Some Medical Conditions in Pregnancy

1. Some Medical Conditions in Pregnancy Max Brinsmead PhD FRANZCOG August 2012

2. 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

3. Haematocrit and Perinatal Mortality

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. Maternal Mortality and Transfusion

13. 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

14. 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

15. 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

16. Thrombocytopenia and Pregnancy • Platelet count in pregnancy is normally >150,000 • Thrombocytopenia 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

17. 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

18. 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

19. 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

20. Management of Thyroid Disordersin 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

21. This is the hand of a 14-year primigravida whom you are seeing for the first time…

22. 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

23. Management of Cardiac Diseasein Pregnancy • Cardiac 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

24. Management of Cardiac Diseasein Labour • Best 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

25. 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