A team of scientists has found that obese women who use oral contraceptives containing estrogen and progestin have a 24-fold increased risk of Venous Thromboembolism (VTE) as compared with non-obese women not using the drugs. VTE refers to a blood clot in a vein and includes two life-threatening conditions: deep venous thrombosis and pulmonary embolism.
The findings have been published in a paper published on Thursday in the ESC Heart Failure journal.
“It is well established that both obesity and oestrogen-containing contraceptives are risk factors for VTE. Despite this, obese women continue to receive these drugs. The scientific evidence indicates that obesity and combined oral contraceptives have a synergistic effect on VTE risk and this should be considered in prescribing decisions. Progestin-only products, including pills, intrauterine devices, or implants are a safer alternative to the combined pill in women carrying excess weight,” Study author Professor Giuseppe Rosano of the IRCCS San Raffaele Pisana, Rome, Italy said in a statement.
According to the scientists, this review paper highlighted the latest evidence on the independent effects of obesity and contraceptives, and blood-clot risk and also provides clinical recommendations.
According to the World Health Organization (WHO), the global prevalence of obesity nearly tripled between 1975 and 2016 – with 15 percent of adult women being obese. Meanwhile, the risk of VTE increases progressively with body mass index (BMI), and in obese women, it is more than double that of non-obese women.
According to scientists, obesity has the most substantial impact on VTE women under 40 years of age, who have a five-fold increased risk compared with non-obese women.
“The particularly high risk in obese women under 40 is important since it is at this age that many seek contraception,” Professor Rosano said in a statement on Thursday.
Meanwhile, combined oral contraceptives are associated with an elevated likelihood of VTE, with users having a three- to seven-fold elevated likelihood of VTE compared with non-users. However, progestin-only products are not associated with an increased risk of VTE, the scientists claim.
The researchers also claimed that the combination of overweight/obesity and the use of combined oral contraceptives potentiates the likelihood of blood clots in women of reproductive age. However, in combined pill users, the risk of VTE was 12-fold higher in overweight women and 24-fold higher in obese women – when compared with normal-weight non-users.
“Obese women taking contraceptives are vulnerable to VTE and should take steps to limit their other predisposing factors for cardiovascular disease, for example by quitting smoking and increasing their physical activity levels,” Professor Rosano stated on Thursday.