Introduction
As recommended by the guidelines of the National High Blood Pressure Education Program in Pregnancy, hypertensive disorders in pregnancies are classified as 1) chronic hypertension, 2) preeclampsia-eclampsia, 3) preeclampsia superimposed on chronic hypertension, and 4) gestational hypertension. In this article, we primarily provide a comparison between the gestational and preeclampsia forms. Although they appear similar they have distinct clinical manifestations and Para clinical tests that support the differentials between both the conditions.
Gestational Hypertension Vs. Preeclampsia
Gestational hypertension is defined as a medical condition with the high blood pressure but without protein in the urine or other organ damage during pregnancy. A percentage of women (10 to 25 percent) with gestational hypertension could also progress to having preeclampsia. The presence of hypertension and proteinuria is the most common criteria used even now to diagnose preeclampsia diagnosis.
In a woman at 20 weeks of pregnancy with whose blood pressure more than140 mm Hg systolic or at least 90 mm Hg diastolic observed on multiple occasions. The values are measured separated by gaps of minimum duration is only considered as accurate measurements.
Difference Between Gestational Hypertension and Preeclampsia in Tabular Form
| Main Parameters of Comparison | Gestational Hypertension | Preeclampsia |
| Definition | Gestational hypertension is diagnosed in pregnant women in whom hypertension criteria satisfied along with additional features that satisfy the criteria for preeclampsia. | This hypertensive disorder which is pregnancy-induced new-onset hypertension, that occurs after 20 weeks of pregnancy occurs in up to 8% of pregnancies globally. |
| Diagnostic Parameters |
2. Otherwise normal blood pressure on history. 3. Protein negative in the urine by dipstick tests 4. No manifestations of pre-eclampsia conditions that prove any of its existence. |
They also include possible Hematologic changes. |
| Characteristic Features | Also referred to as transient or temporary hypertension, gestational hypertension is diagnosed retrospectively when a patient does not develop preeclampsia and if blood pressure returns to normal by the 12-week postpartum visit. | Occurrence of 8 percent has been noted annually in new emergent case analysis as per 2018 typically presenting to clinics after 20 weeks of gestation. |
What is Gestational Hypertension?
Gestational hypertension is diagnosed in patients with the hypertension criteria satisfied plus specific for preeclampsia without proteinuria or severe features. Up to 50% of women diagnosed with gestational hypertension can later develop preeclampsia. Gestational hypertension with severe range blood pressure is considered clinically similar to preeclampsia but with more severe presentational features. It is crucial to remember that both the conditions equally pose risks both fetus and the mother equally.
Gestational hypertension initially referred to as pregnancy-induced hypertension or PIH, is the new onset of hypertension after 20 weeks of gestation. The diagnosis requires that the patient have:
- Elevated blood pressure with (systolic ≥ 140 or diastolic ≥ 90 mm Hg, the latter measured using the fifth
- Previously normal blood pressures on clinical history.
- No protein in the urine by dipstick tests
- No manifestations of preeclampsia eclampsia conditions prove its existence.
Also known as transient or temporary hypertension, gestational hypertension is diagnosed retrospectively when the patient does not develop preeclampsia and if blood pressure returns to normal by the 12-week postpartum visit. The diagnosis of gestational hypertension mandates increased surveillance and monitoring among patients at high and moderate risk values assessed. Based on the intensity or degree of blood pressure, women who develop severe gestational hypertension have worse perinatal outcomes than do women with mild preeclampsia and they also need treatment similar to that of severe preeclampsia.
In circumstances where a woman is 34 weeks pregnant, delivery is advised and the diagnosis is put off since there is a high possibility that the mother and baby would suffer injury. If a woman has severe hypertension that lasts for at least 15 minutes, she should receive antihypertensive medication. To prevent negative consequences such as congestive heart failure, myocardial ischemia, renal failure, and stroke, this can be done with oral nifedipine, intravenous hydralazine, or labetalol. It should be started as soon as feasible and within an hour of presentation.
What is Preeclampsia?
Preeclampsia is a type of hypertensive disorder that is pregnancy-induced new-onset hypertension and occurs in up to 8% of pregnancies all over the world. It generally appears after 20 weeks of gestation, usually near term. Risk is increased in patients with several factors. Some of them that are predisposing them are listed below:
High risk is observed in mothers with:
- Autoimmune disease (e.g., systemic lupus erythematosus, antiphospholipid syndrome)
- Diabetes mellitus or sugar intolerance in body of the mother
- History of preeclampsia
- Multifetal gestation
- Chronic hypertension
- Renal disease
Moderate risk observed in patients with:
- More than or atleast 35 years of age
- Black race or low socioeconomic status
- Family history of preeclampsia (mother or sister)
- History of low-birth-weight infant, adverse pregnancy outcome, or more than 10 years between pregnancies
- Obesity (body mass index > 30 kg per m2)
The presence of hypertension and proteinuria is the most common criteria used even now to diagnose preeclampsia. In a woman at 20 weeks of pregnancy with whose blood pressure more than140 mm Hg systolic or at least 90 mm Hg diastolic observed on multiple occasions. The measurements should differ at least by four or more hours apart. Hypertension is considered severe presentation when blood pressure is at least 160 mm Hg systolic or at least 110 mm Hg diastolic. Severe blood pressure values may facilitate early timely intervention.
Proteinuria in pre-eclampsia patients is defined as 300 mg per 24-hour urine collection, a protein-to-creatinine ratio of at least 0.3 mg per dL, or a urine dipstick test result of 2+. If patients do not have proteinuria, preeclampsia is still diagnosed with some other conditions that coexist.
- if they also have new-onset thrombocytopenia
- renal insufficiency
- impaired liver function combined with epigastric pain
- pulmonary edema
- Refractory headache and vision problems.
New-onset seizures with excluded other etiologies (e.g., epilepsy), are one of the severe manifestations of hypertensive disorders of pregnancy and also the main indicator of maternal mortality.
Management of Preeclampsia
Preeclampsia places both mother and fetus at risk equally. It is, however, a maternal disorder. The mainstay of treatment is early detection and managed delivery to minimize both maternal and fetal risks induced. If the pregnancy is at term, the decision is easy: the baby should be delivered at the earliest. The decision to deliver involves balancing the risks of worsening preeclampsia against those of prematurity with any possible life-saving benefits ratio. Delivery is generally not indicated in pregnant women with mild preeclampsia until 37 to 38 weeks of gestation and should occur by 40 weeks . Magnesium sulfate is still the drug of choice for the prevention and arresting of eclamptic seizures. It has the additional benefit of reducing the incidence of placental abruption or tear caused. However, this requires Serum magnesium levels should be monitored continuously in women with elevated serum creatinine levels, decreased urine output, or absent deep tendon reflexes
Magnesium toxicity could lead to respiratory paralysis, central nervous system depression, and cardiac arrest. Hence this fact needs to be considered while considering the regime for the patient. Also to know the important antidote for such toxicity is calcium gluconate, 1 g infused intravenously over two minutes
Antihypertensive medications are used only to prevent maternal morbidity and have no effect on disease progression or preventing eclampsia.
Main Difference Between Gestational Hypertension and Preeclampsia in Points
Definition
Gestational hypertension is diagnosed in pregnant women in whom hypertension criteria satisfied along with additional features that satisfy the criteria for preeclampsia. But the difference exist in the fact that gestational hypertension do not show a severe clinical presentation like preeclampsia.
Preeclampsia on other hand is a hypertensive disorder that is pregnancy-induced new-onset hypertension that occurs after 20 weeks of pregnancy and occurs in up to 8% of pregnancies globally.
Diagnosis
Gestational hypertension is diagnosed in patients with the hypertension criteria for preeclampsia but without proteinuria or severe features, unlike preeclampsia. Up to 50% of women diagnosed with gestational hypertension can develop preeclampsia. Gestational hypertension with severe range blood pressures is managed however in the same way as preeclampsia with severe features because of similar risk.
Markedly elevated systemic blood pressure measurements, Proteinuria (≥ 5 g/24 hours, Manifestations of end-organ disease, and multiple system involvements are the primary features that lead to the diagnosis. Also, the time of admission of the patient needs to be evaluated. Usually, preeclampsia is presented with hypertension after 20 weeks of pregnancy.
Paraclinical Tests
In case of preeclampsia:
- Markedly elevated blood pressure measurements (systolic ≥ 160 mm Hg or diastolic ≥ 110 mm Hg) taken 6 hours apart with the patient on bed rest
- Proteinuria (≥ 5 g/24 hours or ≥ 3+ on 2 random samples 4 hours apart)
- Manifestations of end-organ disease: oliguria (< 500 mL in 24 hours), cerebral or visual disturbances, lung edema, cyanosis, epigastric or right upper quadrant pain, impaired liver function, thrombocytopenia, or fetal growth restriction.
Hematologic changes include:
- Thrombocytopenia—platelets are dramatically reduced, probably consumed by endothelial damage and injury. Counts can go as low as 20 to 50 x 109/L.
- Hemoconcentration—doctors used to follow preeclampsia with serial records of hematocrits.
- Microangiopathic hemolysis—eventually, the red cells are sheared through the microcirculation.
- Hepatic changes are usually limited to conditions or complications developed by patients with hepatocellular necrosis, demonstrated by elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Occasionally there is subcapsular hemorrhage with even hepatic rupture, which has a 60% maternal mortality rate.
- Neurologic changes are not uncommon and include headache, blurred vision, scotoma (seeing spots or “snow”), hyperreflexia, and rare, cortical blindness, and the generalized seizures of eclampsia.
- Renal changes may include Glomerular endothelins the pathognomonic lesion of preeclampsia. This condition involves the glomeruli that are enlarged, distorted, and filled with occlusions, with hypertrophy of the intra-capillary cells.
- Fetal changes including the Intrauterine growth restriction are very common. Oligohydramnios also occurs, because the amniotic fluid is essentially fetal urine; with poor perfusion through the placenta, the fetus has diminished urine output.
HELLP syndrome which is the abbreviation term or pneumonic form (hemolysis, elevated liver enzymes, and low platelets) used to be classified as a separate syndrome, but current thinking categorizes it as a manifestation of preeclampsia, occurring in about 20% of severe cases
In the case of gestational hypertension, the confirming para clinical tests that can be used are a similar tests but results are either negative or minimal unlike preeclampsia which usually has a severe presentation
- Blood pressure measurement made on multiple occasions separated by fixed duration ago
- Protein presence tested in urine by using the dipstick test.
- Other systemic tests to assess the general health conditions of the patient.
Conclusion
Gestational hypertension is usually diagnosed when blood pressure readings are higher than 140/90 mm Hg in a woman who had normal blood pressure before 20 weeks and has no proteinuria (excess protein in the urine). Preeclampsia can be diagnosed when a woman with gestational hypertension also has increased protein in her urine.
- If a patient has one high-risk factor for preeclampsia or two moderate risk factors, low-dose aspirin therapy should be started between 12 and 28 weeks of gestation.
- Women who are at least 37 weeks pregnant and have preeclampsia or gestational hypertension should deliver immediately.
- Patients with preeclampsia or pregnant hypertension who arrive with severe symptoms at 34 weeks or more gestation should deliver. At less than 34 weeks gestation, expectant care might be taken into consideration.
Expectant care should be halted and delivery undertaken if the mother's or baby's condition deteriorates. Expectant care is inappropriate if the baby is not expected to survive since the elevated risks for the mother are not outweighed by any advantages for the baby.
References
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279097/
- https://www.aafp.org/afp/2019/1115/p649.html
- https://www.tchc.org/application/files/1516/0193/1072/Gestational_Hypertension_and_Preeclampsia.pdf
