1. Changing Prevalence of Cerebral Palsy Coleen Boyle, Ph.D. National Center on Birth Defects and Developmental Disabilities Centers for Disease Control and Prevention

2. What impacts the rate of CP in very preterm infants? Birth rate (live births/1000) Birth weight/preterm birth distribution Survival in preterm/vlbw infants Prevalence of CP in preterm survivors

3. How have each of these factors changed overtime?

4. Factor #1: Birth rate Birth rate has decrease since 1960s, but number of reproductive age women has increased Changes in birth rate do not change rate; but will change absolute number of case children

6. Cerebral Palsy in Atlanta, Atlanta, 1975 - 1991 1975 -19771981 -1985 No. live birth/yr No. case children Cp rate 21,144 36 1.7 26,127 52 1.8 1986 -1991 36,457 77 2.0

7. Factor #2: Birthweight/preterm birth distribution The rate of very preterm births (<32 weeks GA) in the U.S. has increased 9% from 1981 to 1999 (1.81% of all births in 1981 to 1.98% in 1999) Whites – 12% (1.37 1.57) Blacks – unchanged (4.13 4.13)

8. Factor #3: VLBW/Preterm Infant Survival Critical factor because this group is at highest risk of CP and other disability

9. Survival in Infants <1500g, Altanta, 1981-1996

10. Low Birth Weight and DD Birth Weight (gms) Survivors No. Any DD Rate/100 <1000118918.3 1000 - 149926678.8 1500 - 249923,1712.4 2500+330,1780.8

12. Overall Disability at 30 Months Woods et al, 2000

13. Woods et al, 2000 - RESULTS Development – 19% with Bayley >3 SD ; 11% 2-3 SD Neuromotor – 10% with severe disabilities 14% other disabilities Sensory- 2% blind; 2% deaf; 5% no speech

14. Factor # 4: Prevalence of CP in preterm survivors Impact of prenatal factors: role of inflammation, infection Impact of antenatal care/intervention? –corticosteriods; surfactant; others

15. Source: Stanley, Blair & Alberman, 2000 Rates of CP in Neonatal Survivors

16. Source: Stanley, Blair & Alberman, 2000

17. Source: Stanley, Blair + Alberman, 2000

18. Source: Stanley, Blair & Alberman, 2000

19. Source: O’Shea 1998 Pediatrics

20. 1983-1985 <1000 g 1000-1499 g Total 1988-1989 <1000 g 1000-1499 g Total 1990-1994 <1000 g 1000-1499 g Total 15 27 42 16 15 31 27 26 53 266 616 882 208 429 637 560 1108 1668 56 44 48 77 35 49 48 23 32 No. of children with CP No. of singleton survivors <1500 g Prevalence per 1000 survivors <1500 g Table. Prevalence of moderate or severe CP in singleton weighing < 1500 g born in 4 northern California counties Source: Grether: J Pediatr, 136; 2000:133

21. 59 36 20 13 19 7 8 0 3 13 19 7 0 10 20 30 40 50 60 70 79-8484-8989-94 % DyingCPBlindness Bayley MDI <68 Outcome at 1 yr in infants weighing 501 – 800 gm, North Carolina Source: O’Shea et al. Pediatrics 1998:101

22. 44 6.5 62 5.9 67 6.0 0 10 20 30 40 50 60 70 80 1975 - 771981 - 851986 - 91 Percent % Survivors and Prevalence of CP in Infants <1500 g, Atlanta, 1975-1991 births

23. 0 6.1 5.0 6.4 5.8 1 2 3 4 5 6 7 7.0 7.5 1975 - 771981 - 851986 - 91 8 Prevalence of CP <1500 g survivors, Atlanta, 1975 –1991, by race Percent white black

24. Characteristics of CP in infants <1500 g, Atlanta, 1975 - 1991 % Isolated CP% Spastic diplegia 1975 – 1977 1981 – 1985 1986 - 1991 41 46 51 7 36 32

25. Trends in CP – Conclusions Factor 1: Birth rate stable; rise in the number of reproductive age women Factor 2: Proportion of very preterm births has increased Factor 3: Infant mortality in very preterm infants continues to improve Factor 4: Increase - mid to late 1980’s; decrease in early 1990’s