Born Early, Doing Well at School? What Comparing Brothers and Sisters Tells Us

A plain-language guide to Schneuer and colleagues' 2026 Australian study of reading and maths results in more than one million children born at different stages of pregnancy

Many parents of babies born early wonder whether their child will struggle at school. A large Australian study that compared brothers and sisters born at different stages of pregnancy found that children born from 32 weeks onward did almost as well in national reading and maths tests as their siblings born at full term. Children born very early, especially before 28 weeks, were more likely to need extra help at school, particularly with maths.

Why this question matters to families

A full-term pregnancy lasts about 40 weeks. Babies born before 37 weeks are called preterm, and babies born at 37 or 38 weeks are called early term. For parents sitting beside an incubator, the worries come in waves: first about breathing and feeding, later about crawling and talking, and eventually about the first day of school. It is natural to ask whether being born early will hold a child back in the classroom, and families deserve an answer that is honest without being frightening.

What we used to think, and why it was hard to be sure

For years, large studies drawn from health and school records seemed to show a simple pattern: the earlier a baby was born, the more likely the child was to have difficulties at school, even for babies born only a week or two early. A study published in 2026 by Schneuer and colleagues set out to test that pattern more carefully [1]. Earlier, in Scotland, researchers looking at more than 400 000 schoolchildren found that the chance of needing extra educational support rose step by step with each earlier week of birth, all the way from 40 weeks down to 24 weeks [2]. Danish researchers found that children born preterm were somewhat more likely not to finish basic schooling [3], and a study from New South Wales in Australia found more children at risk of developmental problems when they started school after birth at 37 or 38 weeks [4]. A review of several studies suggested a small difference in thinking skills, around 3 points on an IQ (intelligence) test, between babies born at 37 and 40 weeks [5]. For babies born very early, before 32 weeks, the differences were larger and could last into adulthood [6][7]. Experts have described in detail how a very early birth can affect the developing brain [8].

But there was a catch. The reasons a baby arrives early, such as a mother's health, stress, money worries or the family's genes, can also affect how a child does at school. Researchers can adjust for things they can measure, like parents' education, but many family influences are invisible in records. One clever way around this is to compare brothers and sisters. Siblings share the same mother, usually the same home and many of the same genes, so if one was born early and the other on time, any difference between them is more likely to come from the timing of birth itself. This approach is powerful, but it is not perfect [9]. A Danish sibling study had already found that, among teenagers, only those born before 34 weeks had lower exam grades [10]. However, it looked at 15- and 16-year-olds, and nobody knew whether the same was true for younger children. A large study from Quebec, Canada, had also found that family background and social circumstances, such as a mother's education and the family's social and economic circumstances, mattered more than early birth for how far people went in education [11].

How the Australian study worked

The researchers used linked health and school records for children born in New South Wales between 2001 and 2011 and in Victoria between 2005 and 2012. Together these two states account for about 57% of all births in Australia [1]. They looked at results from the National Assessment Program–Literacy and Numeracy (NAPLAN), the reading and maths tests that Australian children sit in grades 3, 5, 7 and 9.

In total, 1 095 816 children had grade 3 results, at age 8 or 9. In New South Wales, 292 027 teenagers also had grade 9 results, at age 14 or 15. About 656 000 children had a brother or sister in the data, so the team could compare siblings directly. Every child's result was compared with that of children born at 39 or 40 weeks.

The researchers also set out how big a difference needed to be before it really mattered in the classroom. They used the same line that Australian schools use to decide that a child is performing below the expected standard and needs a support plan. In statistical language, this is a gap of about 0.2 "standard deviations", a measure of how spread out scores are. Using a clear line like this helps researchers focus on differences that matter in everyday life, rather than ones that are real but too small to notice [12].

What the study found

When all children were compared, those born earlier did slightly less well at almost every stage of pregnancy, but for most groups the differences were very small. Children born at 38 weeks, for example, scored almost exactly the same as children born at 39 or 40 weeks [1].

When brothers and sisters were compared, most of the small differences shrank even further. For children born between 34 and 36 weeks, or at 37 or 38 weeks, the gap with their full-term siblings was tiny, a small fraction of the line schools use to flag a child for extra support. This suggests that much of what earlier studies saw at these stages came from shared family circumstances rather than from the early birth itself.

The picture was different for babies born very early. Children born between 23 and 27 weeks, called extremely preterm, scored clearly lower in both maths and reading than their siblings born at full term. Children born between 28 and 31 weeks, called very preterm, still had a meaningful gap in maths, but not in reading. To give a sense of scale, across all children in New South Wales, about 8 in every 100 children born at 23 to 27 weeks had very low maths scores in grade 3 (far below the average for their year), compared with about 2 in every 100 children born at 39 or 40 weeks.

By grade 9, when brothers and sisters were compared, the only group with a meaningful difference was the children born at 23 to 27 weeks (across all children, those born at 28 to 31 weeks also still lagged in maths), and they scored lower than their grade 3 results alone would have predicted. In other words, the difficulties did not simply fade with time.

One of the most striking findings concerned health problems around the time of birth. Almost all babies born at 23 to 27 weeks, about 95 in every 100 in New South Wales, had at least one serious newborn health problem recorded in their hospital records, compared with about 6 in every 100 babies born at 39 or 40 weeks. Babies born very early are more prone to problems such as serious infections, long-term lung disease and bleeding in the brain [8]. When the researchers set aside children who had such problems, the meaningful differences in school results disappeared [1]. This hints that the illnesses that can come with a very early birth, rather than the early birth alone, may explain much of the later difficulty. Other research points the same way [6].

What this means for your family

If your baby was born at 32 weeks or later, this study is genuinely reassuring. Children born at these stages did almost as well at school as their brothers and sisters born on time. That does not mean every child will have an easy path, and you should still mention any worries about learning to your child's doctor or teacher. National school tests are broad and may miss subtle difficulties, and a large Swedish study found that some developmental diagnoses remained more common after birth between 32 and 36 weeks, even among siblings [13].

If your baby was born before 32 weeks, and especially before 28 weeks or after a difficult stay in intensive care, these findings support asking for regular developmental check-ups that continue into the school years, and for early conversations with teachers about maths and reading. Every child is different, and knowing where extra support may help is a strength, not a label. You may also find our article on how parents can support development during and after a neonatal unit stay helpful ([In[Neo]Sight: early intervention and cognition at five years](https://inneosight.org/en-US/articles/early-intervention-preterm5yr2025)).

For families facing a decision about planned birth at 39 weeks, earlier work by some of the same researchers found no difference in school-entry development after a planned birth at 39 weeks [14], or in school test results after birth at 39 weeks [15], compared with birth later in pregnancy.

What the study could not tell us

Siblings do not grow up in exactly identical circumstances; family life can change between one child and the next. Children who did not sit the tests because of a disability were not included in the main results, so the study cannot speak for children with the most complex needs. The grade 9 results come from one state only.

What researchers are working on next

Researchers now want to understand exactly which newborn health problems affect learning, and whether extra help at school can close the gap for the earliest-born children. They also want to use more detailed tests that might pick up smaller difficulties, and to follow children into adulthood, where earlier studies have found differences in university study [16].

The bottom line

This large study of Australian children suggests that, for babies born from 32 weeks onward, being born early makes very little difference to reading and maths at school once family background is taken into account. For babies born before 28 weeks, and for maths among those born before 32 weeks, differences are real and can last into the teenage years, which is why early, ongoing support matters [1].

References

  1. Schneuer FJ, Lindquist A, Forsythe A, et al. Gestational Age and Childhood Educational Outcomes in Primary and High School Years. JAMA Netw Open. 2026;9(9):e2631747. doi:10.1001/jamanetworkopen.2026.31747 ↩
  2. MacKay DF, Smith GC, Dobbie R, Pell JP. Gestational age at delivery and special educational need: retrospective cohort study of 407,503 schoolchildren. PLoS Med. 2010;7(6):e1000289. doi:10.1371/journal.pmed.1000289 ↩
  3. Mathiasen R, Hansen BM, Andersen AM, Forman JL, Greisen G. Gestational age and basic school achievements: a national follow-up study in Denmark. Pediatrics. 2010;126(6):e1553-1561. doi:10.1542/peds.2009-0829 ↩
  4. Bentley JP, Roberts CL, Bowen JR, Martin AJ, Morris JM, Nassar N. Planned Birth Before 39 Weeks and Child Development: A Population-Based Study. Pediatrics. 2016;138(6):e20162002. doi:10.1542/peds.2016-2002 ↩
  5. Murray SR, Shenkin SD, McIntosh K, et al. Long term cognitive outcomes of early term (37-38 weeks) and late preterm (34-36 weeks) births: A systematic review. Wellcome Open Res. 2017;2:101. doi:10.12688/wellcomeopenres.12783.1 ↩
  6. Twilhaar ES, Wade RM, de Kieviet JF, van Goudoever JB, van Elburg RM, Oosterlaan J. Cognitive Outcomes of Children Born Extremely or Very Preterm Since the 1990s and Associated Risk Factors: A Meta-analysis and Meta-regression. JAMA Pediatr. 2018;172(4):361-367. doi:10.1001/jamapediatrics.2017.5323 ↩
  7. Eves R, Mendonça M, Baumann N, et al. Association of Very Preterm Birth or Very Low Birth Weight With Intelligence in Adulthood: An Individual Participant Data Meta-analysis. JAMA Pediatr. 2021;175(8):e211058. doi:10.1001/jamapediatrics.2021.1058 ↩
  8. Inder TE, Volpe JJ, Anderson PJ. Defining the Neurologic Consequences of Preterm Birth. N Engl J Med. 2023;389(5):441-453. doi:10.1056/NEJMra2303347 ↩
  9. Frisell T. Invited Commentary: Sibling-Comparison Designs, Are They Worth the Effort?. Am J Epidemiol. 2021;190(5):738-741. doi:10.1093/aje/kwaa183 ↩
  10. Husby A, Wohlfahrt J, Melbye M. Gestational age at birth and cognitive outcomes in adolescence: population based full sibling cohort study. BMJ. 2023;380:e072779. doi:10.1136/bmj-2022-072779 ↩
  11. Loose T, Collet O, Nuyt AM, et al. Long-Term Educational Outcomes of Individuals Born Preterm. JAMA Netw Open. 2025;8(10):e2534918. doi:10.1001/jamanetworkopen.2025.34918 ↩
  12. Kallogjeri D, Spitznagel EL Jr, Piccirillo JF. Importance of Defining and Interpreting a Clinically Meaningful Difference in Clinical Research. JAMA Otolaryngol Head Neck Surg. 2020;146(2):101-102. doi:10.1001/jamaoto.2019.3744 ↩
  13. Mitha A, Chen R, Razaz N, et al. Neurological development in children born moderately or late preterm: national cohort study. BMJ. 2024;384:e075630. doi:10.1136/bmj-2023-075630 ↩
  14. Lindquist A, Hastie R, Kennedy A, et al. Developmental Outcomes for Children After Elective Birth at 39 Weeks' Gestation. JAMA Pediatr. 2022;176(7):654-663. doi:10.1001/jamapediatrics.2022.1165 ↩
  15. Hiscock RJ, Atkinson JA, Tong S, et al. Educational Outcomes for Children at 7 to 9 Years of Age After Birth at 39 vs 40 to 42 Weeks' Gestation. JAMA Netw Open. 2023;6(11):e2343721. doi:10.1001/jamanetworkopen.2023.43721 ↩
  16. Ahmed AM, Pullenayegum E, McDonald SD, et al. Association between preterm birth and economic and educational outcomes in adulthood: A population-based matched cohort study. PLoS One. 2024;19(11):e0311895. doi:10.1371/journal.pone.0311895 ↩