Sometimes, a baby's tongue is stuck to the bottom of the mouth. This attachment means the baby can't open his or her mouth wide enough to get a good latch. This is called a tongue-tie. When a baby is checked after it is born, this usually is not checked. If the baby isn't latching on well and is not gaining weight mothers should talk to the nurse or doctor about this. Tongue-tie can be treated and breastfeeding gets better.