simply embryo in the Quran are describing the outer shape stages of what the eye can see. so it is the signs only not the full processes . because i think Allah needs more than hundreds of Quran to speak about the specific process of the embryo alone. have you ever heard about the unformed lump of flesh ? you ever seen it ? we experienced it in my brother's wife when she was a pregnant of unformed lump of flesh and she had to abort it because it wont come to life.
