Many couples will be advised to consider IVF treatment. During a woman’s normal monthly cycle one egg grows and is released (ovulated). As this happens the fallopian tube moves to collect this microscopic egg. Meanwhile sperm must swim from the vagina, through the cervix and womb into the tube to find the egg. Once beside the egg several sperm must bind to it for one to complete its journey and enter the egg. Specialized microscopic hairs and muscle in the wall of the fallopian tube move the fertilized egg down the tube into the womb as it changes to become an embryo. Once inside the womb the embryo must find a place to implant in the womb lining and become a pregnancy.
If the egg is not fertilized by a sperm her period will start 14 days later. If the Fallopian tubes are blocked or cannot pick up the released egg, then the egg and sperm can’t meet and pregnancy doesn’t occur. If the sperms are only produced at low levels or cannot swim well they are unlikely to make it to the egg and pregnancy is unlikely to occur. There are also many other reasons why a couple may not achieve a pregnancy. There IVF is a treatment that brings eggs and sperm together in the laboratory and encourages fertilisation to happen by providing a nourishing environment.
IVF bypasses several of the natural processes of conception in the human body such as:
- The role of the fallopian tubes in collecting the egg as it is released from the ovary (ovulated)
- The need for sperm to swim through the womb into the Fallopian tubes to reach the egg
- The need for the fertilised egg to move down the tube and find its way into the womb
IVF can also control the complex process of a sperm entering and fertilising an egg.It provides a nourishing environment as the fertilized egg develops into an embryo. The last step of IVF is to gently transfer the embryo or embryos back inside the womb where they would have been at that time had all been working as usual in the body.