<Li> The nervous system develops enough to control some body functions . </Li> <Li> The eyelids open and close . </Li> <Li> The cochleae are now developed, though the myelin sheaths in neural portion of the auditory system will continue to develop until 18 months after birth . </Li> <Li> The respiratory system, while immature, has developed to the point where gas exchange is possible . </Li>

Which of the following is the medical term for the period of development from conception to birth