If your baby arrived at 34, 35 or 36 weeks, they may look almost like a term baby. Inside, a few systems are still catching up: keeping warm, holding blood sugar steady, clearing jaundice and feeding well. That is why late preterm babies get a few extra checks, and why the first weeks home need a plan. Below is what to expect, step by step, and what large studies found about how these children do later.

General information, not medical advice. Every baby is different, and your baby’s doctors and nurses know your baby best. If you are worried about your baby right now, call your pediatrician, or 911 in an emergency.
Add as a preferred source on Google

§I.What “late preterm” means

A baby born from 34 weeks and 0 days to 36 weeks and 6 days of pregnancy is called late preterm1. About 1 in 10 babies in the United States is born before 37 weeks (10.41% in 2023)4, and about 7 in 10 of them arrive in these three weeks3. Babies born at 37 or 38 weeks are called early term.

Late preterm babies often look like small term babies, which is why doctors once called them “near term”. Inside, a few systems are still catching up: keeping warm, holding blood sugar steady, clearing bilirubin (the cause of jaundice), breathing and feeding1. In a large US study, 22 in 100 late preterm babies had a newborn health problem, against 3 in 100 born at term, and the risk doubled with each week born before 38 weeks2. Most of these problems are mild and pass in the first days or weeks.

§II.Born at 34, 35 or 36 weeks: each week counts

Because the risk of newborn problems roughly doubles with each earlier week2, a baby born at 34 weeks usually needs more help than one born at 36 weeks. These are typical patterns, not rules: your baby’s own start matters more than the week.

Born at 34 weeks

Your baby arrived about 6 weeks before their due date. Babies born at 34 weeks are the most likely of the three to spend some time in a neonatal intensive care unit (NICU) or special care nursery, most often to help with feeding, breathing, blood sugar or warmth. Some feed partly through a thin tube for a while until they can take full feeds by mouth.

Born at 35 weeks

Your baby arrived about 5 weeks early. Many babies born at 35 weeks can stay with their parents, with extra checks. Feeding and jaundice are the most common things to watch, and some babies need a short stay in special care.

Born at 36 weeks

Your baby arrived about 4 weeks early. Babies born at 36 weeks often feed and breathe like term babies, but they can tire at feeds, sleep through hunger and get more jaundice than babies born at term. They are still late preterm, so the same checks apply.

For milestones and growth, count from the due date, not the birthday, until about age 2: a baby born at 35 weeks is 5 weeks early, so at 3 months old they are about 2 months corrected. Our guide to corrected age shows the formula.

§III.The first days: what is checked and why

Expect a few extra checks in the first days. Each one looks for a common, treatable problem, and most babies need little or no treatment.

What is checked in the first days after a birth at 34 to 36 weeks, and why
What is checkedWhy babies born at 34 to 36 weeks get itWhat you might see
Blood sugarLate preterm babies are checked for low blood sugar through their first 24 hours.5 In a study of babies at risk, about half had low blood sugar at least once, most of it in the first day.6Early, frequent feeds and a few heel-prick checks, with treatment if levels stay low.
TemperatureWith less body fat, these babies lose heat faster than babies born at term.1Skin-to-skin time, a hat, and sometimes a warmer or an incubator for a while.
BreathingThe lungs may not be quite ready. In a large trial, steroid shots given to mothers at 34 to 36 weeks lowered the share of babies needing breathing help in their first three days from about 14 in 100 to about 12 in 100.11Fast breathing that settles in the first hours, and sometimes oxygen or a breathing mask for a short time.
JaundiceEvery newborn’s bilirubin is measured before going home, and a birth before 38 weeks lowers the level at which treatment starts.7A skin or blood check, and light treatment (phototherapy) if the level is high.
FeedingFeeding difficulties are among the most common reasons these babies stay longer or come back.1,9Feeds and weight watched closely, sometimes with pumped milk or formula given by cup, bottle or a thin tube.
Car seatSome hospitals watch babies born before 37 weeks sitting in their own car seat to check their breathing. No trials show whether this check prevents harm, so practice differs.14A watched spell in your own car seat before you leave, often about as long as the ride home, if your hospital does it.

Breathing help means support such as oxygen or a breathing mask; the trial counted it in the first three days of life11. The same trial found that more babies whose mothers had the steroid shots had low blood sugar, which is one more reason blood sugar is checked11.

Late preterm babies go home when they feed well, keep warm, hold their blood sugar steady and have had their jaundice checked, rather than on a set day1. Expect a check-up within a few days of going home, and sooner if jaundice needs watching7.

§IV.Feeding in the first weeks home

Feeding is the part most families find hardest. Babies born at 34 to 36 weeks can be sleepy, tire before they have had enough, and have a weaker suck than babies born at term1. Breastfeeding problems are more common after a birth at 34 to 38 weeks, so guidance for breastfeeding these babies asks for a feeding plan made early, before problems start8.

  • Feed often. Most newborns feed 8 or more times in 24 hours. A late preterm baby may not wake or cry for every feed, so ask whether to wake your baby, and how often.
  • Watch the diapers and the weight. Ask how many wet and dirty diapers to expect each day. Weigh-ins in the first weeks show whether feeds are enough.
  • Protect your milk supply. If your baby tires at the breast, pumping after some feeds and giving that milk can protect your supply while your baby gets stronger. A lactation consultant can help you make a plan.
  • Top-ups are fine when advised. Some babies need extra pumped milk or formula for a while. That is a bridge, not a failure.

Feeding matters because most trips back to hospital in these weeks are for jaundice or feeding. Breastfed late preterm babies went back into hospital more often than other babies, mostly for jaundice, poor weight gain or dehydration linked to taking too little milk9. In another study, late preterm babies who had not needed the NICU had about 3 times the odds of going back into hospital within two weeks10. A feeding plan and early weight checks are the best protection.

§V.Jaundice: why it is checked more closely

Jaundice, a yellow tint to the skin and eyes, is common in all newborns. It is more of a concern after a birth at 34 to 36 weeks, because the liver is less mature and slower feeding means bilirubin leaves the body more slowly. The American Academy of Pediatrics’ 2022 guideline lists a lower week of birth as a risk factor for high bilirubin, and it starts treatment at lower levels for babies born before 38 weeks7.

Bilirubin usually peaks a few days after birth, often after you are home, which is why the first check-up comes soon. Call your baby’s doctor the same day if the yellow color is spreading to the belly or legs, the whites of the eyes look yellow, or your baby is very sleepy, hard to wake for feeds or feeding poorly.

§VI.Sleep: how much, and how safely

Late preterm babies often sleep a lot, and a sleepy baby can sleep through hunger. In the first weeks, feeding comes first: follow your team’s advice on waking your baby for feeds until weight gain is steady.

Safe sleep matters even more after an early birth. In US birth and death records, the risk of sudden unexpected infant death was highest for babies born earliest, and it was still higher than at term for babies born closer to their due date13. The American Academy of Pediatrics’ safe sleep steps apply from the first night home12:

  • Always put your baby to sleep on their back, for naps and at night.
  • Use a firm, flat sleep surface, such as a crib or bassinet mattress with a fitted sheet, and nothing else in it.
  • Keep your baby’s sleep space in your room, close to your bed, but not in your bed.
  • Do not let your baby sleep in a car seat, swing or sling at home. If your baby falls asleep in one, move them to a flat sleep surface.

§VII.Growth and the first year

Most babies lose some weight in the first days and should be back to their birth weight within the first couple of weeks. After that, a steady climb along their own growth curve matters more than any single weigh-in. Your pediatrician plots growth by corrected age, so being smaller than a term-born baby with the same birthday is expected at first.

Routine vaccines follow your baby’s real birthday, not corrected age. Ask too about protection against RSV, a common winter virus that hits young babies hardest: in the United States, either a vaccine given in pregnancy or an antibody shot for the baby is recommended for the first RSV season15. Keeping sick visitors away and washing hands help in the first months.

§VIII.Development through school age

For most babies born at 34 to 36 weeks, development follows the usual path, a few weeks behind their birthday at first and then on track. The research does show small differences across large groups:

  • At age 2. In a UK study of babies born at 32 to 36 weeks, 6 in 100 had a delay in thinking skills, against 2 in 100 born at term, so about 94 in 100 had none16.
  • At age 4. In a Dutch study, about 8 in 100 children born at 32 to 36 weeks had a developmental delay when they started school, about twice the rate of children born at term17.
  • At age 5. In England, 59 in 100 children born at 34 to 36 weeks had not reached a “good level” of development by the end of their first school year, against 51 in 100 born at term, a gap the authors called small next to other factors in a child’s life18.
  • At school. In Scotland, the chance of needing extra help at school rose a little with each week born earlier, even at 37 to 39 weeks19. In Florida, healthy late preterm children were a little more likely than term-born children to have a developmental disability and to be held back in kindergarten20.

So the most likely outcome is a child who does well. It is still worth using corrected age for milestones until about 2, telling teachers about the early birth, and asking for a check if speech, reading, attention or coordination seem harder than expected. The free Child Development Milestones Checker has a born-early option, and Do premature babies catch up? gives the long-term results for every birth week. If anything worries you before age 3, you can ask for a free early intervention evaluation yourself.

§IX.When to call the doctor

You never need a reason from a list to call. In the first weeks, call your baby’s doctor the same day for:

  • Yellow skin that is spreading or deepening, or yellow whites of the eyes.
  • A baby who is very sleepy, hard to wake for feeds, or feeding poorly.
  • Fewer wet or dirty diapers than your team told you to expect.
  • A temperature of 100.4°F (38°C) or higher, or a baby who feels cold and will not warm up. In the first months, a fever always needs a call straight away.
  • Breathing that is fast or hard work, with the skin pulling in between the ribs.

Call 911 if your baby stops breathing, has pauses in breathing, or their lips or skin look blue or gray. Later on, raise milestones that seem late for corrected age, or any skill your baby had and has lost. Our guide to preparing for a pediatrician visit lists what to bring.

Look after yourself too. An early birth, and a NICU stay, can be hard on parents. If worry or sadness stays with you for weeks, tell your own doctor: it is common, and help works.

Add as a preferred source on Google
Questions parents ask

Born at 34, 35 or 36 weeks: common questions

01Is a baby born at 36 weeks premature?

Yes. Any birth before 37 weeks is preterm, and a birth at 34 to 36 weeks is called late preterm. Babies born at 37 or 38 weeks are called early term. A baby born at 36 weeks often looks like a term baby but can still tire at feeds and get more jaundice.

02Do babies born at 34 or 35 weeks need the NICU?

Some do, usually for a short stay to help with feeding, breathing, blood sugar or warmth. The earlier the week, the more likely it is. Many babies born at 35 or 36 weeks can stay with their parents, with extra checks.

03How long do late preterm babies stay in the hospital?

There is no set number of days. Late preterm babies go home when they feed well, keep warm, hold their blood sugar steady and have had their jaundice checked. A baby born at 34 weeks often stays longer than one born at 36 weeks.

04How often should a baby born at 35 weeks eat?

Most newborns feed 8 or more times in 24 hours, and a late preterm baby may need waking for some feeds. Ask your baby’s team how often to feed, and watch wet and dirty diapers and weight checks to know feeds are enough.

05Why is jaundice more of a concern after a birth at 34 to 36 weeks?

The liver is less mature and feeding is often slower, so bilirubin can build up. Guidance from the American Academy of Pediatrics treats a lower week of birth as a risk factor and starts treatment at lower levels before 38 weeks.

06Should I use corrected age for a baby born at 35 weeks?

Yes, for milestones and growth until about age 2. A baby born at 35 weeks is 5 weeks early, so subtract 5 weeks from their age. Routine vaccines still follow the real birthday. Our corrected age guide shows the formula.

07Will a baby born at 34 to 36 weeks catch up?

Most do. In a large UK study, about 94 in 100 babies born at 32 to 36 weeks had no delay in thinking skills at age 2. Small differences in early school skills show up across large groups, so tell teachers about the early birth. Do premature babies catch up? has the full results.

08Are late preterm babies at higher risk of SIDS?

Somewhat. The risk of sudden unexpected infant death is highest for babies born earliest, and it is still a little higher than at term for babies born at 34 to 36 weeks. Safe sleep on the back, on a flat surface in your room, matters from the first night.

Sources · studies and clinical guidance

Evidence used for this article

Figures are rounded from each study’s published results. They describe groups of babies and children, not the outlook for one baby.

  1. Engle WA, Tomashek KM, Wallman C; Committee on Fetus and Newborn. “Late-preterm” infants: a population at risk. Pediatrics. 2007;120(6):1390–1401. doi.org. Used for: What late preterm means, and why these babies are less mature than babies born at term.
  2. Shapiro-Mendoza CK, Tomashek KM, Kotelchuck M, et al. Effect of late-preterm birth and maternal medical conditions on newborn morbidity risk. Pediatrics. 2008;121(2):e223–e232. pubmed.ncbi.nlm.nih.gov. Used for: Newborn health problems after late preterm and term birth, and how the risk rises with each earlier week.
  3. Centers for Disease Control and Prevention. QuickStats: Percentage of infants born late preterm, by mother’s state of residence, United States, 2012. MMWR. 2014;63(20):453. cdc.gov. Used for: The share of preterm babies born at 34 to 36 weeks.
  4. Osterman MJK, Hamilton BE, Martin JA, et al. Births in the United States, 2023. NCHS Data Brief No. 507. National Center for Health Statistics; 2024. cdc.gov. Used for: How many US babies are born preterm.
  5. Adamkin DH; Committee on Fetus and Newborn. Postnatal glucose homeostasis in late-preterm and term infants. Pediatrics. 2011;127(3):575–579. doi.org. Used for: Blood sugar checks for late preterm babies in their first 24 hours.
  6. Harris DL, Weston PJ, Harding JE. Incidence of neonatal hypoglycemia in babies identified as at risk. Journal of Pediatrics. 2012;161(5):787–791. pubmed.ncbi.nlm.nih.gov. Used for: How often babies at risk, late preterm babies among them, have low blood sugar, and when.
  7. Kemper AR, Newman TB, Slaughter JL, et al. Clinical practice guideline revision: management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2022;150(3):e2022058859. doi.org. Used for: Jaundice checks before and after going home, and lower treatment levels for babies born before 38 weeks.
  8. Boies EG, Vaucher YE; Academy of Breastfeeding Medicine. ABM Clinical Protocol #10: breastfeeding the late preterm (34–36 6/7 weeks of gestation) and early term infants (37–38 6/7 weeks of gestation), second revision 2016. Breastfeeding Medicine. 2016;11(10):494–500. pubmed.ncbi.nlm.nih.gov. Used for: Why breastfeeding is harder for babies born at 34 to 38 weeks, and the case for a feeding plan made early.
  9. Tomashek KM, Shapiro-Mendoza CK, Weiss J, et al. Early discharge among late preterm and term newborns and risk of neonatal morbidity. Seminars in Perinatology. 2006;30(2):61–68. pubmed.ncbi.nlm.nih.gov. Used for: Why breastfed late preterm babies went back into hospital more often after going home.
  10. Escobar GJ, Greene JD, Hulac P, et al. Rehospitalisation after birth hospitalisation: patterns among infants of all gestations. Archives of Disease in Childhood. 2005;90(2):125–131. pubmed.ncbi.nlm.nih.gov. Used for: Going back into hospital in the first two weeks after a late preterm birth.
  11. Gyamfi-Bannerman C, Thom EA, Blackwell SC, et al. Antenatal betamethasone for women at risk for late preterm delivery. New England Journal of Medicine. 2016;374(14):1311–1320. doi.org. Used for: What steroid shots before a birth at 34 to 36 weeks change for breathing and blood sugar.
  12. Moon RY, Carlin RF, Hand I; Task Force on Sudden Infant Death Syndrome. Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics. 2022;150(1):e2022057990. doi.org. Used for: Safe sleep steps for every baby.
  13. Ostfeld BM, Schwartz-Soicher O, Reichman NE, Turner-Pakula P, Hegyi T. Prematurity and sudden unexpected infant deaths in the United States. Pediatrics. 2017;140(1):e20163334. pubmed.ncbi.nlm.nih.gov. Used for: Sudden unexpected infant death by week of birth.
  14. Pilley E, McGuire W. Pre-discharge “car seat challenge” for preventing morbidity and mortality in preterm infants. Cochrane Database of Systematic Reviews. 2006;(1):CD005386. doi.org. Used for: The car seat check before going home, and the missing trials behind it.
  15. Centers for Disease Control and Prevention. RSV immunization guidance for infants and young children. cdc.gov. Used for: Protection against RSV for babies in their first RSV season.
  16. Johnson S, Evans TA, Draper ES, et al. Neurodevelopmental outcomes following late and moderate prematurity: a population-based cohort study. Archives of Disease in Childhood: Fetal and Neonatal Edition. 2015;100(4):F301–F308. doi.org. Used for: Thinking skills and movement, vision or hearing problems at age 2 after birth at 32 to 36 weeks.
  17. Kerstjens JM, de Winter AF, Bocca-Tjeertes IF, et al. Developmental delay in moderately preterm-born children at school entry. Journal of Pediatrics. 2011;159(1):92–98. pubmed.ncbi.nlm.nih.gov. Used for: Developmental delay at age 4 after birth at 32 to 36 weeks.
  18. Quigley MA, Poulsen G, Boyle E, et al. Early term and late preterm birth are associated with poorer school performance at age 5 years: a cohort study. Archives of Disease in Childhood: Fetal and Neonatal Edition. 2012;97(3):F167–F173. fn.bmj.com. Used for: School readiness at the end of the first school year, by birth week group.
  19. MacKay DF, Smith GCS, Dobbie R, Pell JP. Gestational age at delivery and special educational need: retrospective cohort study of 407,503 schoolchildren. PLoS Medicine. 2010;7(6):e1000289. doi.org. Used for: Extra help at school, by week of birth.
  20. Morse SB, Zheng H, Tang Y, Roth J. Early school-age outcomes of late preterm infants. Pediatrics. 2009;123(4):e622–e629. pubmed.ncbi.nlm.nih.gov. Used for: Developmental disability and kindergarten in healthy late preterm children in Florida.