Anemia in Newborns
Medically reviewed by Dr. Michael Okonkwo, MD, FAAP · Board-Certified Neonatologist
Content reviewed against published AAP, NIH guidelines
Last reviewed:
If your baby has been diagnosed with or you suspect anemia in newborns, here is what the evidence says.
The short answer
Anemia in newborns means the baby has fewer red blood cells or lower hemoglobin than normal. Causes include blood type incompatibility, blood loss, prematurity, and infections. Mild physiologic anemia is normal around 6-8 weeks as birth red blood cells are replaced. Signs of significant anemia include pallor, lethargy, poor feeding, and rapid breathing.
Key takeaways
- Anemia in newborns means the baby has fewer red blood cells or lower hemoglobin than normal. Causes include blood type incompatibility, blood loss, prematurity, and infections. Mild physiologic anemia is normal around 6-8 weeks as birth red blood cells are replaced. Signs of significant anemia include pallor, lethargy, poor feeding, and rapid breathing.
- Usually normal when: Mild physiologic anemia around 6-8 weeks in a full-term baby who is feeding and growing well
- Call your doctor if: Significant pallor, rapid breathing, poor feeding, or lethargy, which could indicate severe anemia requiring urgent evaluation
- Varies by age — see the age-by-age breakdown below
“Fever itself is not an illness — rather, it is a sign or symptom that the body is fighting an infection. Fever stimulates certain defenses, such as the white blood cells, which attack and destroy invading bacteria.”
This is one of the most common questions parents ask. Searching for answers means you care.
What Parents Should Know
According to AAP, NIH guidelines, anemia in newborns means the baby has fewer red blood cells or lower hemoglobin than normal. Causes include blood type incompatibility, blood loss, prematurity, and infections. Mild physiologic anemia is normal around 6-8 weeks as birth red blood cells are replaced. Signs of significant anemia include pallor, lethargy, poor feeding, and rapid breathing. At 0-1 month, anemia in the first weeks can be caused by blood type incompatibility (ABO or Rh), blood loss during delivery, frequent blood draws (especially in the NICU), infections, or inherited conditions. Signs include pallor (pale skin), rapid heart rate, poor feeding, lethargy, and rapid breathing. Your baby's hemoglobin level was checked at birth. If anemia is significant, treatment may include iron supplementation, erythropoietin, or in severe cases, a blood transfusion. It is generally considered normal when mild physiologic anemia around 6-8 weeks in a full-term baby who is feeding and growing well. However, you should contact your pediatrician promptly if significant pallor, rapid breathing, poor feeding, or lethargy, which could indicate severe anemia requiring urgent evaluation.
Normal vs. Concerning
By Age
What to expect by age
0-1 month
Anemia in the first weeks can be caused by blood type incompatibility (ABO or Rh), blood loss during delivery, frequent blood draws (especially in the NICU), infections, or inherited conditions. Signs include pallor (pale skin), rapid heart rate, poor feeding, lethargy, and rapid breathing. Your baby's hemoglobin level was checked at birth. If anemia is significant, treatment may include iron supplementation, erythropoietin, or in severe cases, a blood transfusion.
1-3 months
Physiologic anemia of infancy is a normal drop in hemoglobin that occurs around 6-8 weeks as the red blood cells made before birth are broken down faster than new ones are produced. In full-term babies, this is usually mild and self-correcting. Premature babies experience a more significant drop (anemia of prematurity) and may need monitoring and treatment. Iron stores from birth begin to deplete during this period.
3-6 months
As your baby's bone marrow becomes more efficient at producing red blood cells, hemoglobin levels recover from physiologic anemia. Breastfed babies may begin iron supplementation at 4 months if not already started, as recommended by the AAP, since breast milk has limited iron content.
6-12 months
Iron-deficiency anemia becomes the most common form of anemia as iron stores from birth are depleted and iron needs increase with growth. Introduction of iron-rich solid foods and continued iron supplementation if breastfeeding help prevent iron-deficiency anemia. Your pediatrician may screen for anemia around 12 months.
What to Tell Your Pediatrician
- Describe when you first noticed anemia in newborns and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if your baby appears paler than usual.
- Mention if you notice your baby seems more tired than normal or feeds poorly.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Mild physiologic anemia around 6-8 weeks in a full-term baby who is feeding and growing well
- Baby has good energy and is alert despite slightly lower hemoglobin levels
- Recovery of hemoglobin levels by 3-4 months
- Your baby appears paler than usual
- You notice your baby seems more tired than normal or feeds poorly
- Your baby was premature and may be at higher risk for anemia
- Significant pallor, rapid breathing, poor feeding, or lethargy, which could indicate severe anemia requiring urgent evaluation
- Baby appears very pale and has a rapid heart rate or seems to tire easily during feeds
What You Can Do at Home
- Keep track of when you notice anemia in newborns — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that mild physiologic anemia around 6-8 weeks in a full-term baby who is feeding and growing well — this is generally within the range of normal.
- At 0-1 month, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Follow any care instructions from your pediatrician. Keep a written log of symptoms to bring to appointments.
- While monitoring at home, seek immediate care if significant pallor, rapid breathing, poor feeding, or lethargy, which could indicate severe anemia requiring urgent evaluation.
Related Conditions
ABO Blood Type Incompatibility in Newborns
ABO incompatibility occurs when a mother and baby have different blood types (most commonly a type O mother with a type A or B baby), causing the mother's antibodies to attack the baby's red blood cells. This can lead to more severe jaundice and anemia in the newborn. It is manageable with monitoring and treatment, and the vast majority of babies do well.
My Baby Looks Very Pale
Babies' skin color can vary naturally depending on temperature, activity, and genetics. However, true pallor (unusual paleness of the skin, lips, or nail beds) can sometimes indicate anemia, poor circulation, or an infection. If your baby looks noticeably paler than usual, especially in the lips, gums, inner eyelids, or palms, it is worth mentioning to your pediatrician.
Polycythemia in Newborns (Too Many Red Blood Cells)
Polycythemia occurs when a newborn has too many red blood cells, making the blood thicker than normal. It can cause a ruddy or deep red skin color and, in significant cases, can affect blood flow to organs. Risk factors include delayed cord clamping, maternal diabetes, and being small or large for gestational age. Most cases are mild and resolve without treatment.
Related Resources
Frequently asked questions
Is anemia in newborns normal?
When should I call the doctor about anemia in newborns?
When is anemia in newborns normal?
What causes anemia in newborns?
What should I mention to my pediatrician about anemia in newborns?
Is anemia in newborns normal at 0-1 month?
Is anemia in newborns normal at 1-3 months?
Should I go to the ER for anemia in newborns?
Does anemia in newborns go away on its own?
References
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss Anemia in Newborns.
Things to mention
- Describe when you first noticed anemia in newborns and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if your baby appears paler than usual.
- Mention if you notice your baby seems more tired than normal or feeds poorly.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- Your baby appears paler than usual
- You notice your baby seems more tired than normal or feeds poorly
- Your baby was premature and may be at higher risk for anemia
Urgent signs to report immediately
- Significant pallor, rapid breathing, poor feeding, or lethargy, which could indicate severe anemia requiring urgent evaluation
- Baby appears very pale and has a rapid heart rate or seems to tire easily during feeds
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of anemia in newborns are normal. Talk to your pediatrician if significant pallor, rapid breathing, poor feeding, or lethargy, which could indicate severe anemia requiring urgent evaluation.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
Was this page helpful?
Related Medical Concerns
ABO Blood Type Incompatibility in Newborns
ABO incompatibility occurs when a mother and baby have different blood types (most commonly a type O mother with a type A or B baby), causing the mother's antibodies to attack the baby's red blood cells. This can lead to more severe jaundice and anemia in the newborn. It is manageable with monitoring and treatment, and the vast majority of babies do well.
My Baby Looks Very Pale
Babies' skin color can vary naturally depending on temperature, activity, and genetics. However, true pallor (unusual paleness of the skin, lips, or nail beds) can sometimes indicate anemia, poor circulation, or an infection. If your baby looks noticeably paler than usual, especially in the lips, gums, inner eyelids, or palms, it is worth mentioning to your pediatrician.
Polycythemia in Newborns (Too Many Red Blood Cells)
Polycythemia occurs when a newborn has too many red blood cells, making the blood thicker than normal. It can cause a ruddy or deep red skin color and, in significant cases, can affect blood flow to organs. Risk factors include delayed cord clamping, maternal diabetes, and being small or large for gestational age. Most cases are mild and resolve without treatment.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.