Outcome of diabetic pregnancy Comparison of North East England with Norway

1. Outcome of diabetic pregnancyComparison of North East England with Norway December 2000 Gillian Hawthorne

2. Dr Hawthorne • Consultant Diabetologist based at Newcastle Diabetes Centre, Newcastle-upon-Tyne • Interested in diabetic pregnancy since 1990 • Studied with David Hadden, Belfast and Lois Jovanovic, New York

3. St Vincent’s declaration • Achieve pregnancy outcome in the diabetic woman that approximates that of the non diabetic woman

4. England and the North East

5. Norway Bergen Medical birth registry

6. Northern Diabetic Pregnancy Survey • Prospective population based survey • Perinatal mortality for diabetic pregnancy 48/1000 compared to background of 8.9/1000 • Congenital malformation rate for diabetic pregnancy 83/1000 compared to 21.3/1000

7. Diabetic Pregnancy outcome for the UK Perinatal Mortality Birth Defect per 1000 Diabetes Background Diabetes Background Merseyside 1990-94 36.1 7.6 9.7% Northern Ireland 37 N/A 5%

8. Perinatal Deaths in Norway 1987-1996 • Perinatal deaths in diabetic pregnancy • 11.8 per 1000 • Perinatal deaths in non-diabetic pregnancy • 6.7 per 1000 • Perinatal deaths = stillbirth at 28 completed weeks or neonatal death <7th day of life

9. Aim of study • To determine if the difference in diabetic pregnancy outcome between Norway and North East England can be explained by procedural differences: • Are there differences in recording data? • Are the differences in recorded outcome real?

10. Methods • All data collected prospectively between 1st July 1994 and 30th June 1997 • In Norway compulsory notification of all pregnancies with gestational age of 16 completed weeks or more • In north East England notification of all diabetic pregnancy to Northern Diabetic pregnancy Survey

11. Standardisation of definitions • Stillbirths defined as all fetal deaths more than 24 completed weeks • Perinatal mortality all stillbirths >24 completed weeks and all live births • Congenital anomalies coded using ICD 8

12. Terminations for birth defects included in both numerators and denominators • Relative risks approximated by odds ratio

13. Perinatal Mortality in North East England Total Number Perinatal Deaths Perinatal mortality /1000 With diabetes 304 13 42.8 Without diabetes 101516 1014 10.0 Relative risk 4.4 [2.5-7.7]

14. Perinatal mortality in Norway Total Number Perinatal Deaths Perinatal mortality /1000 With diabetes 2019 21 10.4 Without diabetes 179754 178542 6.7 Relative risk 1.5 CI [0.97-2.3]

15. Birth Defects in North East England Total Number Birth Defects Birth Defects /1000 Babies of: Mothers with diabetes 309 17 55.0 Mothers without diabetes 101755 2472 24.3 Relative risk 2.5 CI [1.5-4.0]

16. Birth defects in Norway Total Number Birth Defects Birth Defects /1000 Babies of: Mothers with diabetes 2019 58 28.7 Mothers without diabetes 179754 5465 30.4 Relative risk 0.95 CI [0.73-1.2]

17. Summary • In North East England - • The perinatal mortality for offspring of mothers with diabetes was 42.8/1000 - a 4 fold increase in risk compared to offspring of mothers without diabetes • The risk of birth defects was 2.5 fold increased

18. Summary • In Norway • Perinatal mortality was 10.4/1000 for offspring of mothers with diabetes- 1.5 fold increase compared to offspring of mothers without diabetes • Risk of birth defects for offspring of mothers with diabetes was 0.95

19. Relative risks between North East England and Norway • The differences were significant [p=0.0002] for the relative risk of perinatal mortality adjusted for maternal age • The differences were significant [p=0.0008] for relative risks for birth defect adjusted for maternal age

20. Conclusion • In Norway the outcome of diabetic pregnancy is similar to that of the background population • Diabetic pregnancy remains high risk in North East England • Further research is required to understand what is the cause of this difference