Oral Presentation Australasian Diabetes in Pregnancy Society Annual Scientific Meeting 2019

Modestly lower carbohydrate diet for gestational diabetes: are there unintended and potentially adverse effects on offspring? (#20)

Jovana Mijatovic 1 , Marion Buso 2 , Fiona Atkinson 3 , Jimmy C Louie 4 , Tania P Markovic 3 5 , Glynis Ross 5 6 , Jennie Brand-Miller 1 3
  1. The School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
  2. Wageningen University, Wageningen, The Netherlands
  3. Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
  4. School of Biological Sciences, The University of Hong Kong, Hong Kong, China
  5. Royal Prince Alfred Hospital, Sydney Local Health District, Camperdown, NSW, Australia
  6. Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia

Currently, the safety and efficacy of lower carbohydrate diets in gestational diabetes (GDM) management is unclear. They have the potential to raise blood ketone concentration, which in turn may negatively impact infant brain development. To determine the risk of ketonaemia and pregnancy outcomes in women with GDM following a modestly lower carbohydrate (MLC) diet, we conducted a pilot, 6-week randomised controlled trial (MAMI: macronutrient adjustments in mothers to improve GDM) at 2 Sydney Hospitals. The MLC diet prescribed a carbohydrate target of 135g/day, whereas routine care (RC) diet had 180-200g/day. Blood ketones and 3-day food diaries were collected at baseline and after the intervention, whereas pregnancy outcomes were obtained from medical records. Thirty-three women completed the study (MLC = 16, RC = 17). Carbohydrate and total energy intake were significantly lower in MLC vs RC (mean ± SEM, carbohydrate 165 ± 7 g vs 190 ± 9 g; P = 0.042; energy 7040 ± 240 kJ vs 8230 ± 320 kJ; P = 0.006, respectively), but there were no differences in blood ketones (MLC 0.1 ± 0.0 mmol/L vs RC 0.1 ± 0.0 mmol/L; P = 0.308). Infant head circumference was significantly lower in the MLC group (MLC 33.9 ± 0.1 cm vs RC 34.9 ± 0.3 cm; P = 0.046), before and after adjustment for gestational weight gain, weeks gestation at delivery and infant sex (P = 0.043). While the MLC diet contained enough carbohydrates to prevent ketonaemia, it may have reduced the overall energy and nutrient intake with a potentially negative impact on brain development.