Fertilization is when a sperm cell and egg cell unite to form a single cell called a zygote. A zygote can grow into a baby.

A pregnancy in which two fetuses (babies) develop in the womb at the same time.

The menstrual cycle is the monthly process of preparing your eggs and womb for a possible pregnancy.

Ovaries are the sexual organs (gonads) in most female bodies that produce eggs, scientifically called ‘oocytes’.

The total number of healthy eggs in your ovaries at any time is called the ovarian reserve.