Obstetric Complications Flashcards
Define the different hypertensive disorders in pregnancy?
HTN Chronic HTN PIH PET Eclampsia HELLP
HTN = raised BP defined by population (age, sex etc) – in pregnancy, >140/90
Chronic HTN = raised BP <20 weeks or with BP Tx
Pregnancy induced hypertension (PIH) or gestational hypertension (GH) = new hypertension >20 weeks gestation, no proteinuria
Pre-eclampsia (PET) = multisystem disorder characterised by hypertension >20 weeks gestation AND proteinuria (not 100% sensitive – not all fit these criteria)
o Proteinuria: >300mg (0.3g) protein / 24 hours (PCR > 30)
Eclampsia = seizure / convulsive episode caused by PET
HELLP syndrome = haemolysis, elevated liver enzymes + low platelets
Mild, moderate, severe HTN?
Mild 140-149 / 90 - 99
Mod 150-159 / 100-109
Severe 160 / 110
What is pre-eclampsia? (criteria)
How common is it?
> 20 weeks gestation: pregnancy-induced HTN associated with proteinuria (>0.3g/24 hours). Oedema used to be 3rd in the classic triad, but now often not included as it is not specific.
Common: ~20% admissions, commonest cause of iatrogenic early delivery.
Mild PET may affect 6% of pregnancies
Severe in 1% (eclampsia in 1-2% of PET). Leading cause maternal mortality worldwide.
Symptoms of pre-eclampsia?
May be completely asymptomatic
Headache, visual disturbance, epigastric / RUQ pain, nausea / vomiting, rapidly progressive oedema, abdominal tenderness, disorientation/confusion, small for gestational age uterus, IUD, hyper-reflexia / clonus / involuntary movements
Features of SEVERE pre-eclampsia • HTN typically >170/110mmHg + proteinuria • Proteinuria dipstick ++/+++ • Headache • Visual disturbance • Papilloedema • RUQ / Epigastric pain • Hyperreflexia • Platelet count <100*10⁶, abnormal liver enzymes or HELLP syndrome
Pathophysiology of pre-eclampsia?
Diffuse vascular endothelial dysfunction via release of angiogenic and angiolytic factors > widespread circulatory disturbances (to liver, kidneys, CVS, CNS, placenta etc). Failed differentiation of cytotrophoblastic cells during epithelial –> endothelial transformation. Three stages occur:
- Abnormal placental perfusion: abnormal placentation and trophoblast invasion of the endometrium in which there is failure of vascular remodelling of the spiral arteries, therefore spiral arteries fail to become high capacitance, low-resistance vessels –> placental hypoxia and ischaemia
- Maternal syndrome: placental ischaemia causes widespread endothelial dysfunction (poorly understood – possibly oxidative stress mechanisms / prostaglandin imbalance / NO compounds). Increased capillary permeability increases expression of cell adhesion molecules (CAM), increases pro-thrombotic factors and platelet aggregation, and causes vasoconstriction
- Multisystem effects
What are the multisystem effects of pre-eclampsia? (go through each system)
o CNS: eclampsia (fits), hypertensive encephalopathy, IC haemorrhage, cerebral oedema, cortical blindness, CN palsies
o Renal: reduced GFR, proteinuria, increased serum uric acid (also in placental ischaemia), increased creatinine / K / urea, oligo / anuria, AKI (tubular / cortical necrosis)
o Liver: epigastric/RUQ pain, abnormal liver enzymes, hepatic capsule rupture, HELLP (haemolysis, elevated liver enzymes, low platelets) - emergency
o Haematology: decreased plasma volume (normally increased), haemo-contraction, thrombocytopenia, haemolysis, DIC
o CVS: pulmonary oedema (–> ARDS), PE, future hypertension, NB. CVS effects have high mortality
o Placental: IUGR, placental abruption, intrauterine death
What are the main maternal risks of having pre-eclampsia?
(Now very safe in UK):
• Eclampsia (seizures)
• Haemorrhage: placental abruption, intra-abdominal, intra-cerebral
• Cardiac Failure
• Multi-organ failure
• Maternal death (<1 in million in UK but many deaths globally)
• Long-term: subsequent high BP & complications, CV disease (e.g. CVA, IHD)
HELLP & Placental Abruption: rarer complications of HTN especially PET - variable disease(s) often seen (e.g. ELLP)
• Abruption often causes / provokes PET
• Remember FATTY LIVER (acute fatty liver of pregnancy)
Intracranial haemorrhage is the most common cause of death in women who die from hypertensive disorders of pregnancy
In the UK, what are most common causes of direct maternal death?
PET / eclampsia was 2nd biggest in 1985-7, 2012-14 dropped to 7th
- Thrombosis / thromboembolism
- Amniotic fluid embolism
- Haemorrhage
4 / 5. Sepsis / early pregnancy deaths
6/ 7. Anaesthesia / PET or eclampsia
What are the main fetal risks of having pre-eclampsia?
- Prematurity (major cause of mostly iatrogenic early birth; 10% severe PET birth <34 weeks, 1 in 250 first pregnancy <34 weeks due to PET, 10% of all preterm births due to HTN disorders, 50% with severe PET give birth preterm)
- IUGR (15-20% births with PET are <10th percentile)
- Stillbirth (1 in 20 stillbirth without anomalies are associated with PET)
HIGH risk factors for pre-eclampsia?
o Hypertensive disease in previous pregnancy
o CKD
o Autoimmune disease (e.g. systemic lupus erythematosus, antiphospholipid syndrome)
o Type 1 or type 2 diabetes
o Chronic hypertension
If one of these factors - give aspirin
MODERATE risk factors for pre-eclampsia?
First pregnancy Age ≥40 (doubles risk) Pregnancy interval of >10 years BMI ≥35 at first visit (doubles risk) FHx pre-eclampsia (mother 20-25%, sibling up to 40%) Multiple pregnancy
If 2 of these factors, aspirin is needed
Additional risk factors include: genetic abnormalities (triploidy), molar pregnancies.
Investigations for cases of PET?
o U+Es (raised creatinine, K⁺, urea), also serum uric acid (raised urate). o LFTs: abnormal liver enzymes o FBC o Coagulation screen o USS (biometry / AFI / Doppler)
Aims of management for PET?
Protect mother from hypertensive complications (CVS, MI etc), long-term risks – does not prevent progression of PET.
Protect baby by improving condition at birth, steroids + ideal BP for growth, improved gestation (later vs earlier?).
What should be done for pre-eclampsia prior to a pregnancy?
Before pregnancy o Assess risk + likelihood of pregnancy o Weight reduction, stop smoking o Review medications o ACEI, ARB, diuretics, statins - stop and/or prepare to change o Aspirin 75mg, start at 12 weeks (<20) o Folate 400µg – start before pregnancy o Discuss risks: worse BP, PET, SGA, prematurity + longer term outlooks
What should be done for pre-eclampsia during the pregnancy?
When to refer or admit?
Assess risk at booking + during 1st trimester. If BP rises 1st trimester, assess for other causes. Antenatal screening: BP, urine, maternal uterine artery doppler (MUAD).
When to refer: day case referral if any of the 3 major signs or concerning symptoms e.g. persistent headache.
Admission if: BP >170/110 (alone) or >140/90 + proteinuria, significant symptoms (e.g. headache, visual disturbance, RUQ pain), abnormal biochemistry, significant proteinuria (>300mg/day), need for antihypertensive treatment, signs of fetal compromise
Inpatient assessment: BP 4 hourly, daily urinalysis, fluid balance chart +/- collection for protein, regular bloods. Fetal surveillance: movements, CTG, USS, biometry, AFI, umbilical artery doppler
Main treatments for pre-eclampsia?
Aspirin 75mg OD (12 weeks -> birth)
• If 1 high or >1 moderate risk factor for PET
Consensus guidelines: treat BP >160/110 but many clinicians have lower threshold. Oral labetalol 1st line (NICE), nifedipine + hydralazine may also be used.
Severe Hypertension • Stabilise then plan delivery (aim 140-150 / 80-100) • Labetalol oral / IV • Nifedipine oral • Hydralazine IV (?preload)
Monitor effect (mother + baby): fluid balance (? catheter)
• Mg
• Anaesthetist + neonatalogist
Delivery = the only ‘cure’, must be stabilised beforehand
o Induction <34 weeks if severe HTN refractory to Tx or other complications necessitating delivery
o 34-36+6 weeks if mild-moderate HTN, depending on maternal and fetal condition, risk factors and services
o immediate induction (24-48 hours) if >37 weeks
How to look after patients with pre-eclampsia during labour / intrapartum?
• BP hourly or more frequently • Control BP <150/100 • Care with fluids (80mls/hour): (plasma leaks out, lower intravascular circulating volume but adding more fluid > pulmonary oedema!!) • Fluid balance (? Urine output) • Monitor baby: continuous CTG • Epidural for obstetric medications must avoid excess fluids
Main management of HELLP syndrome?
HELLP syndrome usually managed in conjunction with PET (BP control, ultimately delivery, may require blood products where indicated, steroids for fetal development)
• Deliver if platelets <100 or ALT>80
Post-natal factors in pre-eclampsia? Management?
Post natal BP: may rise for first few days, often needs continued treatment- ET risk continuous for few days
- Aim <140/90, reduce if <130/80
- ACEI if hypertension for >2 weeks
- Refer if BP still high at 6-8 weeks
- Exclude persistent proteinuria (i.e. renal disease)
- Lifestyle changes to continue
How to manage the following patients with pre-eclampsia
Mild 140-149 / 90-99
Mod 150-159 / 100-109
Severe 160/110
Mild: measure BP no more than 1/week, proteinuria at each visit using strip or urea/creat ratio, blood tests only as routine antenatal care
Mod: oral labetalol 1st line to keep systolic <150 and diastolic 80-100, BP at least 2/week, proteinuria at each visit, test kidney function, electrolytes, FBC, transaminases, bilirubin - do not carry out further blood tests if no proteinuria at subsequent visits
Severe; ADMIT until BP <159/109, labetalol first line as above, BP at least 4/day, daily proteinuria, blood tests at presentation then weekly: kidney, electrolytes, FBC, transaminases, bilirubin
