Complications and contraindications of oral contraception.

Abstract

OC (oral contraception) can cause hypertension in a small minority, about 5%, of users. There does not seem to be a relationship between estrogen dosage and hypertension, while a relationship between progesterone and hypertension seems more possible. Hypertensive reaction to OC has been primarily seen in patients over 30; length of use is another important factor; the incidence after the 5th year of use is reputed to be 2.5-3 times higher than for the first year. Almost all women who develop hypertension with OC use will return to normal levels after OC termination. Several studies indicate a 4-fold to 6-fold increase in the risk of thrombosis and of thrombophlebitis among OC users and especially among woman over 35. OCs containing 50 mcg or less of estrogen can decrease the incidence of thromboembolic diseases by as much as 25%. It has also been reported that OC use before a surgical procedure increases the risk of postsurgical thromboembolism. Frequency of cerebral thrombosis, however rare, also seems to be higher in OC users, especially smokers. Risk of myocardial infarction is also higher among OC users especially in relation to age and smoking. A British study found that mortality rates among smokers were 10.2/100,000 pill users, versus 2.6 in nonusers in the age group 30-39; rates were 62.0 and 15.9 respectively in women over 40; duration of OC use is also a relevant factor. Absolute contraindications to OC use include any precedent of history of cardiovascular or cerebrovascular disease, impaired liver functions, any known or suspected form of neoplasia, genital bleeding, congenital hyperlipidemia, and obviously pregnancy. Relative contraindications include hypertension, migraine, epilepsy, varicose veins, diabetes, uterine leiomyomas, age over 35, and elective surgery. Potential OC users should be carefully screened to minimize possible risks. Age, health history, and smoking are extremely important. Starting OC with a dose lower than 50 mcg of estrogen is also advisable. A woman on OC should be seen every 6 months. Despite side effects and complications, OCs are the most effective and safest method of contraception a physician can offer.