Diabetes in pregnancy Flashcards
What are the two most common medical disorders complucating pregnanies?
- Hypertension
- Gestational diabetes - ~4% affected
How common is gestational diabetes?
Complicates up to 1 in 20 pregnancies
- 87.5% have gestational diabetes
- 7.5% have type 1 diabetes
- 5% have type 2 diabetes
What are the risk factors for GD?
- age
- FH or PMH
- BMI >30kg/m2
- multiple pregnancy
- Previous macroscopic baby weighing >4.5kg
- South Asian, clack Caribbean, Mddle Eastern ackground
What is the aetiology of GD?
Insulin resistance increases during pregnancy - worst in 3rd trimester
Large demand for insulin cannot be met by pancreatic beta-islet cells
How is gestational diabetes diagnosed?
75g 2 hour oral glucose tolerance test (OGTT)
Diagnose gestational diabetes if the woman has either:
- a fasting plasma glucose level of 5.6 mmol/litre or above or
- a 2‑hour plasma glucose level of 7.8 mmol/litre or above
If a patient has had previous gestational diabetes, when should you test for this?
OGTT at 16 weeks
If normal then repeat at 24-28 weeks gestation
If the patient has not previously had gestational diabetes, when should you test for it?
28 weeks - if risk factors present now and no Hx of previous gestational diabetes
What is the antenatal management of gestational diabetes in terms of follow-up?
Offer review with joint diabetes and antenatal clinic within a week of diagnosis
Clinics should stay in contact with patient every 1-2 weeks throughout pregnancy
How often must the patient monitor their glucose in GD?
T2DM/GD managed on multiple daily insulin injection regimen:
- Fasting
- Pre-meal
- 1 hour post meal
- Bedtime
T2DM/GD managed with diet and extercise changes alone, oral therapy or single dose insulin:
- Fasting
- 1 hour post meal
What are the glucose level targets in a pregnant patient with GD?
fasting: 5.3 mmol/litre
1 hour after meals: 7.8 mmol/litre or
2 hours after meals: 6.4 mmol/litre.
How do you monitor the fetus in GD in pregnancy?
Serial growth scans every 4 weeks from 28-36 weeks gestation
What is the management of a new diagnosis of GD?
All:
- See patient within a week in joint diabetic and antenatal clinic
- Diet and exercise advice
- Self-monitoring glucose
If fasting <7mmol/L:
- Trial of diet and exercise for 1-2 weeks
- If unsuccessful, start metformin
- If targets still not met, add insulin (short-acting)
- If insulin declined or metformin not tolerated/unsuccessful, offer glibenclamide
NB: BUT if <7 mmol/L and scans show macrosomia or hydramnios, then start insulin.
If fasting is 7 or >7mmol/L:
- Start insulin
What type of insulin is used in GD?
short-acting only
What preparations should be made for delivery in a patient with GD?
Elective birth no later than 40+6 weeks gestation (i.e. <41 weeks)
What changes should you make if a diabetic patient becomes pregnant in terms of medication? What lifestyle advice should be offerred?
Weight loss if BMI >27kg/m2; tight glycaemic control reduces complication rates.
Stop oral hypoglycaemics (except metformin) + start insulin
Folic acid 5mg/day - preconception to 12 weeks gestation
What complication of previous diabetes can deteriorate during pregnancy?
Retinopathy - should be treated as can worsen during pregnancy
Which scan should be detailes in a patient with pre-pregnancy diabetes diagnosis?
Anomaly scan at 20 weeks should be detailed including four-chamber view of the heart and outflow tracts
How long should you manage the GD once baby is delivered?
Discontinue treatment immediately
But monitor for new diagnosis of diabetes - fasting blood glucose at 6-13 weeks OR HbA1c after 13 weeks.
Remember to offer OGTT early in subsequent pregnancies (ASAP after booking and again at 24-28 weeks)
When should you suspect T2DM postnatally after GD diagnosis?
Suspect if fasting glucose at 6-13 weeks is _>_7mmol/L; offer diagnostic test.
Fasting blood glucose test 6-13 weeks:
_<_6 mmol/L - mod risk of T2DM, annual HbA1c and lifestyle advice
6-6.9 mmol/L - high risk of T2DM, annual HbA1c and lifestyle advice
_>_7 mmol/L - T2DM likely at present, offer diagnostic test
What are the complications of untreated GD?
Maternal:
- HTN disease
- Traumatic delivery
- Stillbirth
Foetal:
- Macrosomia
- Neonatal hypoglycaemia
- Congenital abnormalities
How do you counsel a patient about GD?
Common condition affecting 4% in pregnancy
Cause: pancreas cannot make enough insulin to meet increased demands
RF: age, FH, PMH, BMI, Asian
Complications if untreated: big baby, baby can have low blood sugar levels when born, abnomalities on scan and you can get high BP and traumatic delivery with risk of stilbirth.
Treatment: (depends but if <7mmol/L fasting then) lifestyle advice incl eating foods with low glycaemic index and exercising e.g. 30min walk after food. Referral to dietician for advice. If this doesn’t work then medication. You will also need to monitor blood glucose levels using a skin prick (incl fasting, 1hr post-meal and before bed)
Prognosis: GD is likely to occur in subsequent pregnancie (about 1 in 2 chance). Over 10 years, >50% develop T2DM.
