Hypertensive disorders in pregnancy

Question 1

Significance of hypertension in pregnancy

Answer 1

hypertensive disorders of pregnancy (HDP) are one of the most common causes of MORTALITY in pregnancy

Question 2

Categories of hypertensive disorders of pregnancy

Answer 2

1. Chronic HTN: preexisting HTN OR NEW ONSET HTN BEFORE 20 weeks gestation
2. Gestational HTN: NEW ONSET HTN WITHOUT PROTEINURIA AFTER 20weeks of gestation
3. Preeclampsia: NEW ONSET HTN AFTER 20 weeks of gestation PLUS NEW ONSET OF :
   - Proteinuria OR
   - Signs of end-organ dysfunction OR
   - Uteroplacental dysfunction
4. Chronic HTN with SUPERIMPOSED preeclampsia: NEW ONSET proteinuria in a women with chronic HTN BUT NO proteinuria, BEFORE 20 weeks gestation

Question 3

Definition of Preeclampsia

Answer 3

*NEW ONSET HTN AFTER 20 weeks gestation PLUS NEW ONSET OF

Proteinuria:
- 24h urinary protein (UTP) >/= 300mg
- Dipstick protein >/= 2+
- Urine protein: creatinine ratio (uPCR) > 0.3mg/dL

OR

Signs of end-organ damage
- Platelet count <100
- LFTs > 2x ULN
- Doubling of Scr in the ABSENCE of other renal disease
- Pulmonary edema
- Neurological complications

*complex multisystem disease: pathophysiology NOT completely understood - probably multifactorial & varied
- MAY PROGRESS RAPIDLY TO ECLAMPSIA: new onset tonic-clonic, focal, or multifocal seizures SUPERIMPOSED on preeclampsia
*eclampsia is a MEDICAL EMERGENCY -> both maternal & fetal risk

Question 4

Prevention of preeclampsia

Answer 4

LOW DOSE ASPIRIN
- Recommended for HIGH RISK pts: HTN on previous pregnancy, Multifetal gestation, Autoimmune disease, DM, CKD etc

Dose: 100mg (or more) daily

MOA: unknown

*WHEN: can initiate ANYTIME between 12 to 18 weeks (ideally before 16 weeks) AFTER 1st trimester, continued UNTIL DELIVERY

Question 5

Treatment of HTN in pregnancy

Answer 5

1. Nifedipine ER (commonly used)
   - Monitor for pedal edema, flushing, headaches
   - most studied & widely used CCB in pregnancy
2. Labetalol (commonly used)
   - Monitor for bronchoconstrictive effects, bradycardia
   - preferred over other betablockers: less A/E on uteroplacental blood flow & fetal growth
3. Methyldopa
   - Extensive safety data in pregnancy BUT low potency & INCREASED A/E (eg. sedation, dizziness) -> rarely used

4.: Hydrochlorothiazide
- generally considered 2nd, 3rd line
- Concerns for potential interference with normal blood volume expansion during pregnancy

5. Hydralazine
   - falling out of favor as AE mimics symptosm associated with preeclampsia & imminent eclampsia eg. N/V, palpitation, flushing, headache, tremor

CI: ACEi, ARBs

Question 6

Indication to treat HTN in pregnancy (BP threshold)

Answer 6

threshold 140/90mmHg