GDM Flashcards
What is the definition of Gestational diabetes mellitus?
Gestational diabetes is a common endocrine disease that is induced by pregnancy.
It occurs when high blood glucose is present and the body cannot produce enough insulin to keep the blood glucose in control.
It is also determined by a carbohydrate intolerance in pregnancy.
GDM is usually recognised at 24 to 28 weeks of gestation based on an abnormal glucose tolerance test
What are the statistics for GDM?
Gestational diabetes affects at least 4-5 in 100 women during pregnancy.
It is commonly diagnosed following an assessment of risk factors followed by elevated plasma glucose levels on testing.
87.5% of diabetes in pregnancy are diagnosed as gestational diabetes
What is the epidemiology for GDM?
Worldwide 1 in 6 pregnancies are affected by GDM
In the UK GDM affects 1 in 3 pregnancies
Middle east/ North Africa has an estimate for 12.9% who have pregnancy induced diabetes
Speak through the physiology and pathophysiology of GDM
In pregnancy there are considerable changes to carbohydrate metabolism driven by placental hormones, these changes help the woman’s body prepare for labour and breastfeeding by laying down fat stores in the first trimester and aid fetal growth in the second and third trimester. In normal healthy person carbohydrates are broken down to by enzymes from pancreatic juices and from enzymes present in small intestine. This is then either absorbed as glucose into blood stream for energy. The excess is stored as glycogen in liver or muscles and released when blood glucose is low. The glucose gets into the blood stream and acts on the beta cells of pancreas to produce insulin. Insulin then acts on target cells within tissues to uptake the glucose for energy.
In pregnant women some of the glucose passes through the placenta by diffusion via Hexose transporters that are not dependent on insulin. When the glucose reaches the fetal circulation, the fetus produces its own insulin and allows the uptake of glucose into its cells for growth, energy and development. However, to make sure that there is adequate amount of glucose for the fetus, the placenta produces hormones placental lactogen, cortisol and progesterone, that interfere with mother’s insulin, causing insulin resistance. Pregnant women must produce 2-3x the usual amount of insulin to overcome this resistance.
Women diagnosed with Gestational Diabetes Mellitus have a deficit in beta cells function and fail to adapt to insulin resistance and produce sufficient levels of insulin. Therefore, their blood glucose levels stay high and are not taken up to maternal tissues. The high levels then cross placenta, and cause high insulin secretion by fetal pancreas and rapid uptake into fetal cells and therefore rapid growth; resulting in macrosomia also known as large for gestational age.
Fetal hyperglycemia results in fetal osmotic diuresis occurring which means the fetus will urinate more frequently because of the diuretic effects of glucose. More fluid will be within the sac which results in or increases the risk of polyhydramnios in pregnancy .
What are the risk factors for GDM?
Risk factors of GDM:
35 years old and older
Body mass index (BMI) of 30 kg/m2 or above - as they have an increased insulin resistance, which goes hand in hand with a sedentary lifestyle and poor nutrition
Family history of diabetes mellitus or GDM
PCOS - this is due to the hormone dysfunctions and increases in insulin resistance that are common in PCOS
Women with a South east asian background and black african and caribbean background
Previous GDM in pregnancy - a previous diagnosis of GDM could point to a chronic issue of insulin resistance, which is why it’s important for early screening tests to be carried out in anc period
What are the maternal complications for GDM?
Maternal complication of GDM:
Hypertensive disorders
Risk of infection
Caesarean section
40-60% risk of future diabetes mellitus II within 10-15 years
Treatment complication: insulin related hypoglycemia
Pre-eclampsia
Likely to reoccur
PPH
Shoulder dystocia
What are the fetal complications of GDM?
Fetal complications of GDM:
Fetal hyperglycemia
Polyhydramnios - high levels of glucose can cause build-up of amniotic fluid, can lead to preterm birth, malposition
Hyperglycemia may lead to congenital abnormalities and stillbirth
Macrosomia - risk of shoulder dystocia, assisted delivery, trauma, postpartum haemorrhage
Hypoglycemia - post-delivery the levels of glucose fall sharply while insulin levels in neonatal blood stream are high. Hypoglycaemia can lead to to brain injury and developmental problems
The baby will have subsequent hyperbilirubinemia, hypocalcemia and increased risk of respiratory distress syndrome
Future risk of childhood obesity
Speak through the management of intrapartum care for Mother
Advise women with GDM to give birth no later than 40+6 weeks gestation. Offer an induction of labour or elective caesarean section if they have not delivered by 41 weeks gestation to prevent the chance of stillbirth or prevent excessive fetal growth and associated birth related complications.
LABOUR WARD: Women in established labour should be treated as high risk and admitted to Labour ward.
General care:
-Hourly maternal vital sign observations: Respiration rate, Sats, blood pressure, heart rate and temperature once in established labour to identify any deviation from norm
-Fetal heart rate monitoring: Intermittent auscultation every 15 minutes for 1 minute or continuous Cardiotocography(CTG) monitoring with 1 hourly fresh eyes and 2 hourly helicopter review
-Hydration/nutrition, mobilisation or pressure area care, bladder care, compression socks to prevent deep vein thrombosis
- Resuscitaire check
- Cannulas for administration of infusions through two lines or Y connecter - 2 hourly cannula observations
- Fluid balance chart
- Pain relief- Entonox, pethidine, epidural to ensure client is comfortable and pain is well managed during labour
ON DIET: Well controlled management with no macrosomia detected and no other risk factors
- Intermittent auscultation every 15 minutes for 1 minute or continuous -Cardiotocography monitoring with 1 hourly fresh eyes and 2 hourly helicopter review
-Hourly maternal vital sign observations: Respiration rate, Sats, blood pressure, heart rate and temperature once in established labour
-Monitor blood glucose levels every 4 hours for diet controlled GDM and hourly on insulin and 2 hourly for GDM on metformin . Ensure that it remains between 4 mmol/l and 7 mmol/l.
-If above 7mmol/l on 2 occasions commence IV insulin and sliding scale.
On Insulin/Metformin established labour:
- Inform Obstetrician, Labour ward coordinator and anaesthetist incase of any complications and to prepare a plan of care
- Inform neonatologist in case of any suspected macrosomia due to risk of shoulder dystocia
- Continuous CTG monitoring - 30 minute interpretation, 1 hourly fresh eyes and 2 hourly helicopter review
- Cannulas for administration of infusions through two lines or Y connecter - 2 hourly cannula observations
- INFUSION: 1000MLS Glucose 5% containing 20mmol/potassium chloride (12 hourly/83ml/hr) and 50ui of insulin in 50ml of normal saline
Blood glucose monitoring : Hourly on insulin and 2 hourly for GDM on metformin . Ensure that it remains between 4 mmol/l and 7 mmol/l.
Sliding scale:
Below 4mmol/l use 0 units of insulin infusion/hour
4.1-6mmol/l use 1 unit of insulin infusion/hour
6.1-8mmol use 2 units of insulin infusion/hour
8.1-10mmol use 4 units of insulin infusion/hour - Dr to review
Induction or augmentation use 0.9 %saline as IV fluid as contains no gluconate that could be metabolised into glucose
Hourly observations
Pain relief
Hydration
Bladder care to allow for descent, urinalysis looking for ketones, signs of infection and preeclampsia
Fluid balance chart
Urine and bloods to be taken for ketones if blood capillaries are over 12 mmol
Consider ketoacidosis before giving IV fluids; Ketoacidosis is a serious complication of diabetes that can be life threatening, it develops when your body doesn’t have enough insulin to allow blood sugar into your cells for use as energy - the risks are intrauterine death and maternal compromise such as organ failure ie. kidneys, fluid in lungs. 1mmol of ketones in urine = ketonacidosis - escalte to obstetric doctors, consider expediting deliver
Speak through the intrapartum management of care for baby
Continuous fetal monitoring on cardiotocography as there is an increased risk of fetal hypoxia
Escalate to Obstetric team if there are any concerns with the CTG trace
In any case of a pathological CTG trace that leads to the delivery being expedited inform the Neonates to be present at delivery
2nd stage:
if macrosomia suspected obstetric registrar and neonatologist should be present for delivery.
Support perineum to help prevent trauma
Following the birth check for baby breathing, colour, tone, if vigorous, the baby can stay skin to skin.
Delayed cord clamping
Facilitate 3rd stage of labour
Stop the infusions and allow for golden hour
Speak through the postnatal management for mother
Women with GDM should stop insulin and/or metformin immediately after delivery and also does not need to follow a controlled diet as the diabetes was induced by pregnancy
No further blood sugar monitoring needs to be performed unless instructed by diabetes antenatal team
All women with GDM with GDM must be instructed to see their GP for a 8-12 week postnatal Glycated haemoglobin Hba1c screening. This test is advised to be offered to women with GDM to exclude diabetes. Women with a fasting glucose level below 5.7mmol/l have a low probability of having diabetes at present and are advised to follow the lifestyle advice given after birth. Women with glucose levels between 5.7mmol/l and 6.4mmol/l are at high risk of developing type 2 diabetes. Women with glucose levels of 6.5mmol/l or above are likely to have type 2 diabetes and are likely to be offered a diagnostic test to confirm diabetes .
Speak through the postnatal management for baby
Initial checks looking for abnormlity or signs of respiratory distress
Weight, HC, Vit K with consent
Thermoregulation to prevent risk of hypothermia that could lead to hypoglycaemia as baby already at risk
Support breastfeeding at least every 3 hours or more often
Explain to parents why BG monitoring is important / signs of unwell baby
Check Capillary blood glucose levels before the second and third feed – looking for two consecutive readings above 2.6mmol/l.
If less then 2.6mmol/l and no signs of hypoglycaemia but more then 2mmol encourage feeding, support expressing
If less than 1.9mmol/l and no abnormal signs contact neonatologist and consider administration of 40% buccal dextrose @200mg/kg, continue bf support, skin to skin, expressing and recheck before the 3rd feed. If low again contact neonatal team
If signs of hypoglycaemia or less than 1mmol/l contact neonatal team immediately and admit to NNU: lethargy, high pitched cry, hypotonia, hypothermia, cyanosis, apnoea…
Speak through your reflection
Overall it would be important to discuss the rationale of care with the mother and partner, tae account of previous scans to rule out an LGA baby., ensure that blood sugars taken are within normal range and ensure that the CTG tracing is reassuring to facilitate a safe and normal delivery. If there are any concerns then an escalation will be made to the co-ordinator, senior obstetricians and neonates if needed.
