Is gestational diabetes associated with congenital malformities?
Having diabetes is associated with a greater risk of malformation at birth. This systematic review looked at whether gestational diabetes is also associated with an increase in risk.
The reviewers found 17 studies that reported malformities in the children of women with gestational diabetes compared to women without.
When they combined all the dat from these studies, gestational diabetes was associated with a statistically significant increase in the risk of malformity. The relative risk was 1.16, or a 16% increase in risk compared with women without diabetes.
Women with diabetes that existed before they got pregnant were seen to have more than double the risk of malformity compared with non-diabetic women.
Users of this research are advised to consider:
- Whether the patient population is similar to those in which this evidence would be applied.
- Look for subgroup analysis for different patient groups (e.g. stratified by glycaemic control, demographics).
- Did the reviewers do enough to find and include all of the best quality studies?
- Whether the reviewers only included good quality studies, or what the effects of any potential bias might be.
- Whether the increase in risk might be caused by other factors.
- Whether it made sense to combine all of the studies in one overall result.
- The baseline risk of malformities and what the absolute risk increase would be for a particular patient or population.
Montserrat B, Apolonia GP et al. Major congenital malformations in women with gestational diabetes mellitus: A systematic review and meta-analysis. Diabetes Metab Res Rev. 2011 Nov 3. doi: 10.1002/dmrr.1304. [Epub ahead of print]