Having a deep latch is the gold standard of breastfeeding. It’s also something that causes a lot of confusion and concern when parents aren’t able to achieve a deep latch on their own. You may know that a shallow latch can cause pain and an inefficient transfer of milk, but sometimes knowing how to fix it can be frustrating and unclear.

A deep latch is one where the baby is able to open their mouth widely, and take both the nipple and some of the breast tissue, into their mouth. When a baby has a shallow latch, the angle of the jaw is significantly narrowed. The more shallow the latch, the more narrow the jaw. This often causes pain when latching, as the nipple becomes pressed against the bony hard palate of the mouth.

As the jaw becomes more and more closed, the posterior part of the tongue has less and less room to lift and drop, and this reduces the air displacement. This results in a much weaker, or potentially eliminated, vacuum, significantly reducing the flow of milk from the breast. Most babies are quick to adapt, and compensate for the lack of a vacuum, by sucking harder or using their tongue more vigorously. This also causes pain for the nipple and fatigue in the baby, because the oral motor muscles are not designed to work in this way for feeding. It also prevents the breast from being fully emptied, and this often has long-term impacts on the supply of the chest or breastfeeding parent.

The very first step in achieving a deep latch is the position of the head and neck (not with the mouth). In order to drink from the breast, the baby must first be able to extend their head and neck backwards to mechanically allow for a wide jaw. Range of motion of the head and neck of a baby matters from day one. When the head rocks backwards into extension, the jaw is able to open fully, and will do so if it can. See the Latch Lesson #1 video below for more instruction:

After the baby has rocked their head back, the chin plants on the breast, providing an anchor point for the baby, who will then reflexively open their mouth as widely as possible until the nipple enters the mouth, and the suck reflex is initiated. The opening of the jaw ends when sucking begins, as the baby’s reflexes are now shifted to help the baby prepare to feed. If the nipple enters the baby’s mouth when it is not gaped widely, the latch will be shallow. If the gape is wide, but the nipple is placed in the middle of the mouth, the baby will close the mouth down until the nipple is at the top of the mouth, and the latch will be shallow. If the baby is able to anchor the chin, gape widely until they come up an over the nipple, the latch will be deep.

If any of these components: the head extension, chin planting, wide gaping or nipple being located at the top of the baby’s mouth does not occur, and a tongue that can move to the top of the mouth, then the latch will not be deep. If the latch is not deep then the latch can not be functional. If the latch is not functional, then the baby is using compensations to feed from the breast.

We can think of a deep latch as similar to drinking from a cup, and a shallow latch as drinking from a straw that is too short to reach the bottom of the cup. When drinking from a cup, when we extend our head backwards, we are able to swallow comfortably and easily empty the contents. If we have a straw, we suck until we get to the end, and then suck harder to get the rest of the liquid out, but no matter how hard we try, there will always be something left in the bottom of the cup. If a mother has an abundant supply, then sucking works just fine initially, and the baby will gain weight appropriately, even with a shallow latch. However, over time milk supply down-regulates to match the emptying of the breast, then the supply gets smaller. When the cup is no longer supersized then the baby slowly stops gaining weight well and begins to fall on their growth curve. Often, this results in a mother who begins to supplement with formula to feed her baby, and this impacts her own feeding goals with her baby.

While the presence of pain always indicates a latch concern, the lack of pain does not define function. While failure to gain weight indicates a latch concern, robust weight gain does not define function. Function is determined by the ability to achieve and maintain a deep latch, throughout an entire feeding. Functional breastfeeding is important. It matters for supporting breastfeeding parents and it matters for the establishment of the oral motor skills that provide the mechanical foundation to creating a healthy airway, the ability to communicate clearly and eat food in a healthy and safe way.