Pregnancy insulin, glucose and BMI contribute to birth outcomes in non-diabetic mothers

  1. Ken K Ong, PhD1,2,
  2. Barbro Diderholm, PhD2,3,
  3. Giuseppina Salzano, PhD2,
  4. Dianne Wingate2,
  5. Ieuan A Hughes, MD2,
  6. Jane MacDougall, MD4,
  7. Carlo L Acerini, MD2 and
  8. David B Dunger, MD (dbd25{at}cam.ac.uk)2
  1. 1MRC Epidemiology Unit, Institute of Metabolic Science, Cambridge, UK
  2. 2Department of Paediatrics, University of Cambridge, Addenbrooke's Hospital, UK
  3. 3Department of Women's and Children's Health, Uppsala University, University Children's Hospital, Sweden
  4. 4Department of Obstetrics and Gynaecology, Rosie Maternity Hospital, Cambridge, UK

    Abstract

    Objective: We investigated the effects of normal variations in maternal glycaemia on birth size and other birth outcomes.

    Research design and methods: Two unselected birth cohorts, one retrospective (n=3,158) and one prospective (n=668), underwent an oral glucose challenge at 28 weeks gestation. In the retrospective study, glycaemia was linked to routine birth records. In the prospective study, offspring adiposity was assessed by skinfold thickness from birth to age 24 months.

    Results: In the retrospective study, within the non-diabetic range (2.1-7.8 mmol/L), each 1 mmol/L rise in mother's 60 min glucose level was associated with a: (mean±SE) 2.1±0.8% (P=0.006) rise in absolute risk of assisted vaginal delivery; 3.4±0.8% (P<0.0001) rise in emergency caesarean; 3.1±0.7% (P<0.0001) rise in elective caesarean; and 46±8 g (P<0.0001) increase in offspring birth weight.

    Results: In the prospective study, fetal macrosomia (birth weight >90th centile) was independently related to mother's fasting glucose (OR=2.61 per +1 mmol/L, 95% CI: 1.15-5.93) and mother's pre-pregnancy BMI (1.10 per +1 kg/m2, 1.04-1.18). Mother's higher fasting glycaemia (P=0.004), lower insulin sensitivity (P=0.01) and lower insulin secretion (P=0.02) were independently related to greater offspring adiposity at birth. During postnatal follow-up, the correlation between mother's glycaemia and offspring adiposity disappeared by 3 months, while mother's pre-pregnancy BMI was associated with offspring adiposity only apparent at 12 and 24 months (both P<0.05).

    Conclusions: Mother's pre-pregnancy BMI and pregnancy glycaemia, insulin sensitivity and insulin secretion all contribute offspring adiposity and macrosomia, and may be separate targets for intervention to optimize birth outcomes and later offspring health.

    Footnotes

      • Received June 19, 2008.
      • Accepted August 5, 2008.

    This Article

    1. Diabetes Care
    1. All Versions of this Article:
      1. dc08-1111v1
      2. dc08-1111v2
      3. 31/11/2193 most recent