The general term used for babies who can not hold their
head up well is
head lag. At birth, all babies have
head lag. Some control over
head movement is reached by 8 weeks so that head lag lessens. By the age of 4-6 months, most babies should be able to hold their head up when pulled by their arms to a seated position. However, there is of course some variation between infants, and some may hold their head up earlier and some a little later.