Poster Presentation International Association of the Diabetes and Pregnancy Study Groups 2022 - Hosted by ADIPS

Does a reduced carbohydrate diet in women with gestational diabetes optimise gestational weight gain and glucose control? (#99)

Rosemary M Hall 1 2 , Fiona Hood 2 , Mark Weatherall 2 , Tutangi A Amataiti 2 , Jeremy D Krebs 1 2
  1. Endocrinology Department, Wellington Hospital, Wellington, New Zealand
  2. Department of Medicine, University of Otago, Wellington, New Zealand

Background: Gestational diabetes (GDM) is associated with adverse effects for women and their offspring which is exacerbated by excess gestational weight gain (GWG). Nutrition therapy is the primary treatment for GDM but little evidence exists to support any particular dietary approach1.2. Anxiety at the diagnosis of GDM triggers spontaneous carbohydrate (CHO) restriction3 and potential benefits have been observed with CHO intake lower than the recommended 175g/day4.5. With appropriate support, and avoidance of potentially harmful ketone production, reducing CHO may optimise GWG and metabolic outcomes for mother and infant.   

Aims: To investigate whether a diet lower in carbohydrate without ketosis, provided with dietetic support, will optimise GWG and improve glycaemic control.

Participants/methods: Women with newly diagnosed GDM were randomised to a reduced CHO diet, or standard nutritional advice based on national guidelines. Dietitians provided regular support and resources for women to consume an intervention diet of 135g/day CHO or standard CHO intake of 215g/day. The primary outcome was the proportion of women who gained weight within their Institute of Medicine (IOM) BMI category6. Secondary outcomes were glucose and metabolic variables in women and baby.

Results: Fifteen women, recruited after a diagnosis of GDM were followed for a mean(SD) of 47.8(14.5) days in the reduced CHO group and 54(25) days in the standard diet until delivery. Baseline CHO intake was 151.4g/day(SD 51.0). By 36 weeks gestation average CHO intake in the reduced CHO group was 136.1g/day CHO (SD 17.8), and 198.7g/day (SD 46.9) in the control group (p<0.004). Only one woman in each group recorded ketones on one occasion. Rate of weight change of 0.3kg increase per week was not different between randomised groups (p=0.94). Only 13% of women had weight gain within their IOM BMI category: 50% above and 37.5% below in the reduced CHO group; 57.1% above, 28.6% below in the standard diet group. There was no evidence of a difference between groups in HbA1c, insulin use, blood pressure, pre-eclampsia, mode of delivery, infant birth weight or head circumference, or admission to neonatal intensive care.

Conclusion: This feasibility study demonstrated that a significant reduction in CHO intake in women with GDM is achievable, without detrimental effects for mother or infant, and may be preferred. Weight gain per week during the intervention was small in both groups with intensive dietetic support. Supporting reduced CHO intake for a longer duration in pregnancy is required to determine effects on GWG and metabolic factors.

  1. Sweeting A, Mijatovic J, Brinkworth GD, et al. The Carbohydrate Threshold in Pregnancy and Gestational Diabetes: How Low Can We Go? Nutrients. 2021;13(8):2599. doi:10.3390/nu13082599
  2. Han S, Middleton P, Shepherd E, Van Ryswyk E, Crowther CA. Different types of dietary advice for women with gestational diabetes mellitus. Cochrane Database of Systematic Reviews. 2017
  3. Ásbjörnsdóttir B, Ronneby H, Vestgaard M, et al. Lower daily carbohydrate consumption than recommended by the Institute of Medicine is common among women with type 2 diabetes in early pregnancy in Denmark. Diabetes Res Clin Pract. 2019;152:88-95. doi:10.1016/j.diabres.2019.05.012
  4. Moreno-Castilla C, Hernandez M, Bergua M, et al. Low-Carbohydrate Diet for the Treatment of Gestational Diabetes Mellitus: A randomized controlled trial. Diabetes Care. 2013;36(8):2233-2238. doi:10.2337/dc12-2714
  5. Cypryk K, Kamińska P, Kosiński M, Pertyńska-Marczewska M, Lewiński A. A comparison of the effectiveness, tolerability and safety of high and low carbohydrate diets in women with gestational diabetes. Endokrynol Pol. 2007;58(4):314-319.
  6. Institute of Medicine and National Research Council Committee to Reexamine IOM Pregnancy Weight Guidelines. The National Academies Collection: Reports funded by National Institutes of Health. In: Rasmussen KM, Yaktine AL. Weight Gain During Pregnancy: Reexamining the Guidelines. Washington (DC): National Academies Press (US). National Academy of Sciences.; 2009.