Routine antenatal thrombophilia screening in high-risk pregnancies: a decision analysis

Thrombophilias have been implicated in complications related to ischemic placental disease including recurrent pregnancy loss, intrauterine fetal demise, preeclampsia, fetal growth restriction, placental abruption, and preterm delivery. Maternal screening and treatment may lower the recurrence of these outcomes. Our objective was to estimate if antenatal screening for thrombophilias with the intention to offer treatment among women with a prior adverse pregnancy outcome (APO) is preferable to no screening. A decision-analytical model was constructed for pregnant women with prior APO, comparing screening for thrombophilia with intention to treat with no screening. Values obtained from previously published studies include probability of positive test: 0.3 (0.1 to 0.6); good outcome with treatment: 0.9 (0.3 to 0.99); no thrombophilia, good outcome: 0.75 (0.5 to 0.9); test negative, thrombophilia positive: 0.05 (0.01 to 0.1); test negative, thrombophilia positive, good outcome: 0.75 (0.5 to 0.9); thrombophilia/test negative, good outcome: 0.98 (0.5 to 0.99). Sensitivity analyses were run over a wide range of assumptions. Thrombophilia screening with intention to treat in women with prior APO associated with ischemic placental disease is the strategy of choice compared with no testing over a wide range of assumptions. Sensitivity analyses support this to be robust. Women with poor pregnancy history related to placental ischemic disease may benefit from thrombophilia screening and treatment in a subsequent pregnancy.