The Effect of Hormonal Contraception on Changes in the Body Mass Index of Women of Reproductive Age

Abstract

Hormonal contraception is widely used by women of reproductive age. Its use may be associated with changes in body weight, which may subsequently affect body mass index (BMI). This study aimed to analyze changes in BMI before and after at least six months of hormonal contraceptive use among women of reproductive age. This quantitative study employed a retrospective cohort study design. Secondary data were obtained from family planning registers and medical records at a Midwife Independent Practice (Tempat Praktik Mandiri Bidan, TPMB). The sample consisted of 44 women of reproductive age who used hormonal contraceptives, with data on their body weight and height recorded both before use and after at least six months of use; the sampling technique employed was purposive sampling. Data were collected via secondary sources from independent midwifery practices (TPMB) and met the following inclusion criteria: complete data, use of hormonal contraception in 2025, and a follow-up contraceptive check-up 6 months after insertion. The contraceptive methods included one-month and three-month injectable contraception. Data were analyzed using a paired t-test with a significance level of α = 0.05. Most participants used one-month injectable contraception (63.6%), while 36.4% used three-month injectable contraception. Mean body weight increased from 61.27 ± 11.53 kg to 62.94 ± 10.97 kg, representing an increase of 1.67 kg. Mean BMI increased from 24.64 ± 4.33 kg/m² to 25.81 ± 4.12 kg/m², with a mean difference of 1.17 kg/m². The proportion of participants classified as overweight increased from 15.9% to 25.0%, while obesity increased from 27.3% to 29.5%. The paired t-test demonstrated a statistically significant difference in BMI before and after hormonal contraceptive use (p = 0.009). Significant changes in BMI were observed after at least six months of hormonal contraceptive use. Regular monitoring of body weight and BMI, along with counseling on healthy dietary patterns and physical activity, should be incorporated into contraceptive services.