'Diabetes and childbirth: the relationship between maternal glycaemic control and

adverse pregnancy outcomes. Exploring the NICE guidelines'

Dr Bobby Huda

Consultant in Diabetes & Metabolism and Honorary Senior

Lecturer

St Bartholomew’s Hospital & Royal London Hospital

Aims

• 1. History & Pathophysiology

• 2. Review of literature

• 3. Pre-conception

• 4. Pre-existing diabetes

• 5. Gestational diabetes

• 6. Post-natal follow up

• 7. Conclusions

Aims

• 1. History & Pathophysiology

• 2. Review of literature

• 3. Pre-conception

• 4. Pre-existing diabetes

• 5. Gestational diabetes

• 6. Post-natal follow up

• 7. Conclusions

NICE GUIDELINES 2015

Historical context

Fetal and maternal mortality

Pathophysiology

• Glucose intolerance develops in pregnancy in those who

have insufficient beta cell capacity to maintain

euglycaemia

• In those with pre-gestational diabetes, insulin sensitivity is

initially increased up to 14 weeks and then decreases,

resulting in significant increases in insulin requirements

Pedersen hypothesis

Effects of diabetes on Fetus and Pregnancy

PLACENTA

• DM can cause functional and structural changes

FERTILITY

• Association of T1DM with premature menopause

and t2DM with PCOS

• MISCARRIAGE

• Spontaneous miscarriage is similar to non DM at around 12-15%

but is increased with poor control.

• UK data showed four-fold increase in spontaneous miscarriage

with HbA1c> 7.5% (58 mmol/mol) vs HbA1c <7.5%

• CONGENITAL MALFORMATIONS

• From CEMACH the prevalence is 41.8/1000 compared with 21/1000

in non-DM births

• With Hba1c in non-DM range the congenital abnormality rate is

around 2%, but can rise up to 10% with HbAc>10% (86 mmol/mol)

• STILLBIRTH

• CEMACH showed that 4-5 fold increase in stillbirth rate in DM pregnancies

• Increases with poor control, diabetic nephropathy, smoking and lower social status

• NEONATE

• Increased risk of delivery pre-term, LGA, birth injury or hypoglycaemia

• CEMACH suggests 50% of neonates are LGA (>90th centile)

• Birthweight >4000g 21% vs 11% in general population

• There was an increased incidence of both shoulder dystocia and Erb’s palsy

• Over half of all babies were admitted to a neonatal unit.(56.4%)

• Increased jaundice and respiratory distress

• MODE OF DELIVERY

• CEMACH found 2x likely to be induced 38.9% vs 21%

general population

• 3x caesarean rate 67% vs 22% general population

• Spontaneous vaginal delivery 24% vs 67% general

population

• 35.8% had a preterm delivery before 37 weeks

Risks to Mother

• Increased risks of pre-eclampsia

• Worsening of retinopathy and diabetic

nephropathy

Evidence for intervention

• Intensive treatment reduced primary outcomes from 4% to 1%

• Also reduced birth weight, macrosomia and LGA

• Note used WHO OGTT criteria (fasting 7.8 mmol/l)

• Target glucose pre-meal 3.5-5.5 mmol/l and 2 hours <7.0 mmol/l

Evidence for intervention

Evidence for association with glucose

• Over 25,000 women had OGTT at 24-28 weeks

• Those with FPG>5.8 mmol/l or 2 hours>11.1 mmol/l were excluded

• Otherwise women and clinicians blinded to OGTT results

IADPSG criteria

Pre-conception

• Give women adequate information about

pregnancy including the risks and the effects

of diabetes on the pregnancy

• Advice around contraception (2015)

• Need for increased CBG monitoring and

frequent healthcare professional contact

(2015)

• Give patients support including emergency

contact numbers (2015)

• Offer weight loss advice for those with

BMI>27 kg/m2

• To take folic acid until 12 weeks gestation

• Offer monthly Hba1c and SHBG

• Offer ketone meter for T1DM (2015)

• Advise CBG targets as will be recommended

for T1DM (2015)

• Aim for HbA1c< 6.5% (48 mmol/mol) (2015)

• Strongly advise to avoid pregnancy if HbA1c>

10% (86 mmol/mol) (2015)

• Continue metformin, stop ACE inhibitors and statins

• Use isophane as first line but consider continuing

Detemir or Glargine if established good control (2015)

• Retinal assessment within last 6 months

• Assess ACR and eGFR in pre-conception

Gestational Diabetes

Risk factors for screening

• BMI>30 kg/m2

• Previous macrosomic baby weighing >4.5kg

• Previous GDM

• Family history of DM (1st degree)

• Minority ethnic origin with high prevalence

Prevalence of DM in different ethnic groups

Detecting GDM

• Glycosuria 2+ or 2 x 1+ on dipstick needs further

testing (NICE 2015)

• The 2 hour 75g oral glucose tolerance test (OGTT) is

recommended

• Those with previous GDM offer OGTT after booking

and again at 24-28 weeks (NICE 2015)

• Otherwise offer at 24-28 weeks (NICE 2015)

Diagnosis of GDM

• Fasting plasma glucose 5.6 mmol/l

• 2 hour value 7.8 mmol/l (NICE 2015)

• Review within 1 week (NICE 2015)

Management of GDM

• Refer all women to a dietician (NICE 2015)

• Trial of diet and exercise if FPG<7.0 mmol/l

• Metformin if not met targets within 1-2 weeks

Management of GDM

• Insulin +/- metformin if FPG>7.0 mmol/l and

consider for FPG 6.0-.6.9 mmol/l or

macrosomia/ polyhydramnios (NICE 2015)

• Glibenclamide if refusing insulin or not

tolerating metformin (NICE 2015)

Monitoring

• Advise women with T1DM or MDI to test pre-

meal and 1 hour after meals (2015)

• Advise those on diet/ oral agents or basal

insulin to test qds (2015)

Capillary blood glucose targets

• Fasting 5.3 mmol/l

• 1 hour after meals 7.8 mmol/l

• Or 2 hours after meals 6.4 mmol/l (2015)

Glycated haemaglobin • Measure HbA1c in all pre-existing DM at booking

and consider for 2/3rd trimesters (2015)

• Measure Hba1c at time of diagnosis in GDM to

rule out overt diabetes (>6.5%)

• Do not use HbA1c routinely to monitor glucose

control (2008)

Insulin and CGM

• Offer insulin analogues

• Provide glucagon in T1DM (2015)

• Offer CSII if adequate control not achieved

• Not routine CGM but offer if recurrent

hypoglycaemia or unstable CBG (2015)

Ketone testing

• Offer women with T1DM blood ketone meter

and strips (2015)

• To test if unwell (2015) and those with DKA

admitted to level 2 care (2008)

Retinal assessment

• Offer retinal assessment with mydriasis at

booking and at 28 weeks (2008/2015)

• Offer 6 months opthalmological follow up for

those with proliferative retinopathy

(2008/2015)

Renal assessment

• If creatinine >120 umol/l or ACR >30 mg/mmol

then refer to nephrologist

• Thromboprophylaxis if >5g/day

• Aspirin 75mg up to 36 weeks (2015)

Fetal monitoring and ANC

• Detailed anomaly scan at 20 weeks

• Offer growth/AFI scans every 4 weeks

• Ensure contact with joint diabetes/antenatal

care every 1-2 weeks throughout pregnancy

(2015)

Delivery and labour

• Use additional insulin for steroids

with agreed protocol (2015)

• Advise women with T1/T2DM to have

elective delivery between 37 and

38+6 weeks (2015)

• Consider <37 weeks if maternal/fetal

complications (2015)

• Advise women with GDM to give

birth no later than 40+6 weeks (2015)

Labour

• Monitor CBG every hour in labour and

maintain between 4-7 mmol/l (2015)

• Use IV insulin/glucose for T1DM and

uncontrolled CBG (2015)

Neonatal care

• Advise to give birth in hospital where advanced

neonatal facilities available (2008)

• Assess baby for complications and admit to

NICU if needed (2008)

• Monitor baby’s CBG and use additional measures

if CBG<2.0 mmol/l on 2 occasions despite

feeding (2015)

Post-natal care

• Reduce insulin doses or stop treatment in

GDM

• If breastfeeding can resume metformin and

glibenclamide (2008)

Post-natal follow up

• GDM offer fasting plasma glucose (FPG) 6-13

weeks postnatally

• Use Hba1c or FPG after 13 weeks (2015)

Post-natal diagnostic criteria

• FPG < 6.0 mmol/l – lifestyle and annual test

• FPG 6.0-6.9 mmol/l – treat as ‘pre-diabetes’

(2015)

• FPG≥ 7.0mmol/l – treat as T2DM after 2nd test

(2015)

Post-natal diagnostic criteria

• Hba1c <5.7% - lifestyle advice and annual test

(2015)

• Hba1c 5.7-6.4% - treat as ‘pre-diabetes’

• HbA1c ≥ 6.5% - after 2nd test treat as T2DM

• If negative test annual test for GDM (2015)

Significant changes in 2015

• The GDM diagnostic criteria

• The target CBG

• Post-natal diagnosis using Hba1c

Conclusions

• Abnormal glucose control in pregnancy is

associated with adverse fetal and maternal

outcomes

• NICE guidelines provide an evidence based

and cost-efficient framework to guide clinical

practice