What are the normal cardiac adaptation to pregnancy?

1. Intravascular volume
2. Cardiac output
3. Peripheral vascular resistance
4. Blood pressure

1. Blood volume increases 40-50% + increased red cell volume = increased intravascular volume. Results in enlarged LV - cardiomegaly of pregnancy
2. Increased HR + increased SV = 40% increase in CO
3. Blood pressure lowers in 1st 28 weeks, reaching nadir at 16-20 wks and returning to normal by 28 wks. Starts to rise after 36 wks.

>130/80mmHg

1. Chronic HTN: systolic >140 or diastolic >90 prior to 20wks
2. Gestational (or PIH): pressures as above, but after 20 wks gestation in previously normotensive woman - NO proteinuria
3. Pre-eclampsia: pressures as above after 20 wks in previously normotensive woman. Proteinuria at least 300 mg in 24hr collection
4. PE superimposed on chronic HTN: new onset or greatly increased proteinuria; sudden exacerbation of HTN or other signs of multisystem involvement such as thrombocytopaenia or transaminitis

Variant of severe PE

Haemolysis, Elevated Liver enzymes, Low Platelets

Indicates high risk for maternal and/or fetal complications

Neuro:

• headache
• visual disturbance (blurred vision & scotomata)
• confusion
• feeling jittery/shaky
• hyperreflexia & seizures

GIT: RUQ/epigastric pain; impaired liver function

Renal: proteinuria; oliguria; pulmonary oedema

Blood: MAHA; thrombocytopaenia

+IUGR, placental abruption, fetal compromise

• nulliparity
• extremes of reproductive age
• multiple gestation
• underlying hypertension
• chronic illness: autoimmune, diabetes, renal disease

• Repeat the BP!!! (2 measurements 4hrs apart, compare with booking BP)
• Cardiorespiratory: exclude pulmonary oedema (lung bases)
• Neuro: exclude impending seizure; hyperreflexia +/- clonus
• GIT: liver tenderness
• Fetus: fundal height, fetal heart

Mother:

• Urinalysis & 24 hr urine
• Bloods: FBC, UEC, LFT, coags & urate

Fetus:

• ultrasound (ideally with MCA Doppler)
• CTG

What is the treatment for pre-eclampsia?

1. Definitive
2. Prophylactic

What must be considered when controlling mother's BP?

1. DELIVERY!
2. Mother: antihypertensives (labetalol & methyldopa); prophylaxis for seizures (mag sulphate)

Abnormal CTG + Abnormal Doppler = caution when controlling mother's BP as placenta entirely dependent on mother's BP (no autoregulation).

1. What is the gestation?
   • viable? (>28wks)
   • is prematurity inevitable?
2. How sick is the mother?
   • treat the BP?
   • terminate the pregnancy before further complications?
3. How sick is fetus?
   • ?delivery

1. Uncontrolled BP despite maximal therapy
2. Complications of PE
   • impending seizure/eclampsia
   • thrombocytopaenia
   • renal/liver impairment
3. Fetal compromise
   • severe IUGR
   • abnormal CTG
4. Term pregnancy (>37/40)

1. Essential hypertension
2. Renal (diabetes, glomerulopathies, SLE
3. Rare: renal artery stenosis, phaeochromocytoma

1. Utero-placental insufficiency
2. IUGR
3. Superimposed PE

Appropriate:

• methyldopa: centrally acting alpha-agonist
• labetalol: beta-blocker with antagonistic activity at vascular alpha₁ receptors

Inappropriate:

• diuretics are not recommended as they contract intravascular volume and thus uterine perfusion
• Contraindicated: ACEI & AIIA: associated with fetal congenital malformation & oligohydramnios, renal artery stenosis and fetal death.