Medical Disorders in Pregnancy

1. Medical Disorders in Pregnancy Dr Than Than Yin

2. Obstetric cholestasis • Unique to pregnancy • Severe pruritus affecting limbs and trunk mainly palm and sole • Developing in the second half of pregnancy (usually during the third trimester)

3. Diagnosis • A typical history of pruritus without rash • Abnormal liver function tests • Moderate < less than three-fold elevation in transamimases ( ALT is the most sensitive) • Raised ALP 9> pregnancy values • Raised Ƴ glutamyltranspeptidase • Mild elevation of bilirubin • Increased total serum bile acid • Exclusion of other causes of itching and abnormal liver function

4. Diagnosis • To exclude other causes of abnormal liver function • Liver scan • Viral serology ( for hepatitis A,B,C and E,EBV and CMV) • Liver autoantibodies( for pre-exisisting liver diseasse, anti-smooth muscle antibodies, antimitochondrial antibodies

5. Management • Counselling • Weekly LFT and bile acids • No evidence of monitoring fetal well-being • To check prothrombin time prior to delivery

6. Intrapartum management • Labour may be induced at 37-38 weeks gestation if persistantly raised bile acid levels • If bile acid levels < 40 µmol/L, reasonable to await spontaneous onset of labour

7. Drug therapy • Vitamin K mandatoroy for women with prolonged prothrombin time, commenced at 32 weeks • Antihistamine • Ursodeoxycholic acid • Dexamethasone • Rifampicin • Cholestyramine • S-Adenosylmethionine • Activated charcol • Epomediol

8. Diagnosis • BP, urinalysis, uric acid, platelet count, clotting screen, blood film • Blood glucose, serum calcium, sodium, liver function tests • CT or MRI • EEG

9. Epilepsy in pregnancy • Many cases are idiopathic • 30% have a family history of epilepsy • Secondary Epilepsy • Previous surgery • Intracranial mass or lesions • Antiphospholipid syndrome

10. Effect of pregnancy on epilepsy • A common indirect maternal death • No effect in majority • Women who have been seizure free for years are unlikely to have seizures in pregnancy • Women with multiple type seizures are more likely to have increase in seizure frequency • The risk of seizures is highest in peripartum • Sudden Unexplained Death in Pregnancy (SUDEP)- risk factors • seizure frequency • Increasing number of antiepileptic drugs • Low IQ • Early onset epilepsy

11. Effect of epilepsy on pregnancy • The fetus is relatively resistant to short periods of hypoxia • No increased risk of miscarriage or obstetric complications • Status epilepticus is dangerous for both mother and fetus • The risk of child developing epilepsy is increased (4-5%) if either parent has epilepsy and, risk is 10-15% if both parents have epilepsy, 10% risk with previously effected sibling

12. Teratogenic risk of anti-epileptic drugs(AED) • Phenytoin, primidone, phenobarbitone, carbamazepine, sodium valproate, lamotrigine, topiramate and levetiracetam all cross the placenta and are teratogenic • Major malformations caused by AEDs • Neural tube defects ( especially valproates 1-3.8% and carbamazepine 0.5-1%) • Orofacial clefts ( particularly Phenytoin, carbamazepine, phenobarbitone and valproate) • Congenital heart defects (particularly Phenytoin, phenobarbitone and valproate) • Minor malformations • Dysmorphic features • Hypertelorism • Hypoplastic nails and distal digits • Hypoplasia of the mid face

13. Teratogenic risk of anti-epileptic drugs(AED) • Metaanalysis of all studies showed that the risk of any one drug is approximately 6-7% • Various theories • Genetic deficiency of the detoxifying enzyme epoxide hydrolase • Cytotxic free radicals • Folic acid deficiency

14. Management • Antenatal management • Folic acid 5mg daily • No need to change the AED if epilepsy is well controlled • Pre-natal screening for congenital abnormalities and detailed ultrasound at 18-20 weeks should be ordered, including fetal cardiac assessment • Vitamin A 10-20mg daily should be prescribed in the last four weeks of pregnancy • Intrapartum management • Risk of seizures increase around the time of delivery • 1-2% will have a seizure during labour and 1-2% will have a seizure in post partum 24 hours period • Should continue regular AED • Effective pain relief and epidural analgesia • Postnatal management • The neonate should recieve 1mg Vitamin K Inj IM • Breast feeding should be encouraged

15. Cardiac disease in pregnancy • Leading cause of maternal death as result of • Myocardial infarction • Ischemic heart disease • Dissecting aortic aneurism • Other heart disease • Peripartumcardiomyopathy • Rheumatic heart disease- 25% of pregnant population who not born in the UK • Congenital heart disease

16. Management • Preconception counselling • Antepartum • Risk assessment • Joint clinic attended by obstetrician, cardiologist, anaesthetist • Echocardiogram • Fetal echocardiogram for women with congenital cardiac disease • 32-34 weeks gestation –multidisciplinary meeting for birth plan • Intrapartum • Early slow incremental epidural analgesia, assisted vaginal delivery • Caesarean section is only necessary for obstetric indications • Postpartum • Anticoagulation • Long observation in high dependency area • Prophylaxis against postpartum haemorrhage • Low dose oxytocin infusion

17. Thyroiddisease in pregnancy Hyperthyroidism Hyperthyroidism 1% of pregnancies Most cases have already been diagnosed Associated with autoimmune diseases, pernicious anemia, vitiligo, type 1 diabetes Commonest causes encountered in pregnancy- Hashimoto’s thyroiditis, treated Grave’s disease • Thyrotoxicosis complicates in 1 in 500 pregnancies • 50% of affected women have a positive family history of autoimmune thyroid disease • 95% are due to Grave’s disease, an autoimmune disorder caused by TSH receptor stimulating antibodies

18. Pregnancy –specific normal ranges