Pre-eclamptic Toxaemia (PET)


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Pre-eclamptic toxaemia (PET) is also called Toxemia of Pregnancy or pregnancy induced hypertension. This is a syndrome that develops after the 20th week of pregnancy. It is characterized by:

  • Persistent high blood pressure at or above 140/90mmHg.

  • Edema or swelling of the feet and ankles.

  • Proteinuria or presence of protein in the urine.
Edema is usually the first sign to occur followed by high blood pressure and then by proteinuria.

Causes of PET

The exact cause of PET is unknown but several theories have been put forward:

  • It is believed to be associated with a defect of the immunological mechanism involved in normal fetomaternal host response.
  • It could be due to abnormal placentation which sets up an inflammatory response in the mother's blood vessels.
  • It could be genetic.
  • Could be related to the diet and vitamin deficiency.

Signs and Symptoms of PET

  • Mild PET: In mild cases of PET, blood pressure is persistently at and above 140/90 mmHg but below 160/110 mmHg. There may be edema and/or proteinuria.

  • Severe PET: In severe cases of PET, blood pressure lies at /above 160/110mmHg. There may be edema all over the body including the face. Grade III Proteinuria is almost always present. The patient may complain of other grave symptoms like headache, giddiness, pain in the upper part of the abdomen (epigastric pain), vomiting, various eye symptoms, and sometimes decrease in the volume of urine (oliguria).

  • All types of PET: In both mild and severe cases, the patient is usually carrying her first pregnancy and is more than 20 weeks pregnant, usually more than 28 weeks.

  • Excessive Weight Gain: There may be abnormal weight gain. Sudden weight gain over 1-2 days, more than 2 pounds a week should be investigated for PET.

  • Pressure Symptoms: Pressure symptoms like breathlessness and palpitation can occur due to the excessive weight gain.

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Tests in PET

  • Blood: Haemoglobin level and serum Uric Acid levels. Liver enzymes may be higher than normal. Platelet count may be low.
  • Urine: The total quantity of urine; presence of protein in the urine.
  • Eyes: The fundus of the eye has to be checked for any changes caused by hypertension.

Complications of PET

  • Eclampsia: The most important complication is eclampsia which is PET complicated with convulsions or fits. Cerebral hypoxia (lack of oxygen in the brain) and cerebral edema due to high blood pressure are the main causes.

  • Placental Abruption: Placental Abruption i.e. bleeding into the base of the placenta leading to fetal death is another important complication.

  • Chronic Hypertension: Some patients may develop chronic hypertension after delivery.

Management / Treatment of Pre-eclamptic Toxaemia (PET)

Mild PET

  • Bed rest: Bed rest should be taken for at least 8 hours at night and 2 hours during the day. She should also lie down in bed on her left side during the other hours as much as possible. Rest causes decrease in hypertension, decrease in oedema and increases the placental blood flow.

  • Diet and Salt Restriction: Pregnancy Diet should be nutritious with adequate fluid intake. Salt should be restricted to 5 mg per day instead of 10 mg per day as advised in normal pregnancy.

  • Medicines: Anti-hypertensive and sedative drugs should be prescribed.

  • Regular monitoring: Regular monitoring of blood pressure, fluid intake and output chart; urine for protein; weight increase; check up of eyes; blood tests.

  • Regular fetal monitoring The rate and rhythm of the fetal heart sound and number of fetal movements per day is monitored.

  • Delivery of the baby: Pregnancy is terminated at 37 weeks after checking for fetal maturity by USG. If cervix is soft and inducible, then labor is induced. If fetus is deemed to be at risk and cervix firmly closed , elective caesarian section should be done.

    Severe PET

  • Total Bed rest: The patient is advised total bed rest, rising from bed only to go to the bathroom. Sometimes in very severe cases, she may even have to use the bed pan.

  • Immediate hospital admission:She is admitted in the hospital immediately as soon as she is diagnosed as a a severe case of pre-eclamptic toxaemia. This ensures constant monitoring of the vital parameters.

  • Medicines:Drugs to control convulsions, hypertension and maintain urine output are prescribed.

  • Regular monitoring:of blood pressure, fluid intake and output chart; urine for protein; weight increase; check up of eyes; blood tests.

  • Regular fetal monitoring The rate and rhythm of the foetal heart sound and number of foetal movements per day is monitored.

  • Delivery of the baby: Pregnancy is terminated at 37 weeks after checking for foetal maturity by USG. If cervix is soft and inducible, then labor is induced. If fetus is deemed to be at risk and cervix is firmly closed, elective cesarian section should be done.

    Occasionally, the baby may need to be delivered earlier, before 37 weeks if the PET is very severe and the mother shows signs of going into eclampsia.

  • Cesarian Section: Caesarian section has to be done if blood pressure cannot be controlled or there is risk of developing complications like eclampsia or eye changes.

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