THE ACOG TASK FORCE ON HYPERTENSION IN PREGNANCY

Important Teaching Points for Medical Students from:

Background on Preeclampsia

Why is preeclampsia important? It can lead to serious maternal and

neonatal morbidity Maternal: seizure, stroke, DIC, bleeding,

liver hematoma Neonatal: growth restriction,

distress/hypoxia in labor, preterm birth It increases a woman’s risk of

hypertension and cardiovascular disease later in life

Important points about preeclampsia We don’t know exactly why it happens It occurs only in association with

pregnancy ALMOST ALWAYS from 20 wks gestation until

delivery RARELY you can see preeclampsia ≤6wks

postpartum or before 20wks gestation It is progressive (worsens as pregnancy

progresses) It is multisystemic

What causes preeclampsia?

Multifactorial We are not 100% certain of the pathogenesis

Gabbe: Obstetrics: Normal and Problem Pregnancies, 6th ed, Elsevier 2012.

Classification of Hypertension in Pregnancy

Classification of hypertension in pregnancy1. Preeclampsia-eclampsia

1. Hypertension in association with thrombocytopenia, impaired liver function, the new development of renal insufficiency, pulmonary edema, or new-onset cerebral or visual disturbances

2. Gestational hypertension1. Blood pressure elevation after 20 weeks of gestation in

the absence of proteinuria or the aforementioned systemic findings

3. Chronic hypertension1. Hypertension that predates pregnancy

4. Superimposed preeclampsia1. Chronic hypertension in association with preeclampsia

Diagnosis of Preeclampsia

Diagnosis of preeclampsia

Blood pressure criteria: SBP ≥140 mm Hg or DBP ≥90 mm Hg Persistent for 4 hours (repeat blood pressure after at least 4

hours) Plus one or both of the following:

Proteinuria ≥300mg protein or more in 24 hour urine collection OR Urine protein:creatinine ratio of ≥0.3 mg/dL OR 1+ protein on urine dipstick (not preferred method)

Systemic findings Thrombocytopenia Renal insufficiency Impaired liver function Pulmonary edema Cerebral or visual findings

Diagnosis of preeclampsia

Diagnosis of preeclampsia

Notice that proteinuria is no longer a necessary part of the diagnosis Waiting to diagnose proteinuria can

delay necessary treatment The amount of proteinuria does not

predict maternal or fetal outcome

Diagnosis of preeclampsia with severe features

Diagnosis of preeclampsia with severe features HELLP syndrome is a form of

“preeclampsia with severe features” (previously known as severe preeclampsia)

Prediction and prevention

Prediction of preeclampsia Screening beyond obtaining an

appropriate medical history to evaluate for risk factors is NOT recommended

Risk factors for preeclampsia

Gabbe: Obstetrics: Normal and Problem Pregnancies, 6th ed, Elsevier 2012

Prevention of preeclampsia For women with:

A medical history of early onset preeclampsia and preterm delivery at less than 34 0/7 weeks gestation, or

Preeclampsia in more than one prior pregnancy

Give them low dose aspirin (81mg) daily beginning in the late first trimester

Dietary modifications do not work Bedrest does not work

Management: Gestational Hypertension

Management of gestational hypertension Management is expectant

Daily fetal kick counts Twice weekly blood pressure measurements Check for proteinuria at every office visit

(urine dipstick) Oral anti-hypertensives are not needed,

unless SBP >160 mmHb and DBP >110 mmHg persistently

If they develop preeclampsia, the management changes

Management: Preeclampsia

Management of preeclampsia For preeclampsia WITHOUT severe features (formerly

known as mild preeclampsia), manage patients expectantly until 37 0/7 weeks: Daily fetal kick counts Twice weekly blood pressure measurement Weekly labs (platelets, AST, ALT) Do not give antihypertensive medications as long as pressures

remain SBP <160 mmHb and DBP <110 mmHg Monitor fetal growth with monthly ultrasounds

If fetal growth restriction is found, perform umbilical artery Dopplers Delivery is recommended at 37 0/7 weeks

When they are being delivered, they probably don’t need magnesium sulfate for seizure prevention

If they develop severe features, the management changes

Management of Preeclampsia with Severe Features

Management of preeclampsia with severe features From 24 0/7 wks- 34 0/7 wks you can

manage them expectantly: At a tertiary hospital (transfer if

necessary) Give BTMZ for fetal lung maturity Treat with antihypertensive medications

for sustained SBP ≥160 or DBP ≥110 A change in the amount of proteinuria

should not affect management or dictate delivery

Management of preeclampsia with severe features From 24 0/7-34 0/7 weeks (continued): If a patient

is sick but stable, you can administer BTMZ and wait ≥48 hours

However, if a patient is unstable or has any of the following, give BTMZ and deliver them immediately: Severe HTN not controlled by IV medications Eclampsia Pulmonary edema Placental abruption DIC Nonreassuring fetal status Fetal demise

Management of preeclampsia with severe features Before 24 0/7 weeks (ie before

viability), deliver them immediately The baby will likely not survive

Management of preeclampsia with severe features Delivery is recommended at 34 0/7

weeks Always give magnesium sulfate for

seizure prophylaxis

Chronic hypertension (cHTN) Chronic hypertension with

superimposed preeclampsia is managed the same as preeclampsia

If severe features develop, it is managed the same as preeclampsia with severe features

Management summaryGestational hypertension

Preeclampsia

Preeclampsia with severe features

Chronic hypertension

Delivery At the onset of labor

37 0/7 wks 34 0/7wks 38 0/7wks

Magnesium sulfate

No Maybe Yes No

BTMZ Only if delivery <34wks for another indication

Only if delivery <34wks for another indication

Yes Only if delivery <34wks for another indication

Inpatient monitoring at tertiary hospital

No No Yes No

PO anti-hypertensives

Only if >160/110 persistently

No Only if >160/110 persistently

Only if >160/110 persistently

Management: simplifiedHigh blood pressure in pregnancy

Onset <20wks gestation

Chronic hypertension

Delivery at 38 0/7 wks

Pt develops superimposed preeclampsia

Delivery at 37 0/7wks

Pt develops superimposed preeclampsia with severe

features

Stable patient

Inpatient monitoring.

Delivery at 34 0/7wks.

Unstable patient

Delivery ASAP after BTMZ

Onset >20wks gestation

Gestational hypertension

Deliver when pt is in labor

Preeclampsia

Deliver at 37 0/7wks

Preeclampsia with severe

features

Stable patient

Inpatient monitoring.

Delivery at 34 0/7wks

Unstable patient

Delivery ASAP after BTMZ

Delivery recommendations

Delivery recommendations

Induction of labor is acceptable as long as maternal and fetal conditions are stable

Epidural and spinal anesthesia are acceptable as long as maternal and fetal conditions are stable

Magnesium sulfate seizure prophylaxis is recommended for: Eclampsia Preeclampsia with severe features It can be considered in non-severe preeclampsia

Postpartum

Postpartum recommendations Women with eclampsia and preeclampsia with

severe features should get magnesium sulfate seizure prophylaxis for 24 hours postpartum

Blood pressures should be monitored postpartum inpatient for at least 72 hours

If postpartum blood pressures are persistently ≥160/≥110, oral antihypertensives should be started

Any woman who presents within 6 weeks postpartum with new-onset hypertension with severe features, consider administering magnesium sulfate

Later in life

Later in life

For women with a history of: Preeclampsia who gave birth at less than

37 0/7 weeks Recurrent preeclampsia

They should have a yearly assessment of: Blood pressure Lipids Fasting blood glucose BMI

Source

Roberts, JR et al. “Executive Summary.” Hypertension in Pregnancy. The ACOG Task Force on Hypertension in Pregnancy. American Congress of Obstetricians and Gynecologists, 2013. Pages 1-11.