Diabetes in pregnancy

• Results in a high risk pregnancy with complications increased for both mother and baby
• Adverse (bad) outcomes can be minimised with good diabetes control

Medical conditions with high blood glucose levels

Gestational diabetes mellitus (GDM)

• High blood glucose first detected in the second half of pregnancy

Early GDM 

• Likely pre-existing prediabetes
• High blood glucose first detected before 20 weeks gestation but is below non-pregnant diabetes criteria
• Increased risk of complications compared to standard GDM

Overt diabetes in pregnancy

• High glucose first detected in pregnancy but meets non-pregnant criteria for diabetes
• Treat as pre-existing diabetes during the pregnancy
• Can only confirm whether or not woman has type 2 diabetes after pregnancy

Pre-existing type 2 or type 1 diabetes

• Diagnosed before pregnancy

Diagnosis and management of diabetes in pregnancy is important

• Diabetes in pregnancy is common and increasing in all age groups
• Affects one in five pregnant Indigenous women
• Aim to keep BGL at normal levels to reduce complications
• Multidisciplinary team management is needed — involving primary care, midwife, obstetrician, diabetes educator, dietitian, nurse practitioner and endocrinologist
• Clear communication and consistency of care between services is important

Pre-pregnancy counselling for women with known diabetes

Optimising health in women with diabetes before pregnancy is needed to reduce risk of complications for both woman and baby

• Discuss pregnancy planning and contraception at routine check-ups with all women of childbearing age
• If HbA1c over 9% suggest delaying conception (becoming pregnant) until close to or lower than 7% 
• Talk about and assist women with
• Target glucose-levels before pregnancy — HbA1c less than 6.5% without hypoglycaemia will minimise risks to woman and baby
• Need to optimise BP, weight, nutrition and physical activity
• Check woman is up-to-date with kidney and diabetes eye checks
• If planning pregnancy or not using reliable contraception
• Review medications
• Start folic acid oral — 5mg once a day  — high dose due to increased risk of congenital anomalies with diabetes
• Monitor for pregnancy at routine visits. Tell woman to notify clinic as soon as thinks she is pregnant

Screening for diabetes in pregnancy

• First antenatal visit — screen all pregnant women who are not already known to have diabetes and have risk factors — best before 13 weeks pregnant
• All Aboriginal women are at high risk — need to test at first antenatal visit
• 24–28 weeks pregnant — screen or re-screen all pregnant women not already known to have diabetes
• For tests and interpretation follow Flowchart 2.4

Blood glucose targets for pre-existing diabetes and GDM

• Provide all women with glucometer and teach to check BGLs
• Self-monitoring 4 times per day — fasting and 2-hours after meals
• Advise to keep BGL diary. Bring diary and meter to each review
• Review BGL diary weekly — usually by diabetes educator or midwife
• If BGLs within target — no change in management
• If 2 or more readings above target in 1 week — review diet, physical activity and medicines
• If BGLs significantly above target — may need more frequent diabetes educator or medical input for titration of therapy. May be done by telehealth
• Frequency of BGL self-monitoring can be reduced or increased according to progress
  
• If BGLs on target with diet change only and normal foetal growth, reduce testing 
• If on insulin with meals, test 6 times per day — before and 2-hours after meals

Antenatal care for pre-existing diabetes

At first antenatal visit

Check

• Do checks for first routine antenatal visit — see Antenatal checklist

Do

Medical consult — include urgent medicines review

• Continue metformin and/or insulin if already prescribed
• Stop medications that are not safe in pregnancy 
• Other glucose-lowering medicines
• ACE inhibitor or ARB  — consider safer options for BP control, eg methyldopa, labetalol
• Statins and other lipid-lowering medicines
• May need to start insulin

Also

• Add to first visit routine investigations 
• Blood for HbA1c, TFT, UEC, B12, Urine ACR
• Diabetes educator consult. Can use telehealth
• Give folic acid oral — 5mg once a day until 12 weeks pregnant
• Give iodine oral — 150microgram once a day. Can be in multivitamin designed for pregnancy and breastfeeding
• If woman has thyroid condition — medical consult
• Give advice on diet and physical activity to help control blood glucose — refer to dietitian
• Start home BGL monitoring
• give glucometer and consumables including diary and pen
• Review pre-pregnancy BMI and discuss healthy weight gain targets
• Arrange as soon as possible
• Ultrasound scan to date pregnancy, if not already done
• Obstetric review
• Endocrinologist/physician review
• Retinal screening, if not done within 3 months before pregnancy. If retinopathy present — repeat screening each trimester — seek ophthalmology advice for treatment
• Make sure woman is on recall system to be followed up after birth — see Postpartum follow-up of medical conditions

Additional antenatal care

Additional care is needed because of increased risk of complications

Check

• Review BGL diary and glucometer every week — see blood glucose targets for pre-existing diabetes and GDM
• Monitor gestational weight gain — see Healthy weight in pregnancy
• Extra ultrasounds as ordered by obstetrician — could include
• Extra ultrasounds for foetal growth in the second and third trimesters
• Management is individualised and will be advised by the managing obstetrician

Do

• Once each trimester
  
• Blood for UEC, LFT, HbA1c, Urine ACR
• Strongly encourage testing for foetal abnormalities
• Education about diabetes in pregnancy
• Antenatal check every 2 weeks until 28 weeks pregnant
• THEN every 1 week from 28–36 weeks
• At 32 week antenatal check — talk to woman about being added to Diabetes in Pregnancy Clinical Registers, if relevant to your jurisdiction
• Medical follow up as needed — at least every 4 weeks — for adjustment of diabetes medicines
• Medical consult for routine prevention of risk of preeclampsia
  
• Aspirin oral — 100–150mg once a day with evening meal from 12 weeks until 36 weeks gestation
• Calcium supplementation oral — up to 1.5g once a day including dietary calcium intake from 12 weeks gestation
• Arrange for transfer to regional centre at 36 weeks to wait for birth — hospital birth

Antenatal care for GDM

At first antenatal visit after diagnosis

Do

• Routine antenatal check — see Antenatal checklist AND
• Blood for UEC, LFT, HbA1c, urine ACR
• Start home blood glucose monitoring
• Give glucometer and consumables including diary and pen 
• Teach woman how to self-monitor and keep BGL diary
• Medical consult
• Diabetes educator consult — can use telehealth
• Review pre-pregnancy BMI and discuss healthy weight gain targets
• Most women can control blood glucose with diet and physical activity
• Arrange obstetric review as soon as possible
• Make sure woman on recall system are followed up after birth — see Postpartum follow-up of medical conditions

Additional antenatal care

Additional care needed due to increased risk of complications

Check

• Review BGL diary and glucometer every week — see blood glucose targets for pre-existing diabetes and GDM 
• Monitor gestational weight gain — see Healthy weight in pregnancy
• Ultrasounds as ordered by obstetrician. Could include
• Extra ultrasounds for foetal growth in the second and third trimesters
• Management is individualised and will be advised by the managing obstetrician

Do

• Education about diabetes in pregnancy
• Antenatal check every 2–4 weeks until 36 weeks pregnant THEN every week from 36 weeks pregnant
• If on insulin — see every week from 28 weeks
• At 28 and 36 weeks
• Blood for UEC, LFT, HbA1c, urine ACR
• Medical follow up as needed — at least every 4 weeks — for adjustment of diabetes medicine
• Consider referral to tertiary (major hospital) diabetes service if BGL is often above target or if advice is needed on medical management
• Arrange for hospital birth — transfer to regional centre at 38 weeks to wait for birth

Education

• Importance of healthy diet, physical activity, healthy weight gain
• Complications — reassure that not all women develop complications and looking after GDM helps to keep woman and baby healthy
• Benefits of keeping BGLs within target range
  
• Need to monitor and record own BGL in pregnancy
• Medicines including insulin might be needed
• Need for extra checks in pregnancy
• Hospital birth recommended
• Baby may also need special care straight after birth
• Advise which clinic staff will give more support and provide access to educational materials

Medicines for pre-existing diabetes and GDM

• Must be prescribed by doctor or nurse practitioner
• Medicines are needed for all women with pre-existing diabetes
• Medicines must be started in GDM when BGLs are very high or are not within target after dietary changes and physical activity have been trialled briefly (for a week)
• Choice of medicine must be based on individual woman’s needs — consider preferences, gestation, BGLs and foetal growth
• Metformin and insulin are safe to use in pregnancy. Other diabetes medicines should not be used

Metformin 

• Is a treatment option in pregnancy
• Crosses the placenta but there is no evidence of harm to the baby during pregnancy
• If woman is on metformin before pregnancy — continue
• For GDM — medicine options can be discussed
• Half of women with GDM on metformin will also end up needing insulin
• Diarrhoea and nausea are common side effects — taking it everyday and after food helps
• Stop if ultrasounds show foetal growth restriction OR small-for-gestational-age OR if mother has inadequate weight gain if she has a low BMI (underweight)
• Use standard doses as for non-pregnant woman

Insulin

• Most women with pre-existing diabetes and about one-third of women with GDM will need insulin
• Recommended if blood glucose not controlled by diet and exercise or metformin. Continue to review diet in woman taking insulin
• See Table 2.12 for suggested regimen

Starting and titrating insulin treatment

• Medical/diabetes educator consult about best insulin regimen — the type of insulin depends on BGL pattern and if it is suitable for that woman 
• Women needing insulin in pregnancy should be referred to tertiary diabetes service
• On advice of doctor or nurse practitioner, other clinicians can titrate insulin according to Table 2.12
• If low or persistent high BGLs — medical consult
• After each change in insulin dose, monitor BGL for 2 days before making another change

Follow-up

• See — Postpartum follow-up of medical conditions