Human beings are mammals, which mean that their young develop inside the mother until they are ready to be born. This development takes place inside the womb or uterus, where the baby gains the nutrients and oxygen it needs for growth from its mother’s own blood, supplied through the umbilical cord.
A woman’s ovaries usually release one egg each month. As it travels through the fallopian tube towards the uterus, it may be fertilized by a sperm that has enter her bady during sexual intercourse.
As soon as it is fertilized, the egg call begins to divide, until it becomes a ball of cells called a blastocyst. This ball then implants itself in the wall of the uterus.
After four weeks, the blastocyst has become an embryo. Its brain, spin and limbs are already forming and its heart will soon begin to beat.
At 12 week, the embryo is now called a foetus. All its organs are formed. For the rest of the time before it is born, it simply has to grow.
From 38 weeks onwards, the baby is ready to be born. It moves down into the pelvis. At birth, the cervix gradually opens and the baby is born through the vagina.