Section 1 of 9Why contraception is used
Contraception is the prevention of pregnancy.
Section 2 of 9Hormonal methods
Hormonal contraceptives use oestrogen and/or progesterone to alter the menstrual cycle.
- It inhibits the release of FSH so that no eggs mature, and so ovulation does not occur.
- It must be taken daily and is very effective if taken correctly.
- and thins the lining of the uterus so that an embryo cannot implant.
- It is useful for women who cannot take oestrogen.
Early contraceptive pills contained high doses of oestrogen, which had more side effects than the modern low-dose versions, such as headaches, nausea, mood changes and a small increase in the risk of blood clots. The pill does not protect against sexually transmitted infections.
Section 3 of 9Non-hormonal methods
- A diaphragm or cap blocks the cervix, and is used with spermicide.
- Condoms also give protection against sexually transmitted infections such as chlamydia and HIV.
- It prevents implantation, and copper-containing devices also kill sperm.
- It can last for years.
- which is unreliable because the cycle varies.
- It is permanent and is very effective.
Section 4 of 9Comparing the methods
| Method | Effectiveness | Drawbacks |
|---|---|---|
| Combined pill | Very high if taken daily | Side effects; must remember; no STI protection |
| Implant or injection | Very high | Irregular bleeding; needs a medical procedure |
| Condom | Good, but depends on correct use | May split or be used wrongly |
| IUD | Very high | Insertion procedure; may cause heavier periods |
| Natural method | Low | Cycle unpredictable |
| Sterilisation | Almost 100 percent | Permanent; surgery needed |
Section 5 of 9Evaluation and links
When evaluating, consider reliability, convenience, side effects, ability to reverse and protection against infection.
- and compare this with a number like 15 in 100 for another method.
The hormonal methods use the knowledge of the menstrual cycle (5.3.1): the pill works by supplying hormones that mimic the feedback that normally prevents ovulation. The topic also links with reproductive health and infection control.
Section 6 of 9Choosing a method: case-style questions
Exam questions often describe a couple and ask for a suitable method.
Remember also that emergency contraception exists, which can be used soon after unprotected intercourse, and works mainly by delaying ovulation or preventing implantation.
Section 7 of 9Exam-style questions
Explain how the combined contraceptive pill prevents pregnancy. [3]3 marks
It contains oestrogen and progesterone [1]. These inhibit the release of FSH from the pituitary [1]. Eggs do not mature and ovulation does not occur [1].
Give two advantages and one disadvantage of using condoms. [3]3 marks
Advantages: they protect against sexually transmitted infections [1]; they have no hormonal side effects, or are easily available [1]. Disadvantage: they can split or be used incorrectly, so are not completely reliable [1].
Out of 200 couples using method A for a year, 6 become pregnant. Calculate the percentage failure rate. [2]2 marks
6 / 200 [1] × 100 = 3 percent [1].
Section 8 of 9Key terms
| Term | Meaning |
|---|---|
| Contraception | Methods used to prevent pregnancy. |
| Barrier method | A method that stops sperm reaching the egg physically. |
| Intrauterine device | A small device placed in the uterus to prevent pregnancy. |
| Spermicide | A chemical that kills sperm. |
| Vasectomy | Surgical cutting of the sperm ducts. |
| Implantation | Attachment of the embryo to the uterus lining. |
| Sexually transmitted infection | An infection passed on through sexual contact. |