Hypertension in Pregnancy Flashcards
what percentage of pregnant women get hypertension
10-15%
mild pre-eclampsia affects 10% of Primigravid women
what is the biggest cause of iatrogenic preterm birth
pre-eclampsia
only cure is delivery
what CVS changes are there in pregnancy
increase in:
- plasma volume
- cardiac output
- stroke volume
- heart read
peripheral vascular resistance decreases
definition of hypertension in pregnancy
> 140/90 on two occasions
> 160/110 once
what are the types of hypertension you get in pregnancy
pre-existing hypertension
pregnancy induced hypertension (PIH)
Pre-eclampsia (PET)
when do PIH and PET resolve
within 3 months after delivery
if not -could have been pre-existing hypertension
risks associated with pre-existing hypertension
PET (risk doubled)
Intrauterine growth restriction
Placental abruption
what is pregnancy induced hypertension
hypertension that occurs in pregnancy - usually in the second half of pregnancy
most commonly resolves within 6 weeks of birth
better outcomes than pre-eclampsia
15% progress to PET - depends on gestation (earlier diagnosed more likely to progress to PET)
recurrence is common in other pregnancies
what is pre-eclampsia
Hypertension
Proteinuria (>0.3g/l or >0.3g in 24 hours)
Oedema
Absence does not exclude the diagnosis
what causes pre-eclampsia
diffuse vascular endothelial dysfunction
widespread circulatory disturbance
affects all organs in the mother and can also affect the baby
what is early pre-eclampsia
pre-eclampsia <34 weeks
uncommon
associated with placental pathology
higher risk of adverse maternal and fetal outcomes
what is late pre-eclampsia >34 weeks
minimal placental disease
maternal factors more common cause (eg. previous hypertension, metabolic syndrome)
what is the pathogenesis behind pre-eclampsia
genetic/environmental predisposition
stage 1- abnormal placental perfusion - placental ischameia
stage 2 - maternal syndrome - an anti-angiogenic state associated with endothelial dysfunction
what systems are involved in pre-eclampsia
CNS Renal Hepatic Haematological Pulmonary Cardiovascular Placental
what liver disease is caused by pre-eclampsia
Epigastric/ RUQ pain
Abnormal liver enzymes
Hepatic capsule rupture
HELLP syndromes,e
Haemoloysis
Elevated liver enzymes
Low platelets
what does placental disease cause
Fetal growth restriction
Placental abruption
Intrauterine death
symptoms of pre-eclampsia
headache visual disturbance epigastric/RUQ pain Nausea/vomiting Rapidly progressive oedema
considerable variation in timing, progression and order of symptoms
Signs of pre-eclampsia
Hypertension Proteinuria Oedema Abdominal tenderness Disorientation Small for gestational age deus Intrauterine fetal death Hyper-reflexia/involuntary movements/clonus
Investigations for pre-eclampsia
Urea and electrolytes Serum urate (usually rises in PET) Liver function tests (look for HELLP) Full blood count Coagulation screen Urine-protein creatinine ratio Cardiotocography Ultrasound for dental assessment
management of hypertension in pregnancy
Asses risk at booking If hypertension <20 weeks- look for secondary cause Antenatal screening - BP, urine Treat hypertension Maternal and fetal surveillance Timing of delivery
what are risk factors for pre-eclampsia
age >40 BMI >30 (doubles risk) Family history Parity (first pregnancy 2-3x increased risk) Multiple pregnancy Previous Pre-eclampsia Birth interval >10 years (doubles risk) Molar pregnancy/triploidy Multiparous women develop more severe disease
medical risk factors for pre-eclampsia
pre-existing renal disease pre-existing hypertension diabetes connective tissue disease thrombophilias (congenital or acquired (antiphospholipid syndrome))
how do you minimise the risk of risk factors for the mother
Low Dose Aspirin
-inhibits cyclo-ocygenase on the prostaglandin pathway and prevents TCA2 synthesis
therefore prevents thrombosis in the placenta
15% reduction in risk of pre-eclampsia and prevents most severe forms of disease
what dose of aspirin do you give mothers at increased risk
150mg dose
what change happens in the uterine artery vessels in pregnancy
they change from high resistance vessels to low resistance vessels
monitored by Maternal Uterine Artery Doppler
what is a normal maternal uterine artery doppler
very low resistance
if high resistance wave form (notch) it implies high resistance in the placenta and the vessels haven’t changed in the way you would expect
highly increases risk of pre-eclampsia - need to increase monitoring
what is the criteria to determine when do refer someone to the daycare unit for investigations
BP >140/90
++ proteinuria
Increased oedema
symptoms - esp persistent headache
criteria to admit the mother
BP >170/110 or >140/90 with ++ proteinuria
significant symptoms
abnormal biochemistry
significant proteinuria >300mg/24h
need for antihypertensive therapy
signs of fetal compromise
how are the women managed as an in patient with pre-eclampsia
4 hourly blood pressure
urinalysis - daily
input/output fluid balance chart
urine PCR - if proteinuria on urinalysis
Bloods - FBS, U&Es, Urate, LFTs - minimum X2 per week
how do you treat hypertension if patient is an inpatient
need to lower to 140-150/90-100, significant drop can harm the baby
Methyldopa - alpha agonist
Labetolol - alpha and beta agonist
when would you use doxazocin
if women resistant to other forms of antihypertensive treatment
only one not safe to use in breast feeding
how do you survey the health of the fetus if the mother has hypertension
Reduced fetal movements
CTG - daily if inpatient
Ultrasound - look for placental disease
- look at size
- amniotic fluid index (marker of fetal renal function)
- umbilical artery doppler (look at resistance in the placenta on the baby side not the maternal)
what do you see on a umbilical artery doppler
resistance of umbilical artery
normal
AEDF - absence of end diastolic volume
REDF - reversal of end diastolic volume (blood starts going back towards baby because resistance is so high)
how soon after diagnosis do most mothers with pre-eclampsia give birth
2 weeks
need to give steroids if preterm - up to 36 weeks
what are crises in eclampsia - also a reason for delivery
eclampsia HELLP syndrome Pulmonary oedema Placental abruption Cerebral haemorrhage Cortical blindness DIC Acute renal failure Hepatic rupture
what is Eclampsia
Tonic-clonic seizure occurring with features of pre-eclampsia
endothelial dysfunction in the cerebral circulation
most common in teenagers
how do you manage eclampsia
control BP
Stop/prevent seizures
Fluid balance
Delivery
what hypertensives are used in life threatening eclampsia
IV labetolol
IV hydralazine
be careful not to cause hypotension because it causes fetal distress
how do you treat seizures in eclampsia
Magnesium Sulphage
4gIV over 5 mins loading dose
1g/ hour IV infusion maintancence dose
if another seizure - give 2g
if persistent seizures consider diazepam 10mg IV
how do you manage eclampsia in birth
aim for vaginal delivery control BP epidural continuous electronic fetal monitoring avoid ergometrine caution with IV fluids
how do you manage hypertension postpartum
breast feeding contraception BP management counselling manage future risk consider long term CVS risk
