Compared with women whose weight remained stable, body mass index gains between the first and second pregnancy were associated with an increased risk of gestational diabetes mellitus in the second pregnancy.
But losing weight between the first and second pregnancies appeared to reduce GDM risk in a second pregnancy, particularly for women who were overweight or obese to begin with.
The study examined a diverse cohort of 22,351 women from Kaiser Permanente in Northern California over a 10-year period.
Women who gained 2.0-2.9 BMI units (approximately 12 to 17 pounds) between the first and second pregnancy were more than two times more likely to develop GDM in the second pregnancy compared with those whose weight remained stable (plus or minus 6 pounds between pregnancies).
Women who gained 3.0 or more BMI units (approximately 18 or more pounds) between the first and second pregnancy were more than three times more likely to develop GDM during the second pregnancy compared with those whose weight remained stable
Conversely, women who lost more than 6 pounds between the first and second pregnancy reduced their risk of developing GDM in the second pregnancy by approximately 50 percent compared with women whose weight remained stable. The association between losing weight and reduced GDM risk was strongest in women who were overweight or obese in their first pregnancy, explained the researchers.
This study is the first to examine whether weight loss before a second pregnancy reduces the risk of recurrent GDM.
Women who lose BMI between pregnancies appear to have a decreased risk of GDM in their second pregnancy, but there was significant variation by maternal overweight or obese status in the first pregnancy. Weight loss was associated with lower risk of GDM primarily among women who were overweight or obese in their first pregnancy, Ehrlich said.
She explained that being overweight or obese prior to pregnancy is a well-established risk factor for GDM. Women of normal weight who go on to develop GDM are likely to be more genetically susceptible to the disease. Thus, lifestyle changes resulting in weight loss may not be as effective in reducing GDM risk among normal weight women, she added.
Source: Kaiser Permanente, USA