Abortion – colloquially called miscarriage – (synonyms: Abortus; ICD-10-GM O06.-: unspecified abortion; ICD-10-GM O03.-: Spontaneous abortion) refers to the premature termination of gravidity with a birth weight of the embryo or fetus of less than 500 g.
Abortion is differentiated on the basis of its cause into:
- Spontaneous abortion – from natural causes.
- Artificial abortion – due to medicinal, chemical or other measures.
Furthermore, the abortion can be distinguished according to the timing:
- Early abortion – up to the 12th week of pregnancy (SSW) (occurrence in 10-15% of all clinical pregnancies; about 80% of all miscarriages are suitable within the first trimester (period of 3 months) as early abortion).
- Late abortion – 13th to 24th week of pregnancy (SSW).
- From the 24th week of pregnancy is called a stillbirth or premature birth
In addition, the abortion is further divided into its different courses:
- Abortus imminens (threatened abortion).
- Abortus incipiens (incipient abortion).
- Abortus incompletus (incomplete abortion).
- Abortus completus (complete abortion)
- Missed abortion (restrained abortion) – form of miscarriage in which the ovule is dead, but is not spontaneously expelled from the uterus (womb).
- Abortus febrilis (febrile) or septic abortion.
- Abortus habitualis (habitual abortion; recurrent spontaneous abortion, RSA; recurrent spontaneous abortion, WSA); ≥ 3. Spontaneous abortions (initially of unclear etiology) before the 20th week of gestation (SSW).
Frequency peak: the risk of miscarriage is greatest at the beginning of gravidity (pregnancy) and reduces as the pregnancy progresses. Approximately 80% of miscarriages occur in the first 12 weeks of pregnancy (SSW). The most frequent miscarriages occur up to the 5th week of pregnancy. Often, the affected woman does not even know she was pregnant at this time. In the 6th-8th SSW, the risk decreases to about 18% and from the 17th SSW to only 2-3%. As the age of the pregnant woman increases, the risk of miscarriage increases. Pregnant women aged 20-24 years have a 9% risk of miscarriage, and the risk increases to 75% in pregnant women over 45 years.
Exact figures on the prevalence (disease incidence) of abortions are not known. It is estimated that very early spontaneous abortions occur in 40-70% of women aged 20-29 years. Of these, only about 15-20% are clinically recognized. Approximately 30% of women will have an abortion in their lifetime.Approximately 1-3% of couples experience a recurrent spontaneous abortion (WSA). The risk of recurrent miscarriage increases primarily with the age of the patient, but also depends on the number of previous miscarriages.
Course and prognosis: The loss of a pregnancy is a tragic experience, both for the woman and for the partnership. Finding the cause is important to reduce the risk of complications in a subsequent pregnancy and to relieve the woman or couple’s fear of another miscarriage.
Comorbidities (concomitant diseases): autoimmune diseases associated with an increased risk of miscarriage are Hashimoto’s thyroiditis (autoimmune disease leading to chronic inflammation of the thyroid gland) and antiphospholipid syndrome.
