Approach to hypertensive disorders in pregnancy: Clinical sciences

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Introduction0:00–0:20

Hypertension in pregnancy is a spectrum of disorders, all characterized by elevated blood pressure. These include chronic hypertension, gestational hypertension, preeclampsia without or with severe features, HELLP, and eclampsia.Your first step in evaluating a patient who presents with a hypertensive disorder of pregnancy is to perform a CABCDE assessment along with a primary obstetric survey to determine if they’re stable or unstable.

Acute Management 0:20–1:24

If the patient is unstable, check for uncontrolled bleeding and control any hemorrhage, as severely elevated blood pressure may cause a placental abruption.
Next, stabilize their airway, breathing, and circulation and consider intubation when appropriate. Obtain IV access and continuously monitor maternal vital signs.
As for the primary obstetric survey, monitor the fetal heart rate and contraction pattern; possibly test for rupture of amniotic membranes; and consider checking cervical dilation if indicated.Here’s a clinical pearl!
Urgent hypertension is defined as 160/110 or higher that persists after retake in 15 to 20 minutes; this requires antihypertensive medication to reduce the risk of maternal stroke.
Let’s take a look at stable patients. Alright, now that unstable patients are taken care of, let’s talk about stable patients.

Stable Patient1:24–1:59

First, obtain a focused history and physical examination. This should include an accurate blood pressure measurement.
A systolic blood pressure greater than or equal to 140, a diastolic blood pressure greater than or equal to 90, or both is considered abnormal during pregnancy.
Once you have recognized the patient has elevated blood pressure, it’s time to investigate further; the first step is to assess the patient’s gestational age.Let’s take a look when the patient is less than 20 weeks gestation.If the patient is less than 20 weeks gestation, assess whether they have a history of hypertension prior to pregnancy.

Gestational Age < 20 weeks1:59–2:46

If the patient does report a history of hypertension, your diagnosis is chronic hypertension. If the patient denies any history of hypertension, still consider a diagnosis of chronic hypertension and continue to monitor them closely throughout the remainder of the pregnancy.
If a second elevated blood pressure is recorded prior to 20 weeks of gestation, the patient meets the diagnostic criteria for chronic hypertension.
However, if they remain normotensive, the elevated blood pressure simply represents an isolated elevated blood pressure in pregnancy and not a true hypertensive disorder.
Okay, let’s shift our focus to patients who present with hypertension from 20 weeks of gestation through 12 weeks postpartum with abnormal blood pressure.

Gestational Age > 20 weeks through 12 weeks PP2:46–4:01

When a pregnant patient who is greater than or equal to 20 weeks gestation has abnormal blood pressure, monitor them closely to see if any repeat elevated blood pressure is noted.
If no repeat blood pressures are elevated, continue to monitor them at subsequent prenatal visits, though they do not meet the criteria for a true hypertensive disorder of pregnancy.
If a second elevated blood pressure is recorded, specifically a systolic pressure of at least 140, or a diastolic pressure of at least 90, or both, and it has been at least 4 hours since the first elevated measurement, you have diagnosed a hypertensive disorder of pregnancy.
Your next step is to order labs to help determine the specific disorder present. This will include a CBC, CMP, LDH, a urine protein to creatinine ratio, also known as P/C ratio, and possibly a 24-hour urine collection to measure total protein.
A uric acid measurement can also be helpful in some cases. Once these labs are sent, assess if the patient has any history of hypertension prior to pregnancy.Let’s take a look when the patient reports no history of chronic hypertension either during or outside of pregnancy.If your patient reports no history of chronic hypertension, consider either gestational hypertension or preeclampsia.

>20 weeks GA and no history of HTN4:01–6:46

To make your diagnosis, review lab results, specifically the urine P/C ratio to assess for proteinuria. Proteinuria is defined as a urine P/C ratio greater than or equal to 0.30, or a 24-hour urine protein with at least 300 mg of protein.
At the same time, assess for signs or symptoms of preeclampsia, which include new-onset headache, visual changes, right upper quadrant or epigastric pain, and possibly shortness of breath.
If all labs are normal, the urine P/C ratio is less than 0.30, and the patient is asymptomatic, your diagnosis is gestational hypertension.
On the flip side, let’s take a look when the patient’s lab demonstrates proteinuria.If the patient’s lab shows proteinuria, your patient has preeclampsia.
Once preeclampsia is diagnosed, you need to assess for severe features. These include blood pressures of at least 160 systolic or 110 diastolic on two occasions at least 4 hours apart; laboratory abnormalities like thrombocytopenia with a platelet count of less than 100,000, renal insufficiency with a creatinine greater than 1.1, elevated liver function tests greater than two times the upper limit of normal; and manifestations such as pulmonary edema, new-onset headache that does not improve with medication, visual symptoms like spots or blurry vision, severe, persistent right upper quadrant abdominal pain, or epigastric pain.
Here’s a clinical pearl! If severe range blood pressures are present, the full 4 hours of blood pressure monitoring is not required in order to make a presumptive diagnosis of preeclampsia with severe features.
This allows for more timely initiation of antihypertensive therapy, which is key to reducing a patient’s risk for seizure, stroke, and other complications.If no severe features are present, the patient's diagnosis is preeclampsia without severe features.
If one or more severe features are present, the diagnosis changes to preeclampsia with severe features. And another clinical pearl!
Even though a patient may meet diagnostic criteria for gestational hypertension on presentation, remember that gestational hypertension can progress to preeclampsia quickly!
Thus, they still need to be closely monitored and have regular blood pressure measurements throughout their antepartum, labor and delivery course.Alright, now that we’ve covered patients at least 20 weeks gestation with no history of chronic hypertension, let’s move on to patients who do report a history of chronic hypertension.

>20 wks GA with a positive history of HTN6:46–8:03

In these patients, elevated blood pressure may simply represent an exacerbation of the patient’s known chronic hypertension, so that should be your first consideration.
However, you must also consider superimposed preeclampsia on chronic hypertension, as patients with chronic hypertension have an increased baseline risk.
To make your diagnosis, review the labs and note any symptoms or other clinical findings of preeclampsia. If proteinuria is absent or at the patient’s baseline, labs are normal, and the patient is asymptomatic, the diagnosis remains chronic hypertension.
On the other hand, if the urine P/C ratio or 24-hour urine protein shows new onset or worsening proteinuria, the patient has superimposed preeclampsia on chronic hypertension.
As before, the next step is assessing for severe features.If absent, the diagnosis is superimposed preeclampsia without severe features; but if one or more are present, the diagnosis is superimposed preeclampsia with severe features.Alright, let’s talk about patients who may possibly have a history of chronic HTN, but in whom clinical findings and labs play a much greater role.

>20 weeks GA with or without a history of HTN8:03–8:17

Your first step here is to review the clinical findings and laboratory results.Let’s start with HELLP syndrome. HELLP syndrome represents one of the most severe forms of preeclampsia.

HELLP Syndrome8:17–8:52

HELLP stands for Hemolysis, Elevated Liver enzymes, and Low Platelets. Patients with HELLP have LDH greater than or equal to 600 due to hemolytic anemia, elevated liver function tests, and thrombocytopenia.
They might also have proteinuria, right upper quadrant pain with generalized malaise, or severe range blood pressures. If you see these findings, your diagnosis is HELLP syndrome.
Finally, let’s talk about eclampsia. If a patient presents with a new-onset tonic-clonic seizure in the absence of other etiologies for a seizure, your diagnosis is eclampsia.

Eclampsia 8:52–9:23

Eclampsia is the convulsive manifestation of the hypertensive disorders of pregnancy, and represents an obstetric emergency.
In addition to seizures, the patient could also have a severe headache, altered mental status, visual symptoms, or proteinuria.
These support the diagnosis of eclampsia. Alright, as a quick recap… The hypertensive disorders of pregnancy are classified based on gestational age, the presence or absence of proteinuria, and whether severe features are present.

Review9:23–9:57

Prior to 20 weeks of gestation, elevated blood pressure typically represents chronic hypertension. After 20 weeks of gestation through 12 weeks postpartum, abnormal blood pressure may represent gestational hypertension, preeclampsia with or without severe features, superimposed preeclampsia on chronic hypertension, HELLP syndrome,
Approach to hypertensive disorders in pregnancy | Osmosis