This is a prospective, cohort study conducted from October 2018 to October 2019, at the General Gynecology Clinic of the Military Police Hospital of Minas Gerais, Brazil.
We included women between the ages of 20-35 years who expressed the desire to use LARCs. Inclusion criteria included the desire for the use of contraception for a minimum of one-year; an active sex life (more than four relationships in the previous month); and normal oncotic cytology.
Exclusion criteria included the evidence of adrenal, cardiovascular, liver or kidney disease; uncontrolled hypothyroidism; diabetes; hyperprolactinemia; severe arterial hypertension; gynecological abnormalities (fibroids, endometriosis, congenital abnormalities, and active uterine infections); clinical history of thromboembolic disease or thrombophilia; smoking; pregnancy, lactation or abortion in the previous four months; any malignant or pre-malignant disease; history of migraines; and use of antidepressant and anticonvulsant medications.
Detailed information was provided on the duration of the study and the place of implantation. Each patient chose the desired type of LARC available, which depended on the number of samples provided by the laboratories: i) CuIUD (Andalan Classic Cu 380®, DKT do Brasil, São Paulo, Brazil) (42 samples), ii) SIUD (Andalan Silverflex®, DKT do Brasil, São Paulo, Brazil) (28 samples), iii) LNG (Mirena®. Bayer SA, Bayer Oy, Turku, Finland) (32 samples), iv) ENG (Implanon®, Schering-Plough, New Jersey, USA) (19 samples). In addition to receiving the devices free of charge, there was no cost to implant the selected method.
The sample size was calculated to compare the averages of sexual function for QS-F and FSFI instruments from four groups of LARCs. For that it would be necessary to perform a test of analysis of variance. Considering an average value of QS-F 80, standard deviation of 20, to detect a difference of 8 in the sexual function score, at least 75 individuals would be necessary in each group, with a 5% significance level and a minimum power of 80% (16) . However, due to the reduced availability of LARCs offered by the manufacturers, our sampling was less than planned. Thus, this study is characterized as a pilot study.
The participants were allocated into four groups by individual interest in the available methods, always respecting the WHO eligibility criteria for each case (17): CuIUD group (copper intrauterine device), SIUD group (silver intrauterine device), LNG group (levonorgestrel intrauterine system), and ENG group (etonogestrel-releasing implant). The data were collected in two moments: immediately prior to LARC placement (Stage 1) and approximately 3 months later (Stage 2).
Sexual function Instruments
Sexual function was assessed using the Female Sexual Quotient (QS-F) and Female Sexual Function Index (FSFI) questionnaires.
The QS-F is a questionnaire developed by the Program on Sexuality Studies of the Institute of Psychiatry of Hospital das Clínicas, School of Medicine of the University of São Paulo (IPq/HCFMUSP) and validated specifically for the Brazilian female population (18). The instrument consists of ten questions with answers scored on a scale from zero to five, with zero indicating “never”, and five, “always”. It assesses the various phases of the sexual response cycle, in addition to the domains desire and sexual interest, foreplay, excitement and harmony, comfort, and orgasm and satisfaction, identifying specific dysfunctions and sexual difficulties (19). The final score obtained is the result of the sum of the points of all questions multiplied by two, which results in a score ranging from 0 to 100. The closer to 100, the greater the sexual performance/satisfaction. Namely: 82-100 points (good to excellent), 62-80 points (fair to good), 42-60 points (unfavorable to fair), 22-40 points (bad to unfavorable), 0-20 points (null to bad). Details on the calculation of the final score can be found in the study by Abdo et al. (20).
The FSFI was developed in the United States in the 2000s, and is one of the main instruments used to assess female sexual function (21, 22).This instrument was translated into and validated for the Portuguese language (22, 23). It consists of 19 multiple-choice questions with increasing scores ranging from 0 to 5 regarding the presence of the questioned function, and six domains (desire, excitement, vaginal lubrication, orgasm, sexual satisfaction, and pain). The total score can vary from 2 to 36 points, with values ≤26 indicating sexual dysfunction (22).
A questionnaire proposed by Higgins et al. (24) on the reasons why patients chose their contraceptive method was administered in the first stage of the study. This questionnaire had seven direct questions on the importance of each of the reasons presented for choosing the contraceptive method. Patients should choose between extremely important, very important, slightly important, and not at all important.
The general medical history of all participants was investigated by the same gynecologist and they underwent gynecological examination as is routinely performed in the gynecology service of the Military Hospital of Minas Gerais. At the first consultation, the material for Pap smear was collected according to the Brazilian Guideline for cervical cancer screening of the José Alencar Gomes da Silva National Cancer Institute (25).
The study participants were assessed for clinical, metabolic, and hormonal parameters and sexual function at two different times during the study (at the initial evaluation and approximately three months after the implantation of the contraceptive device). At the first consultation, blood samples were collected for the following tests: CBC, CRP, blood glucose, glycated hemoglobin, insulinemia, prolactin, TSH, free T4, free and total testosterone, and lipid profile.
Other information relevant to the study, such as sociodemographic data, previous medical history and smoking habit were obtained from the medical records of the Military Police Hospital of Minas Gerais.
LARC implantation followed the recommendations provided by the manufacturers and the care recommended by the Brazilian Federation of Gynecology and Obstetrics (Febrasgo).
Qualitative variables were represented as frequencies, and quantitative variables as mean ± standard deviation (median). The quantitative variables were analyzed with the Shapiro-Wilk normality test. Chi-Square test was used to evaluate the association between qualitative variables, and Kruskal-Wallis test to compare a quantitative variable among four groups. The two-way Analysis of Variance for repeated measures was used to assess the association between the types of LARC and between the stages. The association between the reasons for choosing the methods and the devices was assessed by binomial logistic regression. The analyses were performed using the free R software version 3.5.2 and p <0.05 was considered significant.