PREGNANCY-RELATED HYPERTENSIVE COMPLICATIONS

Gestational hypertension is defined as hypertension (systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg) on at least two occasions at least four hours apart occurring for the first time at ≥20 weeks’ gestation. The diagnosis is characterized by a blood pressure that returns to normal by 12 weeks postpartum. Gestational hypertension is a provisional diagnosis; if the patient has proteinuria or new signs of end-organ dysfunction, then the diagnosis is instead preeclampsia. Gestational hypertension may also progress to preeclampsia (Melvin & Funai, 2022).

Preeclampsia is identified by the above gestational hypertension blood pressure parameters (or systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥110 mmHg on one occasion) in the presence of protein in the urine (proteinuria) or end-organ dysfunction (characterized by low platelets, increased protein creatinine ratio, pulmonary edema, elevated liver function tests, visual changes, and headache) (August, 2022).

Eclampsia is the occurrence of generalized seizures in the presence of preeclampsia without other known cause for the seizures. Seizures can occur any time before, during, or after delivery of the fetus.

Chronic hypertension is defined by a systolic blood pressure ≥140 mmHg and/or diastolic pressure ≥90 mmHg on at least two occasions that is present prior to pregnancy, presents before the 20th week of pregnancy, or persists longer than 12 weeks postpartum.

Preeclampsia superimposed on chronic hypertension is diagnosed in a patient with chronic hypertension who develops worsening hypertension with new onset proteinuria or other features of preeclampsia (e.g., elevated liver enzymes, low platelet count) (August, 2022).

Pathophysiology

Vasospasm in the arterioles of patients with gestational hypertension causes increased blood pressure and a decrease in placenta and uterine perfusion. Renal blood flow is reduced, along with the renal glomerular filtration rate, which produces proteinuria. Headaches and visual disturbances are the result of cellular damage and cerebral edema caused by central nervous system changes in the presence of hypertension. Liver enlargement is the result of hepatic changes that lead to epigastric pain. Generalized vasospasm causes endothelial cell damage, which triggers coagulation pathways, and subsequently, abnormalities in bleeding and clotting can occur.

Maternal and Fetal Implications

Hypertension during pregnancy places patients and their fetuses at great risk for a variety of complications. Some of the most significant maternal complications of hypertension in pregnancy include cerebral vascular accident (CVA, or stroke), disseminated intravascular coagulation (DIC), and placental abruption from the elevated blood pressure.

Additionally, patients are at risk for the development of HELLP syndrome, likely a severe form of preeclampsia. Just as its name implies, HELLP syndrome causes great dysfunction within the body and requires immediate intervention. It is characterized by:

• Hemolysis of red blood cells, which leads to anemia
• Elevated liver enzymes, leading to epigastric pain
• Low platelets, which cause abnormal bleeding and clotting as well as petechiae

Patients with HELLP syndrome whose function continues to decline without intervention can develop eclampsia and are at risk for DIC, placental abruption, acute renal failure, pulmonary edema, liver hematoma/rupture, and retinal detachment (Sibai, 2022). Fetal complications derive from placental abruptions, intrauterine growth restriction, and preterm birth resulting from decreased placenta perfusion.

Medical Treatment

Medical treatment for patients with gestational hypertension greatly depends on the severity of hypertension and the gestational age of the fetus, as well as the potential risk to the patient and fetus.

During early pregnancy, outpatient management is usually appropriate; these patients are monitored at home for blood pressure, proteinuria, and other signs and symptoms of preeclampsia and may be prescribed oral antihypertensives. Regular fetal monitoring is necessary to evaluate fetal well-being.

Severe hypertension requires immediate intervention with intravenous medications such labetalol and/or hydralazine. Glucocorticoids may be administered to enhance fetal lung maturity. Low-dose aspirin started prior to 20 weeks’ gestation for patients with average or high risk of developing preeclampsia may be given to decrease the likelihood of developing preeclampsia or its subsequent placental and fetal effects (Melvin & Funai, 2022).

Magnesium sulfate (MgSO₄) may be prescribed during labor and delivery to prevent seizures and for fetal/neonatal neuroprotection in pregnancies between 24–32 weeks’ gestation. Magnesium sulfate is not used to control hypertension. Magnesium sulfate is administered intravenously via an infusion delivery device during delivery and for 24 hours post delivery. Since MgSO₄ can cause respiratory depression in the neonate, arrangements are made for specialized neonatal care.

Nursing Care

Gestational hypertension presents a great risk to patients and their fetuses. Therefore, it is the responsibility of the nurse to monitor the patient carefully for signs of a decline in health status. The nurse should immediately report increases in blood pressure, visual disturbances, severe headaches, epigastric pain, and oliguria to the appropriate healthcare practitioner.

In the presence of eclampsia, the nurse must be prepared to prevent injury to the patient during seizures and to monitor seizure activity. Bedside rails should be up and padded. Emergency equipment should be readily available, including oxygen, a nonrebreather face mask, and emergency medication.

In the event of a seizure, patients should be protected from injury. The nurse should note the beginning and ending of the seizure and ensure adequate oxygenation after seizure activity has ceased. The nurse should not attempt to insert any object into the mouth during a seizure. The patient should be placed in a lateral position if possible, or the head gently turned to the side to prevent the aspiration of mucus and emesis into the lungs during seizure activity. The nurse may provide oxygen by nonrebreather mask. The nurse obtains vital signs and monitors the fetus following the seizure.

Labor may progress rapidly during seizure activity. Sometimes newborns are delivered suddenly during a seizure. The nurse should be prepared for an imminent delivery in patients with preeclampsia and eclampsia.

Patient Teaching

Patients suffering from gestational hypertension who are being treated on an outpatient basis are taught to monitor themselves and their fetus for a decline in health status. Specifically, patients are taught to notify their healthcare practitioner if they experience symptoms suggestive of preeclampsia (headache, visual changes, epigastric or right upper quadrant pain). They are also instructed to perform daily fetal kick counts to monitor fetal well-being.