Prematurity Research Disproves the Theory that Preemies Catch Up By Age Three

The common belief that preemies catch up by age three is not supported by research.

By Patti Wrape

There seems to be a medical myth that preemies "catch up" developmentally. In fact, recent research seems to suggest that they often do not, at least not without intervention. Researchers at Yale University have conducted brain scans that show key areas of preemies brains appear to be less developed than non-preemies. The earlier the preemie, the less developed these key brain areas appeared to be. Another researcher described a sleeper phenomenon in which preemies appeared developmentally okay until about age three. From my own experience and discussion with other preemie parents it seems that preemies may exhibit knowledge or developmental spikes and may exhibit traits characteristic of autism.

All parents of preemies need to be informed of developmental risks, should have their children undergo frequent developmental screenings (including
from age 3 and up) and should seek early intervention as appropriate."

Please Note: Most source documents listed below can be retrieved from the National Library of Medicine, PubMed Online Database.

1. Children born about 3 months prematurely are 3 to 4 times more likely to struggle in school than children born full term. Compared with children born full term, students born prematurely were more likely to repeat a grade of school (33% versus 18%), receive special education (20% versus 5%) and require extra help with reading, spelling, math, handwriting, speech/language and occupational or physical therapy (16% versus 6%). Study conducted at University of Buffalo, reported in Paediatric & Perinatal Epidemiology, October 2000.

2. Some studies have estimated that as many as 40 to 50% of children born prematurely will have some sort of learning disability. A study was conducted in which none of the premature children suffered from major “preemie” related health problems such as cerebral palsy, chromosonal abnormalities, hearing loss or mental retardation. According to one of the authors of the study: “In a sense, the children in our study represented a kind of sleeper phenomenon”, none had noticeable disabilities. There’s no way to pick up on some of these developmental problems in the first two years of life, so many of these children showed no outward signs of disabilities.” Predicting the Future of Premature Babies, Testing Previews Future Learning Problems, By Holly Wagner

3. Almost half of children who survive extremely preterm birth have neurologic and developmental disabilities. Disability Risk for Extremely Premature Babies, Source: Yale University, ( Posted 10/18/2000.

4. Brain scans of children born prematurely show key areas of the brain are much smaller than those of children born at full term. The study conducted by Yale researchers is the first to relate brain abnormalities in preemies to cognitive outcome and perinatal risk factors. The differences in brain volume on average were dramatic in all regions with reductions ranging from 11 to 35%. While not all preemies showed brain abnormalities, those born at a younger gestational age were most affected. The magnitudes of the abnormalities were directly proportional to how early the children were born and were strongly associated with the IQ of the children at age 8 years. “Premature birth at less than 1,000 grams birth weight (approximately 2 lbs) is a major cause of developmental disability. Infants in this birth weight range represent almost 1% of all births in our country, and the survival rate of these infants is well over 80%, but the incidence of handicap is high. By age 8 years, over 5% are in special education or receiving extensive resource room help. One fifth have already repeated a grade of school.” according to Dr. Laura Ment. “The study shows that when brains develop prematurely outside of the womb, they are vulnerable to developmental disturbances.” Dr. Bradley Peterson. Brain Size in Premature Infants Significantly Smaller than Full Term Babies; Source: Journal of American Medical Association 10/18/2000

5. A quarter of a million babies a year are born prematurely in the United States and the ones doctors can save are getting smaller and smaller. But not getting the chance to finish their time in the womb may come back to haunt these children. A study conducted by British researchers showed that 52% of preemies had problems at age 2 ½, though many other prematurity related problems did not show up until age 5. University of Nottingham, published in New England Journal of Medicine, source EXN Staff, October 17, 2000.

6. Children born extremely prematurely, weighing 2 lbs or less at birth, experience significant learning disabilities that persist into their teenage years. A study conducted at McMaster University in Hamilton, Ontario, Canada, followed 150 premature babies into their teens. Nearly half were receiving special education assistance, compared with just 10% of a control group of children who were not born prematurely but were similar in gender, age and social class. 25% of “preemies” had repeated a grade, compared with just 6% of the control group. Fewer than half of the smallest preemies (those born weighing 1 lb, 9 oz and under) scored in the normal range on most intelligence and achievement tests. Preemies Have Trouble Into Adolescence, Chicago AP

7. The outlook for children born extremely prematurely is precarious at best. Many parents do not know what to expect and their doctors do not know what to tell them. A new study from the United Kingdom suggests that extremely preterm babies who survive to leave the hospital have about a 50-50 chance of being free of disability at age 2 ½ years. Extremely Premature Babies at Risk of Severe Disability, New England Journal of Medicine 2000; 43. 378-384, 429-430.

8. Currently 1 in 10 babies in the United States is born prematurely. Half of extremely premature infants who survive have mental or physical disabilities, a quarter of them severe. Boys are more likely than girls to have problems. Premature Babies: Half of Them Have Disabilities, New England Journal of Medicine 2000; Aug 10; 343 (6): 378-84.

9. It has been more than 20 years since doctors began saving extremely premature infants and about a decade since advances in neonatology vastly improved the survival of babies with very low birth weight - those weighing less than 1,500 grams, or 3 lbs, 4 oz. The tiniest of these babies, micropreemies as they are called, are born as much as 14 weeks early and weigh less than 750 grams, or 1 lb., 1 oz. For the first time thousands of such children are now well into their school years. Conventional medical wisdom, based on previous studies, had been that premature children who were not seriously physically disabled, would catch up to other youngsters by age 5. Many do just fine, but as the first large group of tiny babies grows up, new research is showing that academic and behavioral problems often surface in the school years. As Premature Babies Grow, So Can Their Problems, Sheryl Gay Stolberg

10. A study was done in Israel that measured the emotional and behavioral development of prematurely born children. It found that premature children had higher levels of anxiety, depression and aggression than full term children, and that they had a lower self concept. Premature children were found to have more disturbances at home and school. The smaller the birth weight, the less emotionally adjusted the child will be. Rachel Levy Shifft and Gili Einat, Journal of Clinical Child Psychology V 23 p 328-9

11. Extremely low birth weight infants are at significant risk of neurologic abnormalities, developmental delays and functional delays at 18 to 22 months corrected age. Neurodevelopmental and Functional Outcomes of Extremely Low Birth Weight Infants in the National Institute of Child Health and Human Development Neonatal Research Network 1993-1994. Betty R. Vohr, Linda L. Wright, Anna M Dusick, Lisa Mele, Joel Verter, Jean J. Steichen, Neal P. Simon, Dee C. Wilson, Sue Brolyes, Charles R. Bauer, Virginia Delaney-Black, Kimberely A. Yolton, Barry E. Fleisher, Lu-Ann Papile, Michael D. Kaplan. Pediatrics Vol 105, No 6, June 2000, p 1216-1226.

12. Changing patterns of neurologic and developmental functioning between 1 to 7 years of age were studied in very low birth weight infants. Children received a neurologic assessment at 1 year and were reexamined at age 7. The age 1 and age 7 neurologic assessments were significantly related. The findings of the study indicate that a neurologic classification at 1 year of age provides a guide for monitoring very low birth weight infants and can be helpful in alerting school personal to potential needs. Neurodevelopmental and School Performance of Very Low Birth Weight Infants: A Seven Year Longitudinal Study, BR Vohr and CT Garcia Coll, American Academy of Pediatrics, Volume 70, Issue 3, pp 345-350. 9/1/1985.

13. Comparisons were made among 4 birth weight groups to examine the effect of birth weight on the classroom behavior of children entering elementary school. Extremely low birth weight children had lower attention and language skills, overall social competence, scholastic competence and athletic ability than all other birth weight groups as measured by classroom teachers, even when controlling for neonatal stay, child’s gender and ethnicity, and maternal education. All low birth weight children had lower attention and language skills and scholastic competence and higher daydreaming and hyperactivity scores then normal birth weight children. The classroom behavior of low birth weight children was rated by teachers as poor, even for children who had not failed a grade. Low birth weight children who are on grade level may still be at risk for problems. Classroom Behavior of Very Low Birth Weight Elementary School Children, Klebanov PK, Brooks-Gunn J, McCormick MC, Columbia University Teachers College, New York, NY, Pediatrics 1994, Volume 94, Issue 5, pages 700-708. 11/01/1994.

Educational Status and School Related Abilities of Very Low Birth Weight Premature Children, Ross G, Lipper EG, Auld PA, Department of Pediatrics, Cornell University Medical College, New York, NY, Pediatrics December 1991, 88 (6): 1125-34

14. Eighty Eight premature children with birth weights less than or equal to 1,500 grams were evaluated at ages between 7 to 8 years old to determine their academic status in comparison with those of a matched full term group. Results showed that a much higher proportion of the premature children required special education interventions (48%) than either the full term (control group) children (15%), or the New York State elementary school population (10%). More than half of the premature children who received educational intervention were neurologically impaired or had below normal intelligence. The entire group of premature children differed significantly from the matched full term group on IQ score and on tests of verbal ability, school achievement and auditory memory. Six Year Neurodevleopmental Follow Up of Very Low Birthweight Children, Litt R, Joesph A, Gale R Department of Neonatalogy, Bikur Holim Hospital, Israel, Israel Journal of Medical Science, May 1995. 31 (5) 303-8

15. Twenty Four children born preterm in 1985 with very low birthweights were followed until the age of 6. The mean verbal IQ of these children was significantly lower than the control group. Four of the children had major disabilities and minor neurological deficit was found in another 7. These findings point to possible future learning disabilities and point out the importance of long term follow up in order to identify and address these specific educational needs. Risk Factors for Major Neurodevelopmental Impairments and Need for Special Education Resources in Extremely Premature Infants. Msall ME, Buck GM, Rogers BT, Merke D, Catanzaro NL, Zorn WA. Journal of Pediatrics, October 1991, 119 (4) 606-14.

16. A study comprised of 100 infants born between 24 to 28 weeks gestational age from 1983 to 1984, indicated that 25% of the children had major impairments, such as cerebral palsy, blindness and mental retardation. Another 9% required special education resources and 48% of the additional children would possibly need special education resources. Intellectual and Functional Status at School Entry of Children who Weighed 1,000 Grams or Less at Birth: A Regional Perspective of Births in the 1980’s. Saigal S, Szatmaria P, Rosenbaum P, Campbell D, King S. Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada, Journal of Pediatrics, March 1990. 116 (3) 409-16.

17. A study was conducted on 90 children (average age at time of study 5 ½ years) who were born between 1980 to 1982 and weighing between 501 to 1,000 grams at birth. Of the children, 43% were shown to be at mild to high risk for future learning disabilities. Very Low Birthweight Boys at the Age of 19. Ericson A, Kallen B, Centre for Epidemiology, National Board of Health, Stockholm, Sweden, Arch Dis Child Fetal Neonat Ed, May 1998, 78 (3) 171-4.

18. Long term follow-up (to 18-19 years of age) was made of 260 singleton boys whose birthweight was less than 1,500 grams. These boys had more visual and hearing impairments and were at much higher risk of cerebral palsy and other signs of mental impairment, evident as lower intelligence test scores and shorter schooling. School Performance at 9 Years of Age in Very Premature and Very Low Birth Weight Infants: Perinatal Risk Factors and Predictors at Five Years of Age.

19. A study conducted by the Institute of Preventive Health Care in the Netherlands found that at the age of 9, 19% of very premature children were in special education. Of the children in mainstream education, 32% were in a grade below the appropriate level for age and 38% had special assistance. Collaborative Project on Preterm and Small for Gestational Age Infants in the Netherlands, Hille ET, Den Ouden Al, Bauer L, Van Den Oudenrijn C, Brand R, Verloove-Vanhorick SP. TON Institute of Preventative Health Care, Leiden, The Netherlands, Journal of Pediatrics, September 1994, 125 (3) 426-34.

20. Two Hundred and eighty nine very low birthweight children born in New Zealand in 1986 were assessed at 7 to 8 years of age on measures of behavior, cognitive ability, school performance and the need for special education. The outcomes were compared with a sample group of over 1,000 children. The result was that the very low birthweight children had significantly higher rates of problems and poorer rates of functioning across all outcome measures than the general child sample. These differences persisted even after control for variability in social, family and other characteristics of the two samples and for the degree of sensineural disability. These findings are consistent with a growing body of research evidence which suggests that premature and very low birth weight infants are at increased risk of functional impairment in middle childhood. Cognitive, Educational and Behavioral Outcomes at 7 to 8 Years in a National Very Low BirthWeight Cohort. Horwood LJ, Mogridge N, Darlow BA, Christchurch Health and Development Study, Christchurch School of Medicine, New Zealand. Arch Dis Child Fetal Neonatal Ed, July 1998, 79 (1) F 12-20.

21. A study was conducted of 243 prematurely born very low birthweight (less than 1501 grams) children with a normal birthweight, full term control group for comparison. The children were evaluated at 7 to 8 years of age and findings indicate that the children born preterm (both male and female) were rated by their teachers as expressing more behavior problems than their controls and were less well adjusted to the school environment. The deficits noted in the preterm children applied across social class. It is speculated that the problem behaviors reflect a failure in self regulatory functions.
Behavioral Adjustment in School of Very Low BirthWeight Children, Sykes DH, Hoy EA, Bill JM, McClure BG, Halliday HL, Reid MM. School of Psychology, Queen’s University, Belfast, Northern Ireland, Journal of Child Psychology, Psychiatry, March 1997, 38 (3) 315-25.

22. A study was conducted which categorized children into 4 birthweights grom extremely low to normal and then compared them on indicators of school achievement including: grade failure, placement in special classes, classification as handicapped and math and reading achievement scores. Results indicated that as birthweight decreased, the prevalence of grade failure, placement in special classes and classification as handicapped increased, even when controlling for maternal education and neonatal stay. Extremely low birthweight children scored lower than all other birthweight groups on math and reading achievement tests. School Achievement and Failure in Very Low Birth Weight Children. Klebanov PK, Brooks-Gunn J, McCormick MC. Colombia University, Teachers College, New York. Journal of Dev. Pediatrics, August 1994, 15 (4) 248-56.

23. A study examined achievement, behavior and neuropsychological outcomes at early school age in a population of children born at less than 750 grams, and compared them to a full term birth control group. The preemie children performed more poorly than higher birth weight children on tests of math, in language, perceptual motor and attentional skills. Findings document specific weakness in achievement and neuropsychological skills in children less than 750 grams at birth weight and support the need for early identification and special education interventions. Achievement in Children with Birthweights less than 750 Grams with Normal Cognitive Abilities. Taylor HG, Hack M, Klein N, Schatschneider C. Dept of Pediatrics, Case Western Reserve University School of Medicine, Journal of Pediatric Psychology, Dec 1995, 20 (6) 703-19.

24. Eight hundred and seventy three children in an entire school grade in a Swedish community were studied to show the effect of birth weight. Low birth weight children had lower school performance and IQ scores at age 13 than normal birth weight children irrespective of parental socio-economic status. School Performance and IQ Test Scores at Age 13 As Related to Birth Weight and Gestational Age. Lagerstrom M, Bremme K, Eneroth P, Magnusson D. Dept of Psychology, Stockholm, Sweden. Scandanavian Journal of Psychology 1991, 32 (4) 316-24.

25. A study compared 65, 9 year old children born in 1976 who were very low birth weight and were free of neurological impairment with 65 “normal”, full term, children who were comparative in background, etc. to the low birth weight group. Very low birth weight children scored significantly lower than controls on the WISC-R, Bender-Gestalt, Purdue Pegboard, subtests from the Woodcock Johnson Cognitive Abilities Battery and reading and mathematics achievement tests. Children Who Were Very Low Birthweight: Development and Academic Achievement at 9 Years of Age. Klein NK, Hack M, Breslau N. College of Education, Cleveland State University, Journal of Developmental Behavior Pediatrics, Feb 1989, 10 (1) 32-7.

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I am the mother of natural twin boys (my first children) who were born without any prior warning or complications at 27.5 weeks gestation.In the course of advocating for my premature twin sons my goals for advocating for children born premature, I conducted online research into developmental delays in preemies.