Monotone Operatoren

Abstract

Aims: Vitamin B12 insufficiency has been linked with adiposity and insulin resistance. A study from India showed that B12 insufficiency in pregnancy was associated with higher risk of gestational diabetes (GDM), mediated by body mass index (BMI). It is not known whether the same association exists among pregnant women in the UK. Methods: A retrospective study was done on women attending our antenatal clinic from 2010 to 2013. Information including maternal demographics, first trimester BMI, B12, folate and glucose were collected and multivariate regression models were applied. Results: 247 women (114 GDM, 133 controls) who had B12 levels checked in early third trimester were included. Overall, 26.7% had B12 values <150 pmol/l. GDM mothers were older and more obese than controls and had significantly lower mean B12 (186 vs 225 pmol/l, p = 0.01) with similar folate levels. In all women, first trimester BMI had a significant negative correlation with third trimester B12 (r = -0.203, p = 0.001). Linear regression showed that BMI was the only significant predictor of B12 (β = -0.21, p = 0.002), after adjusting for age, parity, ethnicity and folate. Women in the lowest B12 tertile had significantly higher odds of a diagnosis of GDM than those in the highest tertile (adjusted odds ratio 2.27, 95% confidence interval 1.07, 4.78), after adjusting for BMI and other variables as above. Conclusion: This study shows, for the first time in a UK population, that obese pregnant women in the UK are at risk of B12 insufficiency in pregnancy, which in turn is independently associated with GDM. Further studies are urgently needed to explore this link.