Do Kids That Arrive Early End Up Running Late?

1. Do Kids That Arrive Early End Up Running Late? Geoff Bowen, Psychologist Statewide Vision Resource Centre www.svrc.vic.edu.au

4. Preterm (or premature) infant infant born before 37 completed weeks of gestation Late preterm infant (a recently identified category) infant born between 34 and 36 weeks gestation Moderately preterm infant infant born between 32 and 36 completed weeks of gestation Very preterm infant infant born before 32 completed weeks of gestation Definitions of Prematurity Iams JD and Creasy RK (2006)

5. Definitions • Low birthweight (LBW) • infant who weighs less than 2,500 grams at delivery • Very low birthweight (VLBW) • infant who weighs less than 1,500 gramsat delivery • Extremely low birthweight (ELBW) • infant who weighs less than 1,000 gramsat delivery Source: Iams JD, Creasy RK. Preterm labor and delivery, Chapter 34. In: Maternal-Fetal Medicine: Principles and Practice, 5th ed., 2004.

6. < 1,000 grams 0.7% (of live births) Most (99.3%) are preterm 1,000-2,500 grams 7.2% 63.9% are preterm > 2,500 grams 92.1% 7.6% are preterm Prematurity & Low Birthweight, U.S., 2003 Low birthweight is less than 2,500 grams. Preterm is less than 37 completed weeks gestation. Source: National Center for Health Statistics, 2003 natality file Prepared by March of Dimes Perinatal Data Center, 2006.

7. Overlap in LBW, Preterm & Birth Defects, U.S., 2003 Low Birthweight Births 7.9% Preterm Births 12.3% Among LBW: 2/3 are preterm Among preterm: more than 43% are LBW (some preterm are not LBW) Birth Defects ~3-4% Low birthweight is less than 2,500 grams. Preterm is less than 37 completed weeks gestation. Source: National Center for Health Statistics, 2003 natality file. Prepared by the March of Dimes Perinatal Data Center, 2006.

8. Problems With Outcome Investigation • Figures about outcomes for premature babies have to be interpreted with a degree of circumspection to be sure that like is being compared with like. • Percentages should be taken with caution (small sample size). • Different studies use different criteria for the degree of prematurity for inclusion. • There is a gradation of risk. • The combining issue prematurity and light body weight the for dates.

9. Are the conception dates accurate? • Is prematurity the only factor in the medical problems a baby has. Is the prematurity causal or contiguous with the medical problems? • Human beings are not like lab mice who are genetically homogenous. • In apparently relatively “normal” individuals we can never know whether their functioning has been reduced/affected compared to their hypothetical potential. .

10. Small Sample Size Outcome &Treatment Babies now able to survive born as early as 22-27 weeks’ gestation: ‘extremely preterm’ • birth this early occurs <0.5% pregnancies ~1,000 babies per year in Australia • small sample size a problem in reliably answering important neonatology treatment questions (to reduce chance of random error)

11. need 1000s not 100s babies for reliable evidence • projects must be collaborative and international International health: neonatal/perinatal research Prof. William Tarnow-Mordi and Dr Lisa Askie NHMRC Clinical Trials Centre University of Sydney 2005

12. What Is Clear! What is quite clear is that the more premature and/or extremely small a baby might be , the greater the risk of death and the greater the risk of handicap/disability in those who survive!

13. Risk Factors for PB • History of PB • Multi-foetal pregnancy • Some uterine and cervical abnormalities • Infection • Diabetes Mellitus • Hypertension • Late or no prenatal care • Smoking • Alcohol and illicit drug use • Maternal age <20 or >40 • Genetics Catherine W. Harrison Senior Health Policy Analyst The Joint Commission On Health Care 2006

14. Australian Statistics Around 17,500 Australian babies are born prematurely (before 37 weeks gestation) every year. This accounts for approximately 7 per cent of births. Some babies die as a result of being born too early, but risks are related to the gestation (time spent in the womb) at delivery and birth weight. Those babies that survive often face complications because their organs are too immature to function properly outside the womb. Department of Health Victoria Disability Online 2007

15. Before 24 Weeks Average Birth Weight At 23 Weeks: 588 Grams Some infants born before 24 weeks are not resuscitated at birth because survival without severe disability is unusual. Others are resuscitated but do not live long enough to be admitted to the NICU. Less than one-third of infants born before 24 weeks and admitted to a NICU will survive. Anticipating The Birth Of An Extremely Premature Baby (Published by the Victorian Government Department of Human Services, Melbourne, Victoria, Australia. September 2005)

16. Hospital stay: • Most will spend about four to five months in hospital. • Generally need breathing assistance for at least two months and almost all develop chronic lung disease of prematurity and be discharged home on oxygen. • Some will develop severe damage to their eyes (ROP) necessitating laser therapy. Long term outcomes: • 2/3 discharged home are without disability or will be mildly disabled. • Remaining 1/3 will have severe disability, affecting hearing, vision and overall development.

17. 24 Weeks Average Birthweight: 657 Grams Almost 200 infants of 24 weeks gestation are admitted to NICUs across Australia and New Zealand each year. About half will survive.

18. Hospital stay: • Most are in hospital for three to four months. • Generally need respiratory support of some kind for the first few months. • Almost will develop chronic lung disease of prematurity and require home oxygen. Some will need laser therapy for ROP Long term outcomes: • Long term outcomes are similar to those for the 23-week infant. • Approx 2/3 discharged home will be without disability or mildly disabled, although still independent. • 1/3 will be severely disabled and require help with daily tasks.

19. 25 Weeks Average Birthweight: 767 Grams More than 200 infants born at 25 weeks gestation are admitted to Australian and New Zealand NICUs each year. By this gestation, survival rates have climbed to around 70 per cent.

20. Hospital stay: Generally infants at this gestation spend approximately three to four months in hospital and about six to seven weeks on respiratory support. Long term outcomes: Many infants discharged home at this age will be without disability or be mildly disabled. Some will be severely disabled.

21. 26 Weeks Average Birthweight: 884 Grams Each year, nearly 250 infants of this gestation are admitted to Australian and New Zealand NICUs, 80 per cent of whom survive. Hospital stay: These infants spend approximately three months in hospital. In most cases respiratory support is required for about five weeks. Long term outcomes: Most infants discharged home at this age will be without disability or be mildly disabled. Some will be severely disabled.

22. 27 Weeks Average Birthweight: 1,002 Grams More than 300 infants of 27 weeks gestation are admitted to Australian and New Zealand NICUs each year. The survival rate: 90 per cent. Hospital stay: An average of three months in hospital. These infants often need less time on respiratory support. Long term outcomes: Almost all infants discharged home will be without disability; however a few will have some disability. Some infants will be discharged home on oxygen.

23. 28 Weeks And Beyond Average Birthweight: 1,134 Grams Approx. 450 infants born at 28 weeks are admitted to Australian and New Zealand NICUs each year. The survival rate is greater than 90% Hospital stay: Usually spend nine or ten weeks in hospital. They usually require breathing support for only a few weeks. Long term outcomes: Long term outcomes are brighter for infants born at or beyond 28 weeks. The majority of these infants survive without disability.

24. The Morbidity of Prematurity Neonatal • Death • Respiratory distress syndrome (RDS) • Intraventricular hemorrhage (IVH) & periventricular leukomalacia (PVL) • Necrotizing enterocolitis (NEC) • Patent ductus arteriosus (PDA) • Infection • Metabolic abnormalities • Nutritional deficiencies Source: Iams JD, Creasy RK. Preterm labor and delivery, Chapter 34. In: Maternal-Fetal Medicine: Principles and Practice, 5th ed., 2004

25. Perinatal Mortality & Gestational Age Source: Mercer BM. Preterm premature rupture of the membranes.Obstet Gynecol 2003;101:178-93. Reproduced with permission from Lippincott Williams & Wilkins.

26. Short term • Feeding and growth difficulties • Infection • Apnea • Neurodevelopmental difficulties • Retinopathy • Transient dystonia

27. Long term • Vision impairment • Cerebral palsy • Sensory deficits • Special health care needs • Incomplete catch-up growth • School difficulties • Behavioral problems • Chronic lung disease # “Autism” # Feeding problems/anorexia # ADHD # Pain suffered by PB’s long term effects (# other studies see below)

28. Timing of Outcomes “The most severe diagnoses are usually evident by ages 2 to 4 (CP, major retardation, blindness, deafness).  The less severe diagnoses (low or mildly retarded IQ, learning and behaviour problems, mild visual and hearing problems and problems with hearing and visual processing) are not always known till age 8 to 11 or even later.  There are even some problems that may not show up till late adolescence or adulthood -- eg. seizures, or late loss of vision from ROP.”Timing of Diagnoses of Prematurity Impacts Helen Harrison These observations to the prematurity parents support internet mailing lists on prematurity: Preemie-child and Preemie-L.

29. Oxygen Use In Preterm Babies Most common therapy given to sick, small babies: • 1950s: unrestricted, high O2, subsequent huge increase in blindness • 1960s: increased early mortality due to O2 restriction – for every 1 sight saved (benefit), 16 additional deaths (harm) • 1970s, 80s, 90s: new monitors, no (double masked randomised controlled trial) RCTs • 2000s: two small RCTs in chronic oxygen dependent babies

30. ………. there has never been a shred of convincing evidence to guide limits for the rational use of supplemental oxygen in the care of extremely premature infants. For decades, the optimum range of oxygenation (to balance four competing risks: mortality, ROP-blindness, chronic lung disease and brain damage) was, and remains to this day, unknown.” Silverman WA. A cautionary tale about supplemental oxygen: the albatross of neonatal medicine. Pediatrics 2004; 113(2):394-6

31. Benefits of Oxygen Saturation Targeting, trial II (BOOST II) Study treatment • Inspired oxygen to a target of 85–89% arterial oxygen saturation or 91–95% saturation   Main outcome measures • death or major disability at 2 years of age   • retinal surgery, neonatal chronic lung disease, growth impairment, use of health care resources   Planned accrual  1200 infants   Funding National Health and Medical Research Council

32. Retinopathy of prematurity occurs primarily in premature infants born at 23-28 weeks gestation, or in those weighing less than 1000 grams, although it has also occurred in some full -term infants. The condition is related to retinal blood vessels, which are not fully developed in premature infants. Although oxygen was long believed to be the culprit in causing the disease, it is not a sole factor; the exact cause (and best treatment) of ROP has yet to be discovered (even after over 50 years of study). Current guidelines for perinatal care recommend that all infants born at less than 30 weeks of gestation, or who weigh less than 1300 grams at birth, should be checked for ROP before leaving the hospital, regardless of whether they were exposed to oxygen. (Retinopathy of Prematurity Kate Moss Family Support Specialist, TSBVI Deafblind Outreach 2003)

33. How oxygen causes Retinopathy of Prematurity (ROP): • Early fetal life - retina is avascular. Vessels grow out from the centre, controlled by a growth factor (VEGF), released by normal hypoxic retinal tissue. • After PB, oxygen treatment may flood the retina with oxygen. As lung disease resolves and inspired oxygen is reduced, the ischaemic peripheral retina becomes severely hypoxic. There is abnormally high secretion of VEGF and new vessels and fibrous tissue proliferate and invade the vitreous. • Fibrous contraction leads to retinal detachment and visual loss.

34. Destroying these proliferating vessels by ablative laser surgery can prevent retinal detachment. This saves central vision in some cases, but there is often residual visual loss. • Of survivors at 27 weeks gestation or less, 50% have ROP, 12.5% have severe (Grade III/ IV) ROP,2 56% of these have surgery, but about 10% of those treated become blind. • New recommendations will result in more infants with severe ROP having laser surgery. Of survivors of 28-29 weeks’ gestation, <2% get severe ROP. NHMRC Clinical Trials Centre Which oxygen saturation level should we use for very premature infants? A randomised controlled trial Professor William Tarnow-Mordi et al 2006.

35. “I’m what’s called a retrolental fibroplasia child: When I was born ten weeks premature, they put me in a humidicrib and the only way they could keep me alive was by using pure oxygen. It caused blood vessels to grow, which pulled the retinas off the back of my eyes, so I guess I lost my sight a few hours after birth.” Professor Ron McCallum:

36. Incidence of Neurosensory & Developmental Outcomes – Low Birthweight • Mental Retardation: Incidence in <1,500 g BW: 5% Incidence in <1,000 g BW: 12% Incidence in <800 g BW: 22% Incidence in Total Population: 2-3% • Cerebral palsy: Incidence in <1,500 g BW: 3% Incidence in <1,000 g BW: 6% Incidence in <800 g BW: 9% Incidence in Total Population: 0.5%

37. Sensory Impairment: Incidence in <1,500 g BW: 3% Incidence in <1,000 g BW: 9% Incidence in <800 g BW: 25% Incidence in Total Population: 0.5% • Use of any special education: Incidence in <1,500 g BW: 30% Incidence in <1,000 g BW: 50% Incidence in <800 g BW: 50% Incidence in Total Population: 23% Health Issues in Survivors of Prematurity Jackie York, MD, Michael Devoe, MD South Med J95(9):969-976, 2002 Southern Medical Association Posted 02/13/2003

38. Cerebral Palsy • P B’s who weigh less than 1500 grams are between 20 and 80 times more likely to develop cerebral palsy than full-term babies . • The more prem and the lower the body weight the more likely the development of CP • P B’s can suffer from bleeding in the brain, which can damage delicate brain tissue, or develop periventricular leukomalacia, destruction of nerves around the fluid-filled cavities (ventricles) in the brain.

39. This is because his lungs don’t have the chance to fully develop prior to birth causing lack of oxygen to the brain. • P B’s are also at increased risk for developing cerebral palsy if their oxygen supply is cut off at any time before, during or after birth. • Steroid use can also increase the likelihood of CP. Platt, M., et al. Trends in Cerebral Palsy Among Infants of Very Low Birthweight (<1500 g) or Born Prematurely (<32 Weeks) in 16 European Centres: A Database Study. Lancet, volume 369, January 6, 2006, pages 43-50. Barrington, K. The adverse neurodevelopmental effects of postnatal steroids in the preterm infant: a systematic review of RCTs. BMC Pediatrics 2001;1;1.

40. Hearing Impairment About one in four preterm VLBW babies has peripheral and/or central hearing impairment at term. VLBW and its associated unfavourable perinatal factors predispose the babies to hearing impairment.Jiang ZD, Brosi DM, Wilkinson AR; Hearing impairment in preterm very low birthweight babies detected at term by brainstem auditory evoked responses.; Acta Paediatr. 2001 Dec;90(12):1411-5. [abstract]

41. Autism Children with visual impairments can be on the autism spectrum as well. • It is a brain-based disorder so those children with neurological vulnerabilities (e.g., seizure disorders, septo-optic dysplasia, • Prematurity associated with bleeds, agenesis of the corpus callosum, congenital rubella syndrome, etc.) may be at increased risk. • There needs to be more cautious in the terminology “autistic-like” in that it can result in missed diagnosis and/or delay in procuring appropriate services for those children who are on the autism spectrum.

42. Strategies useful for children who are visually impaired and autistic vary considerably from those effective for children who are just visually impaired Autism is a brain related disorder; that estimated that 50% of blind children have LD and 56% of those with severe LD or IQ<50 have autism) Autism and Visual Impairment Terese Pawletco FOCAL Points, Fall 2002 Volume 1, Issue 2

43. Positive Screening for Autism in Ex-Preterm Infants. • 91 toddlers who had been born prematurely, 26% had positive autism screening scores. 29% toddlers had functional delays in motor abilities, 19% had delayed daily living skills and 23% had communication problems. • Analysis revealed that gestational age, birth weight, male gender, placental inflammation (chorioamnionitis) and severity of illness on admission were all associated with abnormal Modified Checklist for Autism in Toddlers scores. • The study has described a high prevalence of features of autistic spectrum disorders among "survivors of extremely premature birth".

44. This study provides evidence that toddlers who are born prematurely experience some developmental delays and other impairments that may be similar to those seen with autism spectrum disorders. • The population of preterm babies in this study were a 'selected high-risk' group the findings may not apply to healthier preterm populations. • The study descriptive. Little information that can be generalised to the wider population. It is unclear how positive screen tests in a high-risk population translate into actual diagnoses of autism Premature Babies And Autism http://www.medicalnewstoday.com/articles/103100.php Positive Screening for Autism in Ex-preterm Infants: Prevalence and Risk Factors. Study Limperopoulos C, Bassan H, Sullivan NR, et al.Pediatrics 2008; 758-765

45. Cognitive Impairment

46. Many studies from 1987 to 1999 indicate all over the world for very low birth weight = <1,500 g : • Rates of 6% to 23% Severe disability = mental retardation with an IQ <50, cerebral palsy with inability to walk, blindness, or deafness. (Mean = 11.44%) • Rates of 9% to 57% Mild disability = combinations of slow learning (IQ 70-84), coordination, communication, and learning and perceptual disorders. Moderate disability = cognitive disabilities of mild mental retardation (IQ 50-70), hearing loss, or cerebral palsy with the ability to walk. (Mean = 22.5%) Health Issues in Survivors of Prematurity Jackie York, MD, Michael Devoe, MD South Med J95(9):969-976, 2002 Southern Medical Association Posted 02/13/2003

47. Study (2003 in UK) development of all babies born at 25 weeks gestation or less during the first 10 months of 1995: • 308 children who survived, 241 underwent formal psychological assessment using standard cognitive, language, phonetic and speech tests. • Teacher rating of school achievement: 40% were found to have moderate to severe learning difficulties (boys were twice as likely to be adversely affected as girls). • Rates of severe, moderate, and mild disability were 22%, 24%, and 34%, respectively.

48. Disabling cerebral palsy occurred in 30 children representing 12%. • Children with severe disability at 30 months of age, 86% still had moderate-to-severe disability at 6 years of age. • Other disabilities at the age of 30 months were poorly predictive of developmental problems at 6 years of age. Likely that improvement may occur but it is less likely with greater severity. Marlow N. Wilke D. Bracewell MA. et al; Neurologic and developmental disability at six years of age after extremely preterm birth.; N Engl J Med. 2005 Jan 6;352(1):9-19. [abstract]

49. Education and Learning

50. Another study has suggested that children who were very premature may deteriorate rather than improve: • Children compared at the age of 8 and 15 and found - full IQ dropped from an average of 104 to 95 and that the number needing extra educational provision rose from 15 to 24%. • Same children assessed at 8 and 15 and so it does not represent better neonatal care in the younger ones.