Pre-eclampsia
Pre-eclampsia (PE) is a disorder of pregnancy caused by the onset of high blood pressure. In it, there is a large amount of proteinuria,[1][2] which means protein in the urine.
| Pre-eclampsia | |
|---|---|
| Other names | Preeclampsia toxaemia (PET) |
 | |
| A micrograph showing hypertrophic decidual vasculopathy, a finding seen in gestational hypertension and pre-eclampsia. H&E stain. | |
| Medical specialty | Obstetrics |
| Symptoms | High blood pressure, protein in the urine[1] |
| Complications | Red blood cell breakdown, low blood platelet count, impaired liver function, kidney problems, swelling, shortness of breath due to fluid in the lungs, eclampsia[3][4] |
| Usual onset | After 20 weeks of pregnancy[3] |
| Risk factors | Obesity, prior hypertension, older age, diabetes mellitus[3][5] |
| Diagnostic method | BP > 140 mmHg systolic or 90 mmHg diastolic at two separate times[4] |
| Prevention | Aspirin, calcium supplementation, treatment of prior hypertension[5][6] |
| Treatment | Delivery, medications[5] |
| Medication | Labetalol, methyldopa, magnesium sulfate[5][7] |
| Frequency | 2–8% of pregnancies[5] |
| Deaths | 46,900 hypertensive disorders in pregnancy (2015)[8] |
Usually PE happens during the second half of pregnancy (from 20 weeks) or soon after delivery[3][9]. It can develop for the first time in the first 4 weeks after birth.
They are usually picked up as signs and symptoms in routine tests[9]. Sometimes the patient is unaware of the symptoms themselves when its diagnosed.
Cause[change | change source]
Risk[9][change | change source]
Factors have been identified that could increase chances of developing pre-eclampsia. Having previously had it is a risk factor. Genetics and being the first time delivering increases the chance by a small amount. Having an existing medical problem increases it by more. These medical problems are:
If a pregnant woman is considered to be at a high risk of developing pre-eclampsia, they might be advised to take a 75 to 150mg dose of aspirin every day from 12 weeks pregnant until delivery. Evidence suggests this can lower the chances of developing the condition.[9]
Other factors increasing the risk, but by a small amount:
- over the age of 40
- it has been at least 10 years since the last pregnancy
- a family history of the condition – for example, the mother or sister has had pre-eclampsia
- obese at the start of pregnancy – meaning they had a body mass index (BMI) of 35 or more
- if expecting twins or more, such as twins or triplets
Placenta[change | change source]
Pre-eclampsia is thought to be caused by the placenta not developing properly due to a problem with the blood vessels supplying it. The exact cause isn't fully understood.[9] It may be likely that inherited changes in the genes have some sort of role, as the condition often runs in families. But this only explains some cases if it is true.[9]
Signals or substances (hormones[verification needed]) from the damaged placenta affect the mother's blood vessels, causing hypertension.[9] At the same time, problems in the kidneys may cause important proteins that should remain in the mother's blood to leak into her urine, resulting in proteinuria.[9]
The problem with the placenta means the blood supply between mother and baby is disrupted.[9]
Early stages of pregnancy[change | change source]
If the placenta will not develop properly because it does not get enough nutrients, it can cause issues. This may lead to pre-eclampsia.[9]
It's still unclear why the blood vessels don't transform as they should. The same as with earlier causes, pre-eclampsia can be caused by genetic factors. But this only explains one cause if it is true.[9]
Symptoms[change | change source]
Baby[change | change source]
The main sign of pre-eclampsia in the unborn baby is slow growth. This is caused by poor blood supply through the placenta to the baby.[9]
The growing baby receives less oxygen and fewer nutrients than it should, which can affect development. This is called intra-uterine or foetal growth restriction.[9]
If the baby is growing more slowly than usual, this will normally be picked up during antenatal appointments It will be picked up during measurements.[9]
Mother[change | change source]
Most people only experience mild symptoms, but it's important to manage the condition in case severe symptoms or complications develop[9].
Most people only experience mild symptoms, but it's important to manage the condition in case severe symptoms or complications develop[9].
Symptom severity[change | change source]
Severe case[change | change source]
Although many cases are mild, the condition can lead to serious complications for both mother and baby if it is not monitored and treated. Symptoms may be:[9]
- red blood cell breakdown
- a low blood platelet count
- not as good liver function
- kidney dysfunction
- swelling[9]
- shortness of breath, due to fluid in the lung
- visual disturbances.[4][9] (blurring or flashing lights)[9]
If left untreated, it may result in seizures.
Early signs[9][change | change source]
Of pre-eclampsia include having high blood pressure (hypertension), proteinuria. In some cases, further symptoms can develop into the severe symptoms above, but also including:[9]
The earlier pre-eclampsia is diagnosed and monitored, the better the outlook for mother and baby. Symptoms of pre-eclampsia should mean: seek medical advice immediately by calling the midwife, GP surgery or emergency services (EMS).[9]
Diagnosis[change | change source]
Pre-eclampsia is easily diagnosed during the routine checks that happen throughout pregnancy. Signs of high blood pressure are regular, and a urine sample is tested to see if it contains protein, during antenatal appointments.[9]
However, if any of the symptoms of pre-eclampsia between antenatal appointments show, a midwife or GP should be seen for advice.[9]
Tests: blood pressure, blood and urine test, other[change | change source]
- Blood pressure checked with an inflatable cuff and a scale as a pressure gauge (a sphygmomanometer) regularly[9]
- Urine sample. This can easily be tested for protein using a dipstick, usually at every appointment[9]
- Blood test may be checked between 20 weeks and 36 weeks and 6 days pregnant[9]. It measures levels of a protein called placental growth factor (PIGF)
Related pages[change | change source]
References[change | change source]
- ↑ 1.0 1.1 Eiland E, Nzerue C, Faulkner M (2012). "Preeclampsia 2012". Journal of Pregnancy. 2012: 586578. doi:10.1155/2012/586578. PMC 3403177. PMID 22848831.
- ↑ Hypertension in pregnancy. ACOG. 2013. p. 2. ISBN 9781934984284. Archived from the original on 2016-11-18. Retrieved 2016-11-17.
- ↑ 3.0 3.1 3.2 3.3 Al-Jameil N, Aziz Khan F, Fareed Khan M, Tabassum H (February 2014). "A brief overview of preeclampsia". Journal of Clinical Medicine Research. 6 (1): 1–7. doi:10.4021/jocmr1682w. PMC 3881982. PMID 24400024.
- ↑ 4.0 4.1 4.2 American College of Obstetricians Gynecologists; Task Force on Hypertension in Pregnancy (November 2013). "Hypertension in pregnancy. Report of the American College of Obstetricians and Gynecologists' Task Force on Hypertension in Pregnancy" (PDF). Obstetrics and Gynecology. 122 (5): 1122–31. doi:10.1097/01.AOG.0000437382.03963.88. PMC 1126958. PMID 24150027. Archived from the original (PDF) on 2016-01-06. Retrieved 2020-06-22.
- ↑ 5.0 5.1 5.2 5.3 5.4 Cite error: The named reference
WHO2011was used but no text was provided for refs named (see the help page). - ↑ Cite error: The named reference
Hend2014was used but no text was provided for refs named (see the help page). - ↑ Cite error: The named reference
Aru2013was used but no text was provided for refs named (see the help page). - ↑ Cite error: The named reference
GBD2015Dewas used but no text was provided for refs named (see the help page). - ↑ 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 9.12 9.13 9.14 9.15 9.16 9.17 9.18 9.19 9.20 9.21 9.22 9.23 9.24 9.25 9.26 9.27 "Pre-eclampsia". nhs.uk. 2018-01-11. Retrieved 2024-05-29.
