16 - Medical Disorders of Pregnancy Flashcards
What is the definition of anaemia in pregnancy and when is it screened for?
First trimester Hb <110
Second/Third trimester Hb <105
Postpartum Hb<100
It is screened for in booking appointment and then at 28 weeks
Why is anaemia common in pregnancy and what are the presenting symptoms of this?
Plasma volume increases due to water retention so dilutes blood
What are the different causes of anaemia in pregnancy and how can you differentiate between them?
- Low MCV: iron deficiency
- Normal MCV: physiological anaemia
- Raised MCV: B12 or folate deficiency
Women offered haemoglobinopathy screening at the booking clinic for thalassaemia (all women) and sickle cell disease (women at higher risk) as these cause anaemia
How is anaemia in pregnancy managed?t
Determine cause with blood tests
Iron: Ferrous Sulphate 200mg daily
B12: Test for Intrinsic Factor antibodies for pernicious anaemia then give either IM hydroxycobalamin or PO cynacobalamin
Folate: Up dose from 400mcg to 5mg folic acid
Sickle Cell/Thalassemia: 5mg folic acid, refer to haematologist for transfusions and monitoring
What are some risk factors for developing anaemia in pregnancy?
- Haemoglobinpathies e.g Thalassaemia and Sickle cell
- Increasing maternal age
- Low socioeconomic status
- Poor diet
- Anaemia during previous pregnancy
What are the key bloods you should look at for anaemia in pregnancy?
Hb
MCV
What are some issues that antiphospholipid syndrome can cause in pregnancy?
- Inhibition of trophoblastic (precursor to the placenta) function and differentiation
- Activation of complement pathways at the maternal–fetal interface
- Thrombosis of the uteroplacental vasculature causing miscarriage
What are some autoimmune conditions that are associated with antiphospholipid syndrome?
- SLE
- RA
- Systemic Sclerosis
What are the clinical features of antiphospholipid syndrome in pregnancy?
Recurrent Pregnancy Loss and Thrombosis
- DVT/PE
- Stroke
- Livedo reticularis
- Valvular heart disease AR and MR
- CKD due to ischaemia in kidneys
- Thrombocytopaenia
What is catastrophic antiphospholipid syndrome?
What blood tests are used to diagnose antiphospholipid syndrome and which pregnant women should you perform this blood test on?
Any women with 3 or more miscarriages, anyone with atypical DVT or recurrent thromboses
- Anticardiolipin
- Lupus anticoagulant: measures the clotting ability of the blood, longer clotting time if antiphospholipid antibodies
- Anti-B2-glycoprotein I
What is the diagnostic criteria for antiphospholipid syndrome?
Need one laboratory and one clinical criteria
How is antiphospholipid syndrome managed once diagnosed?
Why are pregnant women at increased risk of VTE in pregnancy and when is the risk highest?
Increased coagulability of blood (increased fibrinogen, decreased protein S) and Venous Stasis due to pelvic mass
Postpartum period
PE is big cause of obstetric death
What are some risk factors for VTE in pregnancy and when should you start VTE prophylaxis?
- Smoking
- Parity ≥ 3
- Age > 35 years
- BMI > 30
- Reduced mobility
- Multiple pregnancy
- Pre-eclampsia
- Gross varicose veins
- Immobility
- Family history of VTE
- Thrombophilia
- IVF pregnancy
If 3 risk factors start at 28 weeks, If 4 or more start in first trimester
When is VTE prophylaxis needed in pregnancy despite no risk factors?
- Covid
- Hospital admission
- Surgical procedures
- Previous VTE
- Medical conditions such as cancer or arthritis
- High-risk thrombophilias
- Ovarian hyperstimulation syndrome
What is given for VTE prophylaxis in pregnancy?
LMWH e.g dalteparin, enoxaparin
Started at 28 weeks if risk or as soon as possible if high risk.
Stopped during labour then restarted after delivery for 6 further weeks
If CI then use mechanical prophylaxis like IPC and AES
How do DVTs and PEs present?
DVT
- Unilateral calf or leg swelling (>3cm difference)
- Dilated superficial veins
- Tenderness to the calf
- Oedema
- Colour changes to the leg
PE
- Shortness of breath
- Cough with or without blood
- Pleuritic chest pain
- Hypoxia
- Tachycardia
- Raised respiratory rate
- Low-grade fever
- Haemodynamic instability causing hypotension
How are DVTs diagnosed in pregnant women?
Doppler US
If negative repeat on day 3 and 5
Well’s cannot be used and neither can D-dimers as raised in pregnancy anyway
How are PEs diagnosed in pregnant women?
Initial investigations:
- ECG
- CXR
Definitive Diagnosis
- CTPA
- V/Q Scan
- If DVT on Doppler US and signs of PE does not need further imaging to diagnose to save radiation
How do you decided whether to do a CTPA or VQ scan on a pregnant woman with a suspected PE?
CTPA is gold standard if abnormal CXR
- CTPA: higher risk of breast cancer for mother
- VQ scan higher risk of childhood cancer for fetus
How is a confirmed VTE treated in a pregnant woman?
Start LMWH (e.g dalteparin, enoxaparin) as soon as possible based on weight of woman at booking clinic
Need to continue LMWH until delivery then 6 weeks after
Can switch to oral DOAC after delivery
How is a massive PE with haemodynamic compromise managed in a pregnant woman?
- Unfractionated heparin
- Thrombolysis
- Surgical embolectomy
How is a massive PE with haemodynamic compromise managed in a pregnant woman?
- Unfractionated heparin
- Thrombolysis
- Surgical embolectomy
What is pre-eclampsia and the complications of leaving this untreated?
New high blood pressure in pregnancy with proteinuria with or without oedema
Triad: HTN, Proteinuria, Oedema
Complications: Seizures, End organ damage, IUGR,
What is the definition of the following:
- Chronic hypertension
- Gestational hypertension
- Pre-eclampsia
- Eclampsia
Chronic hypertension: exists before 20 weeks gestation and is longstanding
Gestational hypertension: >140/90 occurring after 20 weeks gestation, without proteinuria.
Pre-eclampsia: pregnancy-induced hypertension associated with organ damage, notably proteinuria
Eclampsia: seizures occur as a result of pre-eclampsia
What is the pathophysiology of pre-eclampsia?
Trophoblast invasion of endometrium sends signals to spiral arteries to reduce their vascular resistance, making them more fragile. Blood flow to these arteries increases and they break down, leaving lacunae where maternal blood flows. Happens around 20 weeks gestation
If lacunae are inadequate, can develop pre-eclampsia. High vascular resistance in the spiral arteries and poor perfusion of the placenta. This causes oxidative stress in the placenta, and the release of inflammatory chemicals into the systemic circulation, leading to systemic inflammation and impaired endothelial function in the blood vessels.