Natural course of gestational diabetes mellitus: long term follow up of women in the SPAWN study

Objectives Long term follow up women with gestational diabetes mellitus (GDM).
Design Case–control study.
Setting Academic obesity unit.
Population Women earlier identified as having gestational diabetes mellitus.
Method Twenty-eight women diagnosed with GDM in 1984–1985, and a control group (   n = 52  ) who gave birth at the same time performed a 2-h oral glucose tolerance test 15 years later. Basic anthropometry and questions about various aspects of eating and exercise habits were furthermore obtained.
Results Ten women (35%) in the GDM group were diagnosed with type 2 diabetes mellitus and none in the control group (   P < 0.001  ). Mean BMI in the diabetic group was  27.4 kg/m²  and in the non-diabetic GDM group  24.6 kg/m² ( P < 0.05)  . The mean weight gain since the first child was 8.4 kg in all GDM versus 8.1 kg in controls (ns). The women who developed type 2 diabetes mellitus, however, gained 15.1 kg since the birth of their first child (   P < 0.05  ).
Conclusions Women who are diagnosed with GDM have a considerably higher risk of developing type 2 diabetes mellitus later in life. Despite a close medical monitoring during pregnancy, the further follow up within the health care system and information about long term consequences of GDM for later type 2 diabetes mellitus development seems to be generally lacking. More active strategies for future weight control and lifestyle advice after delivery might therefore be indicated for women with GDM.