What Are the Causes of Newborns Not Eating?

Newborns need to eat every few hours, since their stomachs don't hold very much milk at one time.

It may take a few days for your baby to wake up and start eating normally after birth. A newborn that suddenly stops eating after that needs medical evaluation, unless you're offering feedings too close together. Many illnesses can cause a newborn to refuse to eat; call your doctor immediately if this occurs, especially if your baby appears ill in any other way.

Normal Reactions

Newborns may need a few days to start eating properly. Any medications you took during labor will affect your baby, perhaps for longer than they affect you, since your baby's immature liver can't break them down easily. Many pain medications can cause temporary drowsiness in a newborn.

Just the act of being born can also cause a newborn to be sleepy and somewhat uninterested in eating for the first day or so. This is normal and won't hurt the baby in any way. If you're breastfeeding, your breast milk normally doesn't come in until day two or three after birth. Until then your baby needs only the colostrum your breasts produce, not milk or formula, Huntsville Pediatric Associates explains.

Infection

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If your newborn has an infection, he may become very lethargic and refuse to eat. Unlike older infants and adult, newborns don't always run fevers when they're sick. In fact, a newborn may have a temperature that's lower rather than higher than normal, KidsHealth explains.

In addition to not eating, a baby with an infection may be very floppy, with poor muscle tone. Certain infections may cause a skin rash. He may have a shrill, high-pitched cry and extreme irritability or may be unresponsive. An infection in a newborn is a life-threatening condition that requires antibiotics; call your doctor immediately or go to the emergency department.

Jaundice

High levels of bilirubin, a byproduct of red blood cell breakdown, in the blood causes jaundice. Around 60 percent of newborns have some degree of jaundice, according to the March of Dimes. Most jaundice in newborns resolves quickly on its own. The liver normally removes bilirubin and excretes it in the stool. An immature liver or breakdown of a larger than normal number of red blood cells can cause jaundice. If you and your baby have different blood types, your baby has a higher risk of developing jaundice.

If your baby has jaundice, his skin and whites of his eyes may have a yellowish tinge.

Jaundice makes a newborn very sleepy.

He may have poor muscle tone or may appear unusually stiff. He may arch his back and neck. These symptoms should prompt an immediate call to your doctor.

Hypoglycemia

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As many as 1 to 3 out of 1,000 newborns experience a drop in blood sugar levels after birth, MedlinePlus reports. Most often these babies are large babies whose mothers have diabetes, including gestational diabetes; premature infants; septic babies; or those with certain genetic disorders.

A baby with low blood sugar may not eat and may become lethargic, but could also become irritable and jittery.

He may turn blue from lack of oxygen and stop breathing for short periods. Your doctor will draw blood to test glucose levels and will give the baby sugar water through an intravenous line if the baby won't drink.