TAUFIK’S RECOMENDATIONS 1

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)