අඩෝ මාරයි නේද බන්. ස්වභාවධර්මය හරිම inerlligent. ඉපදෙනකොට ගර්භාෂයෙන් මුලින්ම කකුල් තියෙන පැත්ත එළියට ආවොත් කකුල් හිර වෙල මැරෙයි. ඒක නිසා මුලින් ඔළුව තියෙන පැත්ත තමයි එළියට එන්නෙ. මුන් ඒක හරියට කරනවා.

But it's much more complicated than that. At childbirth the entire skull & the brain itself changes shape. The skull bones gets overlapped and the head takes a conical shape - an elongated cone - allowing the head to pass through the pelvis. This is really incredible.
This is the reason why the human brain growth really takes place after the birth. The nature has catered for the high risk normal delivery system to take place allowing the head to be squeezed.
Note, there are other changes too that happens to a baby when coming out of the mother's womb. Naturally other support functions have to take over.