Table 1

Characteristics of 798 female first-degree relatives with either factor V Leiden, prothrombin G20210A, or a combination of these defects, including homozygosity

All female relatives
No defectsSingle defectsCombined defects*
Female relatives, n 497 251 50 
Follow-up, y 32 (0.1-35) 28 (0.1-35) 24 (2-35) 
    Factor V Leiden (%) NA 160 (64) 46 (92) 
    Prothrombin G20210A (%) NA 91 (36) 39 (81) 
Ever COC users, n (%) 366 (74) 171 (68) 34 (68) 
Age at start of COC, y 19 (15-47) 20 (15-49) 19 (15-49) 
Duration of COC use, y 8 (0.1-30) 6 (0.1-27) 6 (0.5-16) 
Ever pregnant, n (%) 364 (73) 175 (70) 36 (72) 
Age at first pregnancy 24 (15-41) 24 (15-36) 23 (17-38) 
Number of pregnancies, n 2 (1-10) 3 (1-10) 2 (1-7) 
Total pregnancy time, y 2 (0.3-9) 3 (0.3-9) 2 (0.8-6) 
Age at time of VTE, y 31 (18-46) 34 (17-48) 26 (17-39) 
VTE, n 17 22 11 
Unprovoked, n 
Provoked, n    
    COC use 
    Pregnancy/postpartum 
    COC use + postpartum 
    COC use + other risk factor 
    Major trauma, surgery, immobilization 
All female relatives
No defectsSingle defectsCombined defects*
Female relatives, n 497 251 50 
Follow-up, y 32 (0.1-35) 28 (0.1-35) 24 (2-35) 
    Factor V Leiden (%) NA 160 (64) 46 (92) 
    Prothrombin G20210A (%) NA 91 (36) 39 (81) 
Ever COC users, n (%) 366 (74) 171 (68) 34 (68) 
Age at start of COC, y 19 (15-47) 20 (15-49) 19 (15-49) 
Duration of COC use, y 8 (0.1-30) 6 (0.1-27) 6 (0.5-16) 
Ever pregnant, n (%) 364 (73) 175 (70) 36 (72) 
Age at first pregnancy 24 (15-41) 24 (15-36) 23 (17-38) 
Number of pregnancies, n 2 (1-10) 3 (1-10) 2 (1-7) 
Total pregnancy time, y 2 (0.3-9) 3 (0.3-9) 2 (0.8-6) 
Age at time of VTE, y 31 (18-46) 34 (17-48) 26 (17-39) 
VTE, n 17 22 11 
Unprovoked, n 
Provoked, n    
    COC use 
    Pregnancy/postpartum 
    COC use + postpartum 
    COC use + other risk factor 
    Major trauma, surgery, immobilization 

High factor VIII level was present in 8 (22%), 99 (39%), and 197 (40%) women with combined defects, single defects, and no defects, respectively (in 14 women factor VIII levels were not available). Data are given as median (min − max) unless otherwise indicated.

COC indicates combined oral contraceptive; NA, data not applicable; and VTE, venous thromboembolism.

*

Including 14 homozygote carriers of factor V Leiden, of whom 3 were also heterozygous for prothrombin G20210A, and 4 homozygote carriers of the prothrombin G20210A mutation, respectively.

Restricted to those aged 15-50 years.

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