Opening of the baby's mouth

Why does my one-month old baby’s mouth not open wide with latching?

It is normal for babies to open their mouths less wide after one month of age.

A) The width of the baby’s mouth

In order to latch a baby, the baby’s mouth needs to open.

1) Under one month of age

Babies under one month of age will open their mouths wide, like a little bird, when the top lip is tapped while latching. These babies are guided by reflex.

2) Over one month of age

After one month, babies become more effective at breastfeeding. They also start relying on learned behaviour instead of their reflexes.

By one month of age, babies have learned that their mouth only has to be opened up enough to allow the nipple and the tissues behind the nipple (the nipple rootto enter. They will not open their mouths fully but only part ways when latching.

Some mothers will keep a baby from latching in an attempt to have the baby open up wider. The babies are hungry and become increasingly frustrated when they are not allowed to latch.

As long as the baby is latching well and breastfeeding effectively and any nipple pain is settling or has settled, there is no need to worry about how wide the baby’s mouth is open when latching.

The baby’s lips are also less turned out (flanged) after one month as the breast is less firm.