Week 4 part 2 Flashcards
Women are routinely screened for anaemia twice during pregnancy:
- Booking clinic
* 28 weeks gestation
The normal ranges for haemoglobin during pregnancy are:
Booking bloods > 110 g/l
28 weeks gestation > 105 g/l
Post partum > 100 g/l
The mean cell volume (MCV) can indicate the cause of the anaemia:
- Low MCV may indicate iron deficiency
- Normal MCV may indicate a physiological anaemia due to the increased plasma volume of pregnancy
- Raised MCV may indicate B12 or folate deficiency
Iron requirements for anemic pregnant women
Iron replacement (e.g. ferrous sulphate 200mg three times daily). When women are not anaemic, but have a low ferritin (indicating low iron stores), they may be started on supplementary iron.
If Vitamin B12 deficiency is suspected in pregnancy, what disease needs to be investigated as a cause?
Women with low B12 should be tested for pernicious anaemia (checking for intrinsic factor antibodies).
Management of Vitamin B12 deficiency in pregnant women.
- Intramuscular hydroxocobalamin injections
* Oral cyanocobalamin tablets
Risk factors for VTE in pregnancy:
- 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
The RCOG guidelines (2015) advise starting prophylaxis for VTE
28 weeks if there are three risk factors
First trimester if there are four or more of these risk factors
Management of pregnant women at risk of VTE
Women at increased risk of VTE should receive prophylaxis with low molecular weight heparin (LMWH) unless contraindicated. Examples of LMWH are enoxaparin, dalteparin and tinzaparin.
Prophylaxis is started as soon as possible in very high risk patients and at 28 weeks in those at high risk. It is continued throughout the antenatal period and for six weeks postnatally.
Prophylaxis is temporarily stopped when the woman goes into labour, and can be started immediately after delivery (except with postpartum haemorrhage, spinal anaesthesia and epidurals).
Deep vein thrombosis FEATURES
- Calf or leg swelling
- Dilated superficial veins
- Tenderness to the calf
- Oedema
- Colour changes to the leg
Investigations for DVT in pregnancy
Doppler ultrasound is the investigation of choice for patients with suspected deep vein thrombosis. The RCOG guideline (2015) recommends repeating negative ultrasound scans on day 3 and 7 in patients with a high index of suspicion for DVT.
Investigations for PE in pregnancy
• Chest xray
• ECG
CT pulmonary angiogram (CTPA) or ventilation-perfusion (VQ) scan.
When considering the choice between CTPA and VQ scan:
• CTPA is the test for choice for patients with an abnormal chest xray
• CTPA carries a higher risk of breast cancer for the mother (minimal absolute risk)
• VQ scan carriers a higher risk of childhood cancer for the fetus (minimal absolute risk)
Diagnosis of DVT and PE in pregnancy
Patients with a suspected deep vein thrombosis and pulmonary embolism should have a Doppler ultrasound initially, and if a DVT is present, they do not require a VQ scan or CTPA to confirm a PE. The treatment for DVT and PE are the same.
Women with a massive PE and haemodynamic compromise need immediate management. This is a life-threatening scenario. Treatment options are:
- Unfractionated heparin
- Thrombolysis
- Surgical embolectomy
Pre-eclampsia
Pre-eclampsia refers to new high blood pressure (hypertension) in pregnancy with end-organ dysfunction, notably with proteinuria (protein in the urine). It occurs after 20 weeks gestation, when the spiral arteries of the placenta form abnormally, leading to a high vascular resistance in these vessels.
Pre-eclampsia features a triad of:
- Hypertension
- Proteinuria
- Oedema
Pre-eclampsia complications
Significant cause of maternal and fetal morbidity and mortality. Without treatment, it can lead to maternal organ damage, fetal growth restriction, seizures, early labour and in a small proportion, death.
Chronic hypertension in pregnancy
Chronic hypertension is high blood pressure that exists before 20 weeks gestation and is longstanding. This is not caused by dysfunction in the placenta and is not classed as pre-eclampsia
Pregnancy-induced hypertension or gestational hypertension
Pregnancy-induced hypertension or gestational hypertension is hypertension occurring after 20 weeks gestation, without proteinuria.
Eclampsia
Eclampsia is when seizures occur as a result of pre-eclampsia.
High-risk factors for pre-eclampsia
- Pre-existing hypertension
- Previous hypertension in pregnancy
- Existing autoimmune conditions (e.g. systemic lupus erythematosus)
- Diabetes
- Chronic kidney disease
Moderate-risk factors for pre-eclampsia
- Older than 40
- BMI > 35
- More than 10 years since previous pregnancy
- Multiple pregnancy
- First pregnancy
- Family history of pre-eclampsia
Pre-eclampsia has symptoms of the complications:
- Headache
- Visual disturbance or blurriness
- Nausea and vomiting
- Upper abdominal or epigastric pain (this is due to liver swelling)
- Oedema
- Reduced urine output
- Brisk reflexes
Diagnosis of Pre-eclampsia
- Systolic blood pressure above 140 mmHg
- Diastolic blood pressure above 90 mmHg
PLUS any of:
> Proteinuria (1+ or more on urine dipstick)
> Organ dysfunction (e.g. raised creatinine, elevated liver enzymes, seizures, thrombocytopenia or haemolytic anaemia)
> Placental dysfunction (e.g. fetal growth restriction or abnormal Doppler studies)
Proteinuria can be quantified using:
- Urine protein:creatinine ratio (above 30mg/mmol is significant)
- Urine albumin:creatinine ratio (above 8mg/mmol is significant)