The risk for gestational diabetes during a second pregnancy heightens with increasing weight gain between pregnancies, according to study findings published in Plos Medicine.
Sorbye, MSc, a doctoral candidate in the department of global public health and primary care at the University of Bergen in Norway, evaluated data from the Medical Birth Registry of Norway (2006-2014) on 24,198 mothers and their first two pregnancies to determine the risk for gestational diabetes in the second pregnancy and whether BMI and gestational weight gain modify the risk.
Prepregnant BMI in second pregnancies minus prepregnant BMI in first pregnancy defined weight change, which was divided into six categories by BMI units: less than –2 kg/m2, –2 kg/m2 to less than –1 kg/m2, –1 kg/m2 to less than 1 kg/m2 (reference), 1 kg/m2 to 2 kg/m2, 2 kg/m2 to less than 4 kg/m2 and at least 4 kg/m2.
Overall, the absolute risk for gestational diabetes in second pregnancy was 18.1 per 1,000 pregnancies. Increasing level of prepregnant BMI in second pregnancy was associated with an increasing prevalence of gestational diabetes (P < .001). During the second pregnancy, most participants (53.7%) experienced gestational weight gain of 8 kg to 15.9 kg followed by those with a gain of at least 16 kg (34.9%), 0 kg to 7.9 kg (10.5%) and less than 0 kg (0.8%).
The risk for gestational diabetes was doubled in participants who gained between 1 and 2 BMI units (adjusted RR = 2; 95% CI, 1.5-2.7) compared with participants with stable interpregnancy weight. The risk for gestational diabetes was five times greater in participants who gained at least 4 BMI units (aRR = 5.4; 95% CI, 4-7.4) and 2.6 times higher in participants who gained between 2 and 4 units (aRR = 2.6; 95% CI, 2-3.5) compared with those with stable weight.
The risk for gestational diabetes was 60% lower in participants with overweight (BMI 25 kg/m2) in their first pregnancy who lowered their BMI by at least 2 units before their second pregnancy (aRR = 0.4; 95% CI, 0.2-0.8) compared with participants with overweight who did not decrease their weight as much.
“Antenatal guidelines for monitoring [gestational diabetes] in pregnancy should add interpregnancy weight change as an independent risk factor for [gestational diabetes] with a routine stress-test of glucose tolerance during pregnancy in women with weight gain more than 1 BMI unit,” the researchers wrote. “A possible preventive effect on [gestational diabetes] of losing weight between pregnancies in overweight women needs to be replicated in other studies. Efforts that are targeting women who are overweight in pregnancy and childbirth should expand in focus to promote healthy weight from preconception throughout reproduction. Today, less than 10% of countries’ national policies address healthy maternal weight across the entire spectrum of childbearing.” – by Amber Cox
Disclosures: The researchers report no relevant financial disclosures.