Placenta Previa (Low-Lying Placenta)

The placenta is a sac-like organ in the uterus which provides food and oxygen to the fetus by removing the waste products from the blood. When it covers the cervix in the last trimester causing bleeding before or after the labor, it is known as Placenta Previa or low-lying placenta.

A placenta lies in the lower section of the uterus during early pregnancy, but as the uterus stretches because of the growing fetus, it moves upwards. By the third trimester, it reaches the top of the womb allowing the cervix a clear way for the delivery. If the placenta attaches to the lower part of the uterus, it can cover the cervix during the last trimester and is known as Placenta Previa requiring complete bed rest. The placenta serves many purposes including:

  • Produces hormones promoting the growth of the fetus
  • Protects against the bacterial infections
  • Provides nutrients and oxygen to the baby

Symptoms

The typical symptom include light to heavy vaginal bleeding but if the following situation arises, consult a doctor immediately:

  • Bleeding during the second half period
  • Sharp pains or cramps
  • Bleeding after sex
  • Frequent bleeding a week later

Types

  • Partial: Covers the cervix partially with the possibility of the vaginal birth.
  • Low-lying: The placenta lies at the edge of the cervix in mid-trimester with a chance of vaginal delivery.
  • Marginal: It grows at the bottom of the uterus pushing the cervix but does not cover it causing minor bleeding, however, vaginal births are safe.
  • Major: A severe type where it covers the entire cervix resulting in C-sections and premature deliveries.

Note: All types may require an emergency C-section if it causes heavy bleeding.  

Risk Factors

  • Breech baby (Unusual position of the fetus across the womb)
  • A history of miscarriage
  • Large placenta
  • Multiple pregnancies
  • Abnormal shape of the uterus
  • Any prior diagnosis of Placenta Previa
  • Are Asian
  • A smoker
  • Are older than 35
  • Already had one child
  • Use of cocaine

Diagnosis

Generally, the first signs are visible during the 20-week ultrasound scan which is not a cause of worry as the placenta is low in the first trimester. According to the Royal College of Obstetrician and Gynecologists, only 10% of the cases suffer from it. If  a woman experiences any bleeding in the second half, these methods may be preferred:

  • Transvaginal ultrasound: A probe is placed inside the vagina to see the canal and cervix to determine the condition.
  • MRI: Magnetic Resonance Imaging will determine the location of the placenta
  • Abdominal Ultrasound Scans: Detects whether the placenta is blocking the uterus from opening into the cervix
  • A Doppler Ultrasound: Used in cases of Placenta Accreta

Complications

During labor, the cervix opens allowing the fetus to move into the vaginal canal for the delivery. If the placenta stays in front of the uterus, it causes the internal bleeding due to the stretching requiring an immediate C-section early as the mother can die. Vaginal birth is risky as it may result in severe hemorrhaging during or after the first few hours of the delivery.

Potential Complications to the Mother

Hysterectomy

After the cesarean delivery one may have scar tissue on the uterine walls which increases the risk of Placenta Accrete, Placenta Increta & Placenta Percreta. These conditions are examined using computerized tomography (CT) or MRI scans involving a Hysterectomy as it cannot detach from the womb.

Heavy Bleeding

Requires a blood transfusion

Placental Abruption

The placenta separates from the wall of the uterus developing severe blood loss. Severe cases can cause shock while increasing the risk of death.

Postpartum Endometritis

It is the infection on the lining of the uterus

Potential Complications for the Baby

  • Blood loss
  • Low birth weight
  • Jaundice
  • Congenital malformation
  • Fetal Anemia
  • A more extended stay in the hospital
  • Death
  • SIDS (Sudden Infant Death Syndrome)

What if I have it during the Third Trimester?

Complete bed rest in addition to avoiding sexual intercourse is a solution if one has it during this period. The patient may need to spend the last few days before the delivery at the hospital if suffering from heavy bleeding or cesarean section. Medical, as well as the home-based care, may be required. If the cervical opening is less than 2cm, the obstetrician may need a c-section to stop the massive bleeding.

Treatment

The treatment will depend on the:

  • Amount of bleeding
  • Position of the placenta
  • Trimester
  • Health of the baby
  1. Less or no Bleeding: In case of minimal to no bleeding, the doctor would suggest complete bed rest beside avoiding exercises and sexual intercourse.
  2. Heavy Bleeding: May require a blood transfusion and medications to prevent early delivery. In some cases, a c-section after 36 weeks may be scheduled, and the patient may need corticosteroid injections to promote the growth of the lungs.
  3. Uncontrollable Bleeding: Needs an emergency cesarean delivery.

Prevention

  • Eat a nutritious diet that includes iron-rich foods such as leafy vegetables, red meat, and pulses.
  • A good prenatal care

Managing It

It requires complete medical care which will depend on the bleeding while watching for the position of the placenta. The doctor may recommend scans from 32 weeks if:

  • Experiencing heavy bleeding
  • Having a major Placenta Previa
  • Risk of other complications requiring cesarean after 32 weeks.

If the condition is critical, the patient may stay longer in the hospital starting 34 weeks of pregnancy. Other states like placenta accrete a planned cesarean between the 36 and 37 weeks is helpful. One may need steroids for the baby’s lungs if the symptoms go severe.

Coping with It

  • Education: Get in touch with the mothers having a history of Placenta Previa.
  • Bed rest: Taking complete bed rest and working on projects like writing letters, putting a photo album, and reading about lifestyle changes can prevent such a condition.
  • Be ready for Cesarean delivery: Depending on the type, a woman may need a c-section which is often healthy for both the fetus and the mother.
  • Pampering: Indulge in activities like watching your favorite programs, buying new clothes, reading a book and do everything that offers comfort and support.

How Common is it?

About 6% of women experience a low-lying placenta before the 20th week while approximately 10% of these cases remain in the third trimester. The placenta stays in the lower uterus blocking the cervical openings in 1 out of 200 pregnancies.

Chances of Recurrence

Women with a history of placenta previa have 2-3% of chances of reoccurrence in the future pregnancies.

Prognosis

Women suffering from it do not suffer from any problems in the future as the placenta rises higher into the uterus staying away from the cervix. But those who might have it in the third trimester may face a preterm delivery.

Placenta Previa v/s Placental Abruption (Abruptio Placentae)

Placental abruption occurs when the placenta detaches itself from the implantation site within the uterus causing bleeding and other severe complications. It may also happen with a placenta previa thereby needing a diagnosis through an ultrasound scan for the confirmation.

Facts

  • Happens when the placenta develops low down in the uterus.
  • Most cases occur during the daily ultrasound in the second trimester.
  • Most women with it in the early trimester have no problems later as it stays away from the cervix.
  • In some cases, the placenta remains low in the third trimester calling for a cesarean to prevent the complications.
  • One should eat iron-rich foods to reduce the risk of Anemia.
  • The examination may require a Speculum (A plastic instrument to separate the walls of the vagina) to see the origin of the bleeding.

ICD-9 & ICD-10 Codes

  • ICD-9 code is 641.03
  • ICD-10 code is O44.03

References

Be the first to comment

Leave a Reply

Your email address will not be published.


*


This site uses Akismet to reduce spam. Learn how your comment data is processed.