Chronic Conditions in Pregnancy Flashcards
What is hypertension?
An elevated blood pressure, which is considered to be greater than 140/90mmHg
What are the three hypertensive disorders that can occur during pregnancy?
Chronic Hypertension
Gestational Hypertension
Pre-Eclampsia
What is chronic hypertension?
Hypertension present before getting pregnant or noted before 20 weeks gestation
What three hypertensive classes are contraindicated during pregnancy? Give examples
ACE Inhibitors - Ramipril, Enalopril
Angiotensin Receptor Blockers (ARBs) - Losartan, Candesartan
Thiazide Diuretics - Indapamide
What blood pressure measurement do we aim for during pregnancy?
150/100
What three antihypertensives are prescribed during pregnancy? What class of drug are they?
Labetalol, which is a beta-blocker
Nifedipine, which is a calcium channel blocker
Doxazosin, which is an alpha-blocker
What is the first line hypertensive in pregnancy?
Labetalol
What is gestational hypertension?
New hypertension that develops after 20 weeks’ gestation
What is pre-eclampsia?
New onset hypertension after 20 weeks’ gestation, leading to end-organ dysfunction
It is typically described as a triad of new-onset hypertension, proteinuria and oedema
What is diabetes mellitus?
It refers to a group of metabolic diseases characterised by hyperglycaemia due to insulin insensitivity or decreased insulin secretion
What are the two diabete disorders that can occur during pregnancy?
Chronic Diabetes
Gestational Diabetes
What is chronic diabetes?
It refers to hyperglycaemia present prior to pregnancy
In what two ways do we manage chronic diabetic patients prior to pregnancy?
They should aim for good glycaemic control, with glucose levels ideally falling between 4-7mmol/l or HbA1c should be less than 6.5% (48mmol/mol)
They should take 5mg of folic acid from preconception until 12 weeks’ gestation
Why do we give diabetic patients folic acid prior to pregnancy?
This is to prevent congenital neural tube defects
What two diabetic medications are prescribed during pregnancy?
Metformin
Insulin
What fasting glucose level should diabetic patients aim for during pregnancy (chronic and gestational)?
Below 5.3mmol/l
What glucose level should pregnant diabetic patients aim for one hour post-meals (chronic and gestational)?
Below 7.8mmol/l
What glucose level should pregnant diabetic patients aim for two hour post-meals (chronic and gestational)?
Below 6.4mmol/l
What bedtime glucose level should diabetic patients aim for during pregnancy (chronic and gestational)?
Below 6mmol/l
What diabetic screening is increased during pregnancy?
Retinopathy
When is retinopathy screening conducted in diabetic patients?
28 and 34 weeks’ gestation
How do we deliver babies from a diabetic mother?
A planned delivery between 37 and 38+6 weeks gestation should be arranged
However, if fetal or maternal complications arise we can induce labour earlier
What can we prescribe diabetic patients during labour?
A sliding scale insulin regime
This regime involves infusion of dextrose and insulin based upon the patient’s glucose levels
When do we prescribe diabetic patients a sliding scale insulin regime during labour?
It should be considered for women with type one diabetes or those with poorly controlled blood sugars with type two diabetes
What is gestational diabetes?
It is defined as any degree of glucose intolerance with onset or first recognition during pregnancy
This will resolve after delivery
Describe the pathophysiology of gestational diabetes
It occurs when the body is unable to produce enough insulin to meet the needs of the pregnancy
During pregnancy, insulin requirements of the mother increase, which means that a higher volume of insulin is needed in response to a normal level of blood glucose
A woman with a borderline pancreatic reserve is unable to respond to the increased insulin requirements, resulting in transient hyperglycaemia
After the pregnancy, insulin requirements decreases, and the hyperglycaemia usually resolves
What four hormones produced by the placenta cause increased maternal insulin requirements?
Human placental lactogen
Progesterone
Human chorionic gonadotrophin
Cortisol
Why does fetal hyperglycaemia and hyperinsulinaemia occur with gestational diabetes?
In pregnancy, glucose is transported across the placenta, however insulin is not
This can cause fetal hyperglycaemia, resulting in the fetus increasing its own insulin levels to compensate – hyperinsulinemia
Why does neonatal hypoglycaemia occur after gestational diabetes delivery?
After delivery, the fetus still has high insulin levels, however no longer received glucose from its mother
How do we prevent neonatal hypoglycaemia?
In order to manage this, we regularly monitor blood glucose levels and conduct frequent feeds
What glucose level do we aim for in neonates? How do we manage cases in which this is not achieved?
> 2mmol/l
In asymptomatic cases, normal feeds and glucose monitoring is first line
In cases where this fails, we administer 10% IV dextrose or glucose gel
Why is respiratory distress syndrome a complication of gestational diabetes?
High insulin can cause a reduction in pulmonary phospholipids, which in turn decreases fetal surfactant production
Surfactant acts to reduce the surface tension in the alveoli
What are the five risk factors for gestational diabetes?
Previous Gestational Diabetes
BMI > 30
Previous Macrosomic Baby > 4.5kg
Asian Ethnicity
Diabetic Family History
How do we diagnose gestational diabetes?
We conduct a HbA1c test during the booking clinic. If the levels are raised, we conduct an oral glucose tolerance test
How do we perform an oral glucose tolerance test?
It should be performed in the morning after a fast
The patient has a 75g glucose drink at the start of the test
The blood sugar is measured before the sugar drink and then at two hours.
What oral glucose tolerance test results would indicate gestational diabetes?
Fasting Glucose > 5.6mmol/L
At 2 Hours > 7.8mmol/L
How do we manage gestational diabetes?
This initially involves trialling diet and exercise measures for one to two weeks
If blood sugars remain high, then we can consider prescribing metformin and/or insulin
How do we deliver babies from a gestational diabetic mother?
A planned delivery between 37 and 38 gestation should be arranged
However, if the gestational diabetes is being managed by simple diet and lifestyle measures, we can consider delivery before 40+6 weeks gestation
How do we manage gestational diabetes postnatally?
After delivery, all anti-diabetic medication should be stopped immediately
The blood glucose should be measured before discharge to check that it has returned to normal levels
An oral glucose tolerance test should then be conducted six to eight weeks post-partum
If this is normal, yearly tests should be offered due to the increased risk of developing diabetes in the future
What are the six fetal complications of gestational diabetes?
Macrosomia
Shoulder Dystocia
Respiratory Distress Syndrome
Polyhydramnios
Cardiac Abnormalities
Neonatal Hypoglycaemia
What are the five causes of neonatal hypoglycaemia?
Preterm Birth < 37 Weeks
Maternal Diabetes Mellitus
IUGR
Hypothermia
Neonatal Sepsis
What are the two maternal complications of gestational diabetes?
Future Diabetes
Hypertension
What is venous thromboembolism?
A collective term that describes deep vein thrombosis and pulmonary embolism
What triad is used to describe the pathophysiology of venous thromboembolism?
Virchow’s triad
How does pregnancy result in a hypercoagulable state?
Increased Fibrinogen
Increased Factor VII
Increased VW Factor
Increased Platelets
Decreased Protein S
When is the risk of thromboembolism greatest? Why?
Post-partum
The changes in protein levels become more pronounced as the pregnancy progresses
How does pregnancy result in the stagnation of blood?
This is due to the effects of progesterone and an enlarged uterus
What is Virchow’s triad?
Hypercoagulable State
Stagnation of Blood
Vascular Damage
How does pregnancy result in vascular damage?
It can occur during delivery
What are the six maternal risk factors for venous thromboembolism?
Maternal Age > 35
BMI > 30
Partity > 3
Smoking
Thrombophilia
Varicose Veins
What are the five obstetric risk factors for venous thromboembolism?
Pre-eclampsia
Multiple pregnancy
C-section
Prolonged labour
Postpartum haemorrhage
What are the four clinical features of DVT?
Unilateral Leg Swelling
Dilated Superficial Veins
Oedema
Calf Tenderness
In which leg do DVT’s tend to form in during pregnancy? Why?
Left leg
This is due to the compression effect of the uterus on the left iliac vein
What are the six clinical features of PE?
Shortness of Breath
Cough
Pleuritic Chest Pain
Tachycardia
Tachypnoea
Hypoxia
How do we investigate a suspected DVT?
A compression duplex ultrasound
If the scan is negative, however clinical suspicion remains high, the test can be repeated one week later
How do we investigate a suspected PE?
A CT pulmonary angiogram (CTPA) or a ventilation perfusion (V/Q) scan
What two investigations are invalidated during pregnancy for venousthromboembolism?
Well’s score
D-dimer level
When do we initiate venous thromboembolism prophylaxis in pregnant patients? How long should it be continued for?
They have more than three risk factors in the first two trimesters
This treatment should be continued until six weeks postpartum
What venous thromboembolism prophlaxis is used during pregnancy?
It involves prescription of low molecular weight heparin (LMWH)
What three LMWH’s are prescribed as prophylaxis of VTEs?
Enoxaparin
Dalteparin
Tinzaparin
What two anticoagulants should patients not be prescribed as a prophylaxis of VTEs?
Warfarin
Novel oral anticoagulants
Why is Warfarin contraindicated during pregnancy?
It can lead to warfarin embryopathy, which can lead to facial flattening and short limbs
When can Warfarin be used for prophylaxis treatment of VTEs?
In the postnatal period, including breastfeeding
Why are NOACs contraindicated during pregnancy?
They can cause placental haemorrhage and subsequent fetal prematurity and loss
