The grades of evidence (I-III) and levels of recommendation (A-C) are defined at the end of the "Major Recommendations" field.
The following recommendation is based on limited or inconsistent scientific evidence (Level B):
- Testing for antiphospholipid antibodies should be limited to those women with appropriate medical or obstetric histories.
The following recommendations are based primarily on consensus and expert opinion (Level C):
- Women with antiphospholipid syndrome and no thrombotic history should receive prophylactic doses of heparin and low-dose aspirin during pregnancy and the postpartum period (6 to 8 weeks).
- Women with antiphospholipid syndrome and previous history of thrombosis should receive full anticoagulation throughout pregnancy and the postpartum period (6 to 8 weeks).
- Women with antiphospholipid syndrome should be referred to an internist or hematologist for long-term follow-up.
- Women with antiphospholipid syndrome should avoid estrogen-containing oral contraceptives.
- Because of the risk for growth restriction, consideration should be given to serial ultrasonographic assessment. Antepartum testing should be considered after 32 weeks of gestation, or earlier if there are signs of growth restriction.
Definitions:
Grades of Evidence
I Evidence obtained from at least one properly designed randomized controlled trial.
II-1 Evidence obtained from well-designed controlled trials without randomization.
II-2 Evidence obtained from well-designed cohort or case–control analytic studies, preferably from more than one center or research group.
II-3 Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments also could be regarded as this type of evidence.
III Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.
Levels of Recommendation
Level A — Recommendations are based on good and consistent scientific evidence.
Level B — Recommendations are based on limited or inconsistent scientific evidence.
Level C — Recommendations are based primarily on consensus and expert opinion.
