Pearl index for various contraceptive methods Method used by 100 women for 1 year. Percentage of women becoming pregnant that year while using the method.   1. No contraception 85   2. Withdrawal 35   3. Rhythm (calendar) 14 - 40   4. Rhythm (Billings) 15.5 - 32   5. Spermicides alone   5 - 20   6. Cervical cap   7 - 11   7. Condom   3 - 4   8. Female condom   1 - 5   9. Diaphragm with spermicide   2 - 3 10. Rhythm (temperature)   0.5 - 3 11. Injection   0.03 - 2 12. Hormonal IUD   0.05 - 0.1 13. Pill   0.1 - 0.5 14. Sterilization   0.1 - 0.3 15. Implant   0