Before you were born, you evaluated and decided what type of life experience you wanted in this physical earthly life. You decided you what gender you wanted to be, what type of environment would serve your life purpose, what type of parents you needed to provide you the foundation for that life experience. You decided, planned, and arranged for the type of life experience you needed, desired, and hoped for.

John UK, a midcausal teacher, said, "A person (or fragment) will assess and evaluate the life experience they need and then start planning their incarnation on the physical plane.  They will determine what the priorities are to experience and then evaluate which options on the physical plane will most likely provide those opportunities and experiences.  The fragment who desires to enter the physical body may choose a body that has predisposed physical traits and in certain social or societal features that will help that fragment to obtain the life experience it desires.  But physical abilities for a large part are determined by the gene pool of its parents and social and economic ability are determined by the society.  Therefore, if a person has a talent of physical ability to perform or learn or do something on the physical level, this comes fro the physical body.  The obvious example of this is physical strength, but other talents are also developed through this manner.

To read more about what impacts the life experience one has, see The Basics.

You made your choices and then before being born, you had the opportunity to observe your body and decide to commit or not commit to the birth.

As the time got nearer to the delivery, you (as a spiritual being) go to what we would call a waiting area on the astral plane to get ready for your birth.

At the birth or closely after the birth, you as a spiritual being enters your new body.