Antiphospholipid Syndrome and Pregnancy Differential Diagnoses

Updated: Mar 20, 2020
  • Author: Teresa G Berg, MD, FACOG; Chief Editor: Ronald M Ramus, MD  more...
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Diagnostic Considerations

Careful evaluation is necessary following a spontaneous abortion occurring prior to 10 weeks’ gestation before it can be considered unexplained.

With regard to thrombocytopenia, other possible causes of the disorder, such as HIV infection, and various conditions, such as drug -induced thrombocytopenia, thrombotic thrombocytopenia, gestational thrombocytopenia, and preeclampsia, should be considered. Other autoimmune diseases should also be ruled out in patients with thrombocytopenia.

The following are findings that can be secondary to autoimmune disorders other than APS and that require an appropriate evaluation:

  • Arthritis - Patients may have nonerosive arthritis involving 2 or more peripheral joints

  • Serositis - This may be (1) pleuritis or pleural effusion or (2) pericarditis or pericardial effusion

  • Renal disorder - Proteinuria of 0.5 g/day or the presence of cellular casts

  • Neurologic disorder - Criteria include seizures in the absence of other causes or psychosis in the absence of other causes.

  • Hematologic disorder - Features, without an otherwise explainable cause, include (1) hemolytic anemia with reticulocytosis, (2) leukopenia of less than 4000 cells/µL on at least 2 occasions, (3) lymphopenia of less than 1500 cells/µL, or (4) thrombocytopenia of less than 100,000 cells/µL

  • Immunologic disorder

Systemic lupus erythematosus

Many manifestations of SLE can be seen in women with APS. A complete evaluation to exclude SLE as a primary disorder is appropriate if symptoms are present.

The clinical manifestations of SLE include the following:

  • Skin lesions - 84-71%

  • Arthritis - 63-95%

  • Nephritis - 46-77%

  • Raynaud phenomenon - 10-58%

  • Neuropsychiatric features - 0-59%

  • Lymphadenopathy - 0-58%

  • Pleurisy - 37-56%

  • Mucous membrane ulceration - 7-54%

  • Pericarditis - 29-45%

  • Splenomegaly - 9-18%

  • Aseptic necrosis - 0-10%

Clinical evidence of glomerulonephritis is found in more than 50% of cases. However, if biopsies are performed on all patients, the incidence of some nephritis may be as high as 90%. SLE is associated with encephalopathy and seizures, to a lesser degree with ischemic stroke, and, rarely, with subarachnoid hemorrhage.