Week 27 and babycenter.com says: "Your baby is really starting to grow and fill in the available space in your uterus. This week he weighs in at about 2 pounds and is over 14 inches long. In other developments, your baby can now open and close his eyes, sleeps and wakes at regular intervals, and may suck a finger or thumb. Although still immature, his lungs are capable of functioning in the event of a premature birth, with help from a ventilator and other assistance."