Summary
There is scarce information on the clinical characteristics of contraceptive users
who develop venous thromboembolism (VTE). RIETE is an ongoing registry of consecutive
patients with symptomatic, objectively confirmed, acute VTE. We analyzed the clinical
characteristics and additional risk factors for VTE in all enrolled women aged <50
years who were using or not using contraceptives at presentation with VTE. Of 1,667
women aged <50 years enrolled in RIETE as of December 2007, 593 (36%) were contraceptive
users. Of 270 aged <25 years, 190 (70%) were users. Ninety-two contraceptive users
(16%) had over-weight, 89 (15%) were obese. Of 951 women with no additional risk factors
for VTE (i.e. recent surgery, immobility or cancer) 457 (48%) were contraceptive users.
Eighty-seven (15%) users had recent immobility for ≥4 days, 44 (7.4%) were postoperative.
The most common reason for immobility was lower limb trauma not requiring surgery;
25% of users with recent immobility had received thromboprophylaxis. The most common
type of surgery was non-major orthopaedic surgery. Twenty-one (48%) users with postoperative
VTE had received prophylaxis. The percentage of users and non-users who tested positive
for thrombophilia was similar. Contraceptive use remains the most frequent risk factor
for VTE in women at fertile age. Identifying those at increased risk for VTE seems
to be difficult. In the meanwhile, a higher use of thromboprophylaxis during immobility
or minor surgery should be warranted.
Keywords
Contraceptives - venous thromboembolism - prevention