Chemical Contraception Methods

This section explores chemical contraception options, aligning with SQA Higher Human Biology curriculum requirements.

Definition: The oral contraceptive pill contains synthetic estrogen and progesterone that mimics negative feedback.

Highlight: The 'mini pill' contains only progesterone and works by thickening cervical mucus.

Example: Morning-after pills contain high hormone doses and can be effective up to 72 hours after intercourse.

Fertile Periods and Infertility Treatments

Understanding Fertility Cycles

Men are continuously fertile from puberty, producing sperm in their testes. Women, however, have cyclical fertility, being fertile for only a few days each menstrual cycle. This fertile period typically occurs 1-2 days after ovulation.

Highlight: Women's fertile period is usually limited to a few days each menstrual cycle, while men are continuously fertile.

Two methods to identify the fertile period are:

1. Body temperature measurement: Women's body temperature rises by about 0.5°C after ovulation.
2. Cervical mucus observation: During ovulation, cervical mucus becomes thin and watery, facilitating sperm movement.

Infertility Treatments

Several infertility treatments are available for couples struggling to conceive:

1. Stimulating Ovulation: Drugs can be used to prevent the negative feedback effect of oestrogen on FSH secretion, stimulating ovulation.

2. Artificial Insemination: This involves inserting semen into the female reproductive tract by means other than intercourse.

Definition: Artificial Insemination is a fertility treatment where sperm is directly inserted into the female reproductive tract to increase the chances of conception.

3. Intra-Cytoplasmic Sperm Injection (ICSI): This technique is particularly useful for males with low sperm count or sperm motility issues. A single sperm is injected directly into the egg to achieve fertilization.

4. In Vitro Fertilisation (IVF): This process involves several steps:

   • Ova are surgically removed after hormone stimulation
   • Mature sperm and ova are mixed in a culture dish
   • Fertilized ova are incubated until they form at least 8 cells
   • Two or three embryos are inserted into the uterus for implantation

Example: IVF bbc Bitesize provides detailed explanations and animations of the IVF process, making it easier for students to understand this complex fertility treatment.