Background: Sexuality and contraception are closely linked topics. In theory, hormonal contraception use might affect female sexual function in both positive and negative directions. Some women experience and report adverse sexual function changes while they use hormonal contraception while others report no or positive changes. Questions of causality, the potential mechanisms of action, and how to counsel women reporting adverse changes have been a matter of debate but scientific consensus is lacking on the answers.

Material and Methods: The first study was a cross-sectional study with 1851 women, aged 22, 25 and 28 years, who answered a questionnaire regarding contraception use, positive and negative side effects, contraceptive counselling, and aspects of sexual function. The second study was a randomised double-blind placebo-controlled multicentre clinical trial. In this study we compared 102 women who used a combined oral contraceptive with 100 women who took placebo, regarding sexual function scores evaluated with the Mc Coy Female Sexuality Questionnaire. We measured testosterone level changes in serum and hair as a secondary outcome. The third study was a qualitative study in which we explored women’s experiences of the negative effects of hormonal contraceptive use on sexual function. We interviewed 24 selected women who had reported previous experiences of adverse sexual function changes while using a hormonal contraceptive method.

Results and Conclusions: Young Swedish women who used hormonal contraception, reported a negative change in sexual desire more than twice as often as women who used hormone-free contraceptive methods. A similar difference was seen between users of the levonorgestrel-intrauterine system compared with users of the copper-intrauterine device.

The experience of an adverse sexual desire effect, which the women thought was due to contraceptive use, was a strong predictive factor for reconsideration of the contraceptive method.

We found no change in the total score of sexual function during the use of a combined oral contraceptive compared with placebo. Sexual interest and lubrication which were two aspects of the total sexual function, were found to be negatively associated with the use of the tested combined oral contraceptive. Changes were small however, and the clinical relevance of these findings is therefore unclear. Furthermore, lubrication change did not persist following adjustment for change in self-rated depression scores.

The biologically active fraction of testosterone embedded in hair did not decrease during combined oral contraceptive treatment and no reliable associations were found between the induced serum testosterone level decrease and sexual desire changes. Women reporting negative sexual function effects while using hormonal contraception, described lubrication difficulties and decreased sexual desire associated with both contraceptive use and parts of the menstrual cycle. Associations became obvious with time and experience and consequently contraceptive choice became easier with age, experience, and better understanding, all of which we concluded could be facilitated by a responsive contraceptive counsellor.

Our findings indicate the need for further evaluation of sexual function changes in the selected group of women who seem to be susceptible to the use of hormonal contraceptives.

The effects of testosterone in the body are dependent on the concentrations at the target organs, as well as the susceptibility of the androgen receptor. Steroid hormones circulate in the bloodstream bound to proteins, and only a small part is unbound and free to exert its effect at the receptors. Due to the diurnal variation in testosterone levels, the measured concentrations can change rapidly. Thus, a kind of "long-term measure" of the average free testosterone concentration would facilitate the understanding of the hormones' long-term effects on target organs.

Hair seems at first sight to be a suitable matrix. The current theory is that only the free, unbound fraction of hormones passively diffuse from the bloodstream into the hair matrix as the hair grows. In this thesis, we have developed an analysis capable of analysing testosterone in the hair of men and women. We have systematically explored potential confounding factors and the pattern of testosterone concentrations in different hair segments. Furthermore, we have sought to confirm biological differences such as sex, age and BMI which affect hormone concentrations in the blood. Finally, we have investigated how hair testosterone concentrations change in relation to treatment with oral contraceptives and before an acute myocardial infarction.

Our conclusions are that it is possible to measure testosterone in extracts from hair in very low concentrations. The choice of measurement method needs to balance between high specificity, which mass spectrometry can offer, and adequate detection limits, which can be achieved with immunoassays. Hair testosterone concentrations correlate significantly with testosterone concentrations in saliva, which suggests that hair testosterone reflects the average hormone concentrations in the body. The significant variation in hair growth rate within and between individuals impedes the theoretical relationship between certain hair segments and a specific time in the past. Hair testosterone concentrations are affected by the frequency of hair washing, cosmetic hair treatment, natural hair colour and the biological sex. In hair samples taken shortly after a patient was admitted to hospital due to a myocardial infarction, lower concentrations of testosterone can be seen in hair compared to individuals of the same age who have not had an acute heart attack. This suggests that a reduction in testosterone concentrations occurs shortly before the heart attack, independently of other cardiovascular risk factors. Reduced testosterone concentrations could thus be an independent risk factor for developing an acute myocardial infarction.