What Is a Partial Birth Abortion?

Termination of pregnancy is called abortion if the pregnancy is less than 28 weeks and the fetus weighs less than 1000g. Abortion occurs at 12 weeks of pregnancy, the former is called early abortion, and those who occur at 12 weeks to less than 28 weeks of pregnancy are called late abortion. Abortion is divided into spontaneous abortion and induced abortion. The incidence of spontaneous abortion accounts for about 15% of all pregnancy, and most of them are early abortion. There are two special types of abortion: missed abortion and habitual abortion.

Basic Information

English name

abortion

Visiting department

Obstetrics and Gynecology

Common causes

Genetic factors, environmental factors, immune factors, etc.

Common symptoms

Vaginal bleeding and abdominal pain

Causes of Abortion

Genetic factor

In early spontaneous abortion, 50% to 60% of embryos with abnormal chromosomes account for abnormal numbers of chromosomes, followed by structural abnormalities. The abnormal numbers include trisomy, triploid, and X-monomers; structural abnormalities include chromosome breaks, inversions, deletions, and translocations. Most of the embryos with chromosomal abnormalities have a miscarriage, and very few may continue to develop into fetuses, but some functional abnormalities or malformations may also occur after birth. If an abortion has occurred, the pregnancy product is sometimes only an empty gestation sac or a degraded embryo.

2. Environmental factors

There are many external adverse factors affecting reproductive function, which can directly or indirectly cause damage to the embryo or fetus. Excessive exposure to certain harmful chemicals (such as arsenic, lead, benzene, formaldehyde, chloroprene, ethylene oxide, etc.) and physical factors (such as radiation, noise, and high temperature) can cause miscarriage.

3. Maternal factors

(1) Systemic disease Acute disease during pregnancy, high fever can cause uterine contraction and cause abortion; bacterial toxins or viruses (herpes simplex virus, cytomegalovirus, etc.) enter the fetal blood circulation through the placenta, causing fetal death and abortion. In addition, pregnant women with severe anemia or heart failure can cause fetal hypoxia and may cause miscarriage. Pregnant women suffer from chronic nephritis or hypertension, and the placenta may infarct and cause miscarriage.

(2) Genital malformations of pregnant women due to reproductive organ diseases (such as double uterus, mediastinal uterus, and uterine dysplasia), and pelvic tumors (such as uterine fibroids) can affect the growth and development of the fetus and cause abortion. The internal cervix is lax or severely lacerated, and prone to late abortion due to premature rupture of the membrane.

(3) Endocrine disorders, hypothyroidism, failure to control severe diabetes, and insufficient luteal function can cause miscarriages.

(4) Traumatic pregnancy, especially during early pregnancy, undergoes abdominal surgery or trauma during the second trimester, resulting in contraction of the uterus and miscarriage.

4. Insufficient endocrine function

In early pregnancy, in addition to the progesterone secreted by the gestational corpus luteum of the ovary, placental trophoblasts also gradually produce progestin. After 8 weeks of gestation, the placenta gradually becomes the main site of progesterone production. In addition to progesterone, the placenta also synthesizes other hormones such as -chorionic gonadotropin, placental lactogen, and estrogen. During early pregnancy, the above-mentioned hormone values decrease, and pregnancy is difficult to continue and cause miscarriage.

5. Immune factors

Pregnancy is like an allogeneic transplant. There is a complex and special immunological relationship between the embryo and the mother, which prevents the embryo from being rejected. If the mother and child are not immune, they can cause the mother to reject the embryo and cause abortion. Relevant immune factors mainly include histocompatibility antigen, fetal specific antigen, blood group antigen, and imbalance of maternal cell immune regulation.

Clinical manifestations of abortion

The main symptoms of abortion are vaginal bleeding and abdominal pain. Vaginal bleeding occurs in those who have a miscarriage within 12 weeks of gestation. At the beginning, the villi are separated from the decidua, and the blood sinus is opened, and bleeding begins. When the embryo is completely separated and discharged, bleeding stops due to uterine contraction. The whole process of early abortion is accompanied by vaginal bleeding; in the case of late abortion, the placenta is formed, and the process of abortion is similar to premature delivery. The placenta is discharged after the delivery of the fetus, and there is usually not much bleeding. Abdominal pain during abortion is paroxysmal uterine contraction-like pain. After vaginal bleeding occurs in early abortion, embryo separation and blood clots in the uterine cavity stimulate uterine contraction, and paroxysmal lower abdominal pain occurs. It is characterized by vaginal bleeding that often precedes abdominal pain. Late abortion has paroxysmal uterine contractions and then the placenta is stripped, so vaginal bleeding occurs after abdominal pain. The size of the uterus, whether the cervix is dilated, and whether the membrane is ruptured during miscarriage vary depending on the number of weeks of pregnancy and the process of abortion.

Abortion check

Diagnosing miscarriage is generally not difficult. Diagnosis can be confirmed based on medical history and clinical manifestations, and only a few need auxiliary examination. After the diagnosis of abortion is confirmed, the clinical type of abortion should also be determined, and the management method should be decided.

Medical history

Patients should be asked if they have a history of menopause and recurrent miscarriages, early pregnancy reactions, vaginal bleeding, and the amount and duration of vaginal bleeding, as well as the location, nature and extent of abdominal pain. You should also know whether there is watery vaginal drainage, the color, amount, and odor of vaginal drainage, and whether pregnancy products are discharged.

2. Examination

Observe the general condition of the patient, whether there is anemia, and measure body temperature, blood pressure and pulse. Perform a gynecological examination under sterile conditions, pay attention to whether the cervical mouth is dilated, whether the amniotic sac is bulging, and whether pregnancy products are blocked in the cervical mouth; whether the size of the uterus is consistent with the number of menopause weeks, and whether there is tenderness. The bilateral attachment should be checked for lumps, thickening, and tenderness. The operation should be gentle during inspection, especially for suspected threatened abortion.

3. Auxiliary inspection

For those who have difficulty in diagnosis, necessary auxiliary examinations can be adopted.

(1) B-mode ultrasound imaging is currently widely used. It has practical value for differential diagnosis and determination of abortion type. For those suspected of threatened abortion, whether the embryo or fetus is alive can be determined according to the shape of the pregnancy sac, the presence or absence of fetal heart reflexes and fetal movements, in order to guide the correct treatment. Incomplete abortion and missed abortion can be determined with the help of B-mode ultrasound.

(2) The immunological method used in pregnancy tests and the clinical multi-purpose test strip method in recent years are meaningful for the diagnosis of pregnancy. In order to further understand the prognosis of abortion, radioimmunoassay or enzyme-linked immunosorbent assay is often used for the quantitative determination of HCG.

Abortion treatment

Abortion is a common disease in obstetrics and gynecology. Once the symptoms of abortion occur, it should be timely and appropriately treated according to the different types of abortion.

Threatened abortion

Should pay attention to rest, taboo sex life, vaginal examination operation should be gentle. Progesterone can be added to patients with insufficient corpus luteum function, which has a fetal-prevention effect. Secondly, vitamin E and low-dose thyroxine (for patients with hypothyroidism) can also be used. In addition, psychological treatment of patients with threatened abortion is also very important to stabilize their mood and increase confidence. After treatment, the symptoms are not relieved or worsened, suggesting that there may be abnormal development of the embryo. Perform B-mode ultrasound and -HCG measurement to determine the status of the embryo and treat it accordingly, including termination of pregnancy.

2. Inevitable miscarriage

Once diagnosed, the embryo and placental tissue should be completely discharged as soon as possible. Early abortion should be performed under negative pressure aspiration in time, carefully check the pregnancy products, and send them for pathological examination. Late abortion, factor uterus is larger, those who have difficulty in aspiration or curettage can use 10 units of oxytocin and 500ml of 1% glucose solution for intravenous infusion to promote uterine contraction. When the fetus and placenta are discharged, check for completeness, and cure the uterus if necessary to remove the remaining pregnancy products in the uterine cavity.

3. Incomplete abortion

Once confirmed, curettage or forceps should be performed in time to remove residual tissue in the uterine cavity. Patients with more bleeding should be transfused at the same time and given antibiotics to prevent infection.

4. Complete abortion

If there is no sign of infection, no special treatment is generally required.

5. Miscarriage

Difficult to handle. Because the placental tissue is sometimes organic, it is closely adhered to the uterine wall, which makes it difficult to curettage. If the retention time is too long, coagulation dysfunction may occur, resulting in diffuse intravascular coagulation (DIC) and severe bleeding. Before treatment, blood routine, clotting time, platelet count, fibrinogen, prothrombin time, clot shrinkage test, and plasma protamine paracoagulation test (3P test) should be checked, and preparations for blood transfusion should be made. The uterus is less than 12 weeks of gestation. Fetal curettage is available. Intrauterine contractions are used during the operation to reduce bleeding. If the placenta is mechanized and adheres tightly to the uterine wall, the operation should be particularly careful to prevent perforation. Once it cannot be scraped off, it can be scraped again after 5-7 days. If the uterus is greater than 12 weeks of gestation, oxytocin should be injected intravenously, and prostaglandins or esacridine can be used to induce labor to promote fetal and placental excretion. If coagulation dysfunction, heparin, fibrinogen and fresh blood transfusion should be used as soon as possible. After the coagulation function is improved, induction of labor or curettage should be performed.

6. Habitual abortion

Women with a history of habitual abortion should undergo necessary tests before pregnancy, including ovarian function tests, chromosome tests and blood group identification of both spouses, and sperm tests of their husbands. The woman still needs a detailed reproductive tract examination to determine the presence of the uterus Deformities and lesions, and check for cervical slack. Find out the cause, if it can be corrected, should be treated before pregnancy.

7. Abortion infection

Abortion infections are mostly combined with incomplete abortion. The principle of treatment should be to actively control the infection. If there is not much vaginal bleeding, apply broad-spectrum antibiotics for 2 to 3 days. After the infection is controlled, curettage is performed to remove the residual tissue in the uterine cavity to stop bleeding. If there is a large amount of vaginal bleeding, while injecting broad-spectrum antibiotics and blood transfusion, use oval forceps to clamp out the residual tissue in the uterine cavity to reduce bleeding. Do not use a curette to scrape the uterine cavity to avoid spreading the infection. Antibiotics were continued after the operation, and curettage was performed thoroughly after infection control. If septic shock has been combined, the shock should be actively corrected. If the infection is severe or abscesses are formed in the abdomen or pelvis, surgical drainage should be performed and the uterus removed if necessary.