A miscarriage is a pregnancy loss that occurs prior to 20 weeks; at this point and up to approximately 24 weeks of pregnancy the fetus is unable to survive outside its mother's womb. Miscarriage occurs in about 15-20% of all recognized pregnancies. Most miscarriages occur in the first trimester or up to 12 weeks of pregnancy. Some doctors believe that as many as 50% of all pregnancies end in miscarriage, because some losses occur before a woman realizes she is pregnant.
In most cases, when a woman has a miscarriage in the first trimester of pregnancy, her doctor will tell her that the cause was most likely a chromosomal abnormality. However, other factors also can contribute to first trimester miscarriage. These can include hormonal problems, infections, and maternal health problems.
After an isolated spontaneous miscarriage, the chance of having a successful pregnancy in the future is quite high: 75-80% of women who had a miscarriage go on to have a successful pregnancy the next time they become pregnant. Women who have had repeat miscarriages are advised to receive a medical evaluation to identify the reasons for these miscarriages. In women with two consecutive miscarriages, the risk of having another loss is between 35-40%. In those women with two non-consecutive pregnancy losses, the risk of another miscarriage is between 15-20%.
Genetic (chromosomal) abnormalities are the most frequent cause
Defective implantation, uterine and cervical anomalies
Infection of the uterus by bacteria and viruses
Certain drugs, including alcohol and smoking, can increase the risk of miscarriage.
Mother's physical defects and certain systemic diseases (such as heart disease)
Hormonal (endocrine) abnormalities, such as diabetes and thyroid problems
Certain autoimmune diseases
Abdominal pain, low-back pain, severe menstrual-like cramping
Passage of blood clots or tissue from the vagina
Nausea and sometimes vomiting
Pregnancy test - urine
Pelvic examination: The cervix is examined to determine if it is dilated (open) or closed.
Blood test - (HCG, progesterone)
Pain medication: Tylenol, only if pregnancy is viable.
Bed rest has been recommended in the past but will NOT prevent miscarriage.
Pelvic rest (no intercourse, douching, tampons) is recommended until bleeding stops or if miscarriage continues for two weeks.
Dilatation & Curettage (D&C) to remove remaining tissue.
Provide emotional support.
Types of abortion
Threatened abortion: The early symptoms of pregnancy may be present. Mild cramps with bleeding. Cervix is long and closed. Uterus is the appropriate size for gestational age. Roughly 50% of threatened abortions progress to miscarriage.
Inevitable abortion: Persistent cramps and moderate bleeding. Cervical os is open. (Do not confuse with an incompetent cervix, which is not associated with cramping and is potentially treatable. An incompetent cervix is associated with painless cervical dilatation.)
Incomplete abortion: Physical findings and symptoms are the same as an inevitable abortion but some retained products of conception are in the uterus (blood clots may be mistaken for tissue) or cervical canal, causing ongoing cramping and excessive bleeding. Speculum examination reveals a dilated internal os and tissue present within the uterus or vagina. Bleeding may be heavy.
Complete abortion: All pregnancy tissue was expelled with decreasing or ceasing of cramps and bleeding. On examination, the uterus is firm, and smaller than one would expect for gestational age of pregnancy.
Missed abortion: Fetus has died, no heartbeat by transvaginal ultrasound, and cervix is closed. Signs and symptoms of pregnancy abate; pregnancy test may become negative. May progress to incomplete or inevitable abortion. Uterus is soft and irregular and enlarged for gestational age of pregnancy and, over time, decreases in size.
Septic abortion: Any of the above scenarios and a temperature > 100°F (38°C) without other source of fever may indicate septic abortion. May be associated with IUD or dilatation and curettage (D&C). Abdominal and uterine tenderness are present as well as purulent discharge and possibly shock.