Abortion

Abortion

Abortion is the removal or destruction of an embryo or fetus before birth. It may be spontaneous or induced. Abortion is an extraction or expulsion of an embryo which is capable of independent survival weighing 500 grams or less before the 20^th week of gestation.

Causes of Abortions

1.      Genetic Causes

·         Of all chromosomal abnormalities 50% are autosomal trisomies ( most common trisomy is 16 )

·         Second most common cause of chromosomal anomolies is monosomy X (45XO) 15-20% of all spontaneous ABs
·         Couples that share HLA antigens have increase ab rates

2.      Environmental causes of Abortion

·         Infections: Endometritis, Toxoplasmosis, Herpes

·         Smoking
·         Alcohol
·         Radiation
·         Toxins: Anesthetic agents, Lead, Arsenic, Formaldehyde, Benzene, Ethylene oxide

3.      Uterine Causes

·         Leiomyoma of the uterus: fibroids

·         Uterine anomalies: DES exposure- T shaped uterus, Uterine adhesions, Malformation of the uterus- Uterus didelphys, unicornate uterus, bicornate uterus, uterine septum, Incompetent cervix- congenital or acquired

4.      Medical conditions:

·         Diabetes, Severe malnutrition, Hyperthyroidism

5.      Immunological causes:

·         Client with recurrent fetal loss have antiphospolipid antibodies 80% of the time

6.      Endocrinologic causes:

·         Progesterone deficiency, Hypo or Hyper thyroidism, Diabetes mellitus

 

Types of Abortion

Spontaneous abortion or miscarriages - is a type of abortion that occur without medical or other intervention. About 25% of all pregnancies result in miscarriages, women older than 35 or younger than 17 years old and couples who have difficulty in achieving pregnancy; and women who have had at least two miscarriages has a higher chance of experiencing miscarriage. About 90% of miscarriages occur during the first trimester (first three months, or 12 weeks of pregnancy). Some cases of miscarriages happen even before a woman realizes that she is pregnant, and she even may not realize that she has aborted.

Symptoms of Miscarriage:

§  A typical 10^th week miscarriage is characterized by a very heavy menstrual period. A pregnant woman may experience several days of bleeding and cramps before the contents of the uterus are removed, followed by a short period of bleeding until the lining of the uterus heals.

§  Miscarriage after the 12^th week is like a mild version of the labor of during childbirth, with strong contractions that dilate the cervix and expel the fetus.

§  Miscarriages between the 13^th and 24^th weeks (second trimester) are most often caused by faulty attachment of the placenta to the walls of the uterus or from a weak cervix that dilates too soon.

 

Types of Spontaneous Abortion

§  Threatened abortion is a condition of pregnancy, occurring before the 20^th week of gestation, the patient usually experiences vaginal bleeding with or without some cramps, and the cervix is closed. Bed rest is usually the only treatment needed. In a few cases the symptoms disappear and the rest of the pregnancy is normal.

§  Inevitable abortion is when the bleeding continues and becomes heavy, it usually means that the cervix is dilating and the contents of the uterus are being expelled. Pregnant women will experience lower abdominal cramping and bleeding.

§  Complete abortion is when all the contents are expelled. There is no treatment other than rest is usually needed. All of the tissues that came out should be saved for examination by a doctor to make sure that the abortion is complete. The laboratory examination of the saved tissue may determine the cause of abortion.

§  Incomplete abortion is a name given to abortion where the uterus retains part or all of the placenta. Bleeding may occur because part of the placenta may adhere to the uterine wall and the uterus does not contract to seal the large blood vessels that feed the placenta. The usual treatment is a drug that induces labor by stimulating uterine contractions, a surgical procedure called curettage can also be done to remove the remaining material from the uterus, the goal of this treatment is to prevent prolonged bleeding or infection.

§  Missed abortion - is a case in which an intrauterine pregnancy is present but is no longer developing normally. Before widespread use of ultrasonography, the term missed abortion was applied to pregnancies with no uterine growth over a prolonged period of time, typically 6 weeks after its (fetus) death. A missed abortion is usually indicated by the disappearance of the signs of pregnancy except for the continued absence of menstrual periods. Missed abortions are usually treated by induction of labor by dilation (or dilatation) and curettage (D & C).

Induced abortion - this type of abortion uses drugs or instruments to stop the normal course of pregnancy.

Different methods for performing abortions

§  Menstrual Extraction (endometrial or vacuum aspiration). This method is used for most abortions performed during the first trimester. It is done by suctioning out the lining of the uterus (endometrium) through a thin opening of the undilated cervix. It is a method used after a woman has just missed a period, or anytime up to about the eight week or pregnancy. It can be performed safely in the doctor's office and has a very low rate of mortality.

§  Dilation and Evacuation (D & E) (also called vacuum suction or suction curettage) and Dilation and Curettage (D & C). This method is commonly used for late first trimester or early second trimester abortions. In this method suction is used to remove the fetus and placenta. The cervix is first dilated under local anesthesia using a suction tube that is firm, and a stronger suction is used than in menstrual extraction. Another way of dilating the cervix is the use of a type of dried seaweed, called laminaria, which expands as it absorbs moisture. Some doctors use a hollow, spoon-shaped knife, or curette, to ensure that all the placental tissues are removed by scraping the uterine walls. If curettes are used throughout the procedure instead of suction, the method is called dilation and curettage (D&C). Before the 12^th week of pregnancy, D&E is preferred over D&C because it does not require general anesthesia, causes less discomfort and is less costly. D&C can be used up to the 12^th week of pregnancy. The mortality rate for both D&E and D&C is approximately 3 per 100,000 abortions.

 

§  Prostaglandin or Saline Administration. This method is done by injecting prostaglandins or saline solution through the uterine wall and into the amniotic sac holding the fetus to induce labor and delivery of a nonviable fetus. This procedure is commonly used for second trimester abortions. Prostaglandins may cause nausea, elevated temperatures, and vomiting but are safer than the saline solution. Mortality rate for second trimester abortions performed by this method is approximately 20 per 100,000 abortions.

§  Hysterotomy. This method is similar to caesarian section, the uterus is opened through a small abdominal incision and the fetus is removed. Hysterotomy is usually performed only when other methods have failed repeatedly, it is performed under general anesthesia. It is used between the 12^th and the 24^th week of pregnancy. This method has the greatest risk of complications out of all the abortion procedures, maternal mortality rate is approximately 200 per 100,000 abortions.