The effect of oral contraceptives on the development of deep vein thrombosis

Oralni hormonski kontraceptivi (OHK) koriste se već dugi niz godina kao učinkovita metoda kontracepcije, osim toga i u terapijske svrhe. Tijekom godina otkrivene su i brojne dobrobiti korištenja, no od samih početaka kao ozbiljna nuspojava nametnula se duboka venska tromboza (DVT). Učestalost DVT kao nuspojave danas se značajno smanjila zahvaljujući smanjenju doze estrogenske i gestagenske komponente koje imaju prokoagulacijski učinak te uzrokuju hiperkoagulabilnost krvi. Estrogenska komponenta u dozama kakve danas koristimo (≤0,035 mg) povećava rizik nastanka venske tromboze za 5 puta, a ovisno o vrsti gestagenske komponente za 4-7 puta u odnosu na nekorisnice OHK. Čimbenici rizika kao što su trombofilija, kirurški zahvat, trauma i ozljede, imobilizacija, maligne bolesti dodatno povećavaju rizik nastanka venske tromboze. Proveli smo istraživanje koristeći se medicinskom dokumentacijom pacijenata pregledanih u Ambulanti za hematološke i koagulacijske bolesti KBC-a Zagreb u razdoblju od listopada 2015.g. do lipnja 2017.g. Konačni uzorak činilo je trideset bolesnica generativne dobi (21-50) s dijagnosticiranom venskom tromboembolijom (VTE). Među trideset bolesnica najčešći rizični čimbenici za VTE odnosili su se na trudnoću i babinje te OHK. Sedam bolesnica koristilo je OHK u vrijeme dijagnoze. Ukupno šest imalo je dodatne provocirajuće faktore uz korištenje OHK te je nađena jedna pacijentica s OHK kao jedinim rizičnim čimbenikom. U pet bolesnica kao dodatni rizični čimbenik otkrivena je trombofilija obradom nakon dijagnoze unatoč negativnoj obiteljskoj anamnezi na tromboembolijske bolesti koja se pokazala nepouzdanim pokazateljem sigurnosti korištenja OHK. Iako je pitanje opravdanosti rutinske obrade na trombofiliju u svih pacijentica prije započinjanja terapije OHK-om, VTE vezane uz korištenje OHK mogle bi se ovim postupkom prevenirati u dijela pacijentica.Oral contraceptives (OCs) have been used for many years as an effective method of contraception and for therapeutic purposes. Over the years numerous benefits have been discovered, but from the very beginning deep vein thrombosis (DVT) imposed itself as a serious side effect. Today the incidence of DVT as a side effect has significantly dropped thanks to lowering of the doses of estrogen and progesteron components which have a procoagulant effect and cause hypercoagulability of the blood. The doses of estrogen component that we use today (≤0,035 mg) increase the risk of venous thrombosis 5-fold and depending on the type of progesteron component 4- to 7-fold compared with non-users. Risk factors such as thrombophilia, surgical procedures, trauma and injuries, immobilization, malignant diseases additionally increase the risk of DVT development. We conducted a study using medical documentation of patients examined in the Clinic for hematological and coagulation diseases at the University Hospital Centre Zagreb in the period from December 2015 to June 2017. The sample consisted of thirty women of reproductive age (21-50) with a diagnosis of venous thromboembolism (VTE). Among thirty patients, the most common risk factor for VTE pertained to pregnancy, postpartal period and OCs. Seven patients were using OC at the time of diagnosis. A total of six had additional provoking factors and in one patient OC was found to be the only risk factor. Five patients had thrombophilia as an additional risk, discovered after the diagnosis despite the negative family history of VTE, which turned out to be an unreliable indicator of the safety of OC use. Although it is a question of the relevance of routine screening for thrombophilia prior to a first prescription of OCs, VTE associated with OC use could be prevented by this procedure in some cases