Complex sentence: Not all mothers can nurse hands-free in a baby carrier: large-breasted mothers and mothers of small or hypotonic infants may need to support the breast or help maintain proper positioning of baby's head or body.
Split into simpler sentences: Not all mothers can nurse hands-free in a baby carrier. Large-breasted mothers and mothers of small or hypotonic infants may need to support the breast or help maintain proper positioning of baby's head or body.