Diabetes in Pregnancy Flashcards
1
Q
Define diabetes mellitus
A
A metabolic disorder of multiple aetiologies characterised by chronic hyperglycaemia resulting from defects in insulin secretion, insulin action or both.
2
Q
Define gestation diabetes mellitus (GDM)
A
Carbohydrate intolerance of variable severity with onset or first recognition during pregnancy. Includes women with impaired glucose tolerance (IGT) and impaired fasting glucose (IFG). Affects at least 1/10 pregnancies.
3
Q
Why do patients with T1DM and T2DM need preconceptual care?
A
- High risk patients with poorer fetal outcome
- Needed to optimise glycaemic control
- Review medical and obstetric hx
- Advise on glycaemic control
- Screen for and manage complications
4
Q
List the risks of a diabetic pregnancy
A
- Risks to the mother:
1. Hypo/Hyperglycaemia
2. Ketoacidosis
3. C-section
4. Retinopathy
5. HTN/Pre-eclampsia
6. Nephropathy - Risks to the fetus:
1. Miscarriage
2. Still birth/neonatal death
3. Congenital malformations
4. Premature delivery
5. Birth trauma secondary to macrosomia
6. Neonatal hypoglycaemia
7. Neonatal polycythemia
8. Neonatal hypocalcaemia
9. Neonatal hyperbilirubinaemia
10. Neonatal cardiomyopathy
5
Q
What is the risk of the offspring of a diabetic parent developing diabetes?
A
- T1DM = 2-3% if mother affected; 5-6% if father affected
6
Q
Discuss counselling and contraceptive advice for pre-existing diabetics
A
- Stress need for preparation for pregnancy and counselling
- Intensive preparation should ideally begin 3-6mths before desired time of conception
- Contraceptives should be continued until HbA1c optimised
- Avoid COCP in women with vascular complications and HTN
- Woman should meet team looking after her
7
Q
How is glucose monitoring addressed in preconceptual care and counselling?
A
- Review technique and frequency
- Record measurements 7 times/day (fasting, pre-meals, 1hr post-meals and before bed)
- Targets:
- Fasting and pre-meal = 3.5-5.5mmol/L
- 1hr post-meal = <7mmol/L
- Discuss management of hypoglycaemia
8
Q
What should be discussed in relation to nutritional management in preconceptual care and counselling?
A
- Diet:
- Low GI foods
- Not excessive in fat
- Encouraged to achieve normal BMI prior to pregnancy
9
Q
What advice should be given in relation to gestational weight gain?
A
- Excessive weight gain is a risk factor for adverse outcome
- Advise on expected weight gain according to BMI
10
Q
How and why do we screen for pre-existing nephropathy and HTN in diabetics?
A
- Association between pre-existing nephropathy and poorer pregnancy outcome
- Measure urine PCR to identify renal status prior to pregnancy
- Do baseline serum creatinine and eGFR
- eGFR <40 at beginning of pregnancy may experience irreversible decline in renal function
11
Q
What is the protocol for retinopathy screening for diabetics in pregnancy?
A
- Fundal exam advised prior to conception and once in each trimester for those without retinopathy
- If have established retinopathy = every 6wks
- Advise ophthalmologist
12
Q
What additional blood tests need to be done in diabetic patients?
A
- TFTs
2. Rubella antibodies (where status unknown)
13
Q
What is the criteria for diagnosis of GDM?
A
- Diagnosis done with 75g OGTT
- Fasting = >5.1mmol/L
- 1hr = >10.0mmol/L
- 2hr = >8.5mmol/L
14
Q
Who is screened for GDM?
A
- Best practice is to recommend universal screening with OGTT at 24-28wks
- Can do selective screening on basis of risk
15
Q
List the high risk factors for GDM
A
- Severe obesity (BMI > 30)
- Hx GDM or macrosomic baby
- Presence of glycosuria
- Dx of PCOS
- Strong family hx of T2DM
- Ethnicity (all ethinic subgroups)
- OGTT ASAP if any of these present
16
Q
List the medium risk factors for GDM
A
- BMI 25-30
- Maternal age >30
- Long term steroids
- Previous unexplained perinatal death
- Polyhydramnios and/or macrosomia in existing pregnancy
- Screen at 24-28wks if any of these present
17
Q
List the factors that make a patient low risk for GDM
A
- Age <25
- Weight normal before pregnancy
- Caucasian
- No known DM in first degree relatives
- No hx of abnormal glucose tolerance
- No hx of poor obstetric outcome
- If have all of above do not require GDM screening
18
Q
How is diabetes managed in pregnancy?
A
- Blood glucose checked 7 times a day
- Nocturnal hypoglycaemia or variable fasting glucose - 3am glucose level
- Multi-dose injection regime recommended for most
- Adjust own insulin doses based on intake
- HbA1c checked at booking and every 2-4wks thereafter; target <6%
- Continuous subcut insulin infusion considered for those unable to meet targets
- Decrease in insulin requirements during pregnancy may indicate decrease in placental function
- Pre-pregnancy insulin regime and insulin regime after delivery recorded in notes along with need for sliding scale during delivery
19
Q
What are the doses of insulin used in pregnancy?
A
- If started in first trimester = 0.7U/kg/day
- 2nd trimester = 0.8U/kg/day
- 3rd trimester = 0.9U/kg/day
- 36-40wks = 1U/kg/day
20
Q
How can we prevent and manage DKA in pregnancy?
A
- Patient education about sick day management, frequent BG testing, increased insulin doses and the significance of vomiting and dehydration
- Nausea, vomiting, abdo pain, fever and poor oral intake = high index of suspicion
- Test urinary and plasma ketones if unwell
- Low threshold for admission
21
Q
How can we manage nutrition in a diabetic pregnancy?
A
- Dietician involvement
- 40% carbohydrate, 30% fat, 30% protein per day
- T2DM focus on portion size
- Advise on appropriate gestational weight gain
- Vit D supplementation if of Asian origin
22
Q
How is vomiting managed in a diabetic pregnancy?
A
- Severe nausea of pregnancy = antiemetics
- Severe vomiting = hospitalise
- Check TFTs if hyperemesis gravidarum
23
Q
How can we manage hypoglycaemia in pregnant diabetics?
A
- Partners of all women with pregestational diabetes given a glucagon kit and taught how to use it
24
Q
How do we screen for nephropathy and HTN during pregnancy?
A
- Screened for albumin secretion at booking and/or in first or second trimester
- Close monitoring prior to and during pregnancy
25
Describe the obstetric management of the diabetic patient?
- Dating scan at 11-14wks
- Routine review every 2-4wks up to 34wks and weekly thereafter
- Anomaly scan at 20wks
- Growth scans at 28 and 34 wks
- During labour and delivery continuous CTG and FBS available on request
- Woman instructed on importance of fetal movements and contact obstetric unit if decreased
26
What is important about the timing and mode of delivery?
- Risk of stillbirth balanced against the risks of IOL at 38-39wks and success rate of vaginal delivery following IOL
- Consider risk factors:
* Prepregnancy and within pregnancy glycaemic control
* Evidence of fetal macrosomia
* Compliance with glucose and fetal monitoring
* Previous pregnancy outcomes
27
What is the first intervention used in GDM?
- Trial of diet and exercise
| - If fasting glucose still high = insulin
28
How are T1DM and T2DM patients managed during labour?
- Once labour established insulin sliding scale commenced
- Allowed light diet
- Chart hourly BG
- Keep glucose conc of 4-7mmol/L (prevent neonatal hypoglycaemia)
- If fasting for C-section - background basal dose continues without bolus doses
29
Describe the insulin sliding scale
- Glucose infusion 5% glucose at 100ml/hr
- Insulin infusion:
* 50U in 50ml of 0.9% NaCl
* Start infusion as directed by blood glucose estimation
* Rate of glucose infusion maintained at 100ml/hr
* Rate of insulin infusion adjusted according to BG level
* Use saline if additional fluids needed (DO NOT USE HARTMANNS)
30
What is the protocol for C-section in diabetic patients?
- Set up glucose and insulin infusion at 8am
- Elective C-section = omit breakfast or SC insulin in morning
- IV antibiotics given prophylactically
31
What is the protocol for IOL in diabetic patients?
- Admit evening prior to allow for timely commencement of insulin infusion
- All assessed vaginally on admission
32
How are T1DM and T2DM patients managed post-delivery?
- Half insulin infusion after placenta delivered
- Monitor BG every 2hrs
- Adjust insulin infusion rate according to BG, keeping glucose infusion constant
- Continue IV fluids and insulin infusion until ready to eat
- Start SC insulin at pre-pregnancy dose or planned regime with food
- Discontinue insulin infusion 30-60mins after SC insulin to ensure overlap
33
How are GDM patients managed post-delivery?
- Insulin infusion stopped as soon as placenta delivered
- BG monitoring continued prior to each meal and 1-2hrs postprandially for 24hrs post delivery
- If all values <7 preprandially and <11 postprandially women may discontinue monitoring
34
What is the postnatal follow up for T1DM and T2DM patients?
- Postnatal examination 6-12wks after birth
- If planning further pregnancy - back to prepregnancy care
- If not - back to general diabetes services
35
What is the postnatal follow up for GDM patients?
- Postnatal examination 6-12wks after birth
- Postnatal glucose tolerance test at 6-12wks
- Return to GP care after receiving appropriate dietary and lifestyle advice
- Annual screening recommended
- Planning another pregnancy within 1yr - rebooked for prepregnancy clinic and repeat prepregnancy OGTT rescheduled
