#203 Chronic Hypertension in Pregnancy Flashcards
Chronic hypertension is present in what % of pregnant women?
0.9-1.5%
How is chronic hypertension in pregnancy defined?
Hypertension (140/90) diagnosed or present before pregnancy or before 20wks of gestation; or hypertension diagnosed for the first time during pregnancy that does not resolve in the typical postpartum period
What are the new criteria for diagnosing hypertension in adults/blood pressure categories (since 2018)?
Normal: <120/80
Elevated: SBP 120-129 and DBP <80
Stage 1 HTN: SBP 130-139 or DBP 80-89
Stage 2 HTN: SBP 140 or more or DBP of 90 or more
If patient diagnosed with Stage 1 HTN per ACC/AHA definitions prior to conception, (eg bps 130s/80s), would you manage them as cHTN or non hypertensive?
Reasonable to manage as cHTN
Is it possible to have gHTN in women with elevated bps prior to 20 wks?
Yes, 20-wk convention should not be used dogmatically, but rather for orientation while maintaining clinical judgment.
At what point during gestation does the blood pressure nadir?
16-18wks
How is the systemic vascular resistance changed early in pregnancy?
Decreases by 30%
How does the blood pressure change by 7wks of pregnancy?
Decreases by 10%
Is systolic or diastolic decreased more during pregnancy?
Diastolic is decreased more (by as much as 20mmHg)
What % of women with cHTN have proteinuria at baseline? What is the cause of the proteinuria?
11%. HTN -related nephrosclerosis or, less frequently, undiagnosed CKD
HTN persisting longer than what amount of time may be reclassified as chronic instead of gestational?
12 weeks
What % of cHTN is essential hypertension and what % is secondary hypertension?
86-89% essential
11-14% secondary
What is essential HTN?
HTN due to unknown cause
What is secondary HTN?
Related to underlying renal, endocrine, or vascular conditions
What is the definition of severe HTN during pregnancy?
At or above 160mmHg systolic bp or 110mmHg for diastolic bp.
Does caffeine affect blood pressure?
Yes, can temporarily increase blood pressure. Should not have caffeine 30 mins prior to measure of bp
Does tobacco affect blood pressure?
Yes, can temporarily increase blood pressure. Should not have tobacco 30 mins prior to measure of bp
How do you know if a blood pressure cuff is appropriately sized?
A length 1.5 times the upper arm circumference or a cuff with a bladder that encircles at least 80% of the arm and width of at least 40% of arm circumference
How should a patient be positioned for a blood pressure reading?
Sitting with legs uncrossed and back supported with arm at heart height
Will a blood pressure cuff that is too small read an overestimation or underestimation bp?
Overestimation of actual blood pressure
How should you measure a blood pressure if it needs to be taken in a recumbent position,?
Taken in the left lateral decubitus position and the cuff should be at the level of the right atrium
What % of women with cHTN will depevelop superimposed preeclampsia?
20-50%.
In women with end-organ disease or secondary HTN, what is the risk of superimposed PEC?
As high as 75%
Is preeclampsia or superimposed preeclampsia worse?
Superimposed. Usually has earlier onset, be more severe, and prognosis for the woman and her fetus is worse
Which women are at higher risk of superimposed preeclampsia?
African American, obese, smoke, have had HTN for 4 years or more, have a diastolic bp higher than 100mmHg at baseline, and have a history of preeclampsia
What is the definition of white coat hypertension?
Elevated blood pressure primarily in the presence of health care providers (may account up to 15% of individuals with office HTN)
Compared to a normotensive pregnant woman, what fold increase risk does a woman with cHTN have for CVA, pulmonary edema, renal failure?
fivefold to sixfold increase
What is the incidence of gestational diabetes in women with cHTN vs those without cHTN?
Incidence of gestational diabetes in patients with cHTN = 8.1%, in those without cHTN = 2.3%
Does cHTN affect the risk of postpartum hemorrhage?
Twice the risk
Does cHTN affect the rate of preterm delivery? How?
Increases incidence of indicated preterm delivery, but does not appear to increase rate of spontaneous preterm delivery. 28% incidence of preterm delivery
What is the incidence of low birth weight among women with cHTN?
17%
For women with severe hypertension, end-organ disease, or secondary HTN has what risk of fetal growth restriction, preterm delivery, placental abuprtion, perinatal death?
FGR: 25-40%
Preterm delivery: 67%
Placental abruption: 8-20%
Perinatal death: 11%
What is the risk of fetal growth restriction in patients with superimposed preeclampsia?
As high as 50%
What is the relative risk of perinatal mortality in women with superimposed preeclampsia compared to those with uncomplicated chronic hypertension?
3.6
What are the maternal risks of chronic HTN in pregnancy?
Death, stroke, pulmonary edema, renal insufficiency and failure, myocardial infarction, preeclampsia, placental abruption, cesarean delivery, postpartum hemorrhage, gestational diabetes
What are the fetal and neonatal risk of cHTN?
Stillbirth or perinatal, death, growth restriction, preterm birth, congenital anomalies (eg, heart defects, hypospadias, esophageal atresia)?
Does cHTN increase the risk of congenital anomalies? If so, which?
Yes. Heart defects, hypospadias, esophageal atresia.
What are the risks of exposure to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers during first trimester?
Risk of malformations (eg, renal dysgenesis, calvarial hypoplasia) and fetal growth restriction
What tests should be sent for baseline evaluation for chronic hypertension in pregnancy?
AST, ALT, creatinine, electrolytes, BUN, CBC, spot Ur Pr:Cr or 24hr urine total protein and creatinine as appropriate, EKG or echocardiogram as appropriate
What is the first end-organ typically affected by chronic hypertension?
Kidneys
What level on spot urine protein-to-creatinine ratio safely indicates proteinuria <300mg?
0.15
Do you need to send a 24 hour baseline urine protein on every chronic hypertensive initiating prenatal care?
No, likely unnecessary if spot urine pr:cr <0.15
How does initial creatinine clearance affect the normal intravascular volume expansion during pregnancy and changes in creatinine clearance during pregnancy?
- Mild renal impairment (serum cr 0.9-1.4mg/dL): normal intravascular volume expansion, incremental increase in Cr clearance, but less than normal
- Moderate impairment (Cr 1.4 to 2.4-2.8), only 50% of women will have the expected increase in creatinine clearance despite a normal blood volume expansion
- Severe impairment (Cr > 2.4-2.8), markedly attenuated increase in blood volume and no increase in creatinine clearance
In which women with cHTN should you perform an EKG as a baseline assessment?
For those with poorly controlled HTN for more than 4 years or those suspected of having long-standing HTN based on age (older than 30)
What % of adult patients with hypertension have secondary hypertension?
10%
What is the suspected cause of secondary hypertension if someone has bp lability, episodic pallor, and dizziness?
Pheochromocytoma
What is the suspected cause of secondary hypertension if someone has snoring and hypersomnolence?
Obstructive sleep apnea
What is the suspected cause of secondary hypertension if someone has muscle cramps or weakness?
Hypokalemia from primary aldosteronism or secondary aldosteronism due to renovascular disease
What is the suspected cause of secondary hypertension if someone has weight loss, palpitations, heat intolerance?
Hyperthyroidism
What is the suspected cause of secondary hypertension if someone has edema, fatigue, frequent urination?
Kidney disease or failure
What is the suspected cause of secondary hypertension if someone has history of coarctation repair?
Residual hypertension associated with coarctation
What is the suspected cause of secondary hypertension if someone has central obesity, facial rounding, easy bruisability?
Cushing syndrome
What medications and substances can lead to secondary hypertension?
Alcohol, NSAIDs, cocaine, amphetamines
How does the treatment of mild-to-moderate hypertension affect maternal and fetal risk?
Reduces the risk of developing severe HTN. No effect on incidence of PEC, preterm birth, fetal death, FGR, or any other measured outcome.
At what blood pressure is antihypertensive therapy recommended for chronic hypertension in pregnancy?
Persistent cHTN with systolic pressure 160 or more, diastolic pressure 110 or more, or both. [in setting of other comorbidities or underlying impaired renal function, may treat at lower threshold]
What outcomes are associated with discontinuing antihypertensives in women with mild chronic hypertension?
Higher occurrence of severe HTN, placental abruption, preterm delivery, and NICU admission.
No increase in PEC, FGR, or perinatal abruption
**based on prospective study n=222.
At what blood pressure should women with chronic hypertension be maintained at during pregnancy?
Between 120 and <160mmHg systolic and at or above 80 to <110mmHg diastolic. Can be lower than that if certain comorbid conditions
What two medications are recommended above all other antihypertensive drugs for women who require pharmacologic therapy during pregnancy?
Labetalol and nifedipine
What are considered second-line agents for the treatment of hypertension in preganncy?
Diuretics, like HCTZ (after labetalol and nifedipine)
Why is atenolol not recommended during pregnancy?
Associated with risk of growth restriction and low birth weight
What is the dosage of labetalol?
200-2,400mg/d orally in two or three divided doses. Commonly initiated at 100-200mg twice daily
In which patients should you avoid using labetalol?
Avoid in women with asthma, preexisting myocardial disease, decompensated cardiac function, and heart block and bradycardia
What is the dosage of nifedipine?
30-120mg/d orally of an extended-release preparation. Commonly initiated at 30-60mg once daily
When should you avoid nifedipine use?
Patient with tachycardia
What is the dosage of methyldopa?
500-3,000mg/d orally in 2 to 4 divided doses. Commonly initiated at 250mg twice or three times daily
What are the side effects of methyldopa?
Sedation, depression, dizziness
What is the dosage of HCTZ?
12.5-50mg daily
What medications can be used to urgent blood pressure control in pregnancy?
Labetalol, hydralazine, nifedipine (immediate release)
What is the onset of action of IV labetalol?
1-2 minutes
What is the onset of action of IV hydralazine?
10-20 minutes
What is the onset of action of immediate release nifedipine?
5-10 minutes
What is the maximum cumulative dosage of IV labetalol?
300mg
What is the dosage of a labetalol infusion?
1-2mg/min IV
What is the maximum cumulative dosage of hydralazine?
20mg
What is the maximum daily dosage of immediate release nifedipine?
180mg
How is IV labetalol dosed for urgent blood pressure control in pregnancy?
10-20mg IV, then 20-80mg q10-30min
How is IV hydralazine dosed for urgent blood pressure control in pregnancy?
5mg (IV or IM), then 5-10mg IV q20-40 mins
How is immediate release nifedipine dosed for urgent blood pressure control in pregnancy?
10-20mg orally, repeat in 20 mins if needed, then 10-20mg q2-6h
How quickly after sustained severe range bp is diagnosed (during pregnancy) should treatment be initiated?
Within 60 mins
During management of severe range blood pressure in pregnancy, a drop below what diastolic pressure can be associated FHR abnormalities? Why?
Drop below 80mmHg. Due to the fact that uteroplacental circulation does not autoregulate blood flow.
How does epidural anesthesia affect blood pressure?
Can lower by approximately 15%
How does magnesium sulfate IV infusion affect blood pressure?
Modest if at all lowering of bp
What is the mechanism of action of labetalol?
Mixed alpha-adrenergic and beta-adrenergic blocker
What is the onset of action, time to peak effect, and duration of effect of IV labetalol?
Onset: within 5 mins
Peak effect: 10-20 mins
Duration of action: 6h
What are the adverse effects of hydralazine?
Reflex tachycardia, hypotension, headaches, palpitations, flushing, anxiety, tremors, vomiting, epigastric pain, and fluid retention. Experienced by up to 50% of recipients
What is hydralazine’s duration of action?
Up to 12 hours
How does hydralazine compare to labetalol for treatment of severe range bp in pregnancy?
Hydral is more effective than labetalol in lowering severe range bp in pregnancy, but associated with more adverse maternal and perinatal events (eg, maternal tachycardia, prolonged hypotension, oligouria, cesarean delivery, placental abruption, nonreassuring FHT, and low APGAR scores)
What is the mechanism of action of nifedipine?
Calcium channel blocker
Should you use nifedipine tablets and capsules for acute bp situations?
capsules
What are second-line agents that can be considered in blood pressure emergencies (after nifedipine, labetalol, hydralazine)?
Nicardipine or esmolol by infusion pump or IV enalapril
What is a contraindication to low-dose aspirin use for preeclampsia prophylaxis?
Women with risk factors for gastrointestinal hemorrhage (eg, bleeding disorders or peptic ulcer)
What additional fetal testing should be done for patients with chronic HTN?
Third trimester growth ultrasound. Antenatal fetal testing is recommended if complicated by need for medication, underlying medical conditions that affect fetal outcome, evidence of fetal growth restriction
True or false, women with cHTN and SiPEC have longer first stages of labor?
True
When should pregnant women with chronic hypertension be delivered?
Depends.
cHTN not on meds: 38w0 to 39w6d
cHTN well-controlled on meds 37w0d to 39w6d
Earlier if hard to control HTN (34wk+)
When should you deliver someone with SiPEC w/ severe features?
At 34 wks or beyond at time of diagnosis
What happens to the blood pressure after delivery, why?
Initial decline immediately after (due to blood loss) then bp begins to rise (related to mobilization of extravascular fluid with rise in intravascular volume)
What is blood pressure goal for women postpartum?
Maintain systolic bp not higher than 150mmHg and a diastolic blood pressure 100mmHg
What are the concerns of using NSAIDs in the postpartum period for women with cHTN of PEC?
No, no association with pp bp elevations or other adverse events
What blood pressure medications should be avoided during breastfeeding? Which are ok?
Atenolol and metoprolol are concentrated in breast milk, should be avoided. Other beta blockers, ACE, ARB, CCB are all ok. Diuretics have low concentrations in breast milk, but may reduce quality of milk production.
What can women with cHTN do to help prevent preeclampsia?
Take low-dose aspirin daily started between 12 and 28 wks (optimally before 16wks) and continue therapy until delivery
