HTN in Pregnancy: DDx

Advanced, Clinical Subspecialties

Hypertensive disorders are one of the leading causes of maternal mortality worldwide. Blood pressure typically falls early in pregnancy and reaches nadir between 16-20 weeks gestational age. Later in pregnancy, the blood pressure will return to baseline. There are multiple categories of elevated blood pressure in pregnancy; management varies depending on the classification.

-     Chronic hypertension: occurs in 0.9-1.5%of pregnant women

       -     SBP≥140mmHg  or DBP ≥90mmHg existing before pregnancy or diagnosed before 20-weeks gestation

       -     patient is diagnosed with hypertension during pregnancy but persists ≥12 weeks after delivery

       -     As with hypertension in non-pregnant population, can be primary or secondary hypertension attributable to other causes

-     Gestational Hypertension

       -     New onset SBP ≥140mmHg  or DBP ≥90mmHg on at least 2 occurrences 4 hours apart after 20 weeks of gestation in previously normotensive female

       -     No proteinuria or severe features of pre-eclampsia

       -     10-25% will develop signs/symptoms of pre-eclampsia later in pregnancy

       -     Typically resolve within 12 weeks after delivery (otherwise considered chronic, as above)

-     Pre-eclampsia/Eclampsia/HELLP syndrome

       -     Pre-eclampsia:

              -     New onset SBP≥140mmHg or DBP ≥ 90mmHg on at least 2 occasions 4 hours apart after 20-weeks gestation (i.e. patient was normotensive prior to pregnancy) OR SBP ≥160mmHg or DBP≥110mmHg 

              -     AND

              -     Proteinuria ≥300mg per 24hour urine collection, OR protein:creatinine ratio ≥0.3

              -     OR

              -     If no proteinuria, new-onset hypertension with new onset of one or more of the following (severe features):

                     -     Thrombocytopenia (platelet count <100,000)

                     -     Renal insufficiency (Cr >1.1 or doubling from baseline in absence of other disease)

                     -     Impaired liver function (LFTs 2x upper limit of normal)

                     -     Pulmonary edema

                     -     Cerebral or visual symptoms (new onset headache not responsive to Tylenol)

              -     Pre-eclampsia CAN develop post-partum

              -     Risk factors for pre-eclampsia:

                     -     High risk factors: prior pregnancy with pre-e, multifetal gestation, renal disease, autoimmune disease (SLE, antiphospholipid antibody syndrome), diabetes, chronic hypertension)

                     -     Moderate risk factors: nulliparas/first pregnancy, advanced maternal age, BMI >30, family history

              -     Patients are started on ASA 81mg/day for pre-eclampsia prophylaxis

       -     Pre-eclampsia with severe features

              -     SBP ≥160mmHg or DBP≥110mmHg on 2 occasions at least 4 hours apart

              -     Thrombocytopenia (plt <100,000)

              -     Impaired liver function (LFTs 2x upper limit of normal)

              -     Pulmonary edema

              -     Cerebral or visual symptoms (new onset headache not responsive to Tylenol)

-     Eclampsia:

              -     Seizures occurring in patient with pre-eclampsia without alternate cause for seizure (no other neurologic conditions, drug use, etc.)

-     HELLP Syndrome:

              -     Hypertension + elevated liver enzymes + low platelets

              -     Potentially subtype of pre-eclampsia; patients do not have to have hypertension (~15% lack hypertension or proteinuria), though majority do

              -     Main presenting symptom is often RUQ pain and malaise, may have nausea/vomiting

              -     Associated with higher rates of morbidity/mortality

              -     Typically occurs in 3rd trimester, but can occur postpartum

-     Pre-eclampsia superimposed on chronic hypertension

              -     In patient with chronic hypertension as above, new sudden increase in blood pressure in patient on previously stable anti-hypertensive regimen or elevated BP resistant to treatment  OR new development of proteinuria or increase in proteinuria (if present before/early in pregnancy)

              -     Can be with severe features as well


    Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222. Obstet Gynecol. 2020 Jun;135(6):e237-e260.


Answered correctly


Year asked

Emmarie Myers, MD