Definition: what is preeclampsia?
Preeclampsia, also called pregnancy toxemia or disgravidiais a pathological of frequent pregnancy. It is characterized by:
- high blood pressure (HTA) greater than 140/90 mmHg;
- proteinuria (i.e. the presence of proteins in the urine: the level being greater than 300 mg for 24 hours).
Other signs can be added such as swelling(edema), phosphenes (appearance of spots or sparks in the visual field), a feeling of weight under the ribs …
Pre-eclampsia usually appears around the 5th month of pregnancy. “When not taken care of, preeclampsia can progress to severe complications, especially eclampsia. The latter is manifested by a convulsive crisis linked to an extremely high tension which constitutes an emergency ”, according to Doctor Alexandre Vivanti, obstetric gynecologist at the Béclère de Clamart hospital. The vital prognoses of the mother and her fetus are involved in 10% of eclampsia cases (source 1).
Causes: what causes toxemia of pregnancy?
Eclampsia is a cause of premature birth.
There are other complications of pre-eclampsia: hepatic, renal, coagulation pathologies, cerebral hemorrhages or even placental abruption.
The cause of pre-eclampsia remains a mystery, however, a multitude of risk factors have been identified: the most decisive is the fact that it is a first pregnancy, which is the case for 75% of preeclampsia (source 1).
Management involves hospitalization and close medical supervision.
Pre-eclampsia, a common pathology
Pre-eclampsia affects approximately 5% of pregnancies (source 1) or approximately 40,000 women every year. Theeclampsia is much rarer (thanks to the preventive management of pre-eclampsia), although it remains the second cause of maternal death (source 1).
“No clear cause for preeclampsia has been identified. However, certain risk factors are singled out, ”according to Dr Alexandre Vivanti, obstetric gynecologist.
What are the risk factors for preeclampsia?
The risk factors for preeclampsia:
- A first pregnancy : 70 to 75% of cases of preeclampsia occur during a first pregnancy.
- A recent change of partner : if the mother conceived the child with a man who had only recently been her partner, the risks are increased. Indeed, the spermatozoa are not known by the immunity of the mother who has not had time to adapt to the ntigens of the father (in particular via the cells called “T-regulators”). However, the mother’s immune tolerance would allow better placental implantation and the carrying of paternal antigens by the fetus, all of this reducing the risk of pre-eclampsia.
- Prolonged wearing of the condom by the father (if the father before conception wore the condom during former sexual intercourse): In this case, the insufficient exposure of the mother to her partner’s sperm can lead to intolerance to his antigens, increasing the risks of pre-conception. eclampsia.
- A personal or family history of preeclampsia: It seems that the genetic background contributes up to 50% in the development of the disease. In 2005, several genes involved were identified, including the STOX1 gene. This gene is present in the cells of the uterus and the placenta (source 2).
- A twin pregnancy (or multiple).
- Early pregnancy (before 18) or very late (after 40 years).
- Certain pathologies such as:
– chronic arterial hypertension.
– obesity (BMI greater than 30).
– polycystic ovary syndrome.
– an autoimmune disease.
What are the symptoms of preeclampsia?
Symptoms of preeclampsia usually start around the 20th week of pregnancy. It’s about :
- high blood pressure greater than 140/90 mmHg;
- the presence of protein in the urine : “The urine of a pregnant woman is collected over a period of 24 hours. It is considered that there is proteinuria when the protein concentration in the urine exceeds 0.3 g over 24 hours ”;
- headaches persistent and intense;
- visual disturbances like the phosphenes (visions of spots or scintillating points in front of the eyes), blurred vision, sensitivity to light (photophobia), temporary loss of vision …
- a feeling of bar under the ribs : we speak of “epigastric bar”;
- digestive disorders : nausea, vomiting …
- a decrease in the amount of urine when urinating (oliguria);
- of swelling (edema) face or hands. It sometimes leads to sudden weight gain;
- of hearing problems like tinnitus;
- of neurological disorders like confusions;
- a great fatigue.
What are the risks of complications for the mother and the fetus?
Pre-eclampsia is a condition that predisposes to certain, sometimes severe, complications. It must be taken care of in order to avoid the latter:
Complications for the mother
- Eclampsia : this is a seizure caused by high intracranial arterial hypertension in pregnant women.
- Kidney failure (source 3).
- Hepatic damage: “This is particularly HELLP syndrome which is characterized by inflammation of the liver. It leads to increased destruction of red blood cells in the liver, increased production of liver enzymes, and decreased blood platelets. This syndrome exposes you to a risk of hemorrhage, ”according to Dr Alexandre Vivanti. Note that HELLP syndrome complicates pre-eclampsia in 5 to 20% of cases (source 4).
- A stroke hemorrhagic which can lead to the death of the mother (source 5);
- A detachment of the placenta or retro-placental hematoma : it requires an emergency termination of pregnancy (delivery by cesarean). It is often the cause of premature births.
Complications for the fetus
Three complications are to be feared for the fetus.
- Intrauterine growth retardation : it is detected by ultrasound. If it is very severe, preterm delivery may be induced.
- Premature birth : it results from a childbirth induced well before the term of the pregnancy due to a complication of the pre-eclampsia.
- Fetal death in utero : it can in particular result from a detachment of the placenta.
What prevention against this disease of pregnancy?
Blood pressure monitoring of pregnant women
It is first of all about monitor blood pressure by a monthly assessment of the future mother whether or not she is predisposed to pre-eclampsia:
- blood pressure measurement ;
- urine test looking for an increase in protein concentration.
In women at risk, it is possible to prevent the risk of preeclampsia from 20 weeks of amenorrhea thanks to two biomarkers :
- the PGF (Placenta growth factor) which is a placental growth factor;
- the SFTL1 which is a soluble receptor for vascular growth factor.
The STFL1 / PGF ratio provides a risk score. If the result is greater than 38, the woman is considered at risk. However, in practice few women with a score above 38 will actually have preeclampsia. This score is used to rule out the risk, for example in some women who have risk factors: obesity, diabetes, twin pregnancy, personal or family history, etc.
If there is a history of preeclampsia in a previous pregnancy
The risk of relapse should be avoided by prescribing aspirin low dose from 3 months of pregnancy.
In case of pre-eclampsia
Magnesium sulfate helps prevent eclampsia (seizures) which can be fatal.
Tests: how is preeclampsia detected?
The diagnosis of preeclampsia requires a clinical examination comprising:
- observation of clinical signs and stage of pregnancy. The doctor must then take the patient’s blood pressure;
- questioning the patient about her health history and the context of the pregnancy;
- urine samples over 24 hours.
The diagnosis is made if the patient presents:
- pregnancy-induced hypertension: pregnant women have systolic blood pressure (SBP) greater than 140 mmHg and diastolic blood pressure (DBP) greater than 90 mmHg. Preeclampsia is considered severe when the SAP exceeds 160 and / or the DBP exceeds 110.
- proteinuria detected when urine levels are greater than 0.3 g / 24 h.
Treatments for preeclampsia
If the diagnosis of preeclampsia is made, the pregnant woman must be hospitalized in order to obtain close monitoring. Some exams are performed:
- assessment of the severity of preeclampsia (blood pressure, renal, hepatic and neurological assessment);
- fetal health check : verification of heart rate by monitoring, evaluation of fetal growth using ultrasound, measurement of uterine height, etc.
- rapid onset of cesarean delivery in case of complications.
In case of severe preeclampsia (before the 24th week of pregnancy) a therapeutic termination of pregnancy (ITG) may be proposed.
Several drugs are prescribed for preeclampsia.
- Antihypertensives : some antihypertensives are contraindicated in pregnant women: ACE inhibitors and angiotensin II inhibitors are not recommended in the second and last trimester of pregnancy and their termination may be considered. Diuretics are also not recommended to fight against hypertension (at the risk of hindering the growth of the fetus). The antihypertensive drugs generally prescribed during pregnancy are methyldopa, certain beta blockers and certain calcium channel blockers.
- Corticosteroids injections that accelerate the development of the fetus: they are administered if pre-eclampsia appears before the 34th week of pregnancy;
- Magnesium sulfate by injection is also administered in case of warning signs of eclampsia.