On Oral Contraceptives Use Research Articles

Comparison of Recalled and Validated Oral Contraceptive Histories

From a case-control study of the relation between oral contraceptives and breast cancer carried out in East Germany during 1982-1986, the authors obtained information on oral contraceptive use through interviews of study subjects and from the records of prescribing gynecologists. The degree of agreement regarding information from these two sources was assessed for 234 breast cancer cases and 524 controls who had ever used oral contraceptives. Agreement between information obtained from medical records and that from interviews on total duration of use, number of episodes of use, and time since first and last use was reasonably good, and levels of agreement did not differ appreciably between cases and controls. Lower levels of agreement were observed for individual brand names and the duration of use of specific brands. Attempts should be made to obtain information on specific brands from medical records when investigating the effects of individual preparations.

Trends in oral contraceptive use in a Southern German population

In the surveys of the MONICA project Augsburg, conducted in 1984/85 (S1) and 1989/90 (S2), data on oral contraceptive (OC) use were gathered in two independent representative population-based samples of women aged 25–44 years (medication history over the previous seven days). OCs were categorized according to their oestrogen content (< 50mg, ≥50mg) and according to their progestogen component. The prevalence of OC use was unchanged between the two points in time (23.4% in S1 and 23.7% in S2). OCs with low oestrogen content were used in 49.0% of the OC users in S1 and in 76.6% in S2. The use of the progestogen component changed also: norethindrone (acetate), levonorgestrel, and lynestrenol were used less, desogestrel more often in S2. Gestoden and norgestimate were used by 15% of the OC users in S2. In conclusion, we can say that there was no change in the prevalence of OC use in the study population; however, a change in hormone content towards preparations with lower hormone content was observed.

Postscript: starting oral contraceptives (25 May, page 41)

In our article on oral contraceptives (OCs) we state that ‘oral contraceptives increase the risk of breast cancer with long-term use but reduce the risk of endometrial and ovarian cancer’. Some commentators have questioned the breast cancer risk. The UK National Case-Control (UKNCC) study, which looked at oral contraceptive use in women with breast cancer diagnosed before age 36, found a trend for increased risk associated with duration of use.1 ‘The simplest and most plausible explanation’, say the authors of the study, ‘must be that there is a substantial causal relation between prolonged use and breast cancer in young women.’ The increased risk seems to be associated particularly with OC use before the first full-term pregnancy.2 Several studies found no excess risk in OC users aged 45 or over, few of whom had taken the pill before their first pregnancy.3–5 In the UKNCC study the relative risk of breast cancer was 1.43 after 4–8 years’ use and 1.74 after more than 8 years’ use. In broad terms this means that three women in 1000 who use oral contraceptives for 4 or more years might be expected to be under treatment for breast cancer by age 36, compared with two per 1000 non-users.

Sex steroid hormones and breast cancer: is there a link with oral contraceptives and hormone replacement therapy?

To determine whether use of sex steroid hormones for contraception and hormone replacement therapy alters the risk of breast cancer, and whether the risk varies with their composition, duration of use, the period of a woman's life when the hormones are used, and after successful treatment for breast cancer. The results of important epidemiological reports, readily available from the English literature and published since 1981, were evaluated, using reports of basic scientific work as a background to the problem. An attempt was made to obtain most of the relevant reports. Twenty case-control and seven cohort studies were available on the oral contraceptive pill (OCP) and eleven case-control and five cohort studies on hormone replacement therapy (HRT). The relative risk estimates for breast cancer (and their 95% confidence intervals) determined by each report were tabulated according to the specific conditions of analysis, for example users under age 25, duration of use. Results by meta-analysis from previous studies were also used to determine risk. A significant positive association was present when the risk estimate exceeded 1.0 and the 95% confidence interval did not cross 1.0. Among OCP users, the vast majority of reports showed no significant risk of breast cancer--overall, longest duration of use, and use before first full-term pregnancy. However, a positive association between breast cancer and users under age 25 was found in three of eight reports. Similarly, the majority of reports showed no significant risk of breast cancer among HRT users, overall as well as in relation to duration of use and interval since first use. There was no increased risk with additional progestogen; it may be protective. An improved prognosis was found in users who developed breast cancer. On the limited data, use of hormones for postmenopausal symptoms did not appear to be harmful to women who had been successfully treated for breast cancer. The review revealed good evidence that use of sex steroid hormones had no significant effect on the risk of breast cancer, whether given for contraception or hormone replacement. There was some concern about increased risk with prolonged use of the OCP, especially in younger women. At present, use of these hormones is a matter of informed choice, with individual considerations of the risk-benefit ratio.

MALIGNANT HYPERTENSION AND ANTIPHOSPHOLIPID ANTIBODIES AS PRESENTING FEATURES OF SLE IN A YOUNG WOMAN USING ORAL CONTRACEPTIVES

A 24-year-old woman developed malignant hypertension while on oral contraceptives (OCs). She was found to have incomplete systemic lupus erythematosus (SLE) with DNA antibodies and high levels of antiphospholipid antibodies (APLA). She later developed SLE and has had three miscarriages and a cerebellar infarction.

Oral contraceptives and venous thromboembolism: findings in a large prospective study.

This article reports recent data from the Oxford-Family Planning Association study on oral contraceptives (OCs) and venous thromboembolism. 105 of the over 17000 women in the study suffered a 1st attack of venous thromboembolism uanassociated with pregnancy or the puerperium during the study period. This group was subdivided into 34 women who developed disease within 3 months after a surgical procedure and 71 women suffering thromboembolism unassociated with surgery. The incidence of postoperative thromboembolism in women who used OCs in the month before surgery was almost twice as high as that in nonusers but the difference was not significant. The group of women who became ill independently of surgery was divided into 3 diagnostic categories: certain or probable deep vein thrombosis pulmonary embolism or both; possible deep vein thrombosis pulmonary embolism or both; and superficial venous thrombosis only. There was a strong association between current OC use and certain or probable venous thromboembolism (relative risk 7.2) a weaker association with possible thromboembolism (relative risk 3.1) and little or no association with superficial venous thrombosis (relative risk 1.4). There was no significant association between risk and duration of OC use. The crude incidence of certain or probable thromboembolism/1000 woman-years was 0.62 in women using OCs containing 50 mcg or more of estrogen and 0.39 in those using preparations containing less than 50 mcg of estrogen. These findings are consistent with those obtained in other major studies in this area.

Evidence against oral contraceptives as a cause of neural-tube defects.

Information on oral contraceptive (OC) use, collected at the first antenatal visit, was abstracted from the medical notes in respect of 107 index pregnancies resulting in the delivery of an infant with a neural-tube defect (NTD) and 214 unaffected controls. The relative risk of having an NTD infant for women who had at any time used OCs was 0.82 (95% confidence interval 0.52, 1.32) compared with that in women who had never used OCs. For women who stopped OC use less than 3 months before becoming pregnant or who continued in early pregnancy, the relative risk was 1.18 (95% confidence interval 0.70, 1.98) compared with women who had used OCs at any other time. An analysis restricted to those women who had at any time used OCs did not suggest an association between NTD risk and the interval between stopping OC use and becoming pregnant. None of our analyses therefore provided any evidence that OCs cause NTDs and if a risk exists it can only be small.

Influence of HLA Types on Carbohydrate Effects of a Low-Estrogen Oral Contraceptive

The lymphocyte HLA types were determined for 13 women, who were then separated into a subgroup of those having a "high" risk for insulin-dependent diabetes mellitus (B8, B15, AW30) and a "low-risk" subgroup (B7, BW35). A 3-hour oral glucose tolerance test was conducted on each woman before starting on oral contraceptives (OC) and then 6 months after using them. Both blood glucose and plasma insulin levels were measured. The OC contained 0.035 mg of ethinylestradiol and 0.4 mg of norethindrone. There was a significantly higher 0.5-hour glucose value in the control test in the "high risk" group. There was a significant elevation of the 1-hour plasma insulin value in the 6-month test for the "high-risk" group. The usefulness of the HLA prescreening of women prior to use of OC needs more study.