Maternal Medicine - Hypertensive disease in pregnancy Flashcards
What is the International Society of Hypertension in Pregnancy definition of pre-eclampsia?
Gestational hypertension of at least 140/90 mmHg on two separate occasions ≥4 hours apart accompanied by significant proteinuria of at least 300 mg in a 24-hour collection of urine, arising de novo after the 20th week of gestation in a previously normotensive woman and resolving completely by the 6th postpartum week.
Pre-eclampsia complicates what percentage of pregnancies?
2-8%
Pre-eclampsia causes what % of direct maternal deaths in the UK?
15%
How many women worldwide die of pre-eclampsia each year according to WHO?
70,000
What is the incidence of eclampsia?
2.5/10,000
What happens to placental growth factor in pregnnacy?
Increases, then decreases
Lower levels seen in pre-eclampsia
How many stillbirths without congenital abnormality occurred in mothers with pre-eclampsia?
5%
How many women in their first pregnancy will give birth below 34/40 as a result of pre-eclampsia?
1 in 250 (0.4%)
How many preterm births are from hypertensive disorders?
8-10%
How many pre-term and term births <10th centile are to women with pre-eclampsia?
20-25% preterm
14-19% term
What are the ‘high risk’ factors for pre-eclampsia?
Hypertensive disease in previous pregnancy CKD Autoimmune disease (e.g. SLE, APS) T1 or T2 diabetes Chronic hypertension
What BP limit should be aimed for in chronic hypertension?
And with evidence of target-organ damage?
150/100 (diastolic not lower than 80)
140/90
When should all women with pre-eclampsia have a medical review postnally?
6-8/52
What is the risk of developing gestational hypertension following a pregnancy complicated by pre-eclampsia?
13-53% (1 in 8 to 1 in 2)
What is the risk of developing PET following a pregnancy complicated by PET?
16% (1 in 6)
What is the risk of developing PET following a pregnancy complicated by severe PET, HELLP or eclampsia leading to birth <34/40?
25%
What is the risk of developing PET following a pregnancy complicated by PET leading to birth <28/40?
55%
What are the moderate risk factors for PET?
First pregnancy Age >40 Pregnancy interval >10 years FHx PET BMI => 35 at booking Multiple pregnancy
When should women with chronic hypertension/gestational hypertension be delivered?
Not before 37/40 if BP < 160/110, with or without antihypertensive treatment
What is the PN follow up for women with chronic hypertension?
BP measurement:
OD first 2/7, at least once D3-5, then as clinically indicated if antihypertensive changed
Review treatment 2/52 after delivery; aim BP <140/90
Review at 6-8/52
How are women with mild gestational hypertension managed?
Not admitted/treated
BP once a week
Test proteinuria each visit
Routine antenatal bloods
If high risk/<32/40 - BP and urine twice weekly
How are women with moderate gestational hypertension managed?
Not admitted Commence labetalol (aim <150/80-100) BP twice weekly Proteinuria test each visit Test bloods - no further unless proteinuria develops
How are women with severe gestational hypertension managed?
Admit until BP =<159/109 Labetalol (aim <150/80-100) BP QDS Daily proteinuria test Bloods at presentation, then weekly
Once discharged - BP and urine twice weekly, blood tests weekly
What is the postnatal follow up for women with gestational hypertension?
BP measurement:
OD first 2/7, at least once D3-5, then as clinically indicated if antihypertensive changed
Consider reducing Rx if <140/90; reduce if <130/80
Start treatment if >149/99
Medical review at 2/52 if still on treatment
Review at 6-8/52 - if still on treatment refer for speciaslist assessment of their hypertension
How are women with mild pre-eclampsia managed?
Admit but don’t treat
BP QDS
Don’t repeat proteinuria test
Twice weeklly bloods
How are women with moderate pre-eclampsia managed?
Admit Commence labetalol (aim <150/80-100) BP QDS Don't repeat proteinuria test Bloods three times a week
How are women with severe pre-eclampsia managed?
Admit Commence labetalol (aim <150/80-100) BP >QDS as indicated Don't repeat proteinuria test Bloods three times a week
When should pregnancies complicated by PET deliver?
Not <34/40 unless severe refractory or maternal/fetal indications
34-36+6 depending on maternal/fetal condition, availability of NICU, risk factors
Within 24-48 hours if mild-moderate >37+0
What is the postnatal follow up for women with pre-eclampsia if not on antihypertensives?
BP measurement:
QDS while inpatient
At least once D3-5, then alternate days if abnormal until normal
Start antihypertensives if BP =>150/100
Medical review 6-8/52
What is the postnatal follow up for women with pre-eclampsia if taking antihypertensives?
Consider reducing Rx if <140/90; reduce if <130/80
Start treatment if >149/99
Transfer to community care if no symptoms, BP<=149/99, bloods stable/improving
Medical review at 2/52 and 6-8/52
When should PET/proteinuria bloods be repeated postnatally?
48-72 hours post delivery - if normal don’t repeat
If abnormal repeat as indicated, and at 6-8/52
Proteinuria - if 1+ at 6-8/52, review kidney function at 3/12 and consider renal referral
What is the ultrasound regime for chronic hypertension?
28-30, then 32-34 - if normal no further USS unless clinically indicated
What is the ultrasound regime for mild-moderate gestational hypertension?
Only if diagnosed <34/40
What is the CTG/ultrasound regime for severe gestational hypertension or pre-eclampsia?
CTG at diagnosis then 2/52 USS
Repeat CTG if change FMs, bleeding, abdo pain, maternal condition detriorates
Which women are high risk for pre-eclampsia and what is the ultrasound regime?
Previous: Severe PET PET needing birth <34/40 PET with SGA <10th centile IUD abruption
Scan 4/52 from 28-30/52 (or 2/52 earlier than previous onset if <28/40)
What is the rate of recurrence in previous gestational hypertension?
16-47% (1 in 6 to 1 in 2)
What is the rate of PET in previous gestational hypertension?
2-7% (1 in 50 to 1 in 14)
Which ACE inhibitors may be used when breastfeeding?
Enalapril (not in prem); captopril if informed consent
Which b-blockers may be used when breastfeeding?
labetalol, atenolol, metoprolol
What should be considered concurrently with 1st dose of IV hydralazine antenatally?
500ml crystalloid
What is the dose of MgSO4?
4g loading dose over 5min followed by 1g/hr over 24hrs
Repeat doses of 2-4g over 5 mins if recurrent seizures
What signs/symptoms indicate severe PET when there is mild/moderate hypertension?
Severe headache Visual disturbance Epigastric pain/vomiting Papilloedema Clonus >=3 Liver tenderness HELLP Plt <100 Abnormal LFTs >70
What % of women who developed PET <32/40 will have an abnormal thrombophilia screen?
30%
Which biochemical markers are altered in pregnancies affected by pre-eclampsia?
Decreased VEGF (proangiogenic factor) Increased sFlt1 (antiangiogenic factor)
What risk factors require that a woman should take aspirin in pregnancy
Major: 1 risk factor requires aspirin:
- Chronic hypertension
- Hypertensive disease in previous pregnancy
- Autoimmune disease eg lupus/ APS
- Diabetes
- Chronic kidney disease
Minor: 2 or more of
- First pregnancy
- Bmi over 35
- Age over 40
- Pregnancy interval over 10 yrs
- FHx pre eclampsia
- Multiple pregnancy
By what % does aspirin reduce the risk of developing PET in women at risk of the condition?
17%
NNT = 19
What are the placental biomarkers implicated in PET?
*PLGF (Placental Like Growth Factor - pro-angiogenic)
*PAPP-A (Pregnancy associated plasma protein)
sFLT-1 (soluble FMS-like tyrosine kinase - antiangiogenic)
sENG (soluble endoglin - antiangiogenic)
What is the NNT with low dose aspirin for women with a moderate risk factor for PET to prevent one case?
119
What is the NNT with MgSO4 in PET to prevent one seizure?
90