Thrombophilia: Women-Specific Reference Ranges Can Prevent Misdiagnosis in Women

Background: Thrombophilia is a state where abnormalities of the hemostatic system predispose a patient to thrombosis. Some coagulation factors are generally lower in women than in men. Therefore, the use of routine reference ranges (RRRs) based on male or mixed-sex groups may be misleading in the diagnosis of thrombophilia in women. We hypothesize that this affects the analysis of thrombophilia after pregnancy complications. Therefore, the aim of our study was to investigate the effect of women-specific reference ranges (WRRs) on the interpretation of hemostatic variables in postpartum women. Methods: Coagulant and anticoagulant variables were measured 3 months postpartum in 61 healthy women with an uncomplicated pregnancy and in 197 women who experienced preeclampsia (PE). In 55 of the healthy women, these variables were also measured at least 6 months after an uncomplicated pregnancy and used to calculate WRR. Results: In total, 48% of healthy women had normal results when using routine reference ranges compared with 89% when using WRRs (P < 0.05). In the women with PE, there were normal results in 26% of women when using routine reference ranges compared with 66% when using WRRs (P < 0.05). Conclusion: When using WRRs, fewer abnormalities were seen in healthy women as well as in women with a history of PE, which may prevent misdiagnosis of thrombophilia.