Preeclampsia

Preeclampsia is one of the hypertensive (high blood pressure) disorders of pregnancy. It is a major cause of maternal and perinatal mortality (number of stillbirths and deaths of newborn in the first week of life) and morbidity.

Hypertensive disorders of pregnancy occur in about 10% of all pregnant women around the world. Preeclampsia affects 3–5% of pregnancies. Along with preeclampsia, other diseases which are included in the group of hypertensive disorders of pregnancy are eclampsia, gestational hypertension and chronic hypertension.

In Asia and Africa, nearly one tenth of all maternal deaths are associated with hypertensive disorders of pregnancy.

In India, the incidence of preeclampsia is reported to be 8-10% among the pregnant women. According to a study, the prevalence of hypertensive disorders of pregnancy was 7.8% with preeclampsia in 5.4% of the study population in India*. 

Preeclampsia is a pregnancy specific hypertensive disease with multisystem involvement. It is a disorder of widespread vascular endothelial malfunction and vasospasm that occurs after 20 weeks of gestation and can present as late as 4-6 weeks postpartum (after child birth).

According to the new guidelines given by American Congress of Obstetricians and Gynaecologists (ACOG) in 2013, the diagnosis of preeclampsia does not require the detection of high levels of protein in the urine (proteinuria) along with hypertension. Evidence shows that changes in kidney and liver can occur without signs of proteinuria, and the amount of protein in the urine does not predict how severely the disease will progress.

Preeclampsia is now to be diagnosed by persistent high blood pressure that develops during pregnancy or during the postpartum period and is associated with a lot of protein in the urine or the new development of decreased blood platelets, changes in the kidney or liver function, fluid in the lungs, or signs of brain disorder such as seizures and/or visual disturbances.

HEELP syndrome and eclampsia are the serious complications of the preeclampsia. The majority of deaths related to preeclampsia can be prevented by providing timely and effective care to pregnant women presenting with such complications.

References-

apps.who.int

www.preeclampsia.org

www.acog.org

www.preeclampsia.org

* www.ijpsr.info

Although pathophysiological changes (e.g. inadequate placentation) exist from very early stages of the pregnancy, hypertension and proteinuria usually become apparent in the second half of pregnancy.

Symptoms of preeclampsia-

  • Hypertension (High blood pressure): the presence of (a) a systolic blood pressure (SBP) greater than or equal to 140 mm Hg or a diastolic blood pressure (DBP) greater than or equal to 90 mm Hg or higher, on two occasions at least 4 hours apart in a previously normotensive patient, OR  

(b)SBP greater than or equal to 160 mm Hg or a DBP greater than or equal to 110 mm Hg or higher (In this case, hypertension can be confirmed within minutes to facilitate timely antihypertensive therapy).

  • Proteinuria (Protein in urine): proteinuria of greater than or equal to 0.3 grams in a 24-hour urine specimen, a protein (mg/dL)/creatinine (mg/dL) ratio of 0.3 or higher, or a urine dipstick protein of 1+ (if a quantitative measurement is unavailable) is required to diagnose preeclampsia.
  • Oedema: Swelling of the hands and face, especially around the eyes (swelling of the feet is more common in late pregnancy and probably not a sign of preeclampsia).
  • Sudden weight gain: Weight gain of more than five pounds in a week.
  • Headache: Dull or severe, throbbing headache, unrelieved by regular analgesics.
  • Nausea or vomiting, especially suddenly, after mid pregnancy (not the morning sickness that many women experience in early pregnancy).
  • Abdominal pain: epigastric or in upper right quadrant region, usually under the ribs.
  • Changes in vision like seeing spots or flashing lights; blurred vision, partial or total loss of eyesight.
  • Difficulty in breathing, gasping, or panting.
  • Hyperreflexia

Severe hypertension, hyperreflexia , headache (increasing frequency, unrelieved by regular analgesics) , clouding of vision , oliguria (passing less than 400ml urine in 24 hours) , upper abdominal pain (epigastric pain or pain in right upper quadrant) , pulmonary oedema (difficulty in breathing) are the signs of severe preeclampsia.

References-

emedicine.medscape.com

www.preeclampsia.org

www.nichd.nih.gov

www.preeclampsia.org

japi.org

www.acog.org

 

Re

Causes-

The pathogenesis of preeclampsia is only partially understood and it is related to disturbances in placentation at the beginning of pregnancy, followed by generalized inflammation and progressive endothelial damage.

Risk factors-

  • Primigravida specially in adolescents and women over 35 years of age
  • Obesity
  • High blood pressure or preeclampsia in an earlier pregnancy:

(The risk of preeclampsia recurrence increases with earlier gestational age at the first delivery complicated by preeclampsia and with increasing maternal body mass index.)

  • Having a family history of preeclampsia: Among women who have had preeclampsia, about 20% to 40% of their daughters and 11% to 37% of their sisters may get the disorder.
  • Chronic high blood pressure or kidney disease before pregnancy.
  • Preeclampsia is more common among women who have histories of certain health conditions, such as diabetes, urinary tract infections, migraine headaches, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, periodontal diseases (gum disease), polycystic ovary syndrome, multiple sclerosis, gestational diabetes, and sickle cell disease.
  • Preeclampsia is also more common in pregnancies resulting from egg donation, donor insemination, or in vitro fertilization.
  • Conditions leading to hyperplacentation and large placentas (such as multiple pregnancy, hydatidiform mole, polyhydramnios, hydrops fetalis).

References-

www.nichd.nih.gov

 apps.who.int

 www.ajog.org

Diagnostic criteria for Preeclampsia (ACOG):

Blood pressure:

  • Systolic blood pressure of 140 mmHg or higher or diastolic blood pressure of 90 mmHg or higher on two occasions at least 4 hours apart after 20 weeks of gestation in a woman with a previously normal blood pressure.
  • Systolic blood pressure of 160 mmHg or higher or diastolic blood pressure of 110 mmHg or higher. Hypertension can be confirmed within a short interval (minutes) to facilitate timely antihypertensive therapy.

And

Proteinuria:

  • Greater than or equal to 300mg per 24-hour urine collection( or this amount extrapolated from a timed collection) or
  • Protein/creatinine ratio greater than or equal to 0.3
  • Dip stick reading of 1+( used only if other quantitative methods not available)

Or in the absence of proteinuria, new-onset hypertension with the new onset of any of the following:

Thrombocytopenia- Platelet count less than100,000/microliter

Renal insufficiency- Serum creatinine concentrations greater than1.1mg/dL or a doubling of the serum creatinine concentration in the absence of other renal disease.

Impaired liver function: Elevated blood concentrations of liver transaminases to twice normal concentration.

Pulmonary edema

Cerebral or visual symptoms

According to the new ACOG guidelines 2013, the diagnosis of preeclampsia no longer requires the detection of high levels of protein in the urine (proteinuria). Preeclampsia is now to be diagnosed by persistent high blood pressure that develops during pregnancy or during the postpartum period that is associated with a lot of protein in the urine or the new development of decreased blood platelets, trouble with the kidney or liver, fluid in the lungs, or signs of brain trouble such as seizures and/or visual disturbances.

Tests advised for evaluation of progress of preeclampsia are:  

Blood tests: includes tests for liver and kidney function test, total number of red blood cells, platelet count, and clotting test.  

Urine analysis: the dipstick test greater than 1+ protein on a random urine sample(used only if other quantitative methods not available), however  single sample of urine, or several urine samples collected over a 24-hour period can be used to determine for protein and creatinine whenever possible.

Ultrasonography is used to assess the status of the fetus as well as to evaluate growth of foetus. Apart from transabdominal ultrasonography, umbilical artery Doppler ultrasonography can be performed to assess blood flow for detection of perinatal growth restriction and prematurity.

Nonstress test or biophysical profile: A nonstress test is a simple procedure that checks how baby's heart rate changes when baby moves inside the uterus. A biophysical profile is a prenatal ultrasound evaluation of foetal wellbeing involving a scoring system. It combines a foetal ultrasound with a nonstress test to provide more information about baby's breathing, muscle tone, movement and the volume of amniotic fluid around the foetus.

References-

www.webmd.com

emedicine.medscape.com

www.acog.org

Management of pregnant women with preeclampsia without severe features aims with first consideration of safety of women and her foetus and second with delivery of a mature newborn that will not require intensive or prolonged neonatal care. It depends on the results of maternal and fetal evaluation, gestational age, presence of labour, or rupture of membranes, vaginal bleeding and wishes of the women.

Antepartum management-

Once the diagnosis has made as pregnancy with preeclampsia, women should be evaluated for complete blood count with platelet count, serum creatinine and liver enzyme levels, urine protein (24-hour collection or protein/creatinine ratio). Foetal evaluation can be done with ultrasonography (foetal weight and amniotic fluid index), nonstress test (NST) and biophysical profile (if NST is non reactive).

Management can occur in hospital or at home with restricted activity and serial maternal and foetal evaluation (continued evaluation).

Continued evaluation consists of following:

Foetal evolution:

Daily kick count, ultrasonography for foetal growth every three weeks, amniotic fluid volume assessment once weekly, NST twice weekly ,bio physical profile( if NST non reactive).  (Frequency of these tests can be changed according to clinical findings.)

Maternal evaluation:

Blood pressure assessment: additional BP determination can be done at home or clinic.

Laboratory investigations for CBC, liver enzyme, serum creatinine levels should be done at least once a week.(frequency of these tests can be changed according to clinical finding)

Patients should have a regular diet with no salt restriction.

Women are instructed to report symptoms of severe preeclampsia (severe headaches, visual changes, epigartic pain, and shortness of breath) at each subsequent visit.

Women are advised to immediately come to the hospital/referred to the hospital if they develop persistent symptoms, abdominal pain, contractions, vaginal spotting, rupture of membrane, or decreased foetal movement.                                                                                                                                      

The development of new symptoms or signs suggesting severe preeclampsia or severe hypertension (systolic BP of 160 mm Hg or higher, or diastolic BP of 110 mm Hg or higher on repeat measurement) or evidence of foetal growth restriction, increased amount of liver enzymes or decreased platelet count requires immediate hospitalization.

Antihypertensive therapy: There was insufficient evidence about role of antihypertensive drugs on improvements of foetal and maternal out comes in non severe hypertension,( the National Institute of Health and Clinical Excellence guidelines recommended treatment at BP levels at 150 mm Hg systolic or 100 mm Hg diastolic, or both).

Bed rest: There may be situations in which different levels of rest, either at home or in the hospital may be indicated for individual women. Prolonged bed rest for the duration of pregnancy increases the risk of thromboembolism (formation of a clot (thrombus) in a blood vessel that may break loose and may obstruct another vessel).

Timing of delivery: In women with preeclampsia without severe features between 34 weeks of gestation and 37 weeks of gestation should be in favour of continued monitoring and delivery to 37 completed weeks of gestation ( in the absence of abnormal foetal testing or other severe conditions such as premature rupture of membranes, preterm labour, or vaginal bleeding).

Delivery is indicated in the following conditions:

  • 37 or more weeks of gestation
  • Suspected abruptio placentae (detachment of placenta from uterus)
  • 34 weeks or more of gestation, plus any one of the following:
  • Progressive labour or rupture of membranes
  • Ultrasonographic estimate of foetal weight less than fifth percentile
  • Oligohydramnios (less amount of amniotic fluid )
  • Persistent biophysical profile 6/10 or less (upper limit 10/10)

In women with preeclampsia, a delivery decision should not be based on the amount of proteinuria or change in the amount of proeteinuria only, but all other indicated tests should be kept under consideration

Magnesium sulfate prophylaxis should be initiated if there is progression to severe disease.

Management of Severe preeclampsia-

For women with preeclampsia with severe hypertension during pregnancy (sustained systolic BP of at least 160 mm of Hg or diastolic BP of at least 110 mm Hg),the use of anti hypertensive therapy is recommended.

In pregnancy with severe preeclampsia, the parenteral (intravenous/intramuscular) administration of magnesium sulfate is recommended.

In women with severe preeclampsia at term, early delivery is recommended.

For women with severe preeclampsia at less than 34 weeks of gestation with stable maternal and foetal conditions, it is advised that pregnancy should be continued at facilities with adequate maternal and neonatal intensive care units. Whenever there is an indication, delivery may be considered.   

For women with severe preeclampsia at or beyond 34 weeks of gestation and with unstable maternal and foetal conditions irrespective of gestational age, quick delivery is recommended after maternal stabilization.

Pregnancy with severe preeclampsia before 23-24 weeks of gestation, delivery after maternal stabilization is recommended. Expectant management is not advised.

Antenatal corticosteroid administration should be considered in women with severe preeclampsia receiving expectant management at 34 weeks or less of gestation for foetal lung maturity.

The mode of delivery: should be determined by foetal gestational age, foetal presentation, cervical status, and maternal- foetal condition.

References-

www.acog.org

apps.who.int

Women who have preeclampsia during pregnancy are at increased risk of complications during pregnancy (antenatal), during child birth (intrapartum) and after child birth (puerperium)). The foetus is also at increased risk of complications.

Pregnant women with preeclampsia may have following complications:

  • Eclampsia: when seizures occur in preeclampsia it is termed as eclampsia. Eclampsia can have serious consequences for both mother and baby, delivery becomes necessary, regardless of period of gestation.
  • HELLP syndrome: is a serious condition consists of haemolysis (break down of red blood cells in the blood), elevated liver enzymes and low platelets. It may occur in 10%–20% of women with severe preeclampsia, the only way to treat the condition is to deliver the baby as soon as possible.
  • Placental abruption: Preeclampsia increases risk of placental abruption, in which the placenta separates from the inner wall of uterus before delivery. Severe abruption can cause heavy bleeding and damage to the placenta, which can be life-threatening for both mother and baby.
  • Stroke: the blood supply to the brain can be disturbed as a result of high blood pressure and is known as a cerebral haemorrhage, or stroke.
  • Pulmonary oedema: (Fluid accumulation in the lungs).
  • Kidney failure
  • Liver failure
  • Disseminated intravascular coagulation (disturbance in the blood clotting system of women)
  • Maternal death: can occur due to preeclampsia.

Years after a pregnancy complicated by preeclampsia, women are at increased risk of chronic hypertension, diabetes mellitus, ischemic heart disease, cerebrovascular disease, kidney disease, thromboembolism, hypothyroidism, and even impaired memory.

Foetal complications: These are short and long-term effects:

  • Intrauterine growth restriction: preeclampsia can result into decreased foetal growth termed as intrauterine growth restriction (IUGR) leading to various degrees of foetal morbidity, and mortality. These babies are often smaller than their corresponding period of gestational age.
  • Preterm birth: may occur in women suffering from preeclampsia during pregnancy and because of prematurity may suffer from various complications such as neonatal respiratory distress syndrome.
  • Still birth: Preeclampsia and its complication are an important cause of stillbirth (baby born with no signs of life at or after 28 weeks of gestation).
  • Long-term effects: follow up studies have demonstrated that babies who suffered intrauterine growth retardation are more likely to develop hypertension, coronary artery disease, and diabetes in adult life.

References-

www.obgyn.net

www.ncbi.nlm.nih.gov

www.nhs.uk

The causes of preeclampsia are still unknown, thus effective primary prevention is not possible at this stage. However there are some major risk factors for preeclampsia (such as obesity), and rectification of these factors might result in a decrease in its frequency.

Maternal deaths can occur among severe cases, as the progression from mild to severe can be rapid, unexpected, hence emphasis should be on secondary and tertiary prevention including early detection and proper management of preeclampsia. Proper education of patient and healthcare provider may be the key to the successful detection and management of preeclampsia.

Few recommendations provided by World Health Organization (WHO) and ACOG: 

  • In areas where dietary calcium intake is low, calcium supplementation during pregnancy (at doses of 1.5–2.0 g elemental calcium/day) is recommended for the prevention of preeclampsia in all women, but especially those at high risk of developing preeclampsia.
  • Low-dose acetylsalicylic acid (aspirin, 75 mg) is recommended for the prevention of preeclampsia in women at high risk of developing the condition (risk factors: previous preeclampsia; diabetes; chronic hypertension; renal disease; autoimmune disease; and multiple pregnancies).
  • Magnesium sulfate is recommended for the prevention of eclampsia in women with severe preeclampsia in preference to other anticonvulsants.
  • Diuretics, particularly thiazides, are not recommended for the prevention of preeclampsia and its complications.

Postpartum

  • Use of non-steroidal anti-inflammatory drugs (as it may increase BP) should be replaced by other analgesics in women with hypertension that persists for more than1day postpartum.
  • Use of postpartum magnesium sulfate is continued for 24 hours postpartum to prevent seizure.
  • Treatment with antihypertensive drugs is recommended for severe postpartum hypertension.

Preeclampsia particularly associated with preterm delivery should be considered as a strong risk factor for cardiovascular disease in later life. Therefore these women should be advised to

  • Maintain ideal body weight
  • Engage in aerobic exercise regularly
  • Eat diet high in fiber, vegetables, and fruits and low in fat
  • Avoid tobacco

References-

www.acog.org

apps.who.int

  • PUBLISHED DATE : Jun 01, 2016
  • PUBLISHED BY : Zahid
  • CREATED / VALIDATED BY : Dr. Aruna Rastogi
  • LAST UPDATED ON : Jun 01, 2016

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