Hormone changes. This mostly affects women during their reproductive years where their hormone levels fluctuate during the menstrual cycles. Just before the menstrual bleeding, progesterone levels tend to be lower which may cause fluid retention hence the ankle swelling. Hormone replacement therapies and menopausal effects also trigger fluid retention leading to swelling of the ankles. Use of contraceptive pills with hormones such as estrogen, changes hormone levels that may cause side effects such as ankle swelling and weight gain.