 Female sterilization is a more significant operation than vasectomy, and has greater risks; in industrialized nations, mortality is 4 per 100,000 tubal ligations, versus 0.1 per 100,000 vasectomies.After IUD insertion, users may experience irregular periods in the first 3–6 months with Mirena, and sometimes heavier periods and worse menstrual cramps with ParaGard.However, "ninety-nine percent of IUD users are pleased with them".