What is Preeclampsia (Toxemia, Pregnancy-induced hypertension)

Preeclampsia is a pregnancy induced disease associated with elevated blood pressure and protein in the urine which presents in the second half of pregnancy.

Statistics on Preeclampsia (Toxemia, Pregnancy-induced hypertension)

In developing countries pre-eclampsia affects 3.4% of all pregnancies. Amongst women with pre-eclampsia the more serious condition, eclampsia develops in 2.3%. The risk of developing pre-eclampsia increased almost seven-fold from 1980-2003. This was mainly because of increased rates of smoking and obesity but also because the methods for diagnosing and recording pre-eclampsia improved.
An Australian study reported 4.2% of pregnant women developed pre-eclampsia and 27 per 100,000 pregnancies ended in the death of the mother following complication of pre-eclampsia. Of all pregnancies which ended in induced labour, pre-eclampsia was the reason for induction in 9%.
Preeclampsia usually occurs in late pregnancy. In one study of women with pregnancy hypertension, about half had pre-eclampsia and one in two cases of hypertension occurred within 3 days of delivery. All the pregnant women developed hypertension in the second or third trimester (15-40 weeks pregnancy). In a minority of cases (5%) hypertension started after child birth. On average the women had normal blood pressure again 5-6 weeks after delivery, however one in five women still had high blood pressure six months after their pregnancy.

Risk Factors for Preeclampsia (Toxemia, Pregnancy-induced hypertension)

  • Increased risk is associated with first pregnancies
  • Extremes of age – Very young mothers or advanced maternal age;
  • Multiple pregnancy-twins.
  • New sexual partner
  • Previous history or family history of the disease
  • Obese women
  • Women with a past history of diabetes, hypertension, or kidney disease.

The exact cause of preeclampsia is yet to be identified. Numerous theories of possible causes include: genetic, dietary, vascular (blood vessel), and autoimmune factors. No particular factor however, has been conclusively linked to the disorder. It has been described as a disease originating from the placenta but with widespread effects both for the mother and baby.

Progression of Preeclampsia (Toxemia, Pregnancy-induced hypertension)

Preeclampsia refers to the combination of puffiness/swollen feet, high blood pressure and protein in the urine occurring after the 20th week of pregnancy and often occurs in first-time mothers. The disease can range from mild to severe in the way it presents. A very high blood pressure signifies severe disease. If severe and not treated, its complications can affect the kidneys, liver, clotting systembrain of the mother or cause growth restrictions in the fetus. This can pose a risk to the health of the mother and baby.

Mild Preeclampsia

Mildly raised blood pressure after 20th week with proteinuria but no effects on the brain.

Moderate-Severe Preeclampsia

Highly raised blood pressure with proteinuria and effects on the brain. The effects of preeclampsia on the brain include headache, dizziness, tinnitus, altered mental status, visual changes, and seizures. The visual changes may result from spasm of the blood vessels, insufficient blood supply, and hemorrhage in the visual centre of the brain, or from retinal detachment. Preeclampsia may also occur in women with pre-existing hypertension (superimposed preeclampsia), and in this situation the prognosis is poorer for mother and baby.

How is Preeclampsia (Toxemia, Pregnancy-induced hypertension) Diagnosed?

Diagnosis is made when blood pressure is higher than 140/90 and significant protein in the urine. Tests that may be performed include:

  • Blood tests: to check for abnormal liver function tests, low platelets counts or red blood cell count
  • Proteinuria (protein noted in urine)
  • Ultrasound

Prognosis of Preeclampsia (Toxemia, Pregnancy-induced hypertension)

Does it occur in subsequent pregnancies?
This is the most common question pregnant women ask. Yes, it does and recurrence rate is estimated to vary from 5% to 25%. The Australasian society for the study of hypertension in pregnancy recommends low-dose aspirin early in pregnancy if previous one was preeclamptic. Remember it is always advisable to check with your doctor. Outcome in mild cases is good for both mother and baby but severe disease may be associated with serious complications. Maternal deaths caused by preeclampsia are rare in Western countries. However, in less developed nations, mortality rate is considerably increased. Prognosis for the baby is dependent on the associated effects of preeclampsia on the growing fetus – low birth weight, IUGR, prematurity and so on.
What happens if I develop eclampsia?
Uncomplicated eclampsia usually does not result in permanent neurological deficit.
What is the effect on long term health?
Previously, it was said to have no greater cardiovascular risk than a normal pregnancy. However results of two large studies have shown an associated increase in cardiovascular risk of women in the study. Based on those findings, it is recommended that all women who have had preeclampsia in pregnancy should have their cardiovascular risk assessed regularly and should maintain a healthy lifestyle.

How is Preeclampsia (Toxemia, Pregnancy-induced hypertension) Treated?

The only known cure for preeclampsia is delivery. However, if the baby is still considered to be pre-term, treatment aims to control the disease and delay/prevent development of complications from the disease using medications. Labour is induced as soon as the foetus has a good chance of survival outside of the womb.
In moderate to severe cases patients are usually hospitalized while mild ones are managed on an outpatient basis; with careful monitoring of blood pressure, urine checks for protein, and ultrasound to measure the baby’s growth. Provided everything progresses smoothly, attempts are made to manage the condition till week 34-36 of pregnancy at which delivery can be performed with less complications of prematurity.
Drugs used in the treatment of this disease:

 Trade Names

Generic Names 


 Adalat, Nifecard, Aldomet  Nifedipine, Methyldopa   Lowers blood pressure
 Magnesium Sulphate Injection 49.3%  Magnesium Sulphate   Prevent seizures in sever cases
 Celestone, Cortate  Betamethasone, Deexamethasone   Improve lung maturity of baby


Preeclampsia (Toxemia, Pregnancy-induced hypertension) References

  1. Abalos E, Duley L, Steyn DW, Henderson-Smart DJ. Antihypertensive drug therapy for mild to moderate hypertension during pregnancy (Review). The Cochrane library 2007; 3.
  2. Brown MA. Preeclampisa: a lifelong disorder. MJA 2003; 179 (4): 182-184
  3. Dolea C, AbouZahr C. 2003. Global burden of hypertensive disorders in pregnancy in the year 2000. Evidence and Information for Policy- World Health Organisation. (cited 24 June 2015). Available from: [URL Link]
  4. Anath CV, Keyes KM, Wapner RJ. Pre-eclampsia rates in the United States, 1980-2010: age-period-cohort analysis. BMJ. 2013.; 347. [Full Text]
  5. Duley L, Gulmezoglu AM, Henderson-Smart DJ. Magnesium sulphate and other anticonvulsants for women with pre-eclampsia (Review). The Cochrane library 2007; 3: 6-14.
  6. Roberts CL, Ford JB, et al. Hypertensive disorders in pregnancy- a population based study. Med J Aust. 2005; 182(7): 332-5. Full Text: Full Text
  7. Impey L. Obstetrics and Gynecology. 2nd ed. USA: Blackwell; 2006.
  8. Australian Institute of Health and Welfare and University of New South Wales. Australian Mothers and Babies 2012. 2014. (cited 24 June 2015). Available from: [URL Link]
  9. Podymow T, August P. Postpartum course of gestational hypertension and pre-eclampsia. Hypertens Preg. 2010; 29(3): 294-300. (cited 24 June 2015). Abstract available from: [Abstract]
  10. Norwitz ER Repke JT. Acute complications of Preclampsia. Clinical Obstetrics and Gynecology 2002; 45 Suppl 2: 308-29
  11. King Edward Memorial Hospital for Women. KEMH Clinical Guidelines: Complications of pregnancy- Hypertension in Pregnancy. 2015. (cited June 24 2015).  Available from: [URL Link]
  12. National Health and Medical Research Council. Report on Maternal Deaths in Australia 1994-96. 2001. Available from: http://www.nhmrc.gov.au/publications/synopses/withdrawn/wh32.pdf

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