Reproduction, Fertility and Contraception

Human Reproduction

Sexual reproduction involves the fusion of two specialised cells called gametes.
In humans, the male gamete is called a sperm, and the female gamete is called an ovum or egg.
The sperm fertilises the ovum to form a zygote, which develops into a foetus and eventually a new human.
Fertilisation occurs in the fallopian tubes of the female reproductive system.

The Menstrual Cycle

The menstrual cycle is a roughly 28-day cycle that females go through, which includes ovulation and menstruation.
Ovulation is the release of an egg from an ovary and usually occurs in the middle of the menstrual cycle (around day 14).
If the egg is not fertilised, the lining of the uterus is shed in a process known as menstruation.

Hormones of Reproduction

The menstrual cycle and reproduction are controlled by several hormones including FSH (Follicle Stimulating Hormone), LH (Luteinising Hormone), oestrogen, and progesterone.
FSH stimulates the ovaries to produce oestrogen and to mature an egg.
LH triggers ovulation and stimulates the ovaries to produce progesterone.
Oestrogen and progesterone regulate the menstrual cycle and maintain pregnancy.

Fertility

Fertility refers to the ability to produce offspring.
Infertility can be caused by a number of factors including age, lifestyle choices, environmental factors, and underlying medical conditions.
Treatments for infertility can include medical interventions such as IVF (In Vitro Fertilisation).

Contraception

Contraception refers to methods used to prevent pregnancy.
These methods can be hormonal (e.g., the pill or patches), barrier-based (e.g., condoms), intrauterine devices, sterilisation, or natural methods (e.g., tracking menstrual cycles).
It’s important to understand the differences between these methods in terms of their effectiveness, side effects, and also their ability (or lack thereof) to prevent sexually-transmitted infections.

Puberty

Puberty is the period of time when the body develops and a person becomes sexually mature. Hormones such as testosterone in males and oestrogen in females are key to these changes.
During puberty, primary sexual characteristics (ones we are born with) and secondary sexual characteristics (ones that develop during puberty) become more pronounced.
Puberty signals the time in life when a person can begin to reproduce. It happens in boys around the age of 12 or 13 and girls around the age of 10 or 11. However, the time can differ greatly among individuals.