Purpose: This nonrandomized study aimed to evaluate body weight and composition during the menstrual cycle and during oral contraception with 30 microg of ethinylestradiol plus 3 mg of drospirenone (EE+DRSP).
Design: Multifrequency bioelectrical impedance analysis was carried out in 38 normally cycling women (mean age, 25.5 years) at baseline during the follicular phase (FP) and the luteal phase (LP) of the menstrual cycle and after three and six cycles of EE+DRSP to evaluate total body water (TBW), intracellular water (ICW), extracellular water (ECW), fat mass and fat-free mass. Body weight, waist-to-hip ratio, blood pressure and the plasma concentrations of electrolytes were also determined at each visit.
Results: TBW and ECW increased in the LP. During EE+DRSP, TBW and ECW were significantly lower than in the LP but similar to the values measured in the FP. No significant variations in ICW or in the other parameters were observed.
Conclusion: EE+DRSP maintains the same concentrations in TBW and ECW observed in the FP. This effect is likely due to the antimineralocorticoid activity of DRSP, which counteracts the water retention elicited by estrogen.