hypertension in pregnancy

1. HYPERTENSION
IN PREGNANCY

2. Course Outline
• Terminology and Diagnosis
• Risk factors
• Etiology and Pathophysiology
• Prediction and Prevention
• Management

3. CLASSIFICATIONS
• Gestational Hypertension
• Preeclampsia and Eclampsia Syndrome
• Chronic hypertension of any etiology
• Preeclampsia Superimposed on Chronic
Hypertension

4. Diagnostic Criteria for Pregnancy Associated Hypertension
CONDITION CRITERIA REQUIRED
Gestational Hypertension BP > 140/90 mmHg after 20 weeks in
previously normotensive women
Preeclampsia – Hypertension and:
Proteinuria
• ≥ 300 mg/24h, or
• Protein: creatinine ratio ≥ 0.3 or
• Dipstick 1+ persistent
or
Thrombocytopenia Platelets < 100,000/μL
Renal insufficiency Creatinine > 1.1 mg/dL or doubling of
baseline
Liver involvement Serum transaminase levelsc twice normal
Cerebral symptoms Headache, visual disturbances,
convulsions
Pulmonary edema

5. • blood pressures reach 140/90 mm Hg or greater
for the first time after midpregnancy
• Blood pressure returns to normal by 12 weeks
postpartum.
• proteinuria is not identified
•
■■
Gestational Hypertension

6. Preeclampsia Syndrome
• described as a pregnancy-specific syndrome
that can affect virtually every organ system
• Leading cause of maternal and perinatal
morbidity and mortality with an estimated
50,000-60,000 preeclampsia related deaths per
year world wide

7. Preeclampsia Syndrome
Indicators of Severity of Gestational Hypertensive Disorders
Abnormality Nonsevere Severe
Diastolic BP < 110 mm Hg ≥ 110 mm Hg
Systolic BP < 160 mm Hg ≥ 160 mm Hg
Proteinuria None to positive None to positive
Headache Absent Present
Visual disturbances Absent Present
Upper abdominal
pain
Absent Present
Oliguria Absent Present
Convulsion
(eclampsia)
Absent Present
Serum creatinine Normal Present
Thrombocytopenia
(< 100,000/μL)
Absent Present
Serum transaminase level Minimal Marked
Fetal-growth
restriction
Absent Obvious

8. ECLAMPSIA
• In a woman with preeclampsia, a
convulsion that cannot be attributed to
another cause

9. CHRONIC HYPERTENTION
• High BP known to predate conception or
detected before 20 weeks of gestation

10. CHRONIC HYPERTENSION WITH
SUPERIMPOSED PREECLAMPSIA
• A women with hypertension only in early
gestation who develop proteinuria after 20
weeks of gestation

11. CHRONIC HYPERTENSION WITH
SUPERIMPOSED PREECLAMPSIA
• A women with proteinuria before 20 weeks
of gestation
– Sudden exacerbation of hypertension
– Signs and symptoms: increase in liver
enzymes
– Decrement in platelet level to below 100,000
microliter
– Right upper quadrant pain and severe
headache

12. Incidence and Risk Factors
• Young and Nulliparous
• Obesity
• Multifetal gestation
• Maternal age
• Hyperhomocysteinemia
• Metabolic syndrome

13. Ethiopathogenesis
• Are exposed to chorionic villi for the first time
• Are exposed to a superabundance of chorionic villi, as
with twins or hydatidiform mole
• Have preexisting conditions of endothelial cell activation
or inflammation such as diabetes or renal or
cardiovascular disease
• Are genetically predisposed to hypertension developing
during pregnancy.

14. ETIOLOGY
• 1. Placental implantation with abnormal trophoblastic invasion
of uterine vessels
• 2. Immunological maladaptive tolerance between maternal,
paternal (placental), and fetal tissues
• 3. Maternal maladaptation to cardiovascular or inflammatory
changes of normal pregnancy
• 4. Genetic factors including inherited predisposing genes and
epigenetic influences

16. HELLP SYNDROME
TENNESSE CLASSIFICATION MISSISSIPPI CLASSIFICATION
Moderate to severe thrombocytopenia
With platelets 100,000 ml or less
Class 1: severe thrombocytopenia
(platelets < 50,000 /ml )
Evidence of hepatic dysfunction (ALT >70
IU/L)
Evidence of hemolysis (total serum
LDH>600 IU/L
Hepatic dysfunction with aspartase
aminotransferase 70 IU/L or greater
Class 2: similar criteria except
thrombocytopenia is moderate (>50,000 to
<100,000)
Evidence of hemolysis with an abnormal
peripheral smear in addition to either total
serum lactate dehydrogenase 600 IU/L
Class 3: mild thrombocytopenia (platelets
>100,000 but <150,000/ ml)
Mild hepatic dysfunction (AST and ALT
>40 IU/L) and hemolysis (total serum LDH
>600 IU/L)
Bilirubin 1.2 mg/dl or greater

17. Prevention of Preeclampsia
• Antioxidants: vitamins C and E are not effective.
• Calcium: may be useful in populations with low calcium
intake (not in the USA).
• Low-dose aspirin (60 to 80 mg): beginning in the late first
trimester may have slight effect to reduce preeclampsia
and adverse perinatal outcomes.
• Bed rest or salt restriction: no evidence of benefit.

18. GHTN – PRE Without Severe Features
DELIVERY
yes
No

19. MANAGEMENT OF PREECLAMPSIA
WITH SEVERE FEATURES
Delivery > 34
weeks

20. ACUTE CONTROL OF SEVERE
HYPERTENSION
• Persistent (>15 min) SBP > 160 mmHg or
• Persistent DBP > 105 mmHg
• • IV labetalol
– bolus doses 20-40 mg (max 300/hr)
– continuous IV infusion (1-2 mg/min)
IV bolus doses of hydralazine
• 5, 10, 10 mg q 20 min (max 25 mg)
• • Oral nifedipine
• • 10-20 mg q 20 min (max 60 mg)

21. PREVENTION OF SEIZURES
• Magnesium sulfate
– Intravenous regimen
– Loading dose: 4 or 6 g IV over 20 mins
– Maintenance: 2 g IV per hr
• • If convulsions recur
• 2 g dose of magnesium sulfate
• •Treat: Eclampsia, Preeclampsia (sev),
HELLP

22. FETAL DELIVERY GUIDELINES
preeclampsia w/ severe features
• Expedited delivery (within 72 hrs)
– Fetal distress by FHR tracing or BPP ≤ 4
– Amniotic fluid index < 5 cm
– Ultrasound EFW < 5th percentile
– Reverse umbilical artery diastolic flow
– Labor / ROM
– > 34 weeks’ gestation

23. PROTEINURIA & PREECLAMPSIA
Does the amount matter?
• No differences in outcomes (< 5 vs ≥ 5 g)
– Renal function
– Latency
– Similar outcomes (< 5, 5-9.99, ≥ 10 g/24h)
Delivery decision should not be
based on:
• • Amount of proteinuria
• • Change in amount of proteinuria