Alanna James

Hypertensive Disorders of Pregnancy (HDOP) Epidemiology Classification Risks of HDOP Pregnancy Induced Hypertension Pre eclampsia Eclampsia HELLP

Introduction –Hypertensive disorders Commonest medical complication of pregnancy complicates 10-15% of pregnancies. accounts for 12-25% of antenatal admissions Pre-eclampsia complicates up to 6% of first pregnancies Eclampsia : 1 in 2000 pregnancies in UK. HDOP leading cause of maternal mortality Death rates from eclampsia in UK ~2% Antenatal care geared towards detection of hypertension

Classification–Hypertensive disorders Classified into 4 categories: Pre existing hypertension (chronic/essential hypertension or pre existing renal disease) Pregnancy induced hypertension ** Pre-eclampsia ** Superimposed pre-eclampsia

Risks of hypertension in pregnancy For mother: CVA Renal failure Heart failure Coagulation failure Liver failure Adrenal failure Eclampsia For fetus: IUGR Placental abruption Iatrogenic preterm delivery

Pregnancy induced hypertension Defined as: ‘hypertension occurring for the first time after 20 weeks gestation’. BP >140/90 on 2 occasions at least 4 hours apart Mild – BP >140 systolic or 90 diastolic Moderate - BP >160 systolic or 110 diastolic Rise in BP of > 30mmHg systolic or 20 mmHg diastolic compared to booking BP No proteinuria – but woman with PIH are at higher risk of developing pre-eclampsia.

PIH Investigations & Management Mild PIH: Assessed as outpatient if BP remains below 140/100 with no proteinuria and no signs of IUGR in fetus BP/urine should be monitored 2 x week and fetal growth monitored with fortnightly USS Moderate PIH Should be inpatients or monitored daily in ADAU BP – treated if above 160/110 Renal function monitored- urinary protein, U & E’s, plasma urate, total urinary protein excretion FBC (+ clotting screen if low platelets) LFT’s Fetal monitoring: daily CTG’s, weekly doppler if IUGR detected

Treatment: Anti-hypertensive’s Labetolol Beta blocker Anti-hypertensive action without compromising renal or uterine blood flow Safe for use in 3 rd trimester (26 weeks onwards) (Use methyldopa or nifedipine pre 26 weeks) Side effects in the fetus include: Neonatal hypoglycaemia IUGR Bradycardia 1 st line treatment in Singleton Hospital ( Methlydopa, nifedipine, hydralazine (IV)

Pre-eclampsia = Hypertension + proteinuria +/- oedema

Risk factors for Pre Eclampsia Risk factors include: Nulliparity – less common in multiparous women unless they have changed partner Pre-existing hypertension – up to 1 in 4 will go on to develop PE. BMI >30kg/m 2 Pre-existing renal disease Anti-phospholipid syndrome Diabetes Family history – increased 8 x if sister 4 x if mother had PE

Diagnosis of pre-eclampsia Hypertension Systolic >140 or diastolic >90 Severe if systolic >160 diastolic >110 Proteinuria 2+ on dipstick More than 300mg in 24 hour urine collection Or PCR > 30 mg/mmol +/- Oedema +/- Symptoms 20+ weeks Super-imposed pre-eclampsia occurs in women with pre-existing hypertension who subsequently develop proteinuria.

Symptoms & signs of pre-eclampsia Oedema – caused by proteinuria reducing oncotic pressure in blood leading to fluid retention in tissues. Headache – dragging, throbbing pain in frontal and occipital regions caused by cerebral oedema. Visual disturbances– oedema of optic nerve or retina Abdominal pain – caused by stretching of liver capsule Nausea/vomiting Hyper-reflexia and clonus – caused by cerebral oedema causing upper motor neuron lesion type picture Fetal- Poor placental perfusion, Reduced fetal movements, small for dates

HELLP syndrome Variant of pre-eclampsia characteristed by: Haemolytic anaemia Elevated liver enzymes Low platelets Pathophysiology Activation of clotting cascade leading to microangiopathic haemolytic anaemia This mainly occurs in the liver, downstream liver cells suffer ischaemia, leading to periportal necrosis DIC occurs, consuming platelets. Bleeding> challenge surgery Investigations if this is suspected should include FBC, LFT’s, U & E’s and coagulation screen.

Management of pre-eclampsia 1 Prophylaxis: 75mg aspirin bd from 12 weeks gestation Cured by delivery of placenta (and baby) Until then: Control maternal BP Monitor fetal growth – regular USS/doppler Administer steroids if preterm delivery likely Monitor fluid balance Bloods monitored- U&E, PCR, LFTs, GGT, FBC, group & save Umbilical artery doppler- alarm bells if EDF changes

Management of pre-eclampsia 2 Indications for delivery: Inability to control BP Worsening biochemistry/haematology Severe pre-eclampsia symptoms /Imminent Eclampsia Eclampsia Fetal deterioration

Eclampsia Characterised by the development of tonic-clonic seizures in a patient with pre-eclampsia Management for eclampsia/imminent eclampsia: Magnesium sulphate 4g IVI in 100ml saline over 15 mins then continue at 1g/hr for 24 hours Labetolol 20mg IV or Hydralazine 5mg IV up to 20mg Steroids for fetus (if weeks and not previously received steroids) Deliver baby as soon as mother is stable

Summary- HDOP Common complication of pregnancy High maternal and fetal morbidity and mortality Diagnosis: Often asymptomatic Screening of BP and urine at all antenatal visits Management Control of hypertension Delivery at appropriate time Prediction and prevention

References Hamilton-Fairley, D. Lecture notes Obstetrics & Gynaecology. 3 rd Edition. Wiley Backwell. RCOG Green Top Guidelines: The management of severe pre-eclampsia/eclampsia. Pre-eclampsia Day Assessment Unit protocol Oxfod hanbook of clinical specialites. 8 th edition. Oxford University Press