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DOI: 10.1111/j.1744-4667.2012.00144.x
2013;15:45–50
Review
The Obstetrician & Gynaecologist
http://onlinetog.org
Management of postpartum hypertension
Marie Smith
a,
MRCOG, *
Jason Waugh
b
MRCOG,
Catherine Nelson-Piercy
FRCP FRCOG
c
a
Senior Clinical Lecturer and Consultant Obstetrician, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne NE1 5WW, UK
Consultant, Obstetrics and Maternal Medicine, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne NE1 5WW, UK
c
Consultant Obstetric Physician, St Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, UK
*Correspondence: Marie Smith. Email: [email protected]
b
Accepted on 2 April 2012
postnatal appointment should be offered to discuss future
pregnancy and cardiovascular risk.
Key content
Appropriate treatment of postnatal hypertension is essential to
prevent maternal morbidity and mortality from cerebral
haemorrhage.
Women with pre-eclampsia remain at risk of serious complications
following delivery and should continue to be monitored as an
inpatient for at least 72 hours.
Compared with the antenatal period, a wider choice of
antihypertensive agents are available to prescribe for the postnatal
patient. An understanding of the basic pharmacology and risk–
benefit profiles of each agent will facilitate patient-centred
prescribing.
Following discharge, the community team should be given clear
guidelines for ongoing management of hypertension. A hospital
Learning objectives
Review postpartum cardiovascular physiology following normal
and hypertensive pregnancies.
Demonstrate the principles of management and a suggested
approach to management of postpartum hypertension based on
NICE guidance.
Discuss antihypertensive agents prescribed for women in the
postpartum period.
Keywords: antihypertensive / drug therapy / pre-eclampsia
Please cite this paper as: Smith M, Waugh J, Nelson-Piercy C. Management of postpartum hypertension. The Obstetrician & Gynaecologist 2013;15:45–50.
Introduction
There is an extensive literature discussing the pathophysiology
and management of hypertension in the antenatal and
intrapartum period, however, comparatively little evidence
to guide clinicians treating postpartum hypertension. Poorly
managed postpartum hypertension frequently causes
unnecessary concern for the patient and her carers, delays
discharge from hospital, and will occasionally place women at
risk of significant complications. This overview seeks to
describe the normal postpartum changes in blood pressure
and then consider which patients should be more closely
monitored and treated. The evidence for different
antihypertensive agents will be considered along with the
associated implications for the mother and her new baby.
of patients will have a recorded diastolic pressure greater
than 100 mmHg. This is due to the resolution of the
cardiovascular adaptations to pregnancy, in particular,
mobilisation of fluid accumulated in the extra vascular
space during pregnancy.
A third of women who have had pregnancy
induced hypertension or pre-eclampsia will have sustained
hypertension in the postnatal period although they are
commonly normotensive in the early postpartum period,
possibly reflecting depleted intravascular volumes following
labour. Women particularly at risk of postnatal hypertension
are shown in Table 1. The largest group of women with
postpartum hypertension are those who have developed
hypertension in the antenatal period, however it is
Table 1. Risk factors for developing postnatal hypertension.
Blood pressure and pre-eclampsia in the
puerperium
Following uncomplicated pregnancy most women will
experience increased blood pressure during the postpartum
period such that systolic and diastolic measurements are
increased by an average of 6 mmHg and 4 mmHg,
respectively, over the first 4 days.1 Furthermore, up to 12%
ª 2013 Royal College of Obstetricians and Gynaecologists
Women at risk of developing postnatal hypertension
Preterm delivery triggered by maternal hypertensive disease
Hypertension requiring antenatal treatment
Severe antenatal hypertension (>160/100 mmHg)
Antenatal pre-eclampsia (proteinuric hypertension)
>75%
↑
33%
45
Management of postpartum hypertension
acknowledged that hypertension can occur de novo
following delivery.
Matthys et al.2 described the outcomes of 151 women
readmitted in the postnatal period (up to day 24) who
received a diagnosis of pre-eclampsia. The incidence of
complications was high: 16% eclampsia, 9% pulmonary
oedema and one maternal death. Smaller retrospective
studies3,4 indicate that women who develop postpartum
severe pre-eclampsia or eclampsia after being normotensive
at delivery are more likely to report headaches and nausea
than patients with intrapartum eclampsia. Similarly, Chames
et al.5 found that of 29 women presenting with postpartum
eclampsia, almost all reported at least one prodromal
symptom. In this study 23 (79%) patients had seizures after
48 hours, likewise Lubarsky et al.6 reported a series of 334
cases of eclampsia with 16% of seizures occurring in the
postnatal period and over half of these later than 48 hours
following delivery. Together these data emphasise the need
for prolonged vigilance in the postpartum period and the
importance of investigating reported symptoms in such
women. In the current climate of early postnatal discharge
both hospital and community teams need to have referral
and management guidelines in place.
The potential complications of pre-eclampsia in the
postpartum period are largely similar to those in the
antenatal period with the obvious exception of fetal
complications. There is increasing recognition that systolic
severe hypertension (>160 mmHg) as well as elevated mean
arterial pressures (MAPs) should prompt urgent treatment
to prevent cerebral haemorrhage.7 In the most recent UK
Maternal Mortality Confidential Enquiry there were nine
maternal deaths following cerebral haemorrhage associated
with pre-eclampsia.8 As in the previous triennium, the
inadequate treatment of systolic hypertension was a
recurring theme.
Consideration of antihypertensive agents
The ideal antihypertensive agent to be used in the postnatal
period will reliably and effectively control blood pressure
without diurnal peaks and troughs, will have minimal
maternal side effects, be safe for breastfeeding infants and
be effective with once-daily dosing to maximise compliance
at a time that is often somewhat chaotic for patients. Due to
the paucity of data, it is difficult to recommend one
antihypertensive agent over another9 and this should be
addressed in future research. In the absence of such data the
clinician should be aware of the pros and cons of available
agents (Tables 2 and 3). Perhaps the most important concern
is that hypertension should be recognised and effectively
treated to prevent severe hypertension and to avoid
unnecessary delays in discharge.
b-blockers
The most common agents used are labetalol and atenolol. As
well as the b2 receptor effect of peripheral vasodilation, b1
receptors in cardiac tissue modulate the sympathetic response
whilst renal receptors mediate changes in renin synthesis.
This modest decrement in renin synthesis may contribute to
the overall antihypertensive effect in some patients.
b-blockers may exacerbate asthma and cardiac failure and
should be avoided in patients with pre-existing disease.
Individuals who describe respiratory symptoms after
commencing a b-blocker (symptoms may not be apparent
for several days) should be changed to an alternative agent.
Atenolol has the advantage of only requiring a single daily
dose thus increasing compliance in women who find multiple
dosing regimens difficult. The high lipid solubility of the drug
means that it is concentrated in breast milk and concerns have
previously been raised about transfer to the neonate, however,
only a single case of neonatal b-blockade has been reported
Table 2. Treatment of postnatal hypertension
Drug
Chronic treatment
Labetalol
Atenolol
Nifedipine (SR)
Amlodipine
Enalapril
Acute treatment
Hydralazine
Labetalol
Nifedipine
Dose
Contraindications
Side effects
100 bd–200 mg qds
25–100 mg daily
10–40 mg bd
5–10 mg od
5–20 mg bd
Asthma, cardiac failure, bradycardia, 2nd or
3rd degree AV block
Advanced aortic stenosis
Postural hypotension, headache, urinary
hesitancy, fatigue
Headache, tachycardia, palpitations, flushing
Avoid in AKI
Hypotension, cough, renal impairment
Severe tachycardia, high output cardiac failure
Headache, flushing, anxiety, arrhythmias
As chronic treatment
As chronic treatment
Care to avoid profound hypotension when
used alongside magnesium sulphate
As chronic treatment
5–10 mg IV or IM repeated
if necessary
20 mg IV repeated if necessary
at 20 min intervals
10 mg sublingual repeated if
necessary at 20 min intervals
AKI = acute kidney injury; AV = atrioventricular; bd = twice daily; IM = intramuscular; IV = intravenous; od = once daily; qds = four-times daily;
SR = sustained release
46
ª 2013 Royal College of Obstetricians and Gynaecologists
Smith et al.
Table 3. Use of antihypertensive agents in breastfeeding women
Antihypertensive agents with no known adverse effects on infants
receiving breast milk:
Labetalol
Nifedipine
Enalapril
Captopril
Atenolol
Metoprolol
Antihypertensive agents with insufficient evidence on infant safety
to recommend for use in breastfeeding mothers:
Angiotensin receptor blocking agents
Amlodipine
Angiotensin converting enzyme inhibitors other than enalapril and
captopril
Adapted from National Institute of Health and Clinical
Excellence16
despite extensive use of the drug in breastfeeding women. The
risks in routine clinical practice are therefore minimal.
Calcuim channel blockers
These agents act by inhibiting Ca2+ influx into vascular
myoctyes thereby inhibiting vasoconstriction and reducing
vascular resistance. It has minimal effects on cardiac
conduction and heart rate but may be associated with more
headache than b-blockers. There is minimal excretion into
breast milk.10 Nifedipine (slow release [SR]) is the most
commonly prescribed calcium channel blocker and can
initially be prescribed at a dose of 10–20 mg twice daily.
Once control is established, prescriptions may be converted
to a sustained release preparation (MR) of 30–60 mg daily.
A second-line alternative is amlodipine 5–10 mg once daily.
They can be associated with adverse fetal outcomes when
used in the antenatal period but there are reassuring data
concerning their safety in breastfeeding infants. Enalapril can
be prescribed as a twice-daily dose of 5–20 mg. Although
generally well tolerated, patients can experience profound
hypotension. Due to their association with renal impairment
they should be used with caution in patients who have recent
deterioration of renal function.
Diuretics
Diuretics are rarely used as antihypertensive agents in the
postnatal period with the exception of management of
pulmonary oedema. Although they are safe, postnatal women
are more susceptible to postural hypotension. Furthermore,
mothers who are breastfeeding may experience excessive
thirst and the associated volume contraction may interfere
with successful breastfeeding.
Treatment of acute episodes of
hypertension
Acute episodes of hypertension in the postnatal period
should be managed in the same manner as antenatal or
intrapartum episodes. The agents of choice are labetalol
(oral or intravenous), nifedipine (oral) or hydralazine
(intravenous). Labetalol has the advantage that an oral dose
can be given before intravenous access is established then
further intravenous doses can be given if required.
Hydralazine, is effective although its use as a first-line drug
has been questioned.12 It more commonly causes precipitous
drops in blood pressure and although the concerns about
placental perfusion are no longer relevant, the associated
symptoms are unpleasant for women.
Methyldopa
The most common antihypertensive agent used in the
antenatal period is methyldopa because of its well
established safety record with regard to fetal toxicity.11 It is a
centrally acting a adrenergic agonist, which brings about
reduced systemic vascular resistance via decreased
sympathetic vascular tone. Whilst methyldopa remains a safe
option for treatment of hypertension in the postnatal period,
particularly in women who have had good antenatal control
with the agent, most authorities advise that it should be
discontinued because of its maternal side-effects, in particular,
sedation, postural hypotension and postnatal depression.12
Angiotensin converting enzyme (ACE) inhibitors
ACE inhibitors (such as enalapril) are commonly used
outside of pregnancy to treat hypertension, particularly that
associated with renal disease and proteinuria. Their
mechanism of action is to inhibit angiotensin converting
enzyme (ACE) and therefore decrease production of
angiotensin II (AII) reducing AII mediated vasoconstriction.
ª 2013 Royal College of Obstetricians and Gynaecologists
Management of ongoing postnatal
hypertension
Patients with existing hypertension (Figure 1a)
In situations where hypertension predates the pregnancy it is
advisable to stop methyldopa following delivery and switch
to the prepregnancy dose of the patient’s usual agent/s.
Where newer drugs have been prescribed and mothers are
wishing to breastfeed, pharmaceutical advice should be
sought before delivery. All of the antihypertensive drug
groups have examples of preparations where there is
reassuring experience with breastfeeding. Women who were
previously using diuretics should consider an alternative
while they are breastfeeding.
Hypertension arising during pregnancy or in the
peurperium (Figure 1b)
In patients who were normotensive before pregnancy, one of
the most difficult problems is deciding which women should
47
Management of postpartum hypertension
EssenƟal hypertension
treated in pregnancy
(a)
Restart prepregnancy
medicaƟon
Observe as inpaƟent for
48 hours.
Record BP daily
Aim to keep
BP <140/90
Discharge to community:
communicate plans to GP and CMW
Alternate day BP check unƟl stable
>160/110,
asymptomaƟc
>150/100,
symptoms of
pre-eclampsia
Check compliance, arrange
medical review within 24 hours
Same day obstetric
medical assessment
(b)
Figure 1. (a) Algorithm for the management of postnatal hypertension in women with chronic hypertension. (b) Algorithm for the management
of postnatal hypertension in women without chronic hypertension
48
ª 2013 Royal College of Obstetricians and Gynaecologists
Smith et al.
have antihypertensives prescribed following delivery. From
Table 1, it might be suggested that women who have required
antihypertensives in the antenatal period, women who have
been delivered before 37 weeks of gestation because of
hypertension and women who have had severe hypertension
are most likely to benefit. The perceived advantages of
starting treatment in the early postnatal period are that
episodes of severe hypertension will be reduced and discharge
to the community will not be delayed unnecessarily. Balanced
against this is the possibility of unnecessary treatment and
side effects of medication. A suggested regimen might be
labetalol (providing there is no history of asthma) with
second and third-line agents of calcium antagonist and an
ACE inhibitor (such as enalapril).
The recently published NICE guidance for postpartum
care indicates that blood pressure should be measured within
6 hours of delivery. Furthermore, at the first postnatal
contact, all women should be made aware of the symptoms of
pre-eclampsia (headaches within 72 hours of delivery
accompanied by visual disturbance, or nausea or vomiting)
along with the need to urgently contact an appropriate
health professional.
It is not clear what thresholds should be used to instigate
treatment in women who present with de novo hypertension
in the postnatal period having previously been normotensive.
Current NICE postnatal guidance13 recommends medical
review if the diastolic pressure is >90 mmHg and is
associated with any symptoms of pre-eclampsia or if this
level of diastolic hypertension is sustained over 4 hours. No
systolic thresholds are suggested but extrapolation from the
subsequent hypertension guidelines would indicate that preeclampsia should be excluded when systolic pressure is
>150 mmHg. Newly presenting patients should have a
history and examination taken to exclude impending
eclampsia and have full blood count, electrolytes and liver
function checked.
Regardless of whether antihypertensive agents are
prescribed immediately following delivery, all women
should be closely monitored with regular recordings made
of blood pressure and fluid balance. It is anticipated that the
introduction of modified obstetric early warning system
(MOEWS) charts might facilitate the detection of women
who require further medical review.14 The frequency of
measuring haematological and biochemical indices will need
to be tailored to individual patients. A minimum of oncedaily testing may be required initially in cases where there is
concern about thrombocytopenia or renal compromise,
thereafter frequent sampling is unlikely to change
management in the absence of other clinical triggers.
Furthermore, unnecessary concern may arise if normal
patterns of resolution are not appreciated, if, for example,
ALT reaches peak serum levels 5 days postnatally in normal
pregnancy.15 NICE guidance16 recommends that the platelet
ª 2013 Royal College of Obstetricians and Gynaecologists
count, transaminases and serum creatinine are checked
48–72 hours after birth, or step down from Level 2 care, and
only repeated thereafter if abnormal or clinically indicated.
Given that up to 44% of eclamptic fits occur in the
postnatal period, usually within the first 48 hours following
delivery,17 women with pre-eclampsia should be encouraged
to delay discharge until day 3. Blood pressure at the time of
discharge should be <150/100 mmHg. It is crucial that
the community team receive adequate and prompt
documentation regarding the inpatient management and
the plans for follow-up.
Follow-up
Once discharged, the community midwife should measure
blood pressure on alternate days for the first 2 weeks and
refer for medical review if two measurements >150/
100 mmHg are obtained more than 20 minutes apart.
Local experience and facilities will dictate if this review
should be by the GP or the hospital maternity assessment
unit. Hospital review will be required if patients report
symptoms of pre-eclampsia or if blood pressure (BP) is
>160/100 mmHg. Most women who commence postnatal
antihypertensives will require treatment for at least 2 weeks
and some women, particularly women with early onset or
severe disease may need to continue beyond 6 weeks.18
Medication should be reduced when BP is measured at
130–140/80–90 mmHg and medical review sought if the
patient remains on medication at 2 weeks. If medication is
required beyond 6 weeks then further medical review should
be arranged to investigate the possibility of an underlying
cause. It has recently been reported that up to 13% of women
initially thought to have a diagnosis of pre-eclampsia or
pregnancy-induced hypertension will have underlying disease
not suspected antenatally.19
The 6-week postnatal visit is an opportunity to establish
the diagnosis and to discuss implications for future
pregnancies. All women who have had a diagnosis of
pre-eclampsia should have their blood pressure measured and
the urine tested for proteinuria. The importance of ensuring
that renal impairment detected in hypertensive pregnancies is
indeed attributable to pre-eclampsia has been highlighted
by Fischer et al.20 Renal biopsies taken in the postpartum period
in 176 women who had been diagnosed in pregnancy as
having renal complications of pre-eclampsia established an
alternative diagnosis in a third of cases overall, and this was
increased to almost two thirds in multiparous patients.
The risk of pre-eclampsia in a subsequent pregnancy
depends on the presentation in the index pregnancy. Severe,
early onset pre-eclampsia has a recurrence rate up to 40% in
future pregnancies21,22 although generally the onset of
problems is 2–3 weeks later and it is less severe than in the
first pregnancy.23 Women who present with milder disease,
nearer to term have a risk of recurrence nearer to 10%.
49
Management of postpartum hypertension
Women at increased risk should be offered low-dose aspirin
and increased blood pressure surveillance during a future
pregnancy. Future research should establish the role, if any,
of second trimester uterine artery Doppler assessment.
Finally, it is increasingly recognised that pre-eclampsia is a
risk factor for developing cardiovascular disease in later life
and patients should be made aware of this so that they have
the opportunity make lifestyle choices to minimise their risk.
Conflict of interest
None declared.
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ª 2013 Royal College of Obstetricians and Gynaecologists