Hypertension_in_Pregnancy_Flashcards
How does blood pressure typically change during a normal pregnancy?
In a normal pregnancy, blood pressure usually falls in the first trimester and continues to fall until 20-24 weeks, then increases back to pre-pregnancy levels by term.
What are NICE recommendations for reducing the risk of hypertensive disorders in pregnancy?
NICE recommends that women at high risk of developing pre-eclampsia should take 75mg of aspirin daily from 12 weeks until the birth of the baby.
How is hypertension defined in pregnancy?
Hypertension in pregnancy is defined as systolic > 140 mmHg or diastolic > 90 mmHg, or an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic.
What is pre-existing hypertension in pregnancy?
Pre-existing hypertension is hypertension noted before pregnancy or a blood pressure > 140/90 mmHg before 20 weeks gestation, without proteinuria or oedema.
What is pregnancy-induced hypertension?
Pregnancy-induced hypertension, or gestational hypertension, occurs after 20 weeks gestation without proteinuria or oedema, and typically resolves after birth.
What is pre-eclampsia and how is it diagnosed?
Pre-eclampsia is pregnancy-induced hypertension in association with proteinuria (> 0.3g/24 hours). Oedema may occur but is no longer a primary criterion for diagnosis.
What are the management options for hypertension in pregnancy?
Management includes oral labetalol as the first-line treatment, with alternatives like nifedipine and hydralazine depending on individual circumstances such as asthma.
summarise
Hypertension in pregnancy
It’s useful to remember that in normal pregnancy:
blood pressure usually falls in the first trimester (particularly the diastolic), and continues to fall until 20-24 weeks
after this time the blood pressure usually increases to pre-pregnancy levels by term
NICE published guidance in 2010 on the management of hypertension in pregnancy. They also made recommendations on reducing the risk of hypertensive disorders developing in the first place. Women who are at high risk of developing pre-eclampsia should take aspirin 75mg od from 12 weeks until the birth of the baby.
Hypertension in pregnancy in usually 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 the patient is hypertensive they should be categorised into one of the following groups
- Pre-existing hypertension
A history of hypertension before pregnancy or an elevated blood pressure > 140/90 mmHg before 20 weeks gestation
No proteinuria, no oedema
Occurs in 3-5% of pregnancies and is more common in older women
If a pregnant woman takes an ACE inhibitor or angiotensin II receptor blocker (ARB) for pre-existing hypertension this should be stopped immediately and alternative antihypertensives started (e.g. labetalol) whilst awaiting specialist review
- Pregnancy-induced hypertension
(PIH, also known as gestational hypertension)
Hypertension (as defined above) occurring in the second half of pregnancy (i.e. after 20 weeks)
No proteinuria, no oedema
Occurs in around 5-7% of pregnancies
Resolves following birth (typically after one month). Women with PIH are at increased risk of future pre-eclampsia or hypertension later in life
- Pre-eclampsia
Pregnancy-induced hypertension in association with proteinuria (> 0.3g / 24 hours)
Oedema may occur but is now less commonly used as a criteria
Occurs in around 5% of pregnancies
Management
oral labetalol is now first-line following the 2010 NICE guidelines
oral nifedipine (e.g. if asthmatic) and hydralazine
A 32-year-old primigravida presents to the antenatal clinic for her booking appointment at 8 weeks gestation. She reports that she has been taking ramipril for the past 6 months to control her blood pressure. She has a past medical history of asthma for which she uses a salbutamol inhaler occasionally. On examination, her blood pressure is 154/92 mmHg. You advise that the ramipril should be stopped immediately and alternative antihypertensives should be started, whilst awaiting specialist review.
What is the most appropriate antihypertensive medication to switch this patient onto?
Labetalol
Lisinopril
Losartan
Nifedipine
Spironolactone
Nifedipine
If a pregnant woman takes an ACE inhibitor or angiotensin II receptor blocker (ARB) for pre-existing hypertension this should be stopped immediately and alternative antihypertensives started (e.g. labetalol) whilst awaiting specialist review
Important for meLess important
If a pregnant woman takes an angiotensin-converting-enzyme (ACE) inhibitor such as ramipril, this should be immediately stopped and replaced with a suitable alternative antihypertensive such as labetalol or nifedipine whilst awaiting specialist review.
Labetalol is a beta-blocker licensed as safe for use as an antihypertensive during pregnancy. However, the woman in this scenario has a past medical history of asthma, and thus the use of beta-blockers are contraindicated due to the risk of bronchospasm. Labetalol use with a history of asthma can worsen the symptoms of asthma. Therefore, it is recommended that this woman is switched onto nifedipine, a calcium-channel blocker instead.
Nifedipine is a calcium channel blocker which is licensed for use during pregnancy to control hypertension. It is recommended to be used to control blood pressure during pregnancy when beta blockers, such as labetalol, are contraindicated. Here, the patient has a medical history of asthma, so nifedipine is preferred over labetalol.
Lisinopril is an ACE inhibitor and thus is not recommended during pregnancy due to risks of foetal malformations and renal failure.
Losartan is an angiotensin II receptor blocker (ARB) and is contraindicated in pregnancy as it can cause reduced blood flow to the foetus, and result in foetal growth restriction and death.
Spironolactone is a potassium-sparing diuretic that works as an aldosterone receptor antagonist. Spironolactone is not recommended as the first-line treatment for hypertension in pregnancy due to the risks of causing feminisation of the male foetus.
A 28-year-old pregnant woman is seen at her booking appointment. Her obstetric history revealed she had pre-eclampsia in her last pregnancy. Which of the following medications should this patient be started on at 12-14 weeks gestation to reduce the risk of intrauterine growth retardation?
Low dose labetalol
Low dose methyldopa
Low molecular weight heparin
Low dose aspirin
Unfractionated heparin
Low dose aspirin
The following question tests the understanding of secondary prevention of women with pre-eclampsia. There is A level data showing that low-dose aspirin started at 12-14 weeks’ gestation is more effective than placebo at reducing occurrence of pre-eclampsia in women at high risk, reducing perinatal mortality and reducing the risk of babies being born small for gestational age . There is some evidence that low molecular weight heparin might reduce the placental insufficiency seen in pre-eclampsia, but long-term safety studies are not yet available. Labetalol and methyldopa are both common antihypertensive drugs used in the acute management of pre-eclampsia, however are not given prophylactically and do not reduce intrauterine growth retardation. Similarly to LMWH, unfractionated heparin has not been proven to prevent the development uteroplacental insufficiency.
A 24-year-old female who is 10 weeks in to her first pregnancy presents for review. Her blood pressure today is 126/82 mmHg. What normally happens to blood pressure during pregnancy?
- Falls in first half of pregnancy before rising to pre-pregnancy levels before term
- Systolic + diastolic rises by < 10 mmHg
- Systolic + diastolic falls by < 10 mmHg
- Rise in first half of pregnancy before falling to pre-pregnancy levels before term
- Doesn’t change
Falls in first half of pregnancy before rising to pre-pregnancy levels before term
The correct answer is: Falls in first half of pregnancy before rising to pre-pregnancy levels before term. During a healthy pregnancy, blood pressure will typically fall during the first half of pregnancy due to systemic vasodilation and increased blood volume. The systolic pressure tends to drop by 5-10 mmHg and the diastolic by as much as 10-15 mmHg. This decrease reaches its nadir between the mid-second and early third trimester, after which it gradually rises back towards baseline prepregnancy levels just before term.
The option Systolic + diastolic rises by < 10 mmHg is incorrect because while there may be slight fluctuations in blood pressure throughout pregnancy, a consistent rise in both systolic and diastolic pressures would not be considered normal. It could potentially indicate a hypertensive disorder of pregnancy such as gestational hypertension or preeclampsia.
Similarly, the option Systolic + diastolic falls by < 10 mmHg is also incorrect. While it’s true that both systolic and diastolic pressures can fall during pregnancy, this statement does not account for the fact that these pressures should return to pre-pregnancy levels before term.
The statement Rise in first half of pregnancy before falling to pre-pregnancy levels before term is incorrect because it suggests an initial rise in blood pressure which contradicts with our understanding of physiological changes during early pregnancy where systemic vasodilation leads to a decrease in blood pressure.
Lastly, the idea that blood pressure Doesn’t change during pregnancy is also incorrect. Pregnancy induces several physiological changes including those related to the cardiovascular system resulting in fluctuation of blood pressure as discussed above.
A 34-year-old primiparous woman is 33+6 weeks pregnant. During a recent antenatal visit she had a blood pressure of 152/101 mmHg. She reports some swelling of her hands and feet but no other symptoms. Urinalysis is negative for protein. She has a past history of asthma for which she uses a salbutamol inhaler PRN and depression but she stopped her antidepressant medication when she became pregnant. What is the best management?
Oral methyldopa
IV magnesium sulphate
Oral labetalol
Oral lisinopril
Oral nifedipine
Oral nifedipine
Gestational hypertension is new onset hypertension diagnosed after 20 weeks without significant proteinuria. This woman has moderate gestational hypertension as her systolic blood pressure is between 150-159 mmHg and her diastolic blood pressure is between 100-109 mmHg.
Hypertension Systolic Diastolic
Mild 140-149 mmHg 90-99 mmHg
Moderate 150-159 mmHg 100-109 mmHg
Severe >160 mmHg >110 mmHg
Moderate gestational hypertension does not need to be managed in a hospital setting and patients are normally prescribed oral labetalol. This woman has a history of asthma so a beta blocker is contraindicated. NICE guidelines recommend nifedipine and methyldopa as alternatives to labetalol. Methyldopa is contraindicated in depression. The best option for treatment for this woman’s gestational hypertension is oral nifedipine which is a calcium channel blocker.
IV magnesium sulphate is indicated in eclampsia. Lisinopril is an ACE inhibitor and is contraindicated in pregnancy.
A 36-year-old woman contacts her GP for advice about her medication, having recently discovered that she is 4 weeks pregnant. She has a history of essential hypertension and takes losartan 50mg once daily.
The woman is feeling well in herself and has no other medical history. She takes no other medications and has no allergies.
On examination today, her blood pressure is 130/80mmHg.
Given her medical history, the GP refers the woman for consultant-led obstetric care.
How should her medication be managed today?
Continue losartan
Stop losartan
Stop losartan and start labetalol
Stop losartan and start methyldopa
Stop losartan and start nifedipine
Stop losartan and start labetalol
If a pregnant woman takes an ACE inhibitor or angiotensin II receptor blocker (ARB) for pre-existing hypertension this should be stopped immediately and alternative antihypertensives started (e.g. labetalol) whilst awaiting specialist review
Stopping losartan and starting labetalol is correct. Pregnant women with pre-existing hypertension are at high risk of developing pre-eclampsia, and their care should be consultant-led. If they are taking an ACE inhibitor or an angiotensin II receptor blocker (such as losartan), this should be stopped immediately, as both affect foetal and neonatal blood pressure control and renal function. In most cases, an alternative antihypertensive should be started whilst the woman awaits specialist review. This may not be necessary in specific patients such as those who are symptomatic of hypotension. Labetalol is the first-line treatment for hypertension in pregnancy.
Continuing losartan is incorrect. Angiotensin II receptor blockers should be stopped in pregnancy. Their use may adversely affect foetal and neonatal blood pressure control and renal function. They have also been associated with foetal malformations such as skull defects.
Stopping losartan alone is incorrect as a new agent is needed to control this woman’s blood pressure given the risk of pre-eclampsia.
Stopping losartan and starting methyldopa is not correct. Methyldopa is used as a third-line agent if both labetalol and nifedipine are not appropriate.
Stopping losartan and starting nifedipine is incorrect. Nifedipine is used as a second-line agent if labetalol is not appropriate.
A 32-year-old comes to the GP following a positive pregnancy test. Her last menstrual period was 7 weeks ago. This is the first time she has been pregnant. You review her medical and family history and her concerns. She has systemic lupus erythematosus (SLE) and asthma. You counsel her about vitamin D and folic acid supplements and ask her to arrange a booking appointment with the midwife.
What other advice listed below would be appropriate to provide?
No further actions required
To stop taking corticosteroid inhaler for duration of pregnancy
To take low-dose aspirin from 12 weeks to term of pregnancy
To take low-dose aspirin from now until term of pregnancy
To take prophylactic dose low-molecular-weight heparin (LMWH) from 36 weeks of pregnancy
To take low-dose aspirin from 12 weeks to term of pregnancy
Women with autoimmune conditions such as SLE or antiphospholipid syndrome are at high risk of pre-eclampsia (and should receive 75 mg of aspirin daily)
This patient is at high risk of pre-eclampsia due to the presence of SLE (and additional risk in first pregnancy), and therefore she should be advised to take 75mg aspirin from 12 weeks to the term of pregnancy. A referral to the obstetric medicine team may also be appropriate for closer monitoring of the pregnancy. Low-dose aspirin (75-150mg) is advised from the start of the second trimester until the delivery of the baby.
No further actions required is incorrect. This patient has an autoimmune disease which puts her at high risk of pre-eclampsia and therefore she should be prescribed low-dose aspirin from 12 weeks of pregnancy through to delivery of the baby.
To stop taking corticosteroid inhaler for duration of pregnancy is incorrect. Asthma inhalers, including corticosteroid preventer inhalers, are safe to take in pregnancy and should be continued. Stopping these puts the patient at risk of asthma complications.
To take low-dose aspirin from now until term of pregnancy is incorrect. She has SLE and is therefore at high risk of pre-eclampsia however aspirin therapy would be indicated from 12 weeks. A referral to obstetric medicine would be appropriate in addition.
To take prophylactic dose low-molecular-weight heparin from 36 weeks of pregnancy is incorrect. Whilst this patient is likely at risk for venous thromboembolism (VTE) in pregnancy due to SLE, treatment would be started immediately or from 28 weeks gestation (rather than 36 weeks). The information to calculate VTE risk is not all provided in the stem and a more comprehensive risk assessment would be necessary. Whilst this patient is at intermediate risk for venous thromboembolism (VTE) in pregnancy due to SLE, the decision to initiate LMWH therapy should be made by the obstetric team. A referral to obstetric medicine would therefore be appropriate.
You review a 34-year-old woman who is 13 weeks pregnant. During her previous pregnancy she developed pre-eclampsia and had to have a caesarean section at 36 weeks gestation. Her blood pressure both following the last pregnancy and today is normal. Which one of the following interventions should be offered to reduce the risk of developing pre-eclampsia again?
Prophylactic nifedipine therapy
Prophylactic labatelol therapy
Vitamin B6 supplementation
Extended folic acid supplementation
Low-dose aspirin
The correct answer is low-dose aspirin. Low-dose aspirin (75-150 mg daily) has been shown to reduce the risk of developing pre-eclampsia in women at high risk, such as those with a history of pre-eclampsia in a previous pregnancy. According to the UK National Institute for Health and Care Excellence (NICE) guidelines, low-dose aspirin should be offered from 12 weeks gestation until the birth of the baby for women at high risk of developing pre-eclampsia.
Prophylactic nifedipine therapy and prophylactic labetalol therapy are not recommended for preventing pre-eclampsia. Nifedipine and labetalol are both antihypertensive medications that can be used to manage hypertension during pregnancy, but they have not been proven effective in reducing the risk of pre-eclampsia when used prophylactically.
Vitamin B6 supplementation has not been demonstrated to prevent pre-eclampsia either. Vitamin B6 is sometimes recommended for managing nausea and vomiting during pregnancy, but it does not have a role in preventing pre-eclampsia.
Finally, extended folic acid supplementation is not indicated for reducing the risk of pre-eclampsia. Folic acid supplementation is important during early pregnancy to reduce the risk of neural tube defects, but it does not have an established role in preventing pre-eclampsia. In the UK, folic acid supplementation is recommended until 12 weeks gestation.
