Type 2 Diabetes Risk after Pregnancy, What Women Should Know
The risk of developing type 2 diabetes after pregnancy may be greater than women think, according to a new study. Although the study was conducted among Asian women, the results are a warning for all women who develop gestational diabetes during pregnancy and their subsequent risk of type 2 diabetes.
What is gestational diabetes?
Around week 24 of pregnancy, about 18 percent of women develop gestational diabetes, a condition that occurs in expectant mothers who never had diabetes before they were pregnant. The cause of gestational diabetes is unknown, although it is believed hormones from the placenta are involved in interfering with the activity of insulin in the mother’s body.
Women with gestational diabetes are unable to produce and use all the insulin they need to process glucose (sugar) properly. This results in high levels of glucose in the blood (hyperglycemia), which can have a detrimental effect on the fetus if the gestational diabetes is not treated.
Gestational diabetes and type 2 diabetes
A 2011 report from the Centers for Disease Control and Prevention (CDC) notes that 5 to 10 percent of women with gestational diabetes develop type 2 diabetes immediately after pregnancy, and that women with a history of gestational diabetes have a 35 to 60 percent chance of developing type 2 diabetes within the next two decades.
Now a new study that involved 843 Asian women has shed more light on the topic of type 2 diabetes risk following gestational diabetes. The researchers reported that about 12.5 percent of the women developed type 2 diabetes within two months of giving birth, and that the number of women who were later diagnosed with type 2 diabetes grew at a rate of 6.8 percent per year.
An evaluation of women who developed type 2 diabetes soon after giving birth and those who developed it later revealed that obesity was a risk factor in both groups. In addition, women who developed type 2 diabetes soon after delivery had more distinct defects in beta-cell function, which may be explained in part by genetic predisposition. Beta cells are cells in the pancreas that produce insulin.
The bottom line, according to Soo Heon Kwak, MD, of Seoul National University Hospital and the study’s lead author, is that “the findings indicate as many as half of Asian women who had gestational diabetes will develop type 2 diabetes within eight years of giving birth.”
How to prevent type 2 diabetes after gestational diabetes
All women who have gestational diabetes can be proactive in preventing type 2 diabetes through lifestyle habits, including a healthy diet and exercise. Several large studies back up this advice.
The most recent study was published in the Archives of Internal Medicine. In that study, investigators evaluated dietary data from 4,413 women followed for 15 years and who participated in the Nurses’ Health Study II. All had a history of gestational diabetes.
Three dietary patterns were evaluated: alternate Mediterranean diet (aMED), DASH (Dietary Approaches to Stop Hypertension), and alternate Healthy Eating Index (aHEI). All three diets have similar characteristics in terms of fruit and vegetable intake, low consumption of meats and saturated fats, and carbohydrate quality.
The investigators found that all three diets reduced the risk of developing type 2 diabetes: aHEI was associated with a 57 percent reduced risk, DASH with 46 percent lower risk, and aMED with a 40 percent lower risk. Two factors of the aHEI that differed from the other two diet plans were higher intake of fiber and long-term use of multivitamins. All three diets, however, had positive factors that contributed to a lower risk of type 2 diabetes.
The Diabetes Prevention Program also showed that women with a history of gestational diabetes were able to lower their risk for type 2 diabetes by 50 percent or more when they followed a healthy diet and lost weight, although this approach also included use of the antidiabetes drug metformin. A follow-up study also showed that this reduced risk for type 2 diabetes was still valid a full decade later.
Pregnant women are at considerable risk for gestational diabetes and subsequent type 2 diabetes as well. However, women who are aware of these possibilities can arm themselves with information, talk to their doctors about the risks, and take preventive steps against type 2 diabetes if gestational diabetes does develop.
American Diabetes Association
Centers for Disease Control and Prevention: National diabetes fact sheet: general information and national estimates on diabetes in the United States, 2011. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2011.
Diabetes Prevention Program Research Group: Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. New England Journal of Medicine 2002; 346(6): 393-403.
Knowler WC et al. 10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study. Lancet 2009; 374(9702): 1677-86.
Kwak SH et al. Clinical and genetic risk factors for type 2 diabetes at early or late post partum after gestational diabetes mellitus. Journal of Clinical Endocrinology and Metabolism 2013 Mar 7. Epub ahead of print
Tobias DK et al. Healthful dietary patterns and type 2 diabetes mellitus risk among women with a history of gestational diabetes mellitus. Archives of Internal Medicine 2012 Sept 17. Published online. doi:10.1001/archinternmed.2012.3747