Diabetes in Pregnancy Flashcards
What hormones cause gestational diabetes?
-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
How common is gestational diabetes?
-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
What are the complications of GDM for the baby?
-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)
What is the target HbA1c in type 1 and type 2 diabetes?
- 53 mmol/l Scotland
- 48 mmol/l Wales and England
What development occurs in the first trimester of pregnancy?
Cardiac and neural development
=glucose dependent processes
What are the foetal outcomes in Scotland (T1DM vs all births)?
- 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
What are the risks to the foetus in pre-existing diabetes?
- Miscarriage
- Congenital malformation
- Stillbirth
- Neonatal death
What are the risks in diabetes in general to the foetus?
- 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
What are the maternal risks of diabetes?
- Miscarriage
- Pre-eclampsia
- Preterm labour
- Intrapartum complications
- Progression of microvascular complications (eyes, kidneys)
- Severe hypoglycaemia (especially in first term)
- Ketoacidosis (high neonatal death)
-Death
What is involved in pre-pregnancy planning for diabetic patients?
- Structured education (DAFNE course)
- Diet, weight, exercise advice
- Folic acid 5mg daily (until 12 weeks)
- Renal and retinal assessment (microalbuminuria)
How to we optimise preconception glycaemic control?
- 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)
What medications need to be reviewed preconception?
- Stop statins, ACEi/ARB, oral hypoglycaemics
- Continue metformin, (glibenclamide), commence insulin if required
How does glycaemic control affect eye problems?
-Exacerbates eye disease if bring down glycaemia quickly
=Laser treatment
=Severe background diabetic retinopathy
=Can lead to eye bleeding
Describe retinopathy in pregnancy
- 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
What is Gestational Diabetes?
-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
What is the likelihood of gestational DM complications?
- Macrosomia (linear relationship with glucose)/shoulder dystocia (3%)
- Neonatal hypoglycaemia (from neonatal hyperinsulinaemia)
- Neonatal death (1%)
- Late intra-uterine death (1%)
Who do we screen for GDM?
All women with risk factors or intermediate results in early pregnancy should have a 75g OGTT at 24-28 weeks
What are the risk factors for GDM?
- 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
What figures are required for GDM diagnosis?
-75g OGTT
=Fasting glucose >/5.1mmol/l (>7)
=2 hour >/8.5 mmol/l (>11.1)
Describe management of GDM
-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
Describe the typical antenatal experience
-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
What are the glycaemic targets for pre-existing diabetes?
- 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)
What is the order of treatments if glucose is outside the target?
- Dietary modifications (only 1 in 3 just need diet)
- Metformin (60%)
- Glibenclamide for patients intolerant of Metformin or reluctant for insulin
- Insulin (25%)
Describe hypoglycaemia during pregnancy
- 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
How is the birth plan changed with diabetes?
-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%)
Describe Postnatal Care
-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
