Preeclampsia : Definition, Causes, Symptoms, Signs And Risk Factors

Preeclampsia Definition, Causes, Symptoms, Signs And Risk Factors

Last updated on July 28th, 2018 at 05:27 am

Preeclampsia is defined simply as hypertension in pregnancy. Hypertension is blood pressure that is equal or greater than 140/90mmHg. Presence of high Blood pressure and protein in urine is essential to diagnose preeclapmsia.

Preeclampsia usually occurs after 20 weeks gestational age. This means that, most women that have preeclamsia happens after 5 month pregnancy. However, it could occur earlier before 20 weeks gestation. This includes conditions such as multiple gestation and molar pregnancies.

It is important to visit your doctor early in pregnacy. This is to register for Antenatal Clinic (ANC). Your doctor will also check your blood pressure. If high, It would be rechecked in 4-6 hours time.

Hypertension is one of the most common disorders of pregnancy. It is responsible for increased death of pregnant women worldwide. Its is also one of the causes of increased infant mortality. This is even worse in developing countries. Hypertension has an huge negative effect on the fetus. So if you are pregnant, you should see your doctor. Quickly register for antenatal clinic. This is very important for all women. Why? Because mild to moderate raise in blood pressure, will not show any symptoms most times.

In this article, we will discuss the following

  • What is peeclampsia definition
  • Pregnancy and antenatal care
  • Preeclampsia risk factors in pregnancy
  • Causes of preeclampsia
  • How preeclampsia affects vital organs
  • Preeclampsia symptoms and signs
  • How preeclampsia affects your baby

What Is Preeclampsia Definition?

Preeclampsia is defined as high blood pressure in a pregnant woman after 20 weeks or 5 months of pregnancy, in a woman that previously has a normal blood pressure, with at least 2 separate readings of high blood pressure 4-6 hours apart and protein in urine more than 300mg in 24 hours. This will resolve within 6 weeks after delivery.

High blood pressure or hypertension mean blood pressure that is equal or greater than 140/90mmHg. If you already have hypertension before your pregnancy, then it is termed chronic hypertension. Your Doctor would first have to check your blood pressure. This will help in making such diagnosis.

Preeclampsia And Antenatal Care

It is important to see a doctor when planning to get pregnant. You will be counselled as part of your prenatal care plan. Antenatal care is very important for all women. Your blood pressure is recorded on your first antenatal visits. Some of other investigations done include

  • Complete blood count
  • Genotype
  • Rhesus antibody
  • Test for syphilis (VDRL)- Venereal Disease Research Laboratory
  • Rubella antibody screening
  • Human immunodeficiency virus screening (HIV)
  • Urinalysis- your urine will be collected and tested for protein, Glucose and acetone
  • Abdominal ultrasound- This is very important and routine in ANC. Ultrasound would help tell you your babies gestational age. Ultrasound would also easily detect any abnormality or distress with the baby

Your blood pressure is an important part of your ANC. If your doctor finds your blood pressure high, then he will request more ANC visits.

Preeclampsia Risk Factors In Pregnancy

There are many risk factors that can predispose to preeclamsia in pregnancy. preeclampsia complicates more than 3 percent of pregnancies worldwide. It is a common cause of death for pregnant women and their baby. If you are pregnant, then these are risk factors that may predispose you to preeclampsia.

1. First pregnancy

Peeclamsia is common in primigravidas. Primigravidas are women that are pregnant for the first time. The chances of developing preeclapsia in pregnancy is high for first time moms. With a focused antenatal care your doctor would let you know if you are at risk. Like most first mom ask, Why is preeclampsia likely to be in first time moms?

During pregnancy, there is an exchange of blood between the mother and the fetus. This exposes the mother to some of the genetic make up of the baby. your baby is formed after fertilization of the sperm and ovum. The sperm from the man. While the ovum from the woman. This means that when you are pregnant you are exposed to some of the baby’s fathers genome (that is the genetic make up of the man).

This has a big role to play in development of preeclapsia in your first pregnancy. But there is good news too. Your immune system quickly recognizes those genomes. This would reduce your chances of developing preeclampsia in future pregnancies. From research, the recurrence of preeclampsia in subsequent pregnancies is about 20 percent. Though this protection is lost if you have a new partner.

2. Multiparous women

Multiparous women are women that have delivered more than once. Preeclampsia is a disease of mostly first time moms, but can be present in multigravida. Multigravidas are women that have been pregnant before. Preeclampsia can happen in multiparous women

If you had preeclapsia in your previous pregnancy. This implies that there is a chance that you will develop preeclamsia in your next pregnancy. Though this chance reduces with every pregnancy. If you have been pregnant twice before and had preeclampsia in your previous pregnancies, then there is a likelihood that you will develop preeclampsia in your next pregnancy. But the likelihood of developing preeclampsia reduces.

If you have not been pregnant for more than 10 years. Pregnant women that their last pregnancy is more than 10 or more years are likely to develop preeclampsia.

3. Your age as a risk factor

Preeclampsia is more common at the extreme of ages. It is common in women who are less than 18 years. And also women who get pregnant in their forties. Pregnant women that are more than 40 are at an increase risk of develping preeclampsia.

4. Obesity or body mass index (BMI)

The chances of developing preeclampsia is more when you are obese. If you have a high Body mass index then you at risk of preeclampsia. BMI is a function of your weight in kilograms divided by your height in metres square. Normal BMI is between 18.5 to 25. If your BMI is less than 18.5 then your are underweight. If your BMI is between 25 and 30 then you are overweight. When your BMI is more than 30 then you are obese. This is not good for your pregnancy and your baby.

5. Family history of preeclampsia

Family history is very important when trying to know if u would develop preeclampsia. There is a strong link with preeclampsia occurring in families where the mother or sister already had preeclampsia. This mean that, if your mother or sister had preeclampsia, then you have to let your doctor know about that.

6. Booking investigations

On your first visit to a hospital, blood pressure and urine test will be done. Pregnant women with booking diastolic blood pressure of 80mmHg or more are at risk of having  preeclampsia. Also, booking proteinuria of 1+ is preeclampsia risk factor. Proteinuria is presence of protein in urine.

7. Multiple gestation or twin pregnancy

Research has shown that women with multiple pregnancy are likely to have preeclampsia. This is even higher when its their first pregnancy.

8. Pre existing medical problems

Pregnant women who already have long standing diseases is at risk of developing preeclampsia. These conditions include hypertension, diabetes and kidney disease.

What Causes Preeclampsia In Pregnancy

Its still not clear what causes preeclampsia. It is still debatable or unknown. Though it is believed to be due to

  1. Genetic factors
  2. Immunological factors
  3. Problems with your placenta

The placenta is an organ that is made up of fetal and maternal tissues. The mother supplies nutrients, blood, oxygen to the fetus through the placenta. The placenta is also the organ that removes waste product from the fetus. It also removes deoxygenated blood from the fetus.

Blood suppy to the fetus is relative in pregnancy. In early pregnancy, the blood supply from the mother to the placenta is about 50-70 mls every minute. But as pregnancy progresses, the baby would require more supply. This is to supply more nutrients, oxygen to your growing fetus.

In the third trimester, that is the last 3 months of your pregnancy, about 500-800mls of blood is supplied to the fetus every minute.

This shift or increase of blood supply is due to anatomical changes in the blood vessels by trophoblast. This will easily make these blood vessels to be low resistancer, wider and can then supply much more blood to the fetus

This usually starts happening from the third month( 12 weeks) of pregnancy. And is completed by the fifth month( 20 weeks) of pregnancy.

Having said that, preeclampsia is due to total or partial failure of the anatomical conversion of these blood vessels. 

This would result to reduced blood supply to the fetus (hypoxia). With subsequent release of growth factors and cytokines. This would finally result to widespread endothelial damage and affect vital organ in the body.Some of the organs affected includes the heart, kidneys, liver, brain etc

How Preeclampsia Affects Vital Organs

I already mentioned that preeclampsia can easily affect multiple organs in the body. This includes the heart and blood vessels, kidneys, liver, etc

If the cardiovascular system is affected, It would cause generalized  or widespread vasoconstriction. vasoconstriction is narrowing of blood vessels. This will cause a raise in blood pressure. Futhermore, damage to the endothelium will push fluid to the extravascular space. This would cause swelling of the hands and feets. Sometimes the face can also be swollen. The cardiovascular system involves the heart and blood vessels.

If the kidneys are affected (Renal system), it would cause changes to how the kidney filters its waste. If this change occur, the kidney would not properly filter proteins in your blood. This would allow protein to be lost in urine in large amounts. Loss of protein is in large amounts is abnormal. it only happens if there is a problem with the kidney. This loss of protein will reduce the oncotic pressure in the blood vessels. This will push fluid to the extravascular space, with resultant swelling.

If the neurological system is involved then there is convulsion and cerebral edema. This will lead to ecclamsia. This is a common complication of preeclampsia.

If the hepatic system or liver is affected then there is increase in liver enzymes. There is also associated low platelet count and heamolysis. This is called HELLP syndrome. Heamolysis is rapid break down of red blood cells. Platelets are vital to ensure would healing. due to rapid endothelial damage, more platelets are needed for the healing process. This would would cause reduced platelets in the blood.

Preeclampsia Symptoms And Signs In Pregnancy

Most patients with preeclampsia are asymptomatic. This means they show little or no symptoms. There are two types of preeclampsia. The mild and severe preeclampsia.

In mild preeclampsia, most patients feel no symptoms. Systolic blood pressure is atleast 140mmHg. The Diastolic blood pressure is atleast 90mmHg. Patients have abnormal amount of protein in urine. Protein in urine is atleast 300mg in 24 hours. Or 1+ in a dipstick urine analysis.

In severe preeclampsia, most patients start showing symptoms. Systolic blood pressure is atleast 160mmHg. The diastolic blood pressure is atleast 110mmHg. There is also abnormal amount of protein in urine. Patients that develop severe preeclampsia have a risk of developing ecclampsia.

Some of the common preeclampsia symptoms and signs include

  1. Weight gain. Due to renal and blood vessels changes in preeclampsia there is movement of fluid to the extra-vascular space. This will cause swelling of the feets, face and hands. Weight gain is also normal in pregnancy. Most pregnant women have swelling of the feets. However, should you notice fast swelling of the feets, face and hands then immediately see your doctor
  2. Dizziness. persistent feeling of dizziness is not normal in pregnancy. You should know its a preeclampsia symptom
  3. Headaches. The effect of preeclampsia in the brain can make you have severe persistent headache. This headache is more on the front part of your head. if you develop severe headache in pregnancy, then see your doctor.
  4. Abdominal pain. Some patients with preeclampsia start having pain in their upper abdomen. Sometime on the right side. It is important to see your doctor if you develop this kind of pain in pregnancy.
  5. Change in urine output. Sometimes due to preeclampsia changes on the kidneys, there is reduced urine output. If you experience weight gain and low urine output, then its important to visit your doctor.

Other preeclampsia symptoms includes

  • Increased reflexes
  • Nausea and vomiting
  • Visual disturbances
  • Restlessness
  • Convulsion

How preeclampsia affect your baby?

Preeclampsia is still the cause of death of many infants worldwide. It is also a cause of death of the fetus (intrauterine fetal death). Therefore, It is important to know how preeclampsia affects your baby.

  • The effect of preeclampsia on the fetus is enormous. Preeclampsia creates a very hostile environment for the baby. The placenta provides your baby’s requirements. During preeclampsia, there is reduced supply of blood, nutrients and oxygen. This would affect the baby growth. Preeclampsia will cause growth restriction on your baby. If not well treated will result to delivery of small babies.
  • Poorly controlled blood pressure in pregnancy in an important factor in delivery of premature babies. Survival of premature babies is even worse in centers without the necessary facilities. Babies delivered before 32 weeks or 8 months have immature lungs. This furthers reduces their chances of survival and can cause death.

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Diagnosis, Treatment And Prevention Of Preeclampsia

Preeclampsia affects a diverse group of people. Mothers, family members and doctors that cares for them. Let us share your experiences and questions. If you have any question or suggestion feel free to comment below.

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