Oral contraception and the risk of thromboembolism: what does it mean to clinicians and their patients?

Toward a new concept of "natural balance" in oral estroprogestin contraception

The Pill has undergone many changes since its first appearance some 50 years ago. Key developments included the reduction of ethinylestradiol doses and the synthesis of new progestins in order to increase safety, compliance and efficiency. Low-dose combined oral contraceptives (COCs) are currently the preferred option for millions of women. Due to this widespread use, it has been argued that the safety of COCs should be even better, raising the threshold for excellence. Yet in spite of major improvements, there is still an associated risk of venous thromboembolism (VTE). The next step in COCs' evolution should take total estrogenicity and hepatic estro-androgenic balance into account. The focus on the estrogen component--which has not changed in 50 years--has yielded a new class of natural estrogen pills. Following the introduction of a first quadriphasic pill, a monophasic estradiol pill based on the concept of "natural balance" was subsequently made available. These recent achievements could represent a step forward in the evolution of COCs and pave the way for better safety.

Medication to prevent breast cancer--too much to swallow?

Selective oestrogen receptor modulators effectively reduce breast cancer in women at moderate to high risk, so why aren't they being discussed routinely?

Cost-utility analysis of von Willebrand disease screening in adolescents with menorrhagia

OBJECTIVE

To construct a decision analysis model to evaluate the cost utility of von Willebrand disease (VWD) testing in adolescents with menorrhagia.

STUDY DESIGN

A 20-year Markov decision analytic model was constructed to evaluate the cost utility of two strategies: testing or not testing for VWD. The model includes probabilities of remaining well, suffering an acute menorrhagia bleeding event, surgical complications, oral contraceptive pill complications, or dying. Probabilities, costs, and utilities were estimated from published literature. The prevalence of type 1 VWD in adolescent females with menorrhagia was estimated at 13%.

RESULTS

The cost of testing adolescents with menorrhagia for VWD was $1790, versus $1251 for not testing for VWD. The effectiveness of not testing in quality-adjusted life-years (QALYs) gained (14.237 QALYs) was similar to the VWD testing strategy (14.246 QALYs). Compared with not testing for VWD, screening for VWD had an incremental cost-effectiveness ratio of $62,791 per QALY, a value typically considered economically reasonable.

CONCLUSIONS

In adolescents with menorrhagia, testing for VWD before the initiation of oral contraceptives is cost-effective.

The contraceptive vaginal ring (NuvaRing®) and hemostasis: a comparative study

This open-label, nonrandomized study compared changes in hemostatic variables during NuvaRing and oral levonorgestrel 150 microg/ethinylestradiol 30 microg (LNG/EE) use for six cycles. Eighty-seven women started the study, 44 with NuvaRing and 43 with the LNG/EE oral contraceptive. For most procoagulation variables, there was no difference between NuvaRing and oral LNG/EE; only Factor VII levels increased in the NuvaRing group and decreased in the LNG/EE group. The majority of assessed variables show that anticoagulation and fibrinolytic activity was comparable between the NuvaRing and oral LNG/EE groups. Antithrombin activity and protein C activity both tended to be higher with NuvaRing. Levels of tissue plasminogen activator decreased in both groups but the reduction was smaller with NuvaRing. There were no significant differences in fibrin turnover between the treatment groups. The data show that both NuvaRing and oral LNG/EE are associated with a minimal effect on hemostatic variables.

Estrogen-containing oral contraceptives are allowable in young women with factor V Leiden heterozygosity without a history of thrombosis

An 18-year-old woman without significant past medical and surgical history presents to discuss the safety and efficacy of oral contraceptives. She is sexually active and currently relying on condoms alone for birth control. Her cousin had a deep venous thrombosis (DVT) following a pregnancy. As part of the family screening, this patient was identified as a factor V Leiden heterozygote. The risks and benefits of initiating oral contraceptives are discussed.

Thromboembolism

Venous thomboembolism (VTE) causes only about 2% of maternal deaths in the developing world but is a leading cause of direct maternal deaths in developed countries. Pregnancy increases the risk of VTE through venous stasis, changes in blood coagulability and damage to vessels. Early diagnosis of VTE depends crucially on awareness of the condition but clinical diagnosis is unreliable in pregnancy and objective testing is essential. Compression or duplex ultrasonography is used to diagnose deep venous thrombosis and a ventilation/perfusion scan for pulmonary embolism. Low molecular weight heparins are safe and effective for treatment and for thromboprophylaxis in pregnancy. All women should undergo risk assessment in early pregnancy or preferably before pregnancy. Identifying risk factors such as obesity, or a past or family history of thromboembolism, allows at-risk women to be offered thromboprophylaxis. Guidelines on thromboprophylaxis have reduced deaths after caesarean section and are now being developed for all women.