Weak Feeding Apparatus
Since they have not had enough time to develop in the womb, their muscles, nervous system, and other body parts key to feeding are not fully developed. The actions of sucking and swallowing, as a result, become difficult. An estimated 43% of newborns up to 5 months old have problems feeding due to the following issues.
Since they are overall weaker, their tongue and jaw strength may not be sufficient to enable them to feed - they may feel exhausted doing it.
Underdeveloped gastrointestinal (GI) tract, which means that even when they are able to take in milk, they might not get the nutrients they need from it. They are also more likely to experience GERD or acid reflux, which means they may spit up a large amount of the milk before they can digest it.
They get tired easily and fall asleep. If you try to wake them, they are hardly alert enough to suck.
Some preemies, especially those who were born without good sucking-breathing coordination, will forget to breathe when feeding. Just like in swimming, if you don’t master breathing periodically, it is not possible to move ahead, the baby may start looking pale at your nipple. If your baby seems to be holding his or her breath all the time during feedings, regularly remove the nipple after every three to four sucks.
Babies who have spent a lot of time in the NICU may come to associate their mouths with feeding tubes, ventilator tubes, suctioning, and other unpleasant sensations and experiences. They might have developed fear and aversion. To get around this, try to replace the unpleasant oral associations with more pleasant ones. Gently stroke your baby around the mouth, give your baby your finger to suck, or encourage your baby to touch his or her own mouth or suck on his or her thumb or fist.
Extremely Low Body-Fat
It requires them to stay in an incubator (or isolette) for a certain number of hours per day to stay warm.
Jaundice, a sign of underdeveloped liver function characterised by yellow skin, which can cause a baby to be extra-fussy and feed poorly.