Everything You Know To Know About Placenta Percreta

Earlier on we brought you the news about a woman and her unborn baby that almost died after the placenta kept growing until it burst through her womb. At first the doctors thought she had bad heartburn but when her symptoms got worse and she was rushed back to the hospital they discovered she has Placenta Percreta.

So I decided to do a little bit of research about Placenta Percreta so that I can educate every woman out there and this is what I found.

What is Placenta Percreta?

Placenta percreta is a disorder where the the placenta doesn’t get the signal to stop growing. It occurs when all or part of the placenta attaches abnormally to the myometrium which is the muscular layer of the uterine wall. Three grades of abnormal placental attachment are defined according to the depth of invasion with the first one been Accreta which is a chorionic villi attach to the myometrium, rather than being restricted within the decidua basalis. The second one is Increta and this is a chorionic villi that invade into the myometrium while the last one is Percreta a chorionic villi that invade through the myometrium.

Due to the abnormal attachment to the myometrium, placenta accreta is associated with an increased risk of heavy bleeding at the time of attempted placental delivery. The need for transfusion of blood products is frequent, and hysterectomy is sometimes required to control life-threatening hemorrhage.

What Are The Risk Factor?

An important risk factor for Placenta Accreta is placenta previa in the presence of a uterine scar. Placenta previa is an independent risk factor for placenta accreta.

Additional risk factors for placenta accreta include maternal age and multiparity, other prior uterine surgery, prior uterine curettage, uterine irradiation, endometrial ablation, Asherman syndrome, uterine leiomyomata, uterine anomalies, hypertensive disorders of pregnancy, and smoking.

A woman who has had one prior caesarean has a risk of 3 percent; a second caesarean ups the risk to 11 percent; at the third, 40 percent; fourth, 60 percent; and by the fifth, the risk of Placenta Accreta jumps to 67 percent.

Other risk factors include low-lying placenta, anterior placenta, congenital or acquired uterine defects such as uterine septa, leiomyoma, ectopic implantation of placenta including cornual pregnancy.

Diagnosis/Symptoms

When the antepartum diagnosis of placenta accreta is made, it is usually based on ultrasound findings in the second or third trimester. Sonographic findings that may be suggestive of Placenta Accreta include:

(1) Loss of normal hypoechoic retroplacental zone

(2) Multiple vascular lacunae (irregular vascular spaces) within placenta, giving “Swiss cheese” appearance

(3) Blood vessels or placental tissue bridging uterine-placental margin, myometrial-bladder interface, or crossing uterine serosa1

(4) Retroplacental myometrial thickness of <1 mm

 (5) Numerous coherent vessels visualized with 3-dimensional power Doppler in basal view

Women with a placenta previa or “low-lying placenta” overlying a uterine scar early in pregnancy should undergo follow-up imaging in the third trimester with attention to the potential presence of placenta accreta.

While obstetric ultrasound is the primary tool for the diagnosis of placenta accreta, magnetic resonance imaging can be helpful if ultrasound is inconclusive or if placenta percreta is suspected.

 Complications

Various forms of complications includes the following

(i)                 Damage to local organs (e.g., bowel, bladder, ureters) and neurovascular structures in the retroperitoneum and lateral pelvic sidewalls from placental implantation and its removal;

(ii)               Postoperative bleeding requiring repeated surgery;

(iii)             Amniotic fluid embolism

(iv)             Complications (e.g., dilutional coagulopathy, consumptive coagulopathy, acute transfusion reactions, transfusion-associated lung injury, acute respiratory distress syndrome, and electrolyte abnormalities) from transfusion of large volumes of blood products, crystalloid, and other volume expanders

(v)               Postoperative thromboembolism, infection, multisystem organ failure, and maternal death. The exact incidence of maternal mortality related to placenta accreta and its complications is unknown, but has been reported to be as high as 6-7% in case series and surveys.

Treatment

Yes Placenta Accreta can be treated and the safest and most common treatment is through a planned caesarean section and abdominal hysterectomy if placenta accreta is diagnosed before birth.  Pitocin and antibiotics are used for post-surgical management. When there is partially separated placenta with focal accreta, best option is removal of placenta and oversewing the uterine defect. If it is important to save the woman's uterus then resection around the placenta may be successful. Conservative treatment can also be uterus sparing but may not be as successful and has a higher risk of complications.

In cases where there is invasion of bladder, it is treated in similar manner to abdominal pregnancy and manual placental removal is avoided. However, this may eventually need hysterectomy and/or partial cystectomy.

If the patient decides to proceed with a vaginal delivery, blood products for transfusion and an anesthesiologist are kept ready at delivery.