HTN in pregnancy Flashcards
high risk groups for pre-eclampsia?
hypertensive disease in a previous pregnancy
chronic HTN
type 1 or 2 DM
CKD
AI disorders e.g. SLE and antiphospholipid syndrome
NICE guidance for medication in pregnant women who are deemed high risk of pre-eclampsia?
aspirin 75mg OD from 12 weeks until birth of the baby
define chronic HTN in pregnancy?
HTN present at booking visit or before 20 weeks or already taking antihypertensivie medication before r/f to maternity services.
can be primary or secondary
what is eclampsia?
convulsive condition associated with pre-eclampsia
can explain convulsions during pregnancy, labour or up to 7 days post partum, that are not caused by epilepsy or another neurological disorder.
44% of seizures occur postnatally
what is gestational HTN?
new HTN presenting after 20 wks without significant proteinuria
symptoms patients should be made aware of to seek immediate medical advice as symptoms of pre-eclampsia?
severe headache
visual problems-blurring, flashing before eyes
severe abdo pain just below ribs-*liver subcapsular haematomas
vomiting
sudden swelling of face, hands or feet
normal variation of BP with gestation?
BP decreases until after 20 weeks gestation when there is a slow increase in BP which does not reach hypertensive levels
occurs due to physiological vasodilatory effect of pregnancy-progesterone causes smooth muscle relaxation hence vasodilation that reduces TPR, which is reduced to a greater extent than the increase in CO. Increase in blood volume and CO then exceeds decrease in TPR in later pregnancy to allow the slow rise in BP back to the patient’s norm.
pathogenesis of pre-eclampsia?
failure of trophoblast to invade maternal spiral arterioles means that they retain their smooth muscle and so inability to create a low resistance circulation through arterial dilation. There is reduction in endothelial vasodilators e.g. PGI2 and NO, and maternal plasma volume fails to expand. Endothelial damage causes inflammation and activation and impairment of the coagulation system that can lead to DIC, and systemic effects including fibrin deposition in hepatic sinusoids and thrombosis and fibrinoid necrosis of cerebral arterioles.
endothelial damage also causes oxidative stress
what defines HTN in pregnancy?
BP of 140/90 or higher on 2 occasions more than 4hr apart or single diastolic reading of greater than 110.
or increase in systolic from booking by 30 or more, or diastolic by 15 or more
gold standard measurement technique for proteinuria in pregnancy?
24 hr urine collection
but acceptable 1st line investigation=PCR-30mg/mmol or more should prompt a 24hr urine collection.
what result is abnormal for proteinuria on 24hr urine collection?
300mg or more in 24hrs
what proportion of patients with pre-eclampsia will develop eclampsia?
2%
fetal complications of pre-eclampsia?
fetal death, still birth-HTN and/or proteinuria=highest single RF for stillbirth (20% of cases), stillbirth complicates 7% of cases
fetal growth restriction
those resulting from necessary intervention: prematurity
cerebral haemorrhage
pneumothorax
ventilation
related to both the disease and intervention: cerebral palsy
what preventative medication for eclampsia is given?
magnesium sulfate
define severe pre-eclampsia?
diastolic BP of at least 110 or systolic of at least 160 and/or symptoms and/or biochemical and/or haematological impairment.
biochemical derangement may include raised LFTs, raised urate (breakdown product of purines)-due to reduced renal perfusion or increased production by poorly perfused tissue, raised U+Es
RFs that put a women at moderate risk of developing pre-eclampsia?
age 40 or over 1st pregnancy more than 10 years since last pregnancy multiple pregnancy FH of pre-eclampsia BMI 35 or more at presentation
note smoking reduces the risk-been found that heme oxygenase 1 and its metabolite CO have a protective role.
NICE guidance on pharmacological management of women with moderate risk of pre-eclampsia?
if more than 1 moderate RF take aspirin 75mg OD from 12 weeks of pregnancy and continue until birth.
define pre-eclampsia
new onset HTN in pregnancy after 20 wks, with BP greater than 140/90 and proteinuria (more than 300mg/24hr), multisystem disorder in the 2nd half of pregnancy which resolves after delivery (post placenta delivery) (although can persist up to 3 wks afterwards, perisistence post partum most likely up to 7days).
can be just HTN or proteinuria, but with other features.
NICE definition=new onset HTN in pregnancy after 20 weeks with significant proteinuria
maternal complications of pre-eclampsia?
intracranial haemorrhage and cortical blindness-?secondary to fibrinoid necrosis, MAP 125mmHg
renal tubular and cortical necrosis
pulmonary oedema-reduced plasma protein and capillary leakage
liver-subcapsular haematomas, hepatic rupture, HELLP syndrome-haemolysis, elevated LFTs and low PLT
microangipathic haemolysis, DIC-increased risk with placental abruption (placenta partially or completely separates from uterus before birth)
placental infarction
signs on examination of patient with pre-eclampsia?
hyperreflexia
clonus
oedema
epigastric tenderness
what measurement is indicative of fetal risk in pre-eclampsia?
proteinuria
so fetal growth must be monitored when proteinuria is present in pregnancy even if maternal BP us normal
indications for admission to hospital in pre-eclampsia?
BP persistent over 170/110
or
persistent over 140/90 plus proteinuria or significant symptoms
how is risk to fetus in pre-eclampsia assessed?
fetal movements
CTG-cardiotocography-montior fetal heart and uterine contractions
umbilical doppler
US-fetal size, liquor (AF) volume
management principles for admitted pt with pre-eclampsia?
-minimum 4hrly monitoring
-eclampsia prevention-Mg sulfate-IV Mg sulfate loading dose 4g over 5min, followed by infusion of 1g/hr maintained for 24hrs, is indicated for severe pre-eclampsia in critical care setting if birth is planned within 24hr. severe pre-eclampsia= severe HTN and proteinuria OR mild/mod HTN and proteinuria with 1 or more symptoms-severe headache, visual disturbance, severe upper abdo pain, liver tenderness, papilloedema, 3 or more beats of clonus, HELLP syndrome, falling PLTs to below 100, abnormal liver enzymes-ALT/AST rising to above 70.
aim to prolong pregnancy if baby well on admission and mother is stable.
link between good BP control in pregnancy and pre-eclampsia?
using anti-hypertensives reduce risk of intracranial haemorrhage but uncertainty as to whether can prevent or delay progression to pre-eclampsia.
factors assessed for maternal risk in pre-eclampsia?
BP-systolic for maternal morbidity and diastolic for pre-eclampsia proteinuria-fetal risk PLT count urate LFTs coagulation
what diseases are women at risk of in later life after having pre-eclampsia?
CVD
HTN
options for prevention of pre-eclampsia?
identification and appropriate action for those with RFs at booking visit
early recognition and appropriate action for those with symptoms and signs of pre-eclampsia
low dose aspirin for those at high risk of with 2 or more moderate RFs
calcium supplementation for those at high risk of who have low dietary intake-reduced relative risk of pre-eclampsia but no effect on stillbirth or neonatal death
why do we NOT want to use diuretics in treatment of HTN in pregnancy?
as will reduce plasma volume necessary for adqeuate blood flow to the placenta for good nutrient and O2 supply to fetus, and plasma volume already reduced by leaky capillaries-mediated by endothelial damage resulting from factors released into the blood as a result of hypoxia.
what should women with chronic HTN be advised with regards to BP treatment with ACEIs and AngII RBs in pregnancy?
alternative antihypertensive medication should be discussed with them as these drugs increase the risk of congenital abnormalities.
if non-essential HTN, should be r/f to specialist in hypertensive disorders
BP value aim for patients with chronic HTN in pregnancy?
less than 150/100
or if end organ damage e.g. CKD, then less than 140/90
considerations for timing of birth in women with chronic HTN?
do not offer birth before 37 weeks in those with BP lower than 160/110 with/without antihypertensive tment
after 37wks, timing should be agreed between mother and senior obstetrician.
if methyldopa has been given for BP control in pregnancy, when should it be stopped?
within 2 days of the birth due to risk of postnatal depression
if used for chronic HTN treatment then restart the antihypertensive tment she was on before the pregnancy
other chronic HTN patients receiving tment during preg-continue antenatal tment after birth then r/v long term antihypertensive tment 2wks after the birth.
management of a pt with mild gestational HTN (BP 140/90 to 149/99)?
no requirement for hospital admission or tment
BP should be measured no more than once weekly
test for proteinuria at each visit
only blood tests for routine antenatal care should be performed.
BP and urine twice weekly check if less than 32 weeks or at high risk of pre-eclampsia
management of a pt with moderate gestational HTN (BP 150/100 to 159/109)?
no need for hosp admission
treat high BP- oral labetalol 1st line (mixed alpha and beta blocker), aim for diastolic 80-100 and systolic less than 150
BP check at least twice a week
proteinuria check
U+Es, creatinine, FBC, LFTs
no further blood tests if no proteinuria at subsequent visits
management of a pt with severe gestational HTN (BP 160/110 or higher)?
admit to hospital-until BP 159/109 or lower
oral labetalol-aim for diastolic BP 80-100 and systolic less than 150
measure BP at least 4 times a day
test for proteinuria
blood tests at px and then monitor weekly-U+Es, creatinine, FBC, LFTs
alternative antihypertensives in pregnancy to labetalol?
methydopa
nifedipine
ADRs of labetalol?
bradycardia cold extremities raynauds exacerbation headache heart failure hyper or hypoglycaemia sleep disturbances with nightmares
timing of birth considerations for women with gestational HTN?
birth should not be offered before 37wks to those with BP less than 160/110 with or without antihypertensive treatment
after 37weeks, decision regarding fetal and maternal risk and discussion between mother and senior obstetrician
management of a pt with pre-eclampsia with mild HTN (140-149/90-99)
- admit to hospital
- minimum 4hrly BP
- twice weekly blood tests-FBC, U+Es, LFTs-transaminases and bilirubin
- no need for anti-hypertensive
management of pt with pre-eclampsia with moderate (150-159/100-109) or severe (160/110 or above) HTN?
- admit pt
- treat BP-oral labetalol-aim systolic less than 150 and diastolic 80-100
- BP at least 4X day if moderate, more than 4X if severe
- bloods 3 times a week-FBC, U+Es, LFTs
how should pregnancy be managed in terms of delivery for women with pre-eclampsia?
- conservative management until 34wks, offer birth before 34wks after steroid course and d/c with neonatal and anaesthetic teams if severe HTN develops refractory to tment, or maternal or fetal indications develop as specified in the consultant obstetrician plan.
- birth recommended after 34wks if severe HTN when BP has been controlled and corticosteroid course completed.
- offer birth to those with mild or mod HTN at 34+0 to 36+6 weeks depending on maternal and fetal condition, RFs and availability of neonatal intensive care.
- recommend birth within 24-48hr for those with mild or moderate HTN after 37+0 weeks. Labour may need inducing.
BP monitoring after birth for women with pre-eclampsia?
- if weren’t on any antihypertensives during pregnancy, then measure at least 4X a day whilst inpatient, at least once between days 3 and 5, and on alternate days until BP normal if was abnormal on days 3-5. start BP tment if 150/100 or higher.
- if were on antihypertensives, then at least 4X a day whilst inpatient, and every 1-2 days for up to 2wks once transferred to community care until woman off tment and has no HTN.
ensure all women have a medial review at the postnatal review (6-8wks after birth). here also do urinary reagent strip test.
if mild or moderate HTN, or after step down from critical care, measure PLTs, transaminases and serum creatinine 48-72hrs after birth or step down.
fetal monitoring if chronic HTN, or mild-mod gestational HTN?
- chronic HTN-offer US assess fetal size, and amniotic fluid volume, plus umbilical artery doppler at 28-30wks and 32-34wks. CTG only if fetal activity abnormal.
- mild-mod gest HTN-US and umbilical artery doppler only if diagnosis before 34 wks. CTG only if fetal activity abnormal.
fetal monitoring if pre-eclampsia or severe gestational HTN?
- CTG at diagnosis
- if conservative tx, do US and umbilical artery doppler at diagnosis
- CTG rpt not more than once weekly if all results normal
- rpt CTG if abnormal fetal movements, PV bleeding, abdo pain or deterioration in maternal condition.
- US and umbilical artery not more than every 2 wks
- if any fetal monitoring abnormal tell consultant obstetrician.
US and umbilical artery doppler montoring for women at high risk of pre-eclampsia?
offer between 28 and 30wks, and rpt 4 weeks later if:
severe pre-eclampsia in prev pregnancy
pre-eclampsia that needed birth before 34wks
pre-eclampsia with baby whose birth weight was less than 10th centile
intrauterine death
placental abruption
when should operative delivery be offered in 2nd stage of labour when hypertensive pregnancy disorder?
severe HTN which has not responded to initial tment
tment of recurrent eclamptic seizures?
further dose of IV magnesium sulfate 2-4g over 5mins
corticosteroids in pre-eclampsia?
if birth considered likely within 7 days:
give 2 doses of betamethasone IM 12mg 24hrs apart if between 24-34wks, consider if between 35-36 wks, for fetal lung maturation.
antihypertensive drugs for BP control in those who are in critical care with severe HTN after birth?
1 of:
labetalol-PO or IV
hydralazine-IV-consider volume expansion
nifedipine-PO
risk of pre-eclampsia in future pregnancy after having it in current pregnancy?
1 in 6
if was severe pre-eclampsia or eclampsia, then risk 1 in 2 if baby needed to be born before 28wks, and 1 in 4 if baby needed to be born before 34weeks.
will be advised to take aspirin in future pregnancies from 12 weeks, 75mg OD, to prevent it.
indications in pre-eclampsia for delivery NOW?
-worsening thrombocytopenia or coagulopathy -worsening LFTs/Renal function -severe maternal symptoms -HELLP syndrome -eclampsia -abnormal CTG -reverse umbilical artery end diastolic flow
