Overview of Placenta Accreta

Placenta accreta refers to the penetration of the embryo into part of the uterine wall muscle layer, which occurs in early pregnancy. Placenta accreta is one of the more serious obstetric complications, which can cause internal bleeding, shock, uterine perforation, secondary infection, and even death in pregnant women. Multiple births, abortion, induced labor, cesarean section, puerperal infection, history of hysterectomy, history of pelvic radiotherapy and chemotherapy, placenta previa, and older age are considered to be high-risk factors for placenta accreta. For pregnant women with high-risk factors, prenatal B-ultrasound screening for placenta accreta is necessary. Placenta accreta is one of the more serious complications of pregnancy and is difficult to diagnose. Hysterectomy in patients with placenta accreta has become the number one reason for peripartum hysterectomy.

Causes

Placenta accreta is more common after traumatic or inflammatory damage or scarring of the uterine wall. Therefore, it is more common in women with a history of induced abortion, uterine curettage, cesarean section, surgical placental separation, previous placenta accreta or placenta previa, endometritis, submucosal uterine fibroids, local mucosal atrophy, primiparas, primiparas with a pregnancy age of ≥ 35 years, and after radiotherapy. At present, it is believed that abortion and cesarean section are the main causes of placenta accreta.

Clinical symptoms

Placenta accreta lacks typical clinical symptoms, manifestations and laboratory indicators before delivery. The clinical symptoms after the delivery of the fetus are: incomplete delivery of the embryo, rough face of the pregnant mother, or more than 30 minutes after the delivery of the fetus, the embryo cannot be separated from the endometrium and delivered independently, and must be manually removed. Some manual removal is difficult or it is found that the embryo is closely attached to the uterine myometrium with no gaps. The embryo continues to fail to come out, with or without vaginal bleeding.

Inspection

1.B-ultrasound examination

There is no clear boundary between the embryo and the uterus adhesion surface; the cavity inside the embryo can be seen from the surface; abnormal blood has entered the uterine muscle layer.

2. Magnetic resonance imaging (MRI)

It is of certain value to understand the degree of placenta implantation and whether it damages adjacent internal organs.

3. Endoscopic examination

Deeper placenta accreta can separate the uterus and invade the serosa forward to the bladder and backward to the sigmoid colon. Laparoscopic surgery, ureteroscopy and sigmoid colon examination can be performed for abnormal cases.

diagnosis

1. Adhesive embryos

It is caused by the direct adhesion of the villi to the myometrium of the uterus. There are two types: complete and partial adhesion embryos. Some of these embryos may be able to detach spontaneously, but some will remain in the uterine cavity and need to be detached artificially. The surgical treatment is more difficult, but some of the muscle tissue may be involved. When the excised embryo is sent to pathology, it is often impossible to determine whether the decidua basalis is defective, either by naked eye or under a microscope. For example, when collecting hysterectomy specimens, samples should be taken from several locations in the endometrium where the embryo is attached to, so that the decidua can be found to be damaged and the villi are in direct contact with the myometrium.

2. Implanted embryos

The hair invades part of the uterine myocardium and becomes embedded in a part that cannot be removed on its own. When it is removed artificially, the uterine myocardium is damaged. Pathological examination under the microscope showed that the villi invaded the myometrium.

3. Penetration of Embryos

The villi invade the myometrium and penetrate through the uterine muscle wall directly to the serosa, often leading to uterine rupture.

heal

The condition of placenta accreta is relatively dangerous. If the patient has heavy bleeding, severe infection of the uterine cavity during conservative treatment, or other reasons that seriously endanger the life of the pregnant mother, a hysterectomy is required. However, for pregnant women with little bleeding, no signs of infection during conservative treatment, stable ECG monitoring, small implantation area, and a desire to preserve the uterus, traditional treatment is also an effective method.

prevent

Preventing the occurrence of placenta accreta is a key strategy to reduce maternal and perinatal mortality. We will improve health education knowledge on pregnancy and childbirth, do a good job in promoting family planning policies, provide guidance on contraceptive measures, strictly control the cesarean section rate, further strengthen the management of high-risk pregnancies, improve perinatal health care, improve the prevention, diagnosis and treatment of placenta accreta, and reduce the incidence rate.