Laboratory parameters of the 1st order – obligatory laboratory tests.
- Beta-HCG (human chorionic gonadotropins) – determination is necessary in case of inconclusive findings or abortus imminens (threatened miscarriage) or suspicion of disturbed early pregnancy (early pregnancy). It is performed as a follow-up at 2-day intervals. In an intact pregnancy, the beta-HCG values double per 48 h in the first 7 weeks of gestation; up to the 10th week of gestation, the doubling time can also last three days. Thereafter, the HCG values drop (maximum values 10,000-20,000). Further diagnostics should be performed by vaginal ultrasound.
- Small blood count – to exclude infection.
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification of a possible cause (esp. in women with repeated spontaneous abortions (WSA)).
- Infectious serological examinations – see TORCH complex (called STORCH in German) under the topic “Pregnancy infections”; the TORCH complex includes the most important infectious diseases or their pathogens that may pose a prenatal risk to the child. These are pathogens that can be transmitted intrauterine (in the uterus) to the fetus (to the unborn child) in an expectant mother. This can possibly bring serious consequences such as an abortion (miscarriage) or malformations of the fetus (unborn child).
- Endometrial biopsy (tissue sampling from the endometrium) – to rule out chronic endometritis (inflammation of the uterus) (in WSA).
- Thyroid parameters – TSH (thyroid-stimulating hormone), fT3 (triiodothyronine), fT4 (thyroxine); due tospecific diagnosis of Hashimoto’s thyroiditis see below the disease of the same name.
- Diagnosis of antiphospholipid syndrome (APS) – due toexclusion of antiphospholipid syndrome (APS; antiphospholipid antibody syndrome); autoimmune disease; in abortus habitualis (habitual abortion; recurrent spontaneous abortions, RSA; recurrent spontaneous abortions, WSA); ≥ 3. spontaneous abortions (initially of unclear etiology) before 20 weeks’ gestation (SSW)); most common autoimmune disease; affects two to five percent of the population – predominantly women (gynecotropy); characterized by the following triad:
- Venous and/or arterial thrombosis.
- Thrombocytopenia
- Recurrent spontaneous abortions
Diagnostic criteria for APS see below.
- Thrombophilia diagnosis – for thromboembolic risks (not for the purpose of abortion prophylaxis).
- Antithrombin, protein C and protein S.
- Molecular genetic exclusion of an FVL and the prothrombin G20210A mutation.
- Chromosomal analysis of both partners preconceptionally or from the aborted material – only for habitual abortions (not after a single or consecutive abortion).
- Preimplantation genetic diagnosis for the purpose of abortion prophylaxis – in couples with repeated spontaneous abortions (WSA) without evidence of familial chromosomal defects or monogenic disease.
Diagnostic criteria for antiphospholipid syndrome (APS).
| Clinical criteria |
| ≥ venous and/or arterial thrombosis. |
| 1 or 2 unexplained miscarriages in morphologically unremarkable fetuses> 10th SSWor ≥ 3 miscarriages < 10th SSW |
| ≥ 1 late abortion or preterm delivery <34th SSW due to placental insufficiency or preeclampsia |
| Laboratory criteria (detected 2 times at 12-week intervals). |
| – Anti-cardiolipin AK (IgM, IgG) [moderate to high titers]. |
| – Anti-β2-glycoprotein-1-AK (IgM, IgG) [high titers] |
| – Lupus anticoagulant |
Legend
- SSW: week of pregnancy
- AK: antibody
- Ig: immunoglobulins
By definition, at least one clinical and one laboratory criterion must be met to establish a diagnosis of APS.