2








Prevalence of diabetes in pregnancy

 
     
 

KEY FINDINGS

  • Diabetes in pregnancy varies across England, Wales and Northern Ireland from 1 in 240 to 1 in 333 births.
  • The areas of highest prevalence of diabetes in pregnancy do not necessarily coincide with the areas of highest prevalence of diabetes in the general population.
 
 
 

2.1

 

Introduction

Diabetes is a major public health problem in England, Wales and Northern Ireland with approximately 1.6 million people living with the diagnosis of type 1 or type 2 diabetes in 2004.1 Diabetes has long been recognised as a maternal factor which can lead to complications during pregnancy. Understanding the needs of women with diabetes and quantifying the number of pregnancies affected by diabetes is important for the planning and allocation of resources for services.

The overall or crude prevalence of diabetes (type 1 and type 2 combined) is dependent upon the age structure of the population as risk of diabetes increases substantially with age. Prevalence estimates of 0.3% in people aged below 30 years and 3.4% in people aged between 30 and 60 years old have been given by the PBS Diabetes Population Prevalence Model.2 The prevalence in women aged between 15 and 44 years of diagnosed type 1 and type 2 diabetes of the population of England, Wales and Northern Ireland is estimated at 0.68% and 0.36%, respectively.1

This chapter describes the national and regional prevalence figures for type 1 and type 2 diabetes in pregnancy. The regions described are coterminous with the nine government offices for the regions in England plus Wales and Northern Ireland, according to boundaries as of 1 March 2003.

 
 

2.2

 

National and regional prevalence 2002–03

We estimated the prevalence of diabetes in pregnancy by measuring the prevalence of babies born (live or stillborn) to women with diabetes.

Prevalence figures were calculated using all births in one calendar year (between 1 March 2002 and 28 February 2003) to allow comparisons with regional birth figures. There were 2356 births (stillbirths and live births) to women with pre-gestational diabetes delivered between 1 March 2002 and 28 February 2003. Table 2.1 gives the prevalence of diabetes in pregnancy nationally and regionally according to type of diabetes. Women were assigned to a region based on the maternal postcode of residence. Where the postcode was missing or inaccurate (n = 42), women were assigned to the region of birth according to the hospital of delivery.

Births to women with pre-gestational diabetes accounted for 0.38% of all births in England, Wales and Northern Ireland, or one in every 264 births. The lowest prevalence of pre-gestational diabetes in pregnancy was seen in Yorkshire and Humberside, one in every 333 births, with the highest prevalence in the West Midlands, one in every 240 births.

Type 1 diabetes accounted for 0.27% of all births, or one in every 364 births. The lowest prevalence of type 1 diabetes in pregnancy was seen in Yorkshire and Humberside, one in every 473 births, with the highest in the East Midlands, one in every 294 births.

The prevalence of type 2 diabetes accounted for 0.10% of all births, or one in every 955 births. The lowest prevalences of type 2 diabetes in pregnancy were seen in Wales and Northern Ireland, one in every 2169 and 1792 births, respectively, with the highest prevalences seen in the West Midlands and London, one in every 690 and 572 births, respectively.

When comparing the geographical distribution of diabetes in the general population, it appears that the areas with the highest prevalence of diabetes overall do not necessarily coincide with the areas of highest prevalence of diabetes in pregnancy.2

Type 2 diabetes accounted for 27.6% of diabetes in pregnancy in England, Wales and Northern Ireland and varied from 13.3% in Wales to 44.5% in London (Figure 2.1).

 
 

2.3

 

Discussion

Births to women with pre-gestational diabetes account for 0.38% (1 in 264) of all births within the population of England, Wales and Northern Ireland, ranging from 0.30% to 0.42%.

There is considerable variation in the regional distribution of diabetes with births to women with type 2 diabetes accounting for between 13.3% and 44.5% of all births to women with diabetes (type 1 and 2). This regional variation can be partly explained by the socio-demographic characteristics of these regions with areas of high ethnic diversity and/or social deprivation having a greater number of women with type 2 diabetes.

It is possible, however, that some of the variation seen is due to differences in ascertainment on a regional basis. It was not possible to find an alternative source of data against which to validate the numbers of births to women with pre-existing diabetes within the population of England, Wales and Northern Ireland at the time of the study. As such, the potential levels of under-ascertainment on a regional basis cannot be quantified at this stage.

As the incidence of diabetes continues to increase, particularly that of type 2 diabetes in children and young adults,3,4 there are significant implications for maternity care in the next decade as these women enter childbearing age. This is particularly important, as evidence suggests that the offspring of women with diabetes are themselves at an increased risk of developing diabetes.5

 
 

2.4

 

Conclusion

There is considerable variation in the prevalence of diabetes in pregnancy across England, Wales and Northern Ireland. The relative distribution of type of diabetes also shows substantial variation, with type 2 diabetes a much larger contributing factor in some regions, such as London and the West Midlands. This, combined with the apparent finding that areas of high prevalence of diabetes in pregnancy do not necessarily coincide with areas of high prevalence of diabetes in the entire population, needs to be considered in the planning of diabetes services. Pregnancy services may need to be targeted in different areas to other diabetes services.

 
     

References

  1. Diabetes UK. Diabetes in the UK 2004. London: Diabetes UK; 2004 [http://www.diabetes.org.uk/infocentre/reports/in_the_UK_2004.doc].
  2. Yorkshire and Humberside Public Health Observatory. PBS Diabetes Population Prevalence Model. [http://www.york.ac.uk/yhpho/diabetes.htm].
  3. Pontiroli AE. Type 2 diabetes mellitus is becoming the most common type of diabetes in school children. Acta Diabetol 2004;41(3):85–90.
  4. Rosenbloom A, Joe J, Young R, Winter W. Emerging epidemic of type 2 diabetes in youth. Diabetes Care 1999;22:345–54.
  5. Pettitt DJ, Knowler WC, Baird HR, Bennett PH. Gestational diabetes: infants and maternal complications of pregnancy in relation to third-trimester glucose tolerance in Pima Indians. Diabetes Care 1980;3:458–64.