1. Hypertension in Pregnancy
Dapinderjit Gill
Ross University MS3

2. Hypertension Disorders in Pregnancy
Gestational HTN
Transient HTN of pregnancy
Preeclampsia
Mild
Severe
Eclampsia
Chronic HTN preceding pregnancy
Chronic HTN with superimposed pregnancy- induced hypertension
Superimposed preeclampsia
Superimposed eclampsia
Classification of the American College of Obstetricians and Gynecologists

3. Gestational Hypertension

4. Gestational HTN
sustained systolic blood pressure at or above 140mmHg, or a diastolic blood pressure of 90mmHg or greater
increase in BP must be present on at least two separate occasions, 6 hours or more apart
HTN in late pregnancy (>20 weeks gestation) in the absence of other findings suggestive of preeclampsia
if BP returns to baseline by 12 weeks postpartum = dx. of Transient hypertension of pregnancy
-in the clinical setting, this is sometimes hard to do due to various problems on obtaining reliable assessment of blood pressure.
-position; high when pt. is standing, low when pt. is laying down in lateral position and intermediate when pt. Is sitting
-inappropriate cuff size can over and under estimate BP
-no previous info on baseline BP

5. Gestational HTN
5-10% of pregnancies that proceed beyond 1st trimester develop gestational HTN
increased incidence of up to 30% in multiple gestation
15-25% of women initially diagnosed with gestational HTN develop preeclampsia
Earlier onset of gestational HTN are more likely to progress to preeclampsia

6. Pathophysiology Changes seen in patients
Cardiovascular effects
Elevated BP
Increased cardiac output
Hematologic effects
Third spacing of fluid due to increased blood pressure and decreased plasma oncotic pressure
Renal effects
Atheroscleroticlike changes in renal vessels (glomerular endotheliosis)  decreased glomerular filtration rate and proteinuria
Uric acid filtration is decreased

7. Pathophysiology Changes seen in patients
Neurologic effects
Hyperreflexia/hypersensitivity (does not correlate with severity of disease)
In severe cases, grand mal seizures
Pulmonary effects
Pulmonary edema may occur due
to decreased colloid oncotic pressure
Fetal effects (severe gestational HTN)
Vasospasm  Decreased intermittent placental perfusion  IUGR, oligohydramnios, low birth weight

8. Pathophysiology Mechanisms
Uterine vascular changes
Trophoblastic-mediated vascular changes  decreased musculature in spiral arterioles  development of low resistance, low pressure, high-flow system
Inadequate maternal vascular response
Endothelial damage is also noted within the vessels
Hemostatic changes
Increased PLT activation with increased endothelial fibronectin and decreased antithrombin III and alpha-2-antiplasmin  further endothelial damage is thought to promote further vasospasm
Potential mechanisms that have been postulated

9. Pathophysiology Mechanisms
Changes in prostanoids
During pregnancy, both PGI2 (vasodilation and decreased PLT aggregation) and TXA2 (vasoconstriction and PLT aggregation) are increased with balance favored to PGI2
In preeclampsia, TXA2 is favored
Changes in endothelium-derived factors
Decrease in Nitric oxide  promoting
vasoconstriction

10. Gestational HTN Mild: outpatient with weekly visits, bed rest
Antihypertensive therapy:
Indicated if diastolic pressure is repeatedly above 110mmHg
Hydralazine (Apresoline) 5mg increments IV until acceptable BP is obtained (diastolic pressure to mmHg range)
Other medications that can be used in pregnancy (oral):
methyldopa 250mg BID/TID max 3g/day
Labetalol 100mg max 2400mg/day
Nifedipine 30-60mg max 120mg/day
Magnesium sulfate in severe gestational HTN for seizure prophylaxis

11. Chronic Hypertension

12. Chronic HTN
HTN present before 20th week of gestation or beyond 6 weeks postpartum (>12 weeks postpartum from uptodate.com)
15% of gestational HTN cases go on to develop chronic HTN
25% risk of developing superimposed preeclampsia or eclampsia
Close monitoring of maternal BP and follow appropriate fetal growth and well-being
Pt. should be encouraged to increase the amount of time she rests

13. Preeclampsia

14. Preeclampsia
Development of HTN with proteinuria induced by pregnancy generally in the second half of gestation
More frequent at the extremes of reproductive years
More common in women who have not carried a previous pregnancy beyond 20 weeks
old women or young lady?

15. Preeclampsia Mild: Severe:
BP: systolic > 140mmHg and/or diastolic > 90mmHg
Proteinuria: >300mg on 24h collection of +1 on single sample
Severe:
BP: systolic > mmHg and/or diastolic > 110mmHg
Proteinuria: >5g on 24h collection or +2 on single sample
Multisystem alterations: cerebral or visual disturbances, oliguria, pulmonary edema, cyanosis, epigastric or right upper quadrant pain, thrombocytopenia

16. Preeclampsia

17. Preeclampsia Mild preeclampsia Severe preeclampsia
If immature fetus  bed rest mainly in
lateral decubitus position
HTN therapy if needed
Severe preeclampsia
Magnesium sulfate 4g loading dose with 1-3g/hr infusion rate
Antihypertensive therapy
Induction or cesarean delivery
fetal pulmonary maturity depending on gestational age should be considered (>=34weeks)

18. Eclampsia

19. Eclampsia addition of convulsions in a woman with preeclampsia
occurs in 0.5-4% of deliveries
most cases occur within 24h of delivery with about 3% of cases diagnosed between 2-10 days postpartum
25% have eclamptic seizures before labour, 50% during labour, and 25% after delivery

20. Eclampsia Anticonvulsant therapy
Diazepam or similar drugs
Magnesium sulfate to prevent further seizures
Maintain adequate airway, oxygenation, restraining gently as needed and inserting a padded tongue blade

21. HELLP Syndrome

22. HELLP Syndrome
HTN patients with hemolysis (H), elevated liver enzymes (EL), low platelet count (LP)
4-12% of pt. with severe preeclampsia and eclampsia develop HELLP syndrome
first sx. often missed: nausea, emesis, and non-specific viral-like syndrome
HELLP!

23. HELLP Syndrome Treatment:
cardiovascular stabilization, correction of coagulation abnormalities, and delivery
PLT transfusion before or after delivery if PLT count is <20,000/mm3 (advised at <50,000/mm3 before cesarean)
<32 weeks gestation; steroid therapy may help stabilize maternal PLT count

24. Thank You!

25. References
Beckmann, Charles R.B., Ling, Frank W., Smith, Roger P., Barzansky, Barbara M., Herbert, William N.P., Laube, Douglas W. “Obstetrics and Gynecology”. 5th edition Lippincott Williams & Wilkins. pp Magloire, Lissa etc. “Gestational Hypertension”. May 2011.<uptodate.com> August, Phyllis et. al. “Management of hypertension in pregnancy and postpartum women”. May 2011 <uptodate.com>