hypertension in pregnancy

Hypertension in

PregnancyRamon M. Gonzalez, MD

ProfessorUST Medicine and Surgery

A 26y/o G1 21-22 weeks known hypertensive for 6 years was admitted because of severe

hypertension VS- BP-200/100mmHg, PR- 76/min, RR-20/min, T-36.5C. She was

taking calcium channel blockers for her HPN which she was taking regularly.

Hypertensive Disorders Complicating Pregnancy

• Gestational Hypertension– Systolic BP≥ 140 or diastolic ≥ 90 mmHg for the

first time after 20 weeks gestation– No proteinuria– BP returns to normal before 12 weeks postpartum– Final diagnosis made only postpartum– May have other signs or symptoms of

preeclampsia


• Preeclampsia– Minimum criteria

• BP ≥ 140/90 mmHg after 20 weeks gestation• Proteinuria ≥ 300mg/24 hours or ≥ 1+ dipstick

– Severe preeclampsia• BP ≥ 160/110 mmHg• Proteiunuria 2.0gms/24 hrs or ≥ 2+ dipstick• Serum creatinine > 1.2mg/dl• Platelets < 100,00/ul• Elevated LDH, ALT or AST


• Eclampsia– Seizures that cannot be attributed to other causes

in women with preeclampsia

• Chronic Hypertension– BP ≥ 140/90 mmHg before pregnancy or diagnosed

before 20 weeks gestation– Hypertension first diagnosed after 20 weeks

gestation and persistent after 12 weeks postpartum


• Superimposed Preeclampsia – New onset proteinuria ≥ 300mg/24 hrs in

hypertensive women but no proteinuria before 20 weeks gestation

Pregnancy 20-21 weeks, Chronic

Hypertension

Maternal Assessment

• Duration of hypertension

• Current therapy• Degree of BP

control• Other medical

complications

Maternal Assessment

• Serum creatinine• Quantification of

urine proteins• ECG • Echocardiography• Blood chemistry

1. What are the effects of chronic hypertension on pregnancy?

2. What is the management of chronic hypertension during pregnancy?

3. Can we prevent superimposition of preeclampsia ?

4. What is the management of chronic hypertension with superimposed preeclampsia?

What are the effects of chronic hypertension on pregnancy?

ORs for Fetal Complications: 1995-2008

Pregestational Diabetes-------------------------------------------------------------------------------------------Variable With Chronic HPN W/O Chronic HPN_______________________________________________________

_

Stillbirth 4.30(3.81-4.85) 3.05(2.88-3.23)

Poor fetal growth 2.66(2.40-2.94) 1.20(1.14-1.27)

Spontaneous delivery 4.88(4.63-5.15) 2.90(2.83-2.90)<37weeks

ORs for Maternal Complications: 1995-2008

Pregestational Diabetes--------------------------------------------------------------------------------------------Variable With Chronic HPN W/O Chronic HPN__________________________________________________________Preeclampsia 13.96 (13.29-14.66) 3.80 (3.69-3.91)

CVA 7.14 (4.90-10.40 ) 1.85 (1.41-2.44)

Acute renal failure 35.41 (28.39-44.16) 4.43 (3.57-5.48)

Pulmonary edema 11.97 (7.86-18.24) 4.01 (3.07-5.25)

Ventilation 11.87 (9.22-15.26) 3.34 (2.89-4.00)

Cesarean delivery 5.75 (5.46-6.05) 3.33 (3.26-3.41)

In- hospital mortality 6.02 (2.71-13.40) 2.58 (1.59-4.17)


Chronic Renal Disease-------------------------------------------------------------------------------------------Variable With Chronic HPN W/O Chronic HPN________________________________________________________

Stillbirth 7.29(5.59-9.52) 1.74(1.51-2.02)




Chronic Renal Disease---------------------------------------------------------------------------------------------Variable With Chronic HPN W/O Chronic HPN__________________________________________________________Preeclampsia 27.87(24.85-31.25) 3.28(3.10-3.47)

CVA 13.73(6.63-28.44) 3.53(2.34-5.31)

Acute renal failure 253.4(199.5-321.9) 62.40(54.37-71.63)

Pulmonary edema 23.29(10.32-52.56) 9.06(5.84-14.06)

Ventilation 19.29(11.36-32.76) 8.25(6.43-10.60)

Cesarean delivery 5.73(5.03-6.53) 1.74(1.68-1.81)

In- hospital mortality 27.02(8.72-83.73) 6.88(3.56-13.29)


Collagen Vascular Disease-------------------------------------------------------------------------------------------Variable With Chronic HPN W/O Chronic HPN________________________________________________________

Stillbirth 7.42(5.37-10.25) 2.74(2.35-3.20)




Collagen Vascular Disease---------------------------------------------------------------------------------------------Variable With Chronic HPN W/O Chronic HPN__________________________________________________________Preeclampsia 17.41 (15.09-20.09) 2.96 (2.76-3.18)

CVA 23.00 (11.47-46.14) 7.60 (5.26-10.97)

Acute renal failure 191.5 (141.4-259.4) 12.60 (8.88-17.88)

Pulmonary edema 15.52 (4.92-48.90) 6.08 (3.46-10.69)

Ventilation 26.29 (15.04-45.63) 11.09 (8.46-14.52)

Cesarean delivery 4.38 (3.74-5.12) 1.89 (1.80-1.98)

In- hospital mortality 88.81 (41.90-188.2) 23.81 (14.67-38.66)

What is the management of chronic hypertension during pregnancy?

Management

• Blood pressure control

• Fetal antepartum surveillance

• Prevention of preeclampsia

• Detection of preeclampsia

Blood Pressure Control

• Ca Channel Blockers• Adrenergic Blocking

Agents• Vasodilators• Diuretics• ACE Inhibitors/ARB

– contraindicated

• El Guindy, A.A. and Nabhan, A.F. (2008) • Journal of Perinatal Medicine• Women in the tight control group

– Were less likely to develop severe hypertension (RR 0.32, 95% CI 0.14 to 0.74)

– Delivered babies with older gestational ages (36.6 ±2.2 weeks vs 35.8 ± 2.2 weeks: P<0.05)

– Fewer preterm deliveries (RR 0.52, 95%CI 0.28 to 0.99)– No significant differences between groups regarding

stillbirth or IUGR

A randomized trial of tight vs. less tight control of mild essential and gestational hypertension in pregnancy

Fetal Antepartum Surveillance

• Fetal biometry

• Nonstress test

• Contraction stress test

• Biophysical profile

• Doppler velocimetry

Can we prevent superimposition of preeclampsia?

Preeclampsia

• Pregnancy specific syndrome that can affect virtually every organ system.

• Disorder of unknown etiology affecting 5-10% of all pregnancies.

• In developed countries 16% of maternal deaths were due to hypertensive disorder.

• POGS (2006)- 26.24% maternal deaths were due to hypertensive disorder.

Pathogenesis

• Vasospam– Increased resistance → hypertension– Endothelial cell damage → leakage of blood

constituents, including platelets and fibrinogen

– Decreased blood flow → ischemia of tissues → necrosis, hemorrhage and other end organ disturbances

Pathogenesis

• Endothelial cell activation– Increased pressor responses

• Increased sensitivity to angiotensin II

– Prostaglandin• Prostacyclin: thromboxane A2 ratio decreases

– Nitric oxide• Decreased nitric oxide synthase expression

– Endothelins• Potent vasoconstrictor which is increased in preeclampsia

Cardiovascular System

• ↑ Cardiac afterload – hypertension

• ↑Cardiac preload – Diminished hypervolemia– ↑ intravenous crystalloids

• Extravasation of intravascular fluid into the extracellular space– Pulmonary edema

Blood Volume and Coagulation

• Hemoconcentration– Hallmark of preeclampsia– Vasospasm and endothelial

leakage• Thrombocytopenia • Hemolysis

– Endothelial disruption• HELLP syndrome

Kidneys

• ↓ Glomerular filtration rate and renal plasma flow

• ↑ Serum creatinine• ↑ Uric acid• Proteinuria • Oliguria • “Glomerular capillary

endotheliosis”• Acute renal failure

Liver• Hepatic infarction

• Periportal hemorrhage

• Hepatocellular necrosis

• Elevations of AST/ALT

• Hepatic hematoma

• HELLP syndrome

Brain

• Headaches, visual symptoms

• Convulsions• Intracerebral

hemorrhage• Cortical and subcortical

petechial hemorrhages• Subcortical edema

Uteroplacental Perfusion

Vasospasm↓

Decreased uteroplacental perfusion

↓Increased perinatal

morbidity and mortality

Prevention of Superimposed Preeclampsia

• Systematic Review by Duley et al • 59 trials with 37,560 women given Aspirin

– 17% reduction in the risk of preeclampsia (RR 0.83, 077-0.89), especially in high risk patients

– 8% reduction in the relative risk of preterm birth (RR 0.92, 0.88-0.97)

– 14% reduction in fetal and neonatal deaths (RR 0.86, 0.76-0.98)

– 10% reduction in SGA babies (0.90, 0.83-0.98)

Detection of Preeclampsia

• BP monitoring

• 24 hour urine proteins

What is the management of chronic hypertension with superimposed preeclampsia?

Management

• Termination of pregnancy with the least possible trauma to mother and baby

• Birth of an infant who subsequently thrives

• Complete restoration of health to the mother

Severe Preeclampsia

• Clinical course is progressive deterioration in both maternal and fetal condition

• Associated with high rates of maternal and perinatal morbidity and mortality

Management of Severe Preeclampsia

• Aggressive - High neonatal mortality

and morbidity due to prematurity

- Prolonged NICU stay

- Long term disability

• Expectant - Fetal death

- Asphyxial damage in utero

- Increased maternal morbidity

Odendaal and associates

• Aggressive vs expectant management• 58 patients, 20 were delivered w/in 48 hours• 20 aggressive, 18 expectant• 28-34 weeks• Betamethasone, MgSO4, Antihypertensive

drugs• Maternal and fetal testing

Sibai and colleagues

• Aggressive vs expectant management• 28-32 weeks• 95 patients• Aggressive (n=46); expectant (n=49)• Bed rest, antihypertensives, MgSO4,

betamethasone, maternal and fetal testing, laboratory exams

Expectant Management• Prolongs pregnancy• Higher gestational age• Higher birth weight• Lower incidence of admission to NICU• Lower incidence of neonatal complication• No difference in the incidence of CS,

abruptio placenta, HELLP syndrome and postpartum stay

Guidelines for Expectant Management

• Hospitalization in a tertiary hospital- Good facilities to monitor the mother and fetus- NICU facilities- Trained personnels

• MgSO4• Antihypertensives• Corticosteroids

Maternal Assessment

Maternal Assessment

• Blood pressure measurement- Systolic – 140 – 155 mmHG- Diastolic – 90 – 105 mmHG

• Daily 24 hour urine volume • Maternal symptoms• Search for imminent signs of eclampsia Sibai et al AmJOG 2007

Maternal Assessment

• CBC with platelet counts• Serum creatinine • Liver function test

– AST/ALT– Lactate dehydrogenase

Sibai et al AmJOG 2007

Fetal Assessment

Fetal Assessment• Fetal kick counts• NST • Biophysical profile

scoring• Umbilical artery

Doppler studies• Assessment of fetal

growth

Maternal Indications for Delivery in Women With Severe Preeclampsia

• Persistent severe headache or visual changes; eclampsia

• Pulmonary edema• Uncontrolled severe HPN• Epigastric pain/RUQ pain with AST or ALT >2

times the upper limit of normal


Maternal Indications for Delivery in Women With Severe Preeclampsia

• Oliguria (<500ml/24hr)• HELLP syndrome• Platelet counts <100,000/mm3• Deterioration of renal function (serum creatinine >/=1.5 mg/dl)• Suspected abruptio placenta, progressive labor,

and/or rupture of membranes


Fetal Indications For Delivery In Women With Severe Preeclampsia

• Repetitive late or severe variable deceleration• Biophysical profile </=4 on 2 occasions at 6 hours

apart• IUGR (Estimated fetal weight <5th percentile)• Umbilical artery Doppler with reverse end diastolic

flow• Severe oligohydramnios


Mode of Delivery

• Vaginal delivery- Inducible cervix- No fetal distress

• Cesarean section

Thank You

hypertension in pregnancy

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