shop online.
How To Prevent Placenta Previa?
There is no way to prevent placenta previa since there is no particular cause for it.
However, if the risks for you are high owing to your age, prior surgeries, or previous pregnancies, try to be extra careful and maintain a healthy lifestyle. Most importantly, stay away from cigarette smoking and cocaine consumption as they are associated with the condition.
Next, we answer a few commonly asked questions about placenta previa.
Frequently Asked Questions
1. Is placenta previa genetic (hereditary)?
No, placenta previa is an obstetric complication and not a genetic condition (1).
2. Can I fly with a low-lying placenta?
Avoid flying to avoid bleeding while in flight travel.
Placenta previa could be a stressful diagnosis, which could fill you with fear and anxiety until delivery. However the good news is that it can be managed for a smooth delivery without complications.
Do you have any experiences to share? Please tell us about them in the comments section below.
2. Mabie WC; Placenta previa; Department of Obstetrics and Gynecology, University of Tennessee, Memphis.
3. Shumaila Zia; Placental location and pregnancy outcome; J Turkish-German Gynecol Assoc 2013
4. Frances M. Anderson-Bagga and Angelica Sze.; Placenta Previa
5. Placenta Previa; The University of Rochester Medical Center
6. Robert K. Stoelting, et al.; Placenta Previa; Stoelting’s Anesthesia and Co-existing Disease
7. Bleeding in Pregnancy/Placenta Previa/Placental Abruption; The Children’s Hospital of Philadelphia
8. Placenta Previa; Stanford Children’s Health
9. Heller HT, et al.; Outcomes of pregnancies with a low-lying placenta diagnosed on second-trimester sonography
10 .Bob Flaws; Chinese Medical Obstetrics