Placenta Accreta

Did you know that only 1 out of 2,500 pregnancies are affected by placenta accreta? Placenta accreta is a condition where the placenta suddenly implants itself firmly and deeply in the nearest wall (uterine or rectal) and other organs available.

The atypical placental implantation

The placenta serves as the unborn baby’s life support system. During gestation, it normally attaches itself.  For the case of atypical placental implantation, here are the following grades according to its depth of penetration and intrusion:

  • Placenta increta – chorionic villi intrudes into the uterine myocytes
  • Placenta percreta – chorionic villi intrudes through the uterine myocytes

Pathogenesis of the Placenta Accreta

The placenta forms an atypical attachment to the other walls and internal organs. This happens due to the absence of Decidua Basalis and the Nitrabuch’s layer is partially developed.

In line with this, below are the different forms of accreta according to their firmness of penetration:

Pregnancy week by week

75 – 78% fraction of Placenta Accreta

About 75% of all women have this condition. 75 – 78% fraction is when the placenta is firmly attached to the myometrium without penetrating it.

17% fraction of Placenta Increta

17% fraction is when the placenta only penetrates the uterine myocytes.

5 – 7% fraction of Placenta Percreta

5 – 7% fraction is considered as the worst case where the placenta fully penetrates the myometrium to the perimetrium (by intruding the entire uterine wall).

Percreta can eventually lead to the placenta attaching to other internal organs such as the rectal wall and bladder.

Signs and symptoms of having a Placenta Accreta

Women affected with placenta accreta usually show no apparent signs and symptoms during gestation. However in some rare cases, the accreta is discovered during delivery where the placenta does not disengage from the uterine wall after childbirth.

Contrary to that, enlisted below are the following signs and symptoms detected during a diagnosis:

Via an ante – partum testing below are the following signs which suggest a placenta accreta during the 1st trimester (less than 20 weeks pregnant or during the course of abortion):

  • Deep seated placenta (placenta previa) with a uterine scar tissue placed on top. This type of scar allows the placenta to deeply burrow itself in the uterine wall

With that being said, the abovementioned sign should undergo a follow – up checkup in the next trimester. An immediate medical attention prevents the budding occurrence of placenta accreta.

In line with this, below are the sonographic results which suggest a placenta accreta during the 2nd – 3rd (final) trimester:

  • Vaginal bleeding – this serves as a definitive sign that accreta is present
  • Loss of standard hypoechoic retro – placental region
  • Asymmetrical vascular spaces with a cheesy appearance – Asymmetrical vascular spaces (multiple vascular lacunae in medical terms)
  • Blood vessels linking the uterine – placental border
  • Placental tissue connecting the uterine – placental border
  • Myometrial – bladder interface
  • Crossing uterine serosa1
  • Retro – placental myometrial thickness that is less than 1 millimeter
  • Numerous rational vessels envisaged with 3 – Dimensional power Doppler in basal view

Causes of the Placenta Accreta

Placenta accreta is associated with the aberrations of the uterine wall. In line with this, below are the following causes which contribute to the abnormal attachment:

Placenta Previa overlying a uterine scar tissue

Patients who have a placenta previa overlying a uterine scar tissue have a 40% possibility of being affected with accreta.

The aftermath of Asherman’s syndrome

Asherman’s syndrome (less known as intrauterine adhesions) is a rare condition where the uterus develops scar tissues (adhesions or fibroids) in the inner mucus membrane. The possibility of being affected with accreta is caused by the presence of fibroids.

History of Caesarian delivery

A history of caesarian delivery causes fibroids which increases the possibility of being affected with accreta.

In a like manner, about 60% of women who underwent multiple c – section deliveries experience accreta in the future.

History of dilation and curettage

A dilation and curettage (D&C) is a procedure which removes the tissue in the uterus. Patients who underwent D&C have developed fibroids which may lead to accreta.

Presence of thin decidua during a trophoblastic invasion

The presence of a thin uterine lining during a trophoblastic invasion – when cells begin to form outside the blastocyst can cause accreta.

Ectopic pregnancy

Ectopic pregnancy is when the fetus develops and grows outside the uterus, particularly in the Fallopian tube. This condition increases the possibility of accreta since it can freely attach itself to the nearest wall available.

In line with this is the cornual gestation, a condition where the fetus grows in the interstitial part of the Fallopian tube and invades the uterine wall.

Inherited and/or developed uterine defects

Inheriting or developing uterine defects may lead to placenta due to the presence of fibroids. In line with this, below are the different types of uterine defects:

  • Uterine leiomyomata
  • Uterine septa
  • Uterine anomalies

History of uterine surgeries

Patients who underwent uterine surgeries have the potential to be affected with accreta in the future. With that being said, below are the different types of uterine surgeries:

  • Uterine curettage
  • Uterine irradiation

Hypertensive conditions of gestation

Being affected with hypertensive conditions of gestation has the potential to become an accreta. Hypertensive conditions during gestation are classified into the following categories below:

  • Chronic hypertension
  • Preeclampsia – eclampsia
  • Preeclampsia superimposed on chronic hypertension
  • Gestational hypertension

Endometrial ablation

Endometrial ablation is the surgical procedure which involves destroying (ablates) the uterine lining (endometrium). This type of internal ablation gives the placenta to become a potential accreta.

Factors that increase the risk of having a Placenta Accreta

If the doctor found out some risk factors on the patient, the placenta accreta might require continuous check up to prevent its severity. With that being said, enlisted below are the contributing factors which increase the risk of having a placenta accreta:

Maternal age

Researches show that there is a 40% chance for women age 35 or older to be affected with Placenta accreta, particularly those who underwent caesarian and have a placenta previa overlying a uterine scar.

Multiparity

Multiparity is the condition of giving birth to multiples such as twins, triplets and the like.

Smoking

Smoking cigarettes or e – cigarettes increases the risk of accreta. This is because the nicotine and cocaine content of a cigarette causes blood vessel constriction through the utero – placental area.

Deep seated placenta

Did you know that placenta accreta is present in 5 – 10% women who have a deep seated placenta? Deep seated placenta (placenta previa in medical terms) is when the placenta is placed on the lower part of the womb, partially or entirely covering the cervix. Therefore, the placenta would abnormally implant itself to the nearest wall or organ.

Anterior placenta

Anterior placenta is when the placenta is placed on the frontal part of the uterus. Women with anterior placenta have a higher caesarian rate. Therefore, this imposes the risk of accreta where the placenta grows into the scar.

Complications caused by Placenta Accreta

  • Destructs the internal organs
  • Premature birth – this is considered as the most substantial complication caused by placenta accreta
  • Severe hemorrhaging during and after vaginal delivery. This type of accreta complication is life – threatening to the mother
  • Maternal mortality – which has a 6 – 7% cases that is associated to placenta previa
  • Neurovascular arrangements in the retroperitoneum
  • Crossed pelvic sidewalls from placental embedding and exclusion
  • Complications caused by volume expanders and massive blood and crystalloid transfusion (such as coagulopathy educed by massive transfusion, circulated intravascular coagulopathy, severe transfusion reactions, transfusion – related lung injury (TRALI), severe respiratory distress disorder, and electrolyte aberrations)
  • Post – operative bleeding which entails frequent surgery
  • Post – operative venous thromboembolism
  • Multi – system internal organ failure
  • Amniotic fluid embolism (AFE)

Treatment options for the Placenta Accreta

If a woman found out about her placenta accreta before birth, there is little or nothing she can do about it. But if she found out about it during the course of gestation, bed rest is required to ensure that the baby will be borne into term.

In line with this, enlisted here are the different treatment options for the placenta accreta:

Obstetric ultrasound imaging

Obstetric ultrasound imaging is considered as the primary instrument to detect an accreta. This type of procedure is performed at a specialized facility with an experienced obstetric surgeon who can screen and treat the condition better.

Magnetic resonance imaging

If the ultrasound findings are questionable, magnetic resonance imaging (MRI) must be persisted.

Prearranged caesarian delivery

Prearranged caesarian delivery is considered as the widely performed and safest way to treat Placenta accreta.

Abdominal hysterectomy

Abdominal hysterectomy is a common therapeutic procedure which involves removing the uterus by incising the lower abdomen. If placenta accreta has been detected prior to birth, a woman should undergo abdominal hysterectomy.

Unfortunately, the aftermath of hysterectomy is depressing as it makes a woman unable to conceive.

Manual placenta removal

If placenta is partially detached from the central accreta, manual placenta removal is required. This type of treatment is associated with over suturing the uterine defect.

Conservative treatment of Placenta Accreta

Conservative treatment of placenta accreta has the probability to spare the uterus. However, this treatment has not been proven 100% successful and can impose to higher risks of complications.

In line with this, below are the following optimal procedures for conservative treatment:

  • Leaving the placenta intact with the uterus and its curettage with the use of anti – folate drug. Unfortunately, the effectivity of this procedure is still uncertain
  • Intrauterine balloon catheterization or tamponade to compress uterine bleeding
  • Pelvic vein embolization
  • Hypogastric (internal iliac) artery ligation
  • Consensual uterine artery ligation

Partial cystectomy

If the urinary bladder has been invaded by the accreta, partial cystectomy is the answer.

Blood product transfusion accompanied with anesthesia

If the patient undergoes natural delivery, blood product transfusion accompanied with anesthesia is automatically followed after the process.

Hysteroscopic removal of retained Placenta Accreta

If the patient wanted to ensure the safety of her uterus for future pregnancies, hysteroscopic removal of retained placenta accreta can be done for uterus sparing.

Post – surgical treatment

For post – surgical treatment, take Pitocin and anti – biotics.

However, if a woman wishes to conceive in the future, it is important to discuss the matters of the aforementioned treatment options. This is because some surgical procedures may result complications for the upcoming pregnancy.