[CG] Gestational diabetes (GDM), diagnosing - Diabetic and Antenatal Combined Clinic, PRM, Obstetrics


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As part of the recovery plan from COVID 19, OGTT will be reintroduced at PRM from 12/10/20. Social distancing has been put in place



  1. At time of usual Tuesday morning antenatal clinic at PRM
  2. At other times Monday – Friday 9-4 at Stobhill using contact number 0141 451 5326
  3. E mail dsnnorth@ggc.scot.nhs.uk
  4. Diabetes Registrar – Page 13866

Screening for gestational diabetes PRM – 12/10/2020

At booking

BMI >= 35 

Previous baby > 4.5 Kg

Family history of diabetes {T1 or T2 in first degree relative ie child, parent, brother, sister}

Family origin {South Asia, Middle Eastern, Chinese or Black African/Caribbean}

Previous Pancreatitis

Previous gestational diabetes {needs OGTT at 16 and 26 weeks}


Perform HA1c at booking

If 48 refer direct into combined clinic

If < 48 perform OGTT at 26 weeks gestation in day care (Previous GDM OGTT also at 16 weeks)


During the Pregnancy:

Repeated {> one occasion} heavy glycosuria {2+ or more}


EFW > 97th centile (Intergrowth chart)


Perform OGTT in day care if <35+0 week 

Due to capacity issues, if >34+6 weeks perform random blood glucose and HbA1c – Refer to DSN/ dietician if RBG >= 9 mmol/l or Hba1c >= 39 mmol/mmol (The utility of OGTT in these women is unproven but high blood glucoses need to be excluded)

Diagnostic for gestational diabetes on OGTT if FBG > = 5.1 mmol/l or 2 hour BG >= 8.5 mmol/l.


  1. Refer by e mail to dsnnorth@ggc.scot.nhs.uk IF POSSIBLE INCLUDE PATIENTS EMAIL ADDRESS
  2. Inform patient by telephone (responsibility of the midwife who took the bloods)

PRMU Advice available from:

  1. At time of usual Tuesday morning antenatal clinic at PRMU which will continue throughout
  2. At other times at least Monday – Friday 9-4 at Stobhill using contact number 0141 451 5326 – in this context if meter/ equipment / insulin problems
  3. E mail dsnnorth@ggc.scot.nhs.uk
  4. If there is suspicion of new T1DM eg FBG>10 or presence of polydipsia/polyuria / ketone breath page on call diabetes registrar (#13866) as patient may require admission

Advice for DSN’s and dieticians

After referral

  1. To allow as little face to face contact as possible it would be ideal if patient can be e-mailed beforehand with
    1. general advice on gestational diabetes: at MyDiabetesMyWay: https://www.mydiabetesmyway.scot.nhs.uk/  and elearning with mydiabetesmyway :  https://elearning.mydiabetesmyway.scot.nhs.uk/
    2. online training for specific meter you are going to use eg agamatrix.co.uk/support/videos
  2. patients will be appointed to single appointment face to face session- if possible using Bluetooth meter and connecting to diasend. These will likely be predominantly at the same time as the Tues am clinic - with an extra clinic on Thursday mornings. Hopefully group teachings will be introduced in the near future.
  3. At face to face contact written information on
    1. Targets and contacting the clinic
    2. Dietetic advice and contacts
  4. Follow up phone contact from dietetics to reinforce advice.

Antenatal Care

All women will have initial management with existing obstetric / midwifery follow up. Pathways with written targets as per current practice, with the following exceptions:

  1. women diagnosed with new diabetes / diabetes in pregnancy – for this purpose HbA1c≥48mmol/mol at any time in pregnancy – will be seen at the combined obstetric diabetic ANC
  2. If fasting glucose >= 7mmol/l or 2 hour BG >=11.1mmol/l see at the following week’s combined obstetric diabetic ANC
  3. Women above target for home glucose monitoring (without a dietary reason) should be seen at next Tues am clinic
  4. Women with GDM controlled on diet alone should remain under in their present obstetric/midwifery care. Growth scans and review at their consultant antenatal clinic should be arranged at 32 and 36 weeks. These women should be delivered by T+6.
  5. Women with GDM requiring Metformin (MF) or insulin will be reviewed through the combined obstetric diabetic clinic and have growth scans at 32 and 36 weeks. These women should be delivered by T+6.
  6. If EFW>97th Centile on Intergrowth Chart there should be a documented discussion regarding timing and mode of delivery.

After Pregnancy

For women felt to be at high risk of diabetes immediately after pregnancy (small minority) follow up will be arranged by the diabetes team. For the majority HbA1c at 3-6 months is suggested. 


Guidance for Maternal Medicine in the evolving Coronavirus Pandemic RCOG 3/4/20 (V2)

Saving babies’ lives care bundle version 2: Covid information NHS England Appendix G 3/4/20

Last reviewed: 01 May 2021

Next review: 01 October 2022

Author(s): R Lindsay, F Mackenzie