Abortion diagnostics [Q99.9]
Dipl.-Biol. Uwe Heinrich
It is generally assumed that approximately 50–70% of all embryos perish unnoticed, and that 15% of all noticed pregnancies result in spontaneous abortion. Approx. 50% of these spontaneous abortions are due to chromosomal changes, in most cases numerical aberrations (especially trisomies) that can be usually traced back to a defect in distribution of the chromosomes during maternal meiosis. The age of the women plays a major role. Recent studies could demonstrate numerical aberrations in 20–30 % of all hormonally stimulated oocytes in the context of artificial reproductive techniques.
Besides chromosomal aberrations, exogenous or predisposing genetic factors have an influence on early pregnancy, such as disorders of the coagulation and immune system (antiphospholipid syndrome, factor V-Leiden polymorphism, increase in NK cell activity, subclinical autoimmune disease etc.).
After two or more cytogenetically unexplained miscarriages, both partners should undergo chromosomal analysis to rule out a balanced parental chromosome rearrangement.