Diabetes in Pregnancy

Question 1

What hormones cause gestational diabetes?

Answer 1

-hPL increases and peaks at around 28 weeks pregnancy
=glucose tolerance test at 24-28 weeks gestation (maximum effects)
=insulin resistance if pre-existing diabetes so insulin requirements increase at second trimester onwards

Question 2

How common is gestational diabetes?

Answer 2

-5% of 700,000 pregnant women have pre-existing or gestational diabetes
=87.5% GDM (gone once placenta gone, but increases lifetime risk of T2DM by 10-20%)
=7.5% T1DM
=5.0% T2DM

Question 3

What are the complications of GDM for the baby?

Answer 3

-Macrosomia (4.5kg and above) as exposed to hyperglycaemia in pregnancy
-Neonatal hypoglycaemia (pancreas makes insulin to deal with maternal hyperglycaemia from 11 weeks)
=stuck in birth canal, must fracture humerus/ clavicle to get out= shoulder dystocia
-Anencephaly (prevent with folic acid)
=Perinatal death
-Premature birth (intrauterine growth retardation, placental problems)

Question 4

What is the target HbA1c in type 1 and type 2 diabetes?

Answer 4

• 53 mmol/l Scotland

- 48 mmol/l Wales and England

Question 5

What development occurs in the first trimester of pregnancy?

Answer 5

Cardiac and neural development

=glucose dependent processes

Question 6

What are the foetal outcomes in Scotland (T1DM vs all births)?

Answer 6

• Stillbirth rate= 18.5/ 5.2
• Perinatal mortality rate= 27.8/ 7.6
• Infant mortality rate= 14.2/ 5.0

=Risk from type 2 diabetes increased since this figure

Question 7

What are the risks to the foetus in pre-existing diabetes?

Answer 7

• Miscarriage
• Congenital malformation
• Stillbirth
• Neonatal death

Question 8

What are the risks in diabetes in general to the foetus?

Answer 8

• Foetal macrosomia
• Birth trauma (to mother and baby- being stuck in birth canal)
• Induction of labour or caesarean section
• Transient neonatal morbidity
• Obesity and/or diabetes developing later in the baby’s life

Question 9

What are the maternal risks of diabetes?

Answer 9

• Miscarriage
• Pre-eclampsia
• Preterm labour
• Intrapartum complications
• Progression of microvascular complications (eyes, kidneys)
• Severe hypoglycaemia (especially in first term)
• Ketoacidosis (high neonatal death)

-Death

Question 10

What is involved in pre-pregnancy planning for diabetic patients?

Answer 10

• Structured education (DAFNE course)
• Diet, weight, exercise advice
• Folic acid 5mg daily (until 12 weeks)
• Renal and retinal assessment (microalbuminuria)

Question 11

How to we optimise preconception glycaemic control?

Answer 11

• Monthly HbA1c
• HbA1c as low as possible and <53mmol/mol as minimum (SIGN), (lower with NICE-48)
• Blood glucose meter x4/7, ketone testing in T1DM, hypoglycaemia management and awareness (remember glucagon in fridge)

Question 12

What medications need to be reviewed preconception?

Answer 12

• Stop statins, ACEi/ARB, oral hypoglycaemics

- Continue metformin, (glibenclamide), commence insulin if required

Question 13

How does glycaemic control affect eye problems?

Answer 13

-Exacerbates eye disease if bring down glycaemia quickly
=Laser treatment
=Severe background diabetic retinopathy
=Can lead to eye bleeding

Question 14

Describe retinopathy in pregnancy

Answer 14

• 43% of women with retinopathy show progression during pregnancy
• Sight-threatening retinopathy rare (2%)
• Risk factors are poor glycaemic control and uncontrolled hypertension
• Pre-pregnancy screening, and during each trimester in pre-existing diabetes; early referral to ophthalmology

Question 15

What is Gestational Diabetes?

Answer 15

-Defined as “carbohydrate intolerance of variable severity with onset or first recognition during pregnancy”
=Includes women with undiagnosed type 1, type 2 or monogenic (MODY) DM
=Usually develops after 28 weeks gestation

Question 16

What is the likelihood of gestational DM complications?

Answer 16

• Macrosomia (linear relationship with glucose)/shoulder dystocia (3%)
• Neonatal hypoglycaemia (from neonatal hyperinsulinaemia)
• Neonatal death (1%)
• Late intra-uterine death (1%)

Question 17

Who do we screen for GDM?

Answer 17

All women with risk factors or intermediate results in early pregnancy should have a 75g OGTT at 24-28 weeks

Question 18

What are the risk factors for GDM?

Answer 18

• BMI >30kg/m2
• Previous baby with birth weight > 4.5kg
• Previous GDM
• Family history of diabetes in a 1st degree relative
• Ethnic minority high risk population

Question 19

What figures are required for GDM diagnosis?

Answer 19

-75g OGTT
=Fasting glucose >/5.1mmol/l (>7)
=2 hour >/8.5 mmol/l (>11.1)

Question 20

Describe management of GDM

Answer 20

-HBGM
-Dietetic input
-Metformin / Insulin
=Fasting ≥5.5mM
=Pre-prandial ≥6mM
-Weekly CTG and liquor volumes from 36 weeks
-Induced at term
-Insulin stopped once delivered
=OGTT at 12 weeks,12 monthly screening for T2DM

Question 21

Describe the typical antenatal experience

Answer 21

-Minimum 30 visits to hospital
-Fortnightly visits until 30 weeks
=Ultrasound scans (fetal anomaly, cardiac, fetal growth, liquor volumes)
=Retinal scans (1st antenatal visit, 28 weeks)
=Anaesthetic appointment
-Weekly visits until 36 weeks
-Twice weekly until 39-40 weeks
-Minimal GP and community midwife contact

Question 22

What are the glycaemic targets for pre-existing diabetes?

Answer 22

• Pre-prandial 4-6mM
• 1 hour post-prandial <8mM
• 2 hour post-prandial <7mM
• Before bed <6mM

-Aspirin 75mg from 12-36 weeks (reduces pre-eclampsia risk)

Question 23

What is the order of treatments if glucose is outside the target?

Answer 23

1. Dietary modifications (only 1 in 3 just need diet)
2. Metformin (60%)
3. Glibenclamide for patients intolerant of Metformin or reluctant for insulin
4. Insulin (25%)

Question 24

Describe hypoglycaemia during pregnancy

Answer 24

• Common (14-45% of patients experience a severe hypo)
• Occurs most often during 1st trimester
• Risk factors include previous severe hypos, diabetes duration, impaired hypoglycaemia awareness, erratic control

Question 25

How is the birth plan changed with diabetes?

Answer 25

-Pre-existing diabetes:
=Usually IOL (induction of labour) or elective C section at 37-38 weeks

-GDM: Labour induced before 40 weeks
=Because of increased risk of IUD and other maternal/fetal complications
=Increased risk of instrumental delivery and C Section (60%)

Question 26

Describe Postnatal Care

Answer 26

-Pre-pregnancy planning for next pregnancy!
-Encourage breastfeeding
-Adjust treatment regimen when necessary
-GDM: 50% 5 year risk of T2DM
=Diet, weight, exercise advice
=12 week OGTT
=Annual screening for T2DM