Pregnancy related hypertension - 1 Minute Read Differential Diagnosis

An article recently published with NPR details some shocking statistics concerning pregnancy-related hypertension, and it has been made apparent how little is known about pregnancy hypertension. The newborn is often watched and evaluated very closely, but not as much attention is focused on the Mother, especially postpartum. We also still have very little information on the causes of pregnancy related hypertension, especially conditions surrounding preeclampsia.

Some of the key statistics that emerged from the study were:

• Preeclampsia, or pregnancy-related hypertension, affects 3-5% percent of expectant or new mothers in the U.S. which accounts for 200,000 women a year
• Preeclampsia around the world kills five women every hour, but in developed countries it is highly treatable if recognised and treated quickly.
• Britain has reduced preeclampsia deaths to one in a million by standardizing its approach, resulting in a total of two deaths from 2012 to 2014.  In the US preeclampsia still account for 8% of maternal deaths which equates to 50 to 70 women per year.

Types of Pregnancy Related Hypertension

Pregnancy related hypertension is defined as a pre-existing or new hypertensive disorder complicating pregnancy.  It is the most common medical complication of pregnancy.  The types of pregnancy related hypertension include:

Chronic hypertension

This is when hypertension predates pregnancy or is detected before 20 weeks of gestation.  Reported in 5% of pregnant women and may appear in the postpartum period.

Gestational hypertension (formally known as pregnancy-induced hypertension)

Hypertension without proteinuria developing after 20 weeks of gestation.  This either progresses to preeclampsia or chronic hypertension or resolves and becomes transient hypertension.

Preeclampsia (toxemia of pregnancy)

When Hypertension (blood pressure above 140/90 mm Hg) and proteinuria (>300 mg/24 hours) are both detected after 20 weeks of gestation.  If proteinuria isn’t present then diagnosis requires one of thrombocytopenia, impaired liver function, new renal insufficiency, pulmonary edema or new onset cerebral or visual disturbance.  The most commonly affected are nulliparous women, or those with pregnancies complicated by multiple gestations, and the condition becomes more frequent in women nearing term.

Hemolysis, Elevated Liver enzymes, Low Platelets (HELLP) syndrome

This is a multi-system disorder and is seen as a complication of severe preeclampsia.

Eclampsia

If preeclampsia isn’t detected and treated then eclampsia will develop which is catastrophic, and detected by new-onset grand mal seizures in patients of preeclampsia.

Symptoms of Pregnancy Related Hypertension

As well as the specific symptoms mentioned earlier regarding various types of pregnancy related hypertension, these symptoms should also be evaluated when assessing any hypertension concerns during pregnancy:

• Rapid weight gain due to fluid retention
• Edema of face and hands
• Visual disturbances – blurred vision, scotomata
• Severe headaches
• Nausea/vomiting
• Epigastric or right upper quadrant pain
• Oliguria
• Hyperreflexia
• Chest pain
• Dyspnea
• The patient may be asymptomatic

Diagnosis of pregnancy related hypertension disorders

It is important to recognize these key symptoms and make an early diagnosis to allow the best possible outcome for both mother and baby. If you are unsure and have clinical doubt, using a differential diagnosis tool like Isabel could ensure that you have seen all relevant disorders and considered ‘don’t miss’ diagnoses.

Isabel Differential diagnosis generator with key symptoms of HELLP syndrome

Recognizing post partum eclampsia with a differential tool

Following your differential diagnosis, steps can be taken to confirm diagnosis. Monitor blood pressure and request general blood tests, including levels of creatinine, electrolytes, uric acid, liver enzymes and platelet count. Compare the results with baseline tests performed earlier in pregnancy.  You can also request a urinalysis to detect proteinuria.

Treatment of pregnancy related hypertension conditions

Mild preeclampsia can be treated with antihypertensives and regular checkups until delivery. Corticosteroids may also be used to improve liver and platelet function and prolong pregnancy if not post-partum.

Indications for hospitalization include severe hypertension or severe preeclampsia. If women with a history of preeclampsia develop severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia, then they need to be hospitalized for the remainder of the pregnancy or until preeclampsia symptoms disappear.

Delivery is the only cure for preeclampsia, and often early delivery is the best option for patients with severe hypertension. Gestational age and health of mother and baby should be compared with each other to determine the course of action. Indications that delivery is the most sensible option are:

• Preeclampsia and a mature fetus at or over 37 weeks of gestation
• Gestational age at or over 34 weeks of gestation with signs of maternal or fetal distress
• Severe preeclampsia, regardless of gestational age (see below)
• Hemolysis, Elevated Liver enzymes, Low Platelets (HELLP) syndrome, irrespective of gestational age.

Severe preeclampsia and delivery plans

Severe preeclampsia will require delivery of the baby as soon as possible to stop development of eclampsia. Depending on the length of gestation, treatment can vary:

• Under 23 weeks - consider offering termination
• 23 to 34 weeks – antihypertensives and steroids to enhance fetal lung maturity, with a plan to deliver at 34 weeks with magnesium sulfate prophylaxis
• If mother has severe hypertension, eclampsia, disseminated intravascular coagulation, pulmonary edema, abnormal fetal test results, abruption placentae then delivery should be planned when maternal condition is stable.

Complications of pregnancy related hypertension

Eclampsia (generalized seizures) will develop if preeclampsia is not recognized and treated, which can be life-threatening.  Eclamptic seizures may occur unexpectedly in patients with no apparent or minimally elevated blood pressure and no proteinuria.  Eclampsia may be preceded by premonitory signs including headache, visual disturbances, epigastric pain, constriction sensation in thorax, apprehension, excitability and hyperreflexia so these symptoms should be taken very seriously in a pregnant woman.  What is not often realised is eclampsia can develop antepartum, intrapartum or up to 48 hours postpartum.  It is commonly misunderstood that once the baby is delivered then eclampsia cannot occur, and that is why it is important that maternal health postdelivery is monitored just as closely as it is prior to the baby being delivered, and urgent action taken if the mother develops more symptoms.

The NPR article states that every year in the US, 700 to 900 women die from pregnancy of childbirth-related causes and an additional 65,000 nearly die making it one of the worst records in the developed world.  In the US, maternal deaths increased from 2000 to 2014 and in a recent CDC Foundation, nearly 60% of deaths were preventable.  One of the reasons given by the authors of the article for this trend is confusion amongst caregivers on how to recognise worrisome symptoms in pregnant women and therefore how to recognize and treat obstetric emergencies.  Using a differential diagnosis tool to research these worrisome symptoms and consider the red flagged don’t miss diagnoses in pregnant women and those in the postpartum period could help reduce these statistics and worrying trend.  Adopting standardised care pathways across all states will also help reduce these figures and obtain positive results such as has been seen in the UK.

If you have clinical doubt during diagnosis of hypertension conditions, or any other diagnostic process, consider using the Isabel DDx Generator: