Liver Tumors Oral contraceptives were implicated as a cause of benign adenomas of the liver. These hormonally responsive tumors can cause fatal hemorrhage. They usually regress when OC use is discontinued; risk is related to prolonged use (178). The tumors are rare; about 30 cases per 1 million users per year were predicted with older formulations. Presumably, newer low-dose products pose less risk. A link to hepatic carcinoma was proposed. This cancer is closely associated with chronic hepatitis B and C infections and is usually seen in cirrhotic livers. There are case reports of hepatocellular carcinoma in young women with no risk factors other than long-term OC use (179). A large study from six countries in Europe found no association between use of OCs and subsequent liver cancer (180). A systematic review looked for evidence of harm associated with hormonal contraceptive use among women already at risk because of liver disease (181). The authors concluded from the limited data available that OCs do not affect the course of acute hepatitis or chronic hepatitis, and do not affect the rate of progression or severity of cirrhotic fibrosis, the risk of hepatocellular carcinoma in women with chronic hepatitis, or the risk of liver dysfunction in hepatitis B virus carriers.
Oral Contraceptives and Sexually Transmitted Infections Chlamydial colonization of the cervix appears more likely in OC users than in nonusers but, despite this finding, several case-control studies found a reduced risk of acute PID among OC users (182,183). In contrast, a subsequent study found no protection with OC use (184).
Whether hormonal contraceptives inﬂuence acquisition of HIV remains uncertain. The largest study concluded that overall risk was not increased by oral combination OCs or injected
DMPA (185).
Oral contraceptives have important health benefits (Table 10.7). These include contraceptive and noncontraceptive benefits 182).
Oral contraceptives provide highly effective contraception and prevent unwanted pregnancy, an important public health problem. Where safe abortion services are not available, women seek unsafe services and risk death from septic abortion. Combination OCs block ovulation and offer marked protection from ectopic pregnancy. Risk of ectopic pregnancy in a woman taking combination OCs is estimated to be 1/500 of the risk of women not using contraception; progestin-only OCs appear to increase risk of ectopic pregnancy (186).
As noted earlier, OC use produces strong and lasting reduced risk for endometrial and ovarian cancer. In addition, protection was found for women with known hereditary ovarian cancer. Any past use of OCs conferred a 50% reduction in ovarian cancer risk when women with this history who took OCs were compared with their sisters as controls (OR, 0.5; 95% CI, 0.3–0.8). Protection increased with increasing duration of use (187). The mechanism of action of OCs in the prevention of ovarian cancer is unknown but may involve selective induction of apoptosis (programmed cell death). Macaques treated with EE plus levonorgestrel or levonorgestrel alone showed an increase in the proportion of ovarian epithelial cells in apoptosis in comparison with animals fed a diet containing no hormones (188).
Other documented benefits of OC use include reduction of benign breast disease (189). Use of OCs helps relieve dysmenorrhea (166). Oral contraceptives offer effective therapy for women with menorrhagia and dysfunctional uterine bleeding (163).
Table 10.7 Established and Emerging Noncontraceptive Benefits of Oral Contraceptives
Reduced symptoms of premenstrual dysphoric disordera
Inhibition of ovulation
Treatment of bleeding disorders
Treatment of hyperandrogenic anovulation
Treatment of endometriosis