Cochin Cardiac Club

Health Blog by Dr.Uday Nair

PREGNANCY INDUCED HYPERTENSION(PIH)

 

 
 Hypertensive disorders of pregnancy, previously know as Pregnancy induced hypertension (PIH), are high blood pressure disorders of pregnancy. It has long been one of the major problems for mothers in pregnancy, along with infection and postpartum hemorrhage. Preeclampsia affects 5-8% of all pregnancies but 10-20% of mothers will have a hypertensive disorder during pregnancy.
There are four different levels of hypertensive disorders in pregnancy:

  1. Chronic Hypertension (Discovered prior to 20 weeks gestation.)
  2. Gestational Hypertension
  3. Preeclampsia/Eclampsia
  4. Preeclampsia/Eclampsia superimposed on chronic hypertension
PIH can be detected early during regular prenatal visits, which is one of the reasons they are so very important. If you have PIH and it is untreated you may wind up with a preterm baby, a stillborn baby or a baby who has growth restriction (IUGR), not to mention the effects on your health.
There are still different opinions on the causes of PIH. There are speculations of placental involvement, underlying disease, hormonal involvement etc.

SIGNS AND SYMPTOMS OF PIH

If you experience any of the following warning signs, report them to your doctor:

  • Rapid weight gain, 2-3 kg  in a single week
  • A rise in your blood pressure
  • Protein in your urine
  • Severe headaches
  • Blurry vision
  • Seeing spots in your eyes
  • Severe pain over your stomach, under your ribs
  • Decrease in the amount of urine

Not all of these symptoms or signs may be detected by an individual. This is one of the reasons that it is so important that you keep your regular prenatal appointments is to screen all women for the above symptoms as well as other signs of PIH. If you must miss an appointment be sure to reschedule it right away.
 
There are treatment options for those women suffering from chronic hypertension or gestational hypertension, including hypertensive medications. Some practitioners recommend strategies that are dietary, while others involve exercise and rest. Recently it has been shown that aspirin doesn't help in the treatment for women in a low risk group but can be helpful for a select high risk group. If you have preeclampsia, the only cure is delivering the baby. Talk to your doctor about which options are best for you because this is critical.
 
The important thing to remember is that PIH is a very serious illness. You must be followed closely by your medical professional to help prevent prematurity and death of your baby and other severe complications in the most severe cases.
Now it is also known that even slight rises in the blood pressure during pregnancy can have a lasting effect. Women who have PIH or more severe forms are at greater risk for coronary artery disease later in life.



Diagnosis of  PIH  includes:

The following findings suggest mild preeclampsia:
  • elevated blood pressure reading 140 systolic, or a rise of 30 mm Hg or greater above the patient's normal systolic pressure, measured on two occasions, 6 hours apart; 90 diastolic, or a rise of 15 mm Hg or greater above the patient's normal diastolic pressure, measured on two occasions, 6 hours apart
  • proteinuria - more than 300 mg/ 24 hours. The following findings suggest severe preeclampsia:
  • higher blood pressure readings 160/110 mm Hg or higher on two occasions, 6 hours apart, on bed rest
  • increased proteinuria - 5 g/24 hours or more
  • oliguria - urine output less than or equal to 400 ml/24 hours
  • deep tendon reflexes - possibly hyperactive as central nervous system (CNS) irritability increases.
Typical clinical features especially seizures with typical findings for severe preeclampsia strongly suggest eclampsia. Ophthalmoscopic examination may reveal vascular spasm, papilledema, retinal edema or detachment, and arteriovenous nicking or hemorrhage.
Real-time ultrasonography, stress and nonstress tests, and biophysical profiles evaluate fetal status. In the stress test, oxytocin is administered to stimulate contractions and then fetal heart tones are monitored electronically. In the non stress test, fetal heart tones are monitored electronically during periods of fetal activity without oxytocin stimulation. Electronic monitoring reveals stable or increased fetal heart tones during periods of fetal activity.
Ultrasonography aids evaluation of fetal health by assessing fetal breathing movements, gross body movements, fetal tone, reactive fetal heart rate, and qualitative amniotic fluid volume.


 

Treatment of PIH


Therapy for preeclampsia is designed to halt the disorder's progress specifically, the early effects of eclampsia, such as seizures, residual hypertension, and renal shutdown and ensure fetal survival. Some physicians advocate the prompt induction of labor, especially if the patient is near term; others may take a more conservative approach. Therapy may include anticonvulsants (such as magnesium sulfate), along with complete bed rest, to relieve anxiety, reduce hypertension, and evaluate response to therapy. Antihypertensive therapy doesn't alter the potential for developing eclampsia. Diuretics aren't appropriate during pregnancy.
If the patient's blood pressure fails to respond to bed rest and sedation and persistently rises above 160/ 100 mm Hg, or if CNS irritability increases, magnesium sulfate may produce general sedation, promote diuresis, and prevent seizures. Cesarean birth or oxytocin induction may be required to terminate the pregnancy.
Emergency treatment of eclamptic seizures consists of immediate administration of magnesium sulfate I.V., oxygen administration, and continuous electronic fetal monitoring. After the seizures subside and the patient's condition stabilizes, delivery should proceed with induction of labor or cesarean birth, depending on the circumstances.
 Complications of PIH
Pregnancy induced hypertension may develop into eclampsia , the occurrence of seizures. Fetal complications may occur because of prematurity at time of delivery.

Special considerations

  • Monitor the patient regularly for changes in blood pressure, pulse rate, respiration, fetal heart tones, vision, level of consciousness, deep tendon reflexes, and for headache unrelieved by medication. Report changes immediately. Assess these signs before administering medications. Absence of patellar reflexes may indicate magnesium sulfate toxicity.
  • Assess fluid balance by measuring intake and output and by checking daily weight.
  • Observe for signs of fetal hypoxentia by closely monitoring the results of stress and non stress tests.
  • Instruct the patient to lie in a left lateral position to increase venous return, cardiac output, and renal blood flow.
  • Keep emergency resuscitative equipment and drugs available in case of seizures and cardiac or respiratory arrest. Also keep calcium gluconate readily available at the bedside because it counteracts the toxic effects of magnesium sulfate.
  • To protect the patient from injury, maintain seizure precautions. Don't leave an unstable patient unattended.
  • Assist with emergency medical treatment for the convulsive patient. Provide a quiet. darkened room until the patient's condition stabilizes and enforce absolute bed rest. Carefully monitor administration of magnesium sulfate and give oxygen, as ordered. Don't administer anything by mouth. Insert an indwelling urinary catheter for accurate measurement of intake and output.
  • Inform the patient about tests that evaluate fetal status because the baby's welfare is of prime concern.
  • Provide emotional support for the patient and family. If the patient's condition necessitates premature delivery, point out that infants of mothers with PIH are usually small for gestational age but sometimes fare better than other premature babies of the same weight, possibly because they have developed adaptive responses to stress in utero.

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