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Some Medical Conditions in Pregnancy
Max Brinsmead PhD FRANZCOG
August 2012
Anaemia
The most common pregnancy complication worldwide
Affects 1:2 women in developing countries
Risk of maternal and fetal mortality
Also has substantial morbidity and economic sequelae
Haematocrit and Perinatal Mortality
A Definition of Anaemia:
WHO definition is Hb <110 g/L but…
Hb <100 g/L is more realistic
Needs correction for altitude…
Add 2.5 g/L for every 1000m up to 4000m
Severe when Hb is 40 – 70 g/L
Very severe when Hb is <40 g/L
Causes of Anaemia:
Nutritional deficiency of Iron and Folate
Malaria
HIV (+/- TB)
Sickle cell Disease or Thalassaemia
Hookworm infestation
Chronic renal or Hepatic disease
Often multifactorial
Losses and gains:
Non pregnant iron requirement is 2 mg/day
But this reaches 5 mg/day in 3rd trimester
Will be influenced by age, parity, pregnancy spacing and fetal number
Hookworm >1000 ova/g faeces will cause a loss of 2 mg iron/day
Folate deficiency is aggravated by malaria
B12 deficiency is rare
Investigations for Anaemia:
Blood film – look for micro or macrocytosis, reticulocytes, segmentation neutrophils, Neutrophil & Lymphocyte count
But combined deficiencies can be difficult
Malarial parasites may be intermittent or parasitised RBC’s may have been removed from circulation
Bone marrow can be useful
Malaria and Anaemia:
The picture will depend on whether the woman is immune or non immune to malaria
Splenomegaly = Hyperactive Big Spleen Syndrome
Due to an abnormal immune response to chronic malaria
Requires malarial Rx esp. Proguanil 200 mg/day for life
And Folic acid 5 mg/day
Profound Anaemia or Pre eclampsia?
Oedema can occur with hyperdynamic heart failure
Proteinuria can occur with renal hypoxia
There can be hypovolaemia with both
Profound anaemia may even present with coma
But…
Diastolic BP will be low with anaemia and high with pre eclampsia
Management of Profound Anaemia:
Admit to hospital if Ht is <0.20
Try to be as specific as possible with Rx
Iron dextran infusion can be useful• Calculate dose required• Adrenaline & hydrocortisone on standby• Follow up
Indiscriminate Fe by IM injection is not good
Parenteral folate rarely required but concomitant oral iron always required
Indications for Transfusion:
Heart failure or incipient heart failure
Ht <0.14
Miscarrying or in labour and Ht <0.18
Operation required and Ht <0.24
Other disease is present e.g. renal
Maternal Mortality and Transfusion
Transfusion Precautions:
Use packed cells and pre transfusion Lasix
May require anti malarial drugs
May require lower limb torniquets
NB The Ht will initially fall
The anaemic patient in labour:
Do everything possible to minimise blood loss
Because they may have compensated up to that point but blood loss of even 100 – 200 ml may be fatal
Monitor for signs of fetal hypoxia
Maternal oxygen can be useful
The anaemic patient who fails to respond to
treatment:
Maybe noncompliant
Has underlying renal or hepatic disease
Has chronic infection such as HIV, TB or UTI
Has concomitant malignancy
Has an advanced abdominal pregnancy
Has idiopathic hypoplastic anaemia
Thrombocytopenia and Pregnancy
Platelet count in pregnancy is normally >150,000Thrombocytopenia may be due to:– Malaria e.g. hyperactive spleen disease– HIV
• And transiently with other viral infections– Part of severe anaemia e.g. folate deficiency– Many drugs including alcohol– Fetal death in utero– Late sign in severe pre eclampsia (HELLP)– Idiopathic thrombocytopenia
IdiopathicThrombocytopenia(or ITP)
Is actually an autoimmune condition due to anti-platelet antibodies
Maternal risk of bleeding does not occur until the platelet count is <20,0000
However, there is a risk of passive transfer of antibody and fetal thrombocytopenia– That may result in intra cranial haemorrhage
This can be averted by keeping maternal count >50,000
This is done by the administration of steroids
Steroids for ITP
Inhibit anti platelet antibodies
But also coat and protect the platelets from destruction in the spleen
Check neonatal platelet levels
However, the risk of fetal bleeding is not as great as that which occurs with alloimmune ITP– When the maternal platelet count is usually normal
Thyroid Disorder
Pregnancy is a state of mild hyperthyroidism
Thyroid hormones cross the placenta poorly
But
The developing fetal brain may be dependent on some maternal thyroxin
And
Antithyroid drugs cross the placenta readily
Management of Thyroid Disorders
in Pregnancy
Hypothyroid patients require an increase in their thyroxin replacement therapy
Best option is to dose by 33% ASAP
Hyperthroid patients are best treated by PTU but “run them hot”
I131 therapy is contraindicated
Thyroid surgery is okay after toxic control
This is the hand of a 14-year primigravida whom you are seeing for the first time…
Finger Clubbing here is most likely due to…
Cyanotic congenital heart disease• Tetralogy of Fallot• Eisenmenger’s Syndrome
And you should be worried because there is a very poor prognosis• For the mother• For the fetus
Other High Risk Cardiac Conditions• Pulmonary hypertension• Severe aortic & mitral stenosis• A metal mitral valve replacement (on Warfarin)• Marfan’s syndrome with severe aortic incompetence• Peripartum cardiomyopathy
Management of Cardiac Disease
in PregnancyCardiac output increases throughout pregnancy and reaches a peak in labour
Close monitoring with multidisciplinary care is required
Low threshold for hospitalisation
Vigorous treatment of CCF
Aim for vaginal delivery
Pre term delivery may be required for severe disease
Remember thromboprophylaxis
Management of Cardiac Disease
in LabourBest done as “intensive care”
Low dose epidural good• But requires an expert anaesthetist
Assist the delivery by ventouse or forceps in a semi sitting position
Avoid all oxytocics in the third stage
And use mechanical means to control PPH
LMW heparin prophylaxis against thromboembolism
Progesterone only or T/L best afterwards
Diabetes in Pregnancy
Screening for gestational diabetes has become accepted best practice
Meticulous control of blood sugar before and during pregnancy for the best outcomes
Pre term Caesarean no longer required
But Caesarean may be the best option when fetal macrosomia is suspected