Gestational Diabetes Flashcards
What is gestational diabetes?
- this is diabetes triggered by pregnancy
- there is reduced insulin sensitivity during pregnancy
- this resolves after birth
What is the most significant immediate complication of gestational diabetes?
- a large for dates fetus and macrosomia
- this poses a risk of shoulder dystocia at birth
What is the most significant long-term complication of gestational diabetes?
the mother is at higher risk of developing T2DM after pregnancy
How is gestational diabetes screened for?
- anyone with RFs should be screened with an oral glucose tolerance test (OGTT)
- this is performed at 24-28 weeks gestation
- women with previous gestational diabetes have their OGTT shortly after booking
What are the 5 risk factors that warrant an OGTT?
- BMI > 30
- previous gestational diabetes
- first-degree relative with diabetes
- ethnicity - black Caribbean, Middle Eastern & South Asian
- previous macrosomic baby
macrosomic babies are 4.5kg or more
What features suggestive of gestational diabetes warrant an OGTT?
- large for dates foetus
- glucose on urine dipstick
- polyhydraminos
polyhydraminos = increased amniotic fluid
How is an OGTT performed?
- it should be performed in the morning following a fast
- they drink a 75g glucose drink
- blood glucose is measured before the glucose drink and after 2 hours
during fasting, they are allowed to drink plain water only
What are normal results following an OGTT?
- fasting glucose < 5.6 mmol/l
- glucose after 2 hours < 7.8 mmol / l
results higher than these values suggest gestational diabetes
remember the cutoff values as 5-6-7-8
What additional scans are offered in gestational diabetes?
- USS scans are performed every 4 weeks between 28 to 36 weeks gestation
- these monitor fetal growth and amniotic fluid volume
What is the management for gestational diabetes when fasting glucose is < 7 mmol/l?
- a trial of control through diet / exercise for 1-2 weeks
- if this is unsuccessful, metformin is given
- if control is still not adequate, there is addition of insulin
What is the management for gestational diabetes when fasting glucose > 7 mmol/l?
immediately start insulin +/- metformin
What is the management for gestational diabetes when fasting glucose > 6 mmol/l + evidence of macrosomia?
immediately start insulin +/- metformin
this is the case if there are other complications aside from macrosomia too
What is a potential option for women who decline insulin / cannot tolerate metformin?
glibenclamide
(a sulfonylurea)
typically, metformin and insulin are the only drugs used in gestational diabetes
What advice is given to women about monitoring their blood sugar?
- blood sugar should be monitored several times a day
- target levels are:
fasting:
- 5.3 mmol/L
1-hr post-meal:
- 7.8 mmol/L
2-hr post-meal:
- 6.4 mmol/l
and avoid levels below 4 mmol/l
What advice is given to women with pre-existing diabetes prior to conception?
- they should ensure they have good glucose control prior to conception
- they should take 5mg folic acid from preconception until 12 weeks gestation
What is involved in the management of pre-existing diabetes in pregnancy?
- insulin is continued in T1DM
- all medications should be STOPPED in T2DM and they should be managed only with metformin +/- insulin
What type of screening should be performed in pregnant women with pre-existing diabetes?
retinopathy screening
- performed shortly after booking + at 28 weeks gestation
- there is a high risk of rapid progression to diabetic retinopathy in pre-existing diabetics
this involves referral to an ophthalmologist to check for diabetic retinopathy
What type of delivery is advised in diabetic patients?
gestational diabetes:
- birth can occur up to 40 + 6 weeks
pre-existing diabetes:
- a planned delivery is put in place between 37 and 38 + 6 weeks
What type of diabetes control is considered for diabetics during labour?
sliding-scale insulin regime
- a dextrose + insulin infusion is titrated to blood sugar evels
- this is for T1DM
AND
- poorly controlled T2DM or gestational diabetes
What management is in place for gestational diabetics following birth?
- diabetic medications can be stopped immediately
- a follow up test of fasting glucose is performed after at least 6 weeks
What is the management for women with existing diabetes after birth?
- they should lower their insulin doses
- be aware of hypoglycaemia in the postnatal period
- insulin sensitivity increases after birth + with breastfeeding
What are babies with diabetic mothers at increased risk of?
- jaundice
- neonatal hypoglycaemia
- polycythaemia
- congenital heart disease
- cardiomyopathy
