DIAGNOSIS, EVALUATION, AND MANAGEMENT OF THE HYPERTENSIVE
DISORDERS OF PREGNANCY
JOGC Volume 30, Number 3, March, 2008 (No. 206 March 2008)
CHAPTER 1: DIAGNOSIS AND
CLASSIFICATION
Recommendations: Measurement of
BP
1. BP should be
measured with the woman in the sitting position with the arm at the level of
the heart. (II-2A)
2. An
appropriately sized cuff (i.e., length of 1.5 times the circumference of the
arm) should be used. (II-2A)
3. Korotkoff phase
V should be used to designate diastolic BP. (I-A)
4. If BP is
consistently higher in one arm, the arm with the higher values should be used
for all BP measurements. (III–B)
5. BP can be
measured using a mercury sphygmomanometer, calibrated aneroid device, or an automated
BP device that has been validated for use in preeclampsia. (II-2A)
6. Automated BP
machines may underestimate BP in women with preeclampsia, and comparison of
readings using mercury sphygmomanometry or an aneroid device is recommended.
(II-2A)
7. Ambulatory BP
monitoring (by 24-hour or home measurement) may be useful to detect isolated office
(white coat) hypertension. (II-2B)
8. Patients should
be instructed in proper BP measurement technique if they are to perform home BP
monitoring. (III-B)
Recommendations: Diagnosis of
Hypertension
1. The diagnosis
of hypertension should be based on office or in-hospital BP measurements.
(II-2B)
2. Hypertension in
pregnancy should be defined as a diastolic BP of ≥ 90 mmHg, based on the
average of at least two measurements,taken using the same arm. (II-2B)
3. Women with a
systolic BP of ≥ 140 mmHg should be followed closely for development of
diastolic hypertension. (II-2B)
4. Severe
hypertension should be defined as a systolic BP of ≥ 160 mmHg or a diastolic BP
of ≥ 110 mmHg. (II-2B)
5. For non-severe
hypertension, serial BP measurements should be recorded before a diagnosis of
hypertension is made. (II-2B)
6. For severe
hypertension, a repeat measurement should be taken for confirmation in 15
minutes. (III-B)
7. Isolated office
(white coat) hypertension should be defined as office diastolic BP of ≥ 90
mmHg, but home BP of < 135/85 mmHg. (III-B)
Recommendations: Measurement o
Proteinuria
1. All pregnant
women should be assessed for proteinuria. (II-2B)
2. Urinary
dipstick testing may be used for screening for proteinuria when the suspicion
of preeclampsia is low. (II-2B)
3. More definitive
testing for proteinuria (by urinary protein: creatinine ratio or 24-hour urine
collection) is encouraged when there is a suspicion of preeclampsia, including
in hypertensive pregnant women with rising BP or in normotensive pregnant women
with symptoms or signs suggestive of preeclampsia. (II-2A)
Recommendations: Diagnosis of
Clinically Significant Proteinuria
1. Proteinuria
should be strongly suspected when urinary dipstick proteinuria is ≥ 2+. (II-2A)
2. Proteinuria
should be defined as ≥ 0.3g/d in a 24-hour urine collection or ≥ 30 mg/mmol
urinary creatinine in a spot (random) urine sample. (II-2B)
3. There is insufficient
information to make a recommendation about the accuracy of the urinary albumin:
creatinine ratio. (II-2 I)
Recommendations: Classification
of HDP
1. Hypertensive
disorders of pregnancy should be classified as pre-existing or gestational
hypertension on the basis of different diagnostic and therapeutic factors.
(II-2B)
2. The presence or
absence of preeclampsia must be ascertained, given its clear association with
more adverse maternal and perinatal outcomes. (II-2B)
3. In women with
pre-existing hypertension, preeclampsia should be defined as resistant
hypertension, new or worsening proteinuria, or one or more of the other adverse
conditions. (II-2B)
4. In women with
gestational hypertension, preeclampsia should be defined as new-onset
proteinuria or one or more of the other adverse conditions. (II-2B)
5. Severe
preeclampsia should be defined as preeclampsia with onset before 34 weeks’
gestation, with heavy proteinuria or with one or more adverse conditions.
(II-2B)
6. The term PIH
(pregnancy-induced hypertension) should be abandoned, as its meaning in
clinical practice is unclear. (III-D)
Recommendations: Investigations
to Classify HDP
1. For women with
pre-existing hypertension, serum creatinine, serum potassium, and urinalysis should
be performed in early pregnancy if not previously documented. (II 2B)
2. Among women
with pre-existing hypertension, additional baseline laboratory testing may be
based on other considerations deemed important by health care providers. (III-C)
3. Women with
suspected preeclampsia should undergo the maternal laboratory (II-2B) and fetal
(II 1B) testing described in Table 3.
4. If initial testing
is reassuring, maternal and fetal testing should be repeated if there is
ongoing concern about preeclampsia (e.g., change in maternal and/or fetal
condition). (III-C)
5. Uterine artery
Doppler velocimetry may be useful among hypertensive pregnant women to support
a placental origin for hypertension, proteinuria, and/or adverse conditions.
(II-2B)
6. Umbilical
artery Doppler velocimetry may be useful to support a placental origin for
intrauterine fetal growth restriction. (II-2B)
CHAPTER 2: PREDICTION,
PREVENTION, AND PROGNOSIS OF PREECLAMPSIA
Recommendations: Predicting
Preeclampsia
1. At booking for
antenatal care, women with markers of increased risk for preeclampsia should be
offered obstetric consultation. (II-2B)
2. Women at
increased risk of preeclampsia should be considered for risk stratification
involving a multivariable clinical and laboratory approach. (II-2B)
Recommendations: Preventing
Preeclampsia and its Complications in Women at Low Risk
1. Calcium supplementation
(of at least 1g/d, orally) is recommended for women with low dietary intake of
calcium (< 600 mg/d). (I-A)
2. The following
are recommended for other established beneficial effects in pregnancy:
abstention from alcohol for prevention of fetal alcohol effects, (II-2E)
exercise for maintenance of fitness, (I-A) periconceptual use of a
folate-containing multivitamin for prevention of neural tube defects, (I-A) and
smoking cessation for prevention of low birthweight and preterm birth. (I-E)
3. The following
may be useful: periconceptual use of a folate-containing multivitamin, (I-B) or
exercise. (II-2B)
4. The following
are not recommended for preeclampsia prevention, but may be useful for
prevention of other pregnancy complications: prostaglandin precursors, (I-C) or
supplementation with magnesium, (I-C) or zinc. (I-C)
5. The following
are not recommended: dietary salt restriction during pregnancy, (I-D) calorie
restriction during pregnancy for overweight women, (I-D) low-dose aspirin, (I E)
vitamins C and E (based on current evidence), (I-E) or thiazide diuretics.
(I-E)
6. There is insufficient
evidence to make a recommendation about the following: a heart-healthy diet,
(II-2I) workload or stress reduction, (II-2I) supplementation with iron with/without
folate, (I-I) or pyridoxine. (I-I).
Recommendations: Preventing
Preeclampsia and its Complications in Women at Increased Risk
1. Low-dose
aspirin (I-A) and calcium supplementation (of at least 1 g/d) are recommended
for women with low calcium intake, (I-A) and the following are recommended for
other established beneficial effects in pregnancy (as discussed for women at
low risk of preeclampsia): abstention from alcohol, (II-2 E) periconceptual use
of a folate containing multivitamin, (I-A) and smoking cessation. (I-E)
2. Low-dose
aspirin (75–100 mg/d )(III-B) should be administered at bedtime, (I-B) starting
pre-pregnancy or from diagnosis of pregnancy but before 16 weeks’ gestation,
(III B) and continuing until delivery. (I-A)
3. The following
may be useful: avoidance of inter-pregnancy weight gain, (II-2E) increased rest
at home in the third trimester, (I-C) and reduction of workload or stress.
(III-C)
4. The following
are not recommended for preeclampsia prevention but may be useful for
prevention of other pregnancy complications: prostaglandin precursors (I-C) and
magnesium supplementation. (I-C)
5. The following
are not recommended: calorie restriction in overweight women during pregnancy,
(I-D) weight maintenance in obese women during pregnancy, (III-D) antihypertensive
therapy specifically to prevent preeclampsia, (I-D) vitamins C and E. (I-E)
6. There is
insufficient evidence to make a recommendation about the usefulness of the
following: dietary salt restriction during pregnancy, (III-I) the heart-healthy
diet (III-I); exercise (I-I); heparin, even among women with thrombophilia
and/or previous preeclampsia (based on current evidence) (II-2 I); selenium
(I-I); garlic (I-I); zinc, (III-I) pyridoxine, (III-I) iron (with or without
folate), (III-I) or multivitamins with/without micronutrients. (III-I)
Recommendations: Prognosis
(Maternal and Fetal) in Preeclampsia
1. Serial surveillance
of maternal well-being is recommended, both antenatally and post partum. (II 3B)
2. The frequency
of maternal surveillance should be at least once per week antenatally, and at
least once in the first three days post partum. (III-C)
3. Serial surveillance
of fetal well-being is recommended. (II-2B)
4. Antenatal fetal
surveillance should include umbilical artery Doppler velocimetry. (I-A)
5. Women who
develop gestational hypertension with neither proteinuria nor adverse
conditions before 34 weeks should be followed closely for maternal and
perinatal complications. (II-2B)
CHAPTER 3: TREATMENT OF THE
HYPERTENSIVE DISORDERS OF PREGNANCY
Antenatal Treatment
Recommendations: Dietary changes
1. New dietary
salt restriction is not recommended. (II-2D).
2. There is
insufficient evidence to make a recommendation about the usefulness of the following:
ongoing salt restriction among women with pre-existing hypertension, (III-I)
heart-healthy diet, (III-I) and calorie restriction for obese women. (III-I)
Recommendations: Lifestyle
changes
1. There is insufficient
evidence to make a recommendation about the usefulness of: exercise, (III-I)
workload reduction, (III-I) or stress reduction. (III-I)
2. For women with
gestational hypertension (without preeclampsia), some bed rest in hospital
(compared with unrestricted activity at home) may be useful. (I-B)
3. For women with
preeclampsia who are hospitalized, strict bed rest is not recommended. (I-D)
4. For all other
women with HDP, the evidence is insufficient to make a recommendation about the
usefulness of bed rest, which may nevertheless, be advised based on practical
considerations. (III-C)
Recommendations: Place of care
1. In-patient care
should be provided for women with severe hypertension or severe preeclampsia.
(II-2B)
2. A component of
care through hospital day units (I-B) or home care (II-2B) can be considered
for women with non-severe preeclampsia or non-severe (pre-existing or
gestational) hypertension.
Recommendations: Antihypertensive
therapy for severe hypertension (BP of ≥ 160 mmHg systolic or ≥ 110 mmHg
diastolic)
1. BP should be
lowered to <160 mmHg systolic and < 110 mmHg diastolic. (II-2B)
2. Initial
antihypertensive therapy should be with labetalol, (I-A) nifedipine capsules,
(I-A) nifedipine PA tablets, (I-B) or hydralazine. (I-A)
3. MgSO4 is not
recommended as an antihypertensive agent. (II-2 D)
4. Continuous FHR
monitoring is advised until BP is stable. (III-I)
5. A variety of
antihypertensive drugs may be used in the first trimester of pregnancy (e.g.,
methyldopa, labetalol, and nifedipine). (II-2B)
Recommendations: Timing of
delivery of women with preeclampsia
1. Obstetric
consultation is mandatory in women with severe preeclampsia. (III-B)
2. For women at
< 34 weeks’ gestation, expectant management of preeclampsia (severe or non-severe)
may be considered, but only in perinatal centres capable of caring for very
preterm infants. (I-C)
3. For women at
34–36 weeks’ gestation with non-severe preeclampsia, there is insufficient
evidence to make a recommendation about the benefits or risks of expectant management.
(III-I)
4. For women at ≥ 37
weeks’ gestation with preeclampsia (severe or non-severe), immediate delivery
should be considered. (III B)
Recommendations: Magnesium
sulphate (MgSO4) for eclampsia prophylaxis or treatment
1. MgSO4 is
recommended for first-line treatment of eclampsia. (I-A)
2. MgSO4 is
recommended as prophylaxis against eclampsia in women with severe preeclampsia.
(I-A)
3.MgSO4 may be
considered for women with non-severe preeclampsia. (I-C)
4. Phenytoin and
benzodiazepines should not be used for eclampsia prophylaxis or treatment,
unless there is a contraindication to MgSO4 or it is ineffective. (I-E)
Recommendations: Plasma volume
expansion for preeclampsia
1. Plasma volume
expansion is not recommended for women with preeclampsia. (I-E)
Recommendations:
Therapies for HELLP syndrome
1. Prophylactic
transfusion of platelets is not recommended, even prior to Caesarean section,
when platelet count is > 50 x 109 /L and there is no excessive
bleeding or platelet dysfunction. (II-2D)
2. Consideration
should be given to ordering blood products, including platelets, when platelet
count is < 50 x 109 /L, platelet count is falling rapidly, and/or
there is coagulopathy. (III-I)
3. Platelet
transfusion should be strongly considered prior to vaginal delivery when
platelet count is < 20 x 109 /L. (III-B)
4. Platelet transfusion
is recommended prior to Caesarean section, when platelet count is < 20 x 109/L.
(III-B)
5. Corticosteriods
may be considered for women with a platelet count < 50 x109 /L.
(III I)
6. There is
insufficient evidence to make a recommendation regarding the usefulness of
plasma exchange or plasmapheresis. (III-I)
Recommendations:
Other therapies for treatment of preeclampsia
1. Women with
preeclampsia before 34 weeks’ gestation should receive antenatal corticosteroids
for acceleration of fetal pulmonary maturity. (I-A)
2. Thromboprophylaxis
may be considered when bed rest is prescribed. (II-2C)
3. Low-dose
aspirin is not recommended for treatment of preeclampsia. (I-E)
4. There is
insufficient evidence to make recommendations about the usefulness of treatment
with the following: activated protein C, (III-I) antithrombin, (I-I) heparin,
(III-I) L arginine, (I-I) long-term epidural anaesthesia, (I-I)
N-acetylcysteine, (I-I) probenecid, (I-I) or sildenafil nitrate. (III-I)
Postpartum
Treatment Recommendations: Care in the six weeks post partum
1. BP should be
measured during the time of peak postpartum BP, at days three to six after
delivery. (III-B)
2.
Antihypertensive therapy may be restarted post partum, particularly in women
with severe preeclampsia and those who have delivered preterm. (II-2 I)
3. Severe postpartum
hypertension should be treated with antihypertensive therapy, to keep systolic
BP < 160 mmHg and diastolic BP < 110 mmHg. (II-2B)
4. Antihypertensive
therapy may be used to treat non-severe postpartum hypertension, particularly
in women with comorbidities. (III-I)
5. Antihypertensive
agents acceptable for use in breastfeeding include the following: nifedipine
XL, labetalol, methyldopa, captopril, and enalapril. (III-B)
6. There should be
confirmation that end organ dysfunction of preeclampsia has resolved. (III-I)
7. Non-steroidal
anti-inflammatory drugs (NSAIDs) should not be given post partum if
hypertension is difficult to control or if there is oliguria, an elevated
creatinine (i.e., ≥ 100 µM), or platelets < 50 x 109 /L. (III-I)
8. Postpartum
thromboprophylaxis may be considered in women with preeclampsia, particularly
following antenatal bed rest for more than four days or after Caesarean
section. (III-I)
9. LMWH should not
be administered post partum until at least two hours after epidural catheter
removal. (III-B)
Recommendations:
Care beyond six weeks post partum
1. Women with a
history of severe preeclampsia (particularly those who presented or delivered
before 34 weeks’ gestation) should be screened for pre-existing hypertension,
(II-2B) underlying renal disease, (II-2B) and thrombophilia. (II-2C)
2. Women should be
informed that intervals between pregnancies of < 2 or ≥10 years are both
associated with recurrent preeclampsia. (II-2D)
3. Women who are
overweight should be encouraged to attain a healthy body mass index to decrease
risk in future pregnancy (II-2A) and for long-term health. (I-A)
4. Women with
pre-existing hypertension should undergo the following investigations (if not
done previously): urinalysis; serum sodium, potassium and creatinine; fasting
glucose; fasting total cholesterol and high-density lipoprotein cholesterol,
low-density lipoprotein cholesterol and triglycerides; and standard 12-lead electrocardiography.
(III-I)
5. Women who are
normotensive but who have had an HDP, may benefit from assessment of traditional
cardiovascular risk markers. (II-2B)
6. All women who
have had an HDP should pursue a healthy diet and lifestyle. (I-B)
