Maternal obesity and gestational diabetes

Question 1

what are the maternal outcomes of maternal diabetes on pregnancy?

Answer 1

• Infertility
• Neural tube defects
• Higher miscarriage rates
• GDM
• Preeclampsia
• Macrosomia
• Fetal growth restriction
• Post dates

Prolonged labour and c-section

Question 2

what congenital abnormalities of the fetus is associated with maternal diabetes?

Answer 2

cardiac, neural tube defects, cleft lip/palae, caudal regression syndrome

Question 3

which diabetic medications should we AVOID in pregnancy?

Answer 3

ACE inhibitors/ARBs–> main adverse effects trimester 2 and 3
Statins
Glitazones
Sulphonylureas

Question 4

why is pregnancy diabetogenic?

Answer 4

• HPL (human placental lactogen), progesterone antagonise insulin
• Glucose is major energy substrate for the fetus
–> Pregnancy causes insulin resistance

Question 5

what are some pre-pregnancy counselling advice you should give to a diabetic woman?

Answer 5

1. optimise diabetes and glucose control as well as manage diabetic complications
2. review diabetic medications
3. detect and optimise any other autoimmune conditions
4. lose weight if relevant
5. folate supplementation
6. smoking cessation

Question 6

describe antenatal care in a pregnant woman who has known diabetes?

Answer 6

Frequent visits
Multidisciplinary management between obstetrician, endocrinologist, dietician, diabetes educator, neonatal paediatrician

maintain HbA1c and BSLs within target range:
fasting 4-5.5mmol/L (look at both peaks and troughs)
and then 2 hrs later, postprandial less than 7mmol/L

monitor complications
regular monitoring of proteinuria and eye reviews
avoiding hypos and ketoacidosis

see an opthalmologist each trimester

Question 7

a diabetic woman has a fall in her insulin requirements during pregnancy. what must we consider?

Answer 7

if we see reduced insulin requirements then you have to consider that the placenta is NOT working as well as it should and it is often an indication for delivery

Question 8

what are some intrapartum care management considerations for a mother who has known diabetes and her baby?

Answer 8

CTG continuous for fetus

maternal- sliding scale insulin vs dextrose infusion
regular BSL monitoring, monitor urinary ketones

anticipating complications e.g. shoulder dystocia due to macrosomia, post partum haemorrhage due to uterine atony–> active management of 3rd stage labour with oxytocin

Question 9

what is gestational diabetes?

Answer 9

a woman is diagnosed with diabetes for the first time during pregnancy

Question 10

how many women with gestational diabetes develop type 2 diabetes in the long term?

Answer 10

30-50%

Question 11

how is gestational diabetes diagnosed?

Answer 11

fasting blood sugar > 5mmol/L

or blood glucose 1 hr post 75g of oral glucose is > 10mmol/L

or 2 hr post 75g oral glucose > 8.5mmol/L

Question 12

who should be involved in the care of a woman with gestational diabetes?

Answer 12

Ideally, a team comprising an obstetrician, diabetes physician,diabetes educator, dietician and midwife should care for the woman with abnormal glucose tolerance. Education and frequent self-monitoring of capillary glucose levels is standard.

Question 13

a woman with known gestational diabetes comes in with her BSL log book. She has been trialling diet and exercise to control her sugar levels. When would we consider prescribing insulin for her?

Answer 13

If there are 2 x fasting sugars > 5mmol/L per week, consider protaphane

if there are > 3 x 2hr post prandial sugars per week > 6.7mmol/L consider Novorapid

Question 14

when should we consider referring a pregnant woman to diabetes clinic?

Answer 14

evidence of fetal macrosomia
suboptimal control of glucose levels despite diet and insulin medications
HbA1c >6.5%

Question 15

tell me about HPL the hormone during pregnancy?

Answer 15

From the early second trimester, there is a progressive increase in insulin demand. This is largely due to the effect of the placental hormone human placental lactogen (hPL). This hormone structurally resembles growth hormone and shares the common property of promoting insulin resistance.

Question 16

describe postnatal review and management of women with gestational diabetes

Answer 16

Cease all insulin immediately following birth.

Blood glucose monitoring should continue twice daily (either fasting or 2 hour postprandial measurements) for 48 hours. If fasting blood glucose is <6 and 2hr post prandial blood glucose is <8, cease monitoring. If blood glucose levels exceed these targets, the diabetic education team should be contacted.

A woman’s GP should be notified as part of her discharge summary about the diagnosis of her GDM and asked to organise a follow-up 75g Glucose Tolerance Test (GTT) at 6-8 weeks postpartum using WHO non-pregnant criteria for impaired fasting glucose.

Question 17

a woman with type 2 diabetes has become pregnant. a medication review is warranted. what must we consider in terms of medication?

Answer 17

Metformin can be continued with women with type 2 DM or PCOS. All other oral hypoglycaemic agents are contraindicated during pregnancy.

Women with pre-existing diabetes treated with oral agents should ideally be commenced on insulin prior to conception if diabetes control is unsatisfactory.

• Antihypertensive therapy should be optimized for pregnancy. Drugs contraindicated in pregnancy should be changed prior to conception. These include; ACE inhibitors and A2 receptor blockers
• Lipid lowering therapy must be ceased

Question 18

when do we do a OGTT during pregnancy?

Answer 18

26-28 weeks

Question 19

how do we screen for GDM during pregnancy?

Answer 19

26-28 weeks screening

or earlier screening with OGTT and random/fasting blood sugar tests if the woman is deemed high risk of developing GDM

Question 20

Tell me how you would advise a patient with GDM about monitoring/managing their blood sugar levels during pregnancy?

Answer 20

All patients should perform home glucose monitoring at least 4 times each day before breakfast, and 2 hours after each meal

o The targets less than 5.0mol/L fasting and less than 6.7 mmol/L after meals
o Insulin therapy will usually be basal-bolus with at least 1 dose of medium/long-acting insulin each day and short/rapid-acting insulin before each main meal or insulin pump
o Patients should be advised to undertake 30 minutes of exercise (e.g. brisk walking) at least 4 times per week unless medically contraindicated
o The dietician should review all patients
o Hb1c should be measured at the first visit and repeated monthly. The target level is less than 6.0%.

Question 21

what is the model of care we use for pregnant women who are obese?

Answer 21

Obstetrician led or modified shared care bc high risk pregnancy

Question 22

what is the normal maternal weight gain during pregnancy?

Answer 22

Normal BMI- maternal weight gain of 11-16kg
Overweight- maternal weight gain of up to 6.7-11.2kg
Obese- maternal weight gain of < 6.7kg

Question 23

what are some extra antenatal/intrapartum considerations for a pregnant woman who is obese?

Answer 23

Extra antenatal considerations:

• Growth scans at 30/40 and then every 3 weeks for serial follow up
• Early GTT at 16 weeks if detected will be labelled as GDM however in reality it is probably undiagnosed type 2 diabetes
• Technically they should be on 5mg folate however often they present late and have already missed the boat for neural tube formation
• Increased number of antenatal reviews
• Early anaesthetic review–> difficulties of regional anaesthesia

Intrapartum considerations:

• Early epidural

Question 24

what are some neonatal complications of gestational diabetes in the mother? and how do we manage this?

Answer 24

Newborn is at risk of hypoglycaemia, higher risk of infection, transient tachypnoea of the newborn and HMD and JAUNDICE
• Early feeding within 1 hr post birth
• BSL close monitoring in the postpartum period

Question 25

when should we plan for delivery in a pregnant woman with GDM?

Answer 25

GDM managed with diet–> aim for spontaneous delivery. If delivery has not occurred by 41 weeks induction is required

GDM managed with insulin- plan for induction/c-section at latest 39 weeks. Can be earlier if compromised fetal wellbeing