Contraception prevents pregnancy by interfering with fertilisation, ovulation or implantation.
HORMONAL METHODS — prevent ovulation:
COMBINED PILL — contains oestrogen and progesterone. Oestrogen inhibits FSH production → no egg maturation → no ovulation. Taken daily.
PROGESTERONE-ONLY PILL (mini-pill) — thickens cervical mucus (stops sperm reaching egg) and may also prevent ovulation.
IMPLANT — small rod inserted under skin of upper arm, releases progesterone for up to 3 years. Prevents ovulation.
INJECTION — progesterone injected every 8–12 weeks. Prevents ovulation.
HORMONAL IUD (Mirena coil) — releases progesterone locally in the uterus.
BARRIER METHODS — prevent sperm reaching the egg:
MALE CONDOM — placed over the penis. ALSO protects against STIs — the only contraceptive that does this.
FEMALE CONDOM — inserted into the vagina. Also protects against STIs.
DIAPHRAGM — placed over the cervix before sex.
NON-HORMONAL:
COPPER IUD (copper coil) — T-shaped device placed in the uterus. Copper ions are toxic to sperm. No hormones involved.
SURGICAL (permanent):
VASECTOMY — vas deferens cut or tied in males → sperm cannot be released.
TUBAL LIGATION — fallopian tubes cut or tied in females → eggs cannot reach the uterus.
Fertility Treatments
Some couples have difficulty conceiving naturally. Medical treatments can help.
FSH AND LH TREATMENT (fertility drugs):
Women who don't ovulate regularly are prescribed FSH (and sometimes LH) to stimulate egg maturation and ovulation.
Risk: can cause multiple eggs to mature at once → multiple pregnancy (twins, triplets).
IN VITRO FERTILISATION (IVF):
'In vitro' means 'in glass' — fertilisation takes place in a laboratory dish, outside the body.
The IVF process:
1. The woman is given FSH (and LH) to stimulate the ovaries to produce multiple eggs.
2. Eggs are collected from the ovaries using a fine needle under sedation.
3. Eggs are mixed with sperm in a laboratory dish — fertilisation occurs.
4. Embryos develop for 2–5 days in the laboratory.
5. One or two embryos are placed into the woman's uterus through the cervix.
6. Progesterone is given to help maintain the uterus lining for implantation.
7. If an embryo implants successfully, pregnancy begins.
Success rates: approximately 30–40% per cycle for women under 35, declining with age.
Ethical Considerations
Both contraception and fertility treatment raise important ethical questions.
CONTRACEPTION:
Some religious groups oppose artificial contraception (e.g. the Catholic Church teaches natural family planning only).
Emergency contraception ('morning-after pill') is controversial — some consider it preventing implantation of a fertilised egg.
Condoms are widely supported as they also prevent spread of STIs.
FERTILITY TREATMENT (IVF):
Multiple embryos are often created — unused embryos may be frozen, destroyed or donated to research. This raises questions about the moral status of embryos.
Pre-implantation genetic diagnosis (PGD) — testing embryos for genetic conditions before implantation. Raises concerns about 'designer babies'.
IVF is expensive — raises questions about who should have access.
The physical and emotional burden on women undergoing IVF is significant.
Donor eggs or sperm raise questions about identity and donor anonymity.
⚠️ Common Mistake
The contraceptive pill does NOT protect against STIs — only BARRIER METHODS (condoms) protect against both pregnancy AND sexually transmitted infections. The combined pill prevents OVULATION by inhibiting FSH — without ovulation, there is no egg to fertilise. In IVF, FSH is given to stimulate MULTIPLE egg production — not to help with implantation (progesterone does that).