Bone mineral density in users of two kinds of once-a-month
combined injectable contraceptives
C.R.T. Juliato, L. Bahamondes, M. Villarreal, B.
Sobreira-Lima, J.A. Simões, A.M.S. Fernandes
Human Reproduction Unit, Department of Obstetrics and
Gynaecology, School of Medicine, Universidade Estadual de Campinas (UNICAMP),
Campinas, Brazil
Background The objective of this study was to compare
bone mineral density (BMD) between users of two kinds of once-a-month combined
injectable contraceptives (CIC) and controls.
Design and methods This cross-sectional study included 97 women
of 20 to 45 years of age, using CIC containing either 25 mg of
medroxyprogesterone acetate and 5 mg of oestradiol cypionate (MPA/E2Cyp) (for 12
to 82 months) or 50 mg of norethindrone oenanthate and 5 mg of oestradiol
valerate (NET-EN/E2Val) (for 12 to 60 months) matched by age (± 1 year) and
body mass index (BMI, kg/m2) (± 1) with users of the TCu 380A intrauterine
device as controls. BMD was evaluated at the midshaft of the ulna and at the
distal section of the radius of the non-dominant forearm using double X-ray
absorptiometry.
Results There were no differences in BMD between users of
either CIC and non-users at either section of the forearm studied. There were
also no differences in BMD between users of the two CIC at either section of the
forearm.
Conclusions Women aged 20 to 45 years old, currently
using one of these two kinds of CIC, presented similar BMD to controls paired by
age and BMI (kg/m2).
KEY WORDS Bone mineral density, Combined injectable
contraceptives, Contraception