Preeclampsia: what it is and how to deal with it

Beware of warning signs, first of all a rise in pressure and the appearance of swelling in the limbs.

Pre-eclampsia (also called gestosis) is a pathological condition that occurs during the second half of gestation (after the 20th week), but possibly also after childbirth, in 2-8% of future mothers.

From a clinical point of view, this condition is characterized by new onset hypertension (in women with previously normal blood pressure), stable (present in several successive measurements spaced 4-6 hours), with values greater than 140/90 mmHg and associated with proteinuria (presence of protein in the urine) with values equal to or greater than 0.3 grams in the urine of 24 hours.

The term that defines it is characterized by the prefix “pre” because, if not recognized and treated properly, it can evolve into a much more severe form, called eclampsia, which involves a high risk of death both for the fetus or newborn and for the mother.

Symptoms

Pre-eclampsia can occur asymptomatically or manifest with non-specific disorders, such as water retention with edema in the lower limbs (which are however often present during pregnancy even under normal conditions) or in the hands and face, headache, abdominal pain, nausea.

In case of progression from pre-eclampsia to eclampsia, the symptoms become dramatic, as they result from the suffering of vital organs caused by vascular damage and coagulation alterations:

– neurological signs (convulsions, persistent headache, visual disturbances, accentuation of muscle-tendon reflexes, alteration of consciousness up to coma)

– cardiovascular failure

– Renal

– liver failure

– pulmonary edema

– foetal growth abnormalities

-Premature.

This condition should be treated in a hospital setting with maternal and neonatal intensive care units to try to support vital functions, control neurological symptoms and avoid, as far as possible, organ damage.

In particular, magnesium sulfate prophylaxis in women with pre-eclampsia has been shown to be effective in preventing progression to eclampsia.

A complication of pre-eclampsia is the syndrome indicated by the acronym HELLP, characterized by:

• destruction of red blood cells
• reduction in platelet count
• increased liver enzymes.

HELLP syndrome often presents with attenuated symptoms (abdominal discomfort and general malaise), but can rapidly evolve unfavorably.

Why the pressure doesn’t have to rise

To clarify the reason why an increase in blood pressure values in pregnancy can lead to pathological phenomena such as to compromise the outcome so seriously is Rossella Nappi, gynecologist and head of the Research Center for medically assisted procreation of the San Matteo Hospital in Pavia.

“Pre-eclampsia and eclampsia are the most serious risks to which gestational hypertension is exposed,” explains the gynecologist. “In other words, a spectrum of blood pressure disorders related to pregnancy, more likely if there are overweight problems, if the woman is over 35 or hypertensive already before conception, or in case of twin pregnancy.”

“Blood pressure is an important parameter of the mother-fetus relationship,” adds Rossella Nappi. “It is essential that it always tends to be low enough to facilitate exchanges, so that the unborn child gets as much blood as possible and is ‘pumped’ to the placenta in the most efficient way.”

The causes

Although not all etiopathogenetic mechanisms underlying pre-eclampsia are known, one of the main ones is placental insufficiency, which in turn predisposes to hypertension. The conditions of the uterine wall, which tends to change with advancing age, and some metabolic factors can in fact compromise the correct development of the placenta and its blood circulation.

«In the early stages of pregnancy, the woman’s pressure tends to decrease, to favor the adaptation of the organism to the new situation» explains Rossella Nappi. “Unfortunately, however, after the 20th week, when the placenta has already formed completely, in about 5% of women (1-2% in young women) pressure problems occur. The risk increases, as well as with increasing age, in case of overweight, obesity and gestational diabetes. Age (and stiffer uterus) and weight (and therefore altered metabolic factors) can in fact interfere with the correct engraftment of the embryo in the uterus and with the formation of the placenta, which may be smaller or with less developed blood vessels. This causes resistance in the passage of blood from mother to fetus, and the consequence is an increase in blood pressure.”

Come diagnosticare il rischio

Lo screening della pressione arteriosa e dei parametri urinari, soprattutto dopo le prime 20 settimane di gravidanza e, in caso di dubbio, la flussimetria Doppler delle arterie uterine rappresentano gli strumenti diagnostici più importanti per scoprire precocemente una condizione di pre-eclampsia e per mettere in atto i provvedimenti utili a prevenire le complicanze più pericolose.

The latter is the priority objective: if, in fact, pre-eclampsia is reversible in itself, and generally begins to resolve spontaneously after childbirth, its complications are difficult to control.

The pharmacological treatment of hypertension allows to avoid the damage directly related to pressure values, such as placental abruption and the serious maternal diseases mentioned above, even if it is not able to modify the progression of the disease, which can rapidly progress to eclampsia.

The crisis

The treatment of pre-eclampsia must aim to counteract mortality and complications for the newborn, while closely monitoring the clinical condition of the mother.

“Unfortunately, during pregnancy not all available antihypertensive therapies can be prescribed, and sometimes the compensation fails: the woman has a pressure rise that can even reach 180-220 maximum and 140 minimum. An event that can lead to placental abruption,” explains Rossella Nappi.

It is an obstetric emergency, because in a short time it can turn into eclampsia, the result of a spectrum of disorders that causes an attack of very acute pressure up to the risk of cerebral hemorrhage, renal and hepatic crisis.

«The only way to interrupt the crisis – continues the gynecologist – is to give birth to the woman: therefore the gynecologist must manage a possible picture of pressure disorders in order to bring the woman as far ahead as possible in the pregnancy, at least at the 32nd week, so that, in case of an emergency, there are no excessive dangers for the baby because it is too premature . In some cases, evaluating the picture of the situation, to avoid the risk of placental abruption it is also possible to anticipate the date of delivery (around the 36th week), inducing it or practicing a caesarean after administering cortisone therapy to deal with the possible respiratory distress of the newborn at birth.

Alarm bells

To summarize, what are the signs to watch out for during pregnancy? First of all, the increase in blood pressure.

The gynaecologist explains: “We must control the pressure at various times of the day: in the pregnant woman the minimum (diastolic pressure, that of the release of mother-fetal blood) must not exceed 80 mmHg, while the maximum must not go beyond 130 “.

Consistently higher values, especially if never previously detected, should lead to the suspicion of a condition of pre-eclampsia.

Another significant element can be a change in the water balance, i.e. the ratio between the amount of liquids taken and that of liquids eliminated, which is maintained mainly by renal function.

“To keep it efficient – explains Professor Nappi – the pregnant woman must drink two liters of water a day, follow a low-salt diet and control body weight. The alteration of the water balance can be detected by the woman herself: if she drinks two liters of water, but expels only one with the urine, edema may appear, ie swelling in the legs (you can see it if pressing on the ankle remains a small depression), or she may struggle to wear shoes or rings. In these cases it is always advisable to undergo a check.”

One of the most important tests is the evaluation of the possible loss of protein with the urine, which can be the basis of fluid retention and be the consequence, as well as one of the earliest signs, of kidney damage. Normally, in fact, the proteins present in the blood do not pass through the kidney filter, except in small quantities. In pregnancy these amounts may be slightly higher, but high and persistent proteinuria values should be considered suspect. The search for protein is carried out in the collected urine in 24 hours.

Close surveillance for women at risk

The controls described must be planned and repeated at regular intervals in all pregnant women, but with particular attention in women at risk:

– women who already before conception suffer from hypertension, diabetes, obesity, kidney dysfunction, vascular diseases (such as anti-phospholipid syndrome, an autoimmune disease that predisposes to thrombosis)

– women who have a history of pre-eclampsia in previous pregnancies or in the family

– women aged >35-40 years or very young (<18 years)

– women facing multiple pregnancies.

For cases at risk, the possibility of carrying out, depending on the clinical conditions, some prophylactic treatments (with low-dose acetylsalicylic acid, heparin, calcium and polyunsaturated fatty acid and antioxidant supplementation) has been studied, but none of these measures has so far demonstrated a safe preventive efficacy.

In summary, the only preventive strategy against pre-eclampsia and its complications is to undergo regularly for the entire course of pregnancy (and in case of pre-eclampsia even for a certain period after delivery) the controls and diagnostic investigations recommended by the gynecologist.