A Case History of Hypertension in Pregnancy Max Brinsmead MB BS PhD April 2014

Carol is a 36-year old Intensive Care Nurse who has been trying to have a baby for 5 years. She conceives spontaneously and commences antenatal care in Sydney. During a “weekend away” in Coffs Harbour she comes to Maternity feeling a little unwell and asks to have her BP checked. It is 160/105. The midwife starts a CTG and asks that you come to see this patient.

Carol is pregnant with a BP of 160/105 Is this preeclampsia or pregnancy-induced hypertension How urgent is this review What further history do you require Preeclampsia is sustained hypertension in the 2nd half of pregnancy accompanied by evidence of some other organ involvement. Returns to normal after 3m Not urgent, but symptoms are worrying… This pregnancy. Other pregnancies. Personal and Family medical history. Social circumstances. Symptoms.

Carol with a BP of 160/105 Gestation is 33 weeks by dates and early scans Never pregnant before. All tests thus far, including PAPP-A for triploidy, are normal. Had “nephritis” aged 6 years but recovered after 6 weeks. Mother is hypertensive on medication Married to another nurse. Non smoker. Usually fit and healthy but just “feels unwell and thought her BP might be up”. BP in the first trimester was 105–115/60–75 and was 130/80 one week ago.

Carol G1P0 at 33 weeks with a BP of 160/105 What further information do you require What tests are desirable Would you admit this patient to the antenatal ward? Repeat BP after resting. Cardiovascular and pregnancy examination. Test urine for protein FBC, UEC, LFTs, Urate, Proteinuria quantification, UMCS Pregnancy ultrasound YES

Carol G1P0 at 33 weeks BP 160/105 Cardiovascular exam is normal apart from accentuated 2nd heart sound. Mild generalized oedema noted. Symphysis-fundal height 29 cm Knee jerks are active but there is no sustained clonus Oedema is no longer regarded as a sign of preeclampsia Because oedema is a “good sign” in pregnancy This uterus is small for dates It is normal to have 1-2 beats of clonus but sustained clonus is a sign of imminent eclampsia

Ward test proteinuria + HB 128 Hct 0.36 Platelets 231 Carol G1P0 at 33 weeks BP 160/105 Ward test proteinuria + HB 128 Hct 0.36 Platelets 231 UEC and LFT’s normal. S Creat normal. Urate 0.38 24-hr urine protein 0.25G (normal <0.3G) UMCS – no red/white cells or casts. Culture negative Estimated Fetal Weight (EFW) by ultrasound <10th centile with evidence of head-sparing IUGR. Reduced amniotic fluid index. Umbilical UA Dopplers 95th centile

Estimated Fetal Weight by Ultrasound Is made by ultrasonic measurements of head biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and Femur Length (FL) Has an error of not less than ± 20% Fetal growth restriction is either generalised (symmetrical) or head-sparing (asymmetrical) Asymmetrical IUGR arises from a redirection of cardiac output to support vital brain growth

Is largely composed of fetal urine Amniotic Fluid Is largely composed of fetal urine It’s volume is a reflection of fetal urine output Which, in turn, is a reflection of fetal cardiac output/function, fetal oxygenation and welfare Will be absent if there is renal agenesis or urine output obstruction Is often expressed as the Amniotic Fluid Index (AFI)

Umbilical Artery Doppler Study Upper panel represents peak (systolic) and trough (diastolic) flow often expressed as S/D ratio Lower panel is constant flow through a uterine vein UA Doppler reflects downstream placental resistance Is the 1st change to occur with placental disease

Umbilical Artery Doppler changes with Gestation

Abnormal UA Doppler Flows When flow ceases in the diastolic phase (AEDF) the S/D ratio is very high (∞) Flow may even reverse in the diastolic phase (RDF) as shown opposite

Why is that an important diagnosis Carol G1P0 33 weeks BP of 160/105 but no significant proteinuria. Clinical and scan evidence of IUGR Is this preeclampsia Why is that an important diagnosis YES Preeclampsia is an unpredictable disease with significant maternal and fetal mortality and morbidity

Systems involved in Preeclampsia Renal Significant proteinuria Renal failure biochemistry Oliguria Hepatic Elevated transaminases Epigastric or RUQ pain Haematological Thrombocytopenia Haemolysis DIC CNS Eclampsia or stroke Hyperreflexia with sustained clonus Severe headache or visual disturbance Cardiovascular Pulmonary oedema Placental IUGR Abruption

Carol 33 weeks with preeclampsia in hospital Carol 33 weeks with preeclampsia in hospital. BP rises to 180/110 at 6 pm with dull headache. No sustained clonus Does this hypertension require treatment Why What drug will you use What BP would you aim to achieve Yes Risk of eclampsia, cerebral haemorrhage and pulmonary oedema Aldomet or Labetalol with a loading dose Reduce BP to 120- 150/80-100 so as not to further compromise uterine blood flow

Carol 33 weeks with preeclampsia Carol 33 weeks with preeclampsia. Over the next 2 days her BP continues to rise, especially at night What measures can you use to control the BP How will you monitor fetal wellbeing on a daily basis Use drugs to maximum possible doses. Then add in other drugs from a different class For example, Aldomet + Labetalol + Nifedipine + Prazosin Fetal movement charts and non stress cardiotocography (CTG)

Antenatal (Non stress) CTG 10–40 min of continuous FHR Tocograph for fetal movements + maternal trigger Is an assessment of fetal CNS and cardiac oxygenation High negative predictive value when “reactive"

Carol now 34 weeks. BP difficult to control Carol now 34 weeks. BP difficult to control. She develops severe epigastric pain and vomiting. Deteriorating preeclampsia with a significant risk of fits Acute liver swelling stretches its capsule. Maybe subcapsular haematoma AST 240, ALT 115 (NR <70) What is the most likely diagnosis What causes the pain What tests may be useful

A course of steroids to promote fetal lung maturation Carol 34 weeks with uncontrolled hypertension and epigastric pain. Ultrasound shows no further fetal growth and AEDF with Doppler of the umbilical arteries. DELIVERY A course of steroids to promote fetal lung maturation How will you CURE this patient What steps may be desirable on behalf of the baby

How can you deliver this patient Carol 34 weeks with severe preeclampsia and fetal compromise requires delivery Induction of labour best for mother but baby may not tolerate the hypoxic stress of contractions. Cervix may be unfavourable. Caesarean quick and best for baby but riskier for mother and may compromise her future deliveries How can you deliver this patient Describe the pros and cons of each method

First aid is more important than drugs As preparations are being made for a Caesarean Carol has a grand mal seizure. You are present as it commences… First aid is more important than drugs Protect from injury Secure an airway Administer oxygen Then secure IV access IV MgSO4 loading dose and maintain by infusion What do you do

IV Hydrallazine or Diazoxide used most in Australian practice Carol 34 weeks has had an eclamptic fit. MgSO4 continues by infusion. Her BP is 180/120. IV Hydrallazine or Diazoxide used most in Australian practice Risk of respiratory and cardiac arrest. Monitor urine output, respirations, O2 saturation, knee jerks and serum Mg levels What drugs are useful now to lower BP What are the risks from the MgSO4 and how is that avoided

Not less than 24 hours after delivery Carol undergoes urgent Caesarean section and is transferred to Intensive Care for postoperative care Not less than 24 hours after delivery Separation of mother and infant interferes with bonding and lactation. Insomnia and stress to Carol and her relatives. May increase the risk of thromboembolism How long should the MgSO4 infusion continue What are the problems that may arise from intensive care

The baby weighs 1800g and has signs of IUGR. Hypoglycaemia due to depleted glycogen liver stores Monitor blood glucose levels. Early feeding by suckling or D-tube or IV glucose may be required What is the most common neonatal problem for this baby How is it avoided

The baby does well. Carol’s BP still requires treatment postpartum. 24-72 hours but renal/hepatic function may get worse before it gets better Keep BP <150/100, drugs may be required for 6-12 weeks Any antihypertensive drug can be used (but some patients don’t respond to ACE inhibitors) When would expect recovery of renal or hepatic dysfunction How about the hypertension What drugs are used in the control of hypertension

Carol’s BP is normal off all medication by 6 weeks Carol’s BP is normal off all medication by 6 weeks. Tests for autoimmune disease and thrombophilia are negative 50 – 66% Low dose aspirin (100 mg daily preferably commencing in the 1st trimester) reduces risk by >17% Also use Ca supplements 1.5G/day YES What is the risk that she will develop preeclampsia in a subsequent pregnancy How could that risk be reduced Is Carol at risk of hypertension in the future