Ethnicity and Gestational Diabetes
By Dr. Kate Dudek
Gestational Diabetes Mellitus (GDM) is a glucose intolerance that develops during pregnancy; which, if left untreated, can have long-term health implications for both the mother and her baby.
Worldwide, the prevalence of GDM is increasing, paralleling the rise in cases of type 2 diabetes. Obesity is a major risk factor for the development of both GDM and type 2 diabetes, with over 70% of women with GDM having a BMI of over 25. These women have a 50% chance (at least) of developing type 2 diabetes in the decade that follows their GDM diagnosis. Addressing obesity is key to reducing the growing number of women being diagnosed with GDM.
However, obesity is not the only factor that increases a woman’s risk of developing GDM; with one of the greatest non-modifiable risk factors thought to be ethnicity. Ethnicity is defined as “belonging to a social group that has a common national or cultural tradition” (Oxford English Dictionary), and the differences in prevalence rates of GDM across different ethnicities are quite striking. Women from the Middle East have amongst the highest rates of GDM, at up to 20%; whilst the risks in part of Europe are almost negligible, for example, the risk of developing GDM in Sweden is only 0.4-1.5%.
One large scale study looked at Kuwait in detail. It identified that 12.6% of pregnancies were affected by GDM. This figure increased to 18% when only women aged over 35 were considered (age is another major risk factor for GDM diagnosis). Prevalence rates across neighbouring countries are not dissimilar; Bahrain (10%), Saudi Arabia (15.4%), Qatar (16.3%) and UAE (20.6%). In the Kuwait study it was actually found that Kuwaiti women were at lower risk of GDM than non-Kuwaiti women living in Kuwait (10.2% vs 16.5%). This is probably due to a high proportion of Asian women living in the region. South Asian women have a 7-fold greater risk of developing GDM than women from the US or Australia. Their risk is significantly greater than the risk for women from other Asian sub-populations, including South East Asia and East Asia.
There are, however, problems with comparing across different countries, primarily because there is a distinct lack of universally accepted diagnostic criteria and screening approaches. Furthermore, the management of the condition should vary according to ethnicity, and the potential maternal and perinatal outcomes will differ depending on where in the world you are.
For a start, BMI is widely used as a screening tool and it can be highly successful at identifying those women at greatest risk in some parts of the world. It will potentially successfully identify over 90% of African-American women with the condition. However, in Asia, its use it questionable, as many women with the condition have a healthy, or even low BMI. Perhaps in this part of the world, the best option is for all women to undergo diagnostic screening.
Where obesity is identified as a concurrent risk, it is important to assess the normal diet and eating habits of a particular cultural group. In parts of Asia the diet is very rice-heavy; in the Middle East it is usual to have a large meal mid-afternoon, a small breakfast and a very late dinner. Therefore, carbohydrate intake and timing can vary substantially in different parts of the world, regardless of GDM prevalence. The impact of fasting during the holy month of Ramadan also needs to be taken into account, as many diabetics will still wish to fast.
As a final note, extra care should be taken of migrants living in a foreign country. They may struggle to manage their condition if all their health care is provided in a language that they are unfamiliar with. These women are at greater risk of additional complications if their GDM remains untreated.
- Bener, A, et al. “Prevalence of Gestational Diabetes and Associated Maternal and Neonatal Complications in a Fast-Developing Community: Global Comparisons.” International Journal of Women's Health, vol. 3, 2011, pp. 367–373., doi:10.2147/IJWH.S26094.
- Fadl, H E, et al. “Maternal and Neonatal Outcomes and Time Trends of Gestational Diabetes Mellitus in Sweden from 1991 to 2003.” Diabetic Medicine, vol. 27, no. 4, Apr. 2010, pp. 436–441., doi:10.1111/j.1464-5491.2010.02978.x.
- Groof, Z, et al. “Prevalence, Risk Factors, and Fetomaternal Outcomes of Gestational Diabetes Mellitus in Kuwait: A Cross-Sectional Study.” Journal of Diabetes Research, vol. 2019, no. 9136250, 3 Mar. 2019, doi:10.1155/2019/9136250.
- Yuen, L, and V W Wong. “Gestational Diabetes Mellitus: Challenges for Different Ethnic Groups.” World Journal of Diabetes, vol. 6, no. 8, 25 July 2015, pp. 1024–1032., doi:10.4239/wjd.v6.i8.1024.