Black couple. Image credit

Black couple. Image credit

ZIMSEC O Level Combined Science Notes:Contraception:Ways to prevent pregnancy

How it works

  • Can be done in both men and women
  • In men it is known as a vasectomy
    • Sperm duct is cut and tied
    • During sexual intercourse ejaculated fluid contains no sperm
  • In Women there are two types of sterilisation:
    1. Tubal Ligation-tubes from the ovary are cut and tied to prevent ova from reaching the sperm
    2. Tubal Occlusion-clips are clamped on to the tubes to prevent ova from reaching sperm


  • 99.9% for vasectomy
  • 99.4-99.8% female sterilisation


  • It’s permanent and effective
  • Safe and simple operation
  • Vasectomy is usually an outpatients procedure
  • Female sterilisation is done using a local anaesthetic making it easy and less risky
  • There is no effect on sexual desire/performance
  • No effect on the menstrual cycle


  • Permanent method/ not reversible
  • There are risks associated with operations
  • Vasectomy is not effective immediately

Side effects

  • Can result in psychological trauma if one has a change of heart.

To access more topics go to the Combined Science Notes page