3








Description of the women

 
     
 

KEY FINDINGS

  • Women with type 1 diabetes are different from women with type 2 diabetes with respect to certain demographic characteristics such as age, ethnicity and parity.
  • There is a significant gradient of deprivation seen in women with diabetes, most pronounced for women with type 2 diabetes of Black or Other ethnic minority ethnic origin.
 
 
 

3.1

 

Introduction

This chapter describes the 3733 women who had type 1 or type 2 diabetes prior to pregnancy and booked or delivered between 1 March 2002 and 28 February 2003. Seventy-three women had more than one pregnancy within this time period (70 with two pregnancies and two with three pregnancies). For the purposes of the following descriptions and for consistency with the remainder of the report, these women are counted once for each pregnancy episode. Women with more than one pregnancy were no different to women with only one pregnancy with respect to type of diabetes, age at delivery, ethnicity or deprivation.

 
 

3.2

 

Maternal characteristics

 
 

3.2.1

 

Type of diabetes

Women with type 2 diabetes accounted for 27.3% of women in this study. Of the 1041 women with type 2 diabetes, 276 (26.5%) were documented as having been on insulin before their last menstrual period.

 
 

3.2.2

 

Age

The median age of the women with type 1 and type 2 diabetes at delivery was 31 years which was not significantly different from the general population.1 Women with type 2 diabetes were on average older at onset of diabetes (median age 29 years compared with 15 years for women with type 1 diabetes) and thus had a shorter duration of the disease. This reflects the difference in disease profile between the two types of diabetes. This is also reflected in the higher age at delivery of the women with type 2 diabetes compared with those women with type 1 diabetes. Within this pregnancy cohort, there were 67 women with type 2 diabetes with an age of onset of diabetes of less than 20 years.

 
 

3.2.3

 

Ethnicity

When women with type 1 and type 2 diabetes were considered together, maternal ethnic origin was not significantly different to the general maternity population of England which reports 80.3% White, 5.8% Black (Black Caribbean, Black African and Black Other), 10.5% Asian (Indian, Pakistani and Bangladeshi) and 3.4% Chinese and other ethnic background.2 A much higher proportion of women with type 2 diabetes were of Black, Asian or Other ethnic minority origin compared with women with type 1 diabetes (48.5% versus 8.5%), again largely reflecting the profile of the disease.

 
 

3.2.4

 

Gravidity

A total of 1507 women (39.7%) were primigravid. Women with type 1 diabetes were significantly more likely to be primigravid (Table 3.1) (P < 0.001). This difference is largely explained by the higher median age at delivery of women with type 2 diabetes. This itself will be partly driven by the later age of onset of type 2 diabetes.

 
 

3.2.5

 

Deprivation

The relationship of diabetes in pregnancy with deprivation was explored by the application of an Index of Multiple Deprivation (IMD) score.3 This was based on the postcode of residence of the women and the corresponding Super Output Area as defined by the Office for National Statistics. Each Super Output Area has a deprivation score calculated using multiple-source data. These deprivation scores were ranked and quintiles of deprivation derived for the national population. It should be noted that these quintiles are based on the entire population of England, not just the maternity population. Women within this study were then placed into the appropriate quintile of deprivation. As this measure is based only on the population of England, women within our study who were normally resident in Wales and Northern Ireland were excluded for the purposes of Tables 3.2, 3.3, 3.4.

Due care should be taken when interpreting these data as there are limitations when applying population based statistics at the individual level. No individual-level data on occupation or social class were collected in the data-capture questionnaire for this study.

There was a higher proportion of women with type 2 diabetes than expected in the higher quintile categories, particularly in the most deprived quintile (45.1% compared with expected 20%). There was only a slight increase in the proportion of women in the fifth quintile for women with type 1 diabetes (Table 3.2).

The relationship between type of diabetes and deprivation was further explored according to ethnic origin (Tables 3.3 and 3.4). For women of White ethnic origin, there was a clear increase in the numbers of type 2 women with increasing quintile of deprivation. Over 30% of White women with type 2 diabetes fell into the most deprived quintile, compared with the expected 20%. No such increase was seen in women of White ethnic origin with type 1 diabetes.

For women of Black or Other ethnic minority origin, this increase was seen in women with both type 1 and type 2 diabetes. Over one-third of all women of Black, Asian or Other ethnic minority origin with type 1 diabetes fall in to the most deprived quintile. The gradient was much more pronounced in women with type 2 diabetes with nearly 60% of women of Black, Asian or Other ethnic minority origin with type 2 diabetes falling into the most deprived quintile.

 
 

3.3

 

Maternal deaths

There were five deaths of women within this cohort within 1 year of delivery. These deaths were identified by linkage with the CEMACH maternal death enquiry database.4 This linkage exercise was performed using date of delivery and a free text search for diabetes. All five of the women identified had type 1 diabetes. These five deaths consisted of one direct death (maternal collapse at 34 weeks of gestation due to possible pulmonary embolism) and four late maternal deaths: one death from ischaemic heart disease, one following mitral valve replacement, one secondary to sepsis following renal failure and one from malignant melanoma.

Previous reports on confidential enquiries into maternal deaths have only referenced women with diabetes if complications of diabetes itself were the cause of death.5 This report includes deaths from all causes and are thus higher. Further exploration of the causes and contributing factors to the deaths of these women will be examined and described in the next report on confidential enquiries into maternal deaths in the UK due to be published by CEMACH in late 2007.

 
 

3.4

 

Conclusion

Women with type 1 diabetes are different to women with type 2 diabetes with respect to certain demographic characteristics. Many of these are a reflection of the profile of the disease with type 2 diabetes traditionally being a disease of later life and being more common in people of Black, Asian or Other ethnic minority origin.

The most striking observation from the maternal demographic data was the strong association seen between deprivation and women with type 2 diabetes. This association was particularly seen in women of Black, Asian and Other ethnic minority origin.

It is possible that these data on deprivation are a reflection of the entire population of people with diabetes rather than specific to the maternity population with diabetes.

Targeting of services, however, will need to take account of the differing profiles of women with type 1 and type 2 diabetes.

 
     

References

  1. Office for National Statistics. Key Population and Vital Statistics, 2002 [www.statistics.gov.uk/statbase/Product.asp?vlnk=539].
  2. Department of Health. NHS Maternity Statistics, England 2002–03. Statistical Bulletin 2004/10 [www.dh.gov.uk/PublicationsAndStatistics/Statistics/StatisticalWorkAreas/StatisticalHealthCare/StatisticalHealthCareArticle/fs/en?CONTENT_ID=4086521&chk=wV7ZSA].
  3. Office of the Deputy Prime Minister. Index of Deprivation 2004 [www.odpm.gov.uk/stellent/groups/odpm_control/documents/contentservertemplate/odpm_index.hcst?n=4610&l=3].
  4. CEMACH Maternal Death Enquiry [www.cemach.org.uk/programmes.htm].
  5. Lewis G, editor. Why Mothers Die 2000–2002. The Sixth Report of the Confidential Enquiries into Maternal Death in the United Kingdom. London: RCOG Press; 2004.