Fertilization is a natural process which results in the formation of a new cell, when male and female reproductive cells; the egg and sperm fuse together. This occurs within the fallopian tube of women and may take about a week to complete.
This process involves different stages, during which many physical and chemical changes take place. When the fusion occurs, genetic information is passed onto the new cell from the male and female cells. This determines the gender of the baby.
How Does It Begin?
In females, it all starts before the onset of their regular menstrual period. During monthly cycle, your body begins its preparation in anticipation of fertilization, by building up a lining in the uterus.
Ovulation is a process which occurs during mid-menstrual cycle, that is 12 to 15 days before the onset of your next period. In this process, an egg is released in order to be fertilized. The ovaries release an egg or ovum that is matured into the Fallopian tubes. As the egg is moving down the Fallopian tube, if it meets a sperm on the way, it gets fertilized.
Sperm cells, present in semen are released into the female vagina during intercourse. These cells swim towards the uterus and once they reach the Fallopian tube, one of the sperms combines with the egg present there. This stage is called fertilization. Immediately the new cell starts diving and multiplying itself in the next 24 hours within the Fallopian tube. At this stage, the multi-cell formation is known as zygote.
Sperm can survive up to 5 days and the egg stands a chance to get fertilized in 24 hours before being released during the ovulation phase. If the sperm cell has Y chromosome, the baby is going to be a boy and if the sperm cell has X chromosome, the baby is going to be a girl. Not all sperm cells will be able to reach the Fallopian tube and not all the fertilized cells survive. They may be expelled naturally by your body, when you have your period.
The zygote continues to multiply and move towards the uterus. It takes about 4-5 days to reach the uterus, where it forms into a mass of cells. The zygote is now under embryonic development. After 3 or 4 days in the uterus, the embryo burrows itself into the uterine surface, which completes the process of conception successfully.