You all must be wondering through the topic that I might describe the spiritual process onto which many of you must not be interested but here it's completely opposite.
Actually these days I am reading a book based on enlightenment and it is amazing! And the process which led a soul take a rebirth is really very interesting , here's how-
If a soul needs to take a rebirth as human, it circles around the place of its rebirth. when the soul or I should preferably say a bardo being( It means a soul struck in intermediate phase after death and before rebirth) so when it comes closer to the place of its parents and when it sees its parents of rebirth copulating , it develops the strong desire to join in but as its not possible so its desire is frustrated and it dies in anger, as it dies the bardo being experiences all the signs of death clearly and when the clear light of death ceases , its consciousness enters the union of sperms and ovum insight the mother's womb, it enters by passing through the mouth of father then descending through the sex organ into the mother's womb.
The first moments after conception only black appears to the mind of new human being and then all the remaining signs of death appears in the reverse order as the consciousness becomes more gross. and then comes the steps we all know that it is in the form of liquid and then gradually hardens up after few weeks resembles like a fish and later the process takes place of normal pregnancy.
That's how life comes into the body.
The citing of the entire knowledge goes to Venerable Geshe Kelsang Gyasto! As I learnt it through a book and wrote it in my way here. the book was written by him in 1997 when I was born, my father bought it in 2000 and now after actually 20 years I am reading it. Although I am not deeply a spiritual person but still somewhat believe in certain things.
I just wasn't clear on how the bardo being enters when the test tube baby or surrogacy methods are used.
No offence to anyone who doesn't believe into the concept of rebirth and spirituality. We all are gifted with free will and can follow what we believe.