Antenatal Care: HTN & Pre-eclampsia Flashcards
In normal pregnancy, how does BP change?
1st trimester: BP usually falls (particularly the diastolic), and continues to fall until 20-24 weeks
After this: BP usually increases to pre-pregnancy levels by term
What is HTN in pregnancy defined as?
Systolic >140 mmHg or diastolic >90 mmHg
OR an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic
After establishing that a pregnant woman is hypertensive, she should be categorised into one of what 3 groups?
1) Pre-existing HTN
2) Pregnancy-induced HTN (gestational HTN)
3) Pre-eclampsia
Women who are at high risk of developing pre-eclampsia should take what?
Aspirin 75mg od from 12 weeks until the birth of the baby.
When should women at risk of pre-eclampsia start taking aspirin?
From 12 weeks until birth
What is pre-existing HTN in pregnancy defined as?
A history of hypertension before pregnancy or an elevated blood pressure > 140/90 mmHg before 20 weeks gestation
Who is pre-existing HTN in pregnancy more common in?
Older women
Is there proteinuria or oedema in pre-existing HTN in pregnancy?
No proteinuria, no oedema
If a woman taking an ACEi or ARB for pre-existing hypertension becomes pregnant, what should happen?
Stopped immediately and alternative antihypertensives started (e.g. labetalol) whilst awaiting specialist review
What is pregnancy-induced (gestational) HTN defined as?
HTN occurring in the second half of pregnancy (i.e. after 20 weeks)
What is cut off point for HTN being defiend as ‘pre-existing’ or ‘pregnancy-induced’?
20 weeks gestation
Is there proteinuria or oedema in pre-existing HTN in pregnancy?
No proteinuria, no oedema
What are women with gestational HTN at risk of?
Increased risk of future pre-eclampsia or hypertension later in life
How does gestational HTN resolve?
Resolves following birth (typically after one month).
What is pre-eclampsia defined as?
Pregnancy-induced hypertension in association with proteinuria (> 0.3g / 24 hours)
Is there proteinuria or oedema in pre-existing HTN in pregnancy?
Proteinuria: yes
Oedema: can occur but is now less commonly used as a criteria
What % of pregnancies does pre-eclampsia affect?
Around 5%
1st line HTN medication in pregnancy?
oral labetalol
If patient is asthmatic, 1st line medication for HTN in pregnancy?
oral nifedipine and hydralazine
What is pre-eclampsia?
Pre-eclampsia refers to new high blood pressure (hypertension) in pregnancy with end-organ dysfunction, notably with proteinuria (protein in the urine).
Key finding in pre-eclampsia?
Proteinuria
At what gestation age does pre-eclampsia occur?
After 20 weeks gestation
Pathophysiology of pre-eclampsia?
It occurs after 20 weeks gestation:
1) the spiral arteries of the placenta form abnormally,
2) this leads to a high vascular resistance in these vessels and poor perfusion of placenta
3) causes oxidative stress in the placenta, and the release of inflammatory chemicals into the systemic circulation
4) systemic inflammation and impaired endothelial function in the blood vessels.
What triad is seen in pre-eclampsia?
1) HTN
2) Proteinuria
3) Oedema
Complications of pre-eclampsia?
Pre-eclampsia is a significant cause of maternal and fetal morbidity and mortality.
- maternal organ damage
- fetal growth restriction
- seizures
- early labour
- death
What is eclampsia?
Eclampsia is when seizures occur as a result of pre-eclampsia.
Pre-eclampsia risk factors are categories into high and moderate risk factors.
What are some high risk factors for pre-eclampsia?
1) Pre-existing HTN
2) Previous HTN in pregnancy
3) Existing autoimmune conditions (e.g. SLE)
4) Diabetes (1 or 2)
5) CKD
What are some moderate risk factors for pre-eclampsia?
1) Age >40y
2) BMI >35
3) >10 years since previous pregnancy
4) Multiple pregnancy
5) First pregnancy
6) FH of pre-eclampsia
These risk factors for pre-eclampsia are used to determine which women are offered aspirin as prophylaxis.
Which women would be offered aspirin?
One high risk factor
OR
More than one moderate risk factor.