Classification according to ICD-10 (International Classification of Diseases 10th revision):
• O03 - Spontaneous abortion - spontaneous pathological termination of pregnancy.
• O02.1 - Miscarriage - a condition in which intrauterine fetal death occurs without expulsion of the fetal egg from the uterus.
• O20.0 - Threatened abortion is a threatened abortion, manifested by increased uterine tone and/or bloody discharge from the uterus before 22 weeks of gestation.
• N 96 - Habitual miscarriage - loss of pregnancy three times or more.
• O60 - Premature birth - delivery that occurred at a period of 22 to 37 completed weeks and with a fetal weight of more than 500 g.
The stages of the disease are:
• Threatening abortion - there are sensations of heaviness or slight pulling pains in the lower abdomen and in the sacrum. Bleeding is usually absent. The uterus is enlarged according to the delay in menstruation, there are no changes in the vaginal part of the cervix.
• Spontaneous miscarriage that has begun - the severity of the pain symptom increases, bloody discharge from the genital tract appears. The size of the uterus corresponds to the gestational age. The cervix is preserved, its canal is closed or slightly open.
• Abortion in progress - the appearance of cramping pain, increased bloody discharge. The cervix is shortened, the cervical canal is open. An abortion in progress may result in an incomplete abortion, when the fetal egg is partially expelled from the cavity. And in the uterus, the fetal membranes, chorionic tissue, placenta are retained.
• Failed spontaneous miscarriage (missed pregnancy) - after the death of the fetal egg, there is no contractile activity of the uterus, the dead fetal egg is not expelled from the uterus, but undergoes secondary changes (autolysis, mummification, resorption of amniotic fluid).
• With isthmic-cervical insufficiency (inability of the muscles of the cervix to hold the fetus and its membranes), abortion most often begins with premature rupture of amniotic fluid (due to infection and violation of the integrity of the membranes). A miscarriage occurs fairly quickly and painlessly.
• Premature birth - begins with an increase in the tone of the myometrium, dull pain in the lower abdomen, which then develop into cramping. The smoothing of the cervix and the opening of the uterine os progresses.
The disease does not always go through all stages. It can stop at one of them with timely treatment or when the factor that provoked the threat is not so strong.