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Complications of Pregnancy

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Preeclampsia

 

Preeclampsia is characterized by new onset of hypertension and proteinuria after 20 weeks of gestation. It complicates 5 to 8 percent of pregnancies and is associated with iatrogenic prematurity. Clinical manifestations of preeclampsia can appear anytime between the second trimester and the first few days postpartum.


Clinical evaluation

Screening

Pregnant women are routinely screened for signs and symptoms of preeclampsia at each prenatal visit. Women at high risk for preeclampsia should be seen in early pregnancy to assess blood pressure, establish accurate pregnancy dating, and perform baseline laboratory tests.


Risk factors for preeclampsia :
  • 1. Primigravid state.
  • 2. History of preeclampsia.
  • 3. A higher blood pressure at the initiation of pregnancy and a large body size.
  • 4. A family history of preeclampsia is associated with a two to fivefold increase in risk.
  • 5. Multiple pregnancy.
  • 6. Preexisting maternal hypertension.
  • 7. Pregestational diabetes.
  • 8. Antiphospholipid antibody syndrome.
  • 9. Vascular or connective tissue disease.
  • 10. Advanced maternal age (>35 to 40 years).

Late pregnancy screening

Measurement of blood pressure and urine protein at regular intervals in the late second and third trimesters is critical for diagnosis of preeclampsia. A rising blood pressure is usually the first sign of disease. Women should report possible signs of preeclampsia, such as persistent or severe headache, visual changes, right upper quadrant or epigastric pain, sudden large weight gain, or facial edema.

Diagnosis of Preeclampsia

Systolic blood pressure >140 mm Hg
or
Diastolic blood pressure > 90 mm Hg
AND
A random urine protein determination of 1+ on dipstick or 30 mg/dL or proteinuria of 0.3 g or greater in a 24-hour urine specimen

Criteria for Gestational Hypertension

Systolic blood pressure >140 mm Hg
Diastolic blood pressure >90 mm Hg
AND no proteinuria
Developing AFTER the 20th week of gestation in women known to be normotensive before pregnancy


Criteria for Severe Preeclampsia

New onset proteinuria hypertension and at least one of the following :
  • Symptoms of central nervous system dysfunction:
  • Blurred vision, scotomata, altered mental status, severe headache.
  • Symptoms of liver capsule distention: Right upper quadrant or epigastric pain.
  • Severe blood pressure elevation: Systolic blood pressure >160 mm Hg or diastolic >110 mm Hg on two occasions at least six hours apart
  • Thrombocytopenia: Less than 100,000 platelets per mm3.
  • Intrauterine fetal growth restriction.
  • Pulmonary edema or cyanosis.
  • Cerebrovascular accident.
  • Coagulopathy.

Maternal assessment of women with hypertension after midpregnancy.

Mild preeclampsia includes those women who satisfy the criteria for preeclampsia but do not have any features of severe disease. . Hypertension should be confirmed by at least two measurements at least several six hours apart.


Laboratory evaluation consists of hematocrit (hemoconcentration suggests preeclampsia), platelet count, protein excretion, serum creatinine, serum uric acid, serum alanine and aspartate aminotransferase concentrations (ALT, AST), and lactic acid dehydrogenase concentration (LDH).


Eclampsia refers to the development of seizures in a woman with preeclampsia. Preeclampsia-eclampsia is caused by generalized vasospasm, activation of the coagulation system, and changes in autoregulatory systems related to blood pressure control.


Edema and intravascular volume. Most women with preeclampsia have edema. Although peripheral edema is common in normal pregnancy, sudden and rapid weight gain and facial edema often occur in women who develop preeclampsia.

Hematologic changes. Increased platelet turnover is a consistent feature of preeclampsia. The most common coagulation abnormality in preeclampsia is thrombocytopenia.


Liver involvement may present as right upper quadrant or epigastric pain, elevated liver enzymes and subcapsular hemorrhage or hepatic rupture.


Central nervous system. Headache, blurred vision, scotomata, and, rarely, cortical blindness are manifestations of preeclampsia; seizures in a preeclamptic woman are defined as eclampsia.


Fetus and placenta. The fetal consequences are fetal growth restriction and oligohydramnios. Severe or early onset preeclampsia result in the greatest decrements in birth weight.


Management of preeclampsia

The definitive treatment of preeclampsia is delivery. Delivery is recommended for women with mild preeclampsia at or near term and for most women with severe preeclampsia or severe gestational hypertension regardless of gestational age. Exceptions may be made for women remote from term (less than 32 to 34 weeks of gestation) who improve after hospitalization and do not have significant end-organ dysfunction or fetal deterioration.


Fetal assessment consists of daily fetal movement counts and nonstress testing and/or biophysical profiles at periodic intervals. A sonographic estimation of fetal weight should be performed to look for growth restriction and oligohydramnios, and it should be repeated serially.


Fetal Assessment in Preeclampsia :

Mild preeclampsia : Daily fetal movement counting Ultrasound examination for estimation of fetal weight and amniotic fluid determination at diagnosis. Repeat in three weeks if the initial examination is normal, twice weekly if there is evidence of fetal growth restriction or oligohydramnios.
Nonstress test and/or biophysical profile once or twice weekly. Testing should be repeated immediately if there is an abrupt change in maternal condition.


Severe preeclampsia : Daily nonstress testing and/or biophysical profile

Antenatal corticosteroids to promote fetal lung maturation should be administered to women less than 34 weeks of gestation who are at high risk for delivery within the next seven days.

Maternal monitoring. Laboratory evaluation (eg, hematocrit, platelet count, creatinine, urine protein, LDH, AST, ALT, uric acid) should be repeated once or twice weekly in women with mild stable preeclampsia.

Symptoms. Patients should call immediately if they develop severe or persistent headache, visual changes, right upper quadrant or epigastric pain, nausea or vomiting, shortness of breath, or decreased urine output. Decreased fetal movement, vaginal bleeding, abdominal pain, rupture of membranes, or uterine contractions should be reported immediately.

Women with severe preeclampsia should be delivered or hospitalized for the duration of pregnancy. Prolonged antepartum management may be considered in selected women under 32 weeks of gestation, such as those whose condition improves after hospitalization and who have no evidence of end-organ dysfunction or fetal deterioration.


Timing and indications for delivery.

Delivery at or by 40 weeks of gestation should be considered for all women with preeclampsia. Women with mild disease and a favorable cervix may benefit from induction as early as 38 weeks, while those with stable severe disease should be delivered after 32 to 34 weeks if possible (with demonstration of fetal pulmonary maturity).

Laboratory

Platelet count, creatinine, urine protein, and liver enzymes, should be repeated once or twice weekly in women with mild stable preeclampsia. Protein excretion can be quantified with a protein-to-creatinine ratio.
A rising hematocrit suggests progression to more severe disease, while a falling hematocrit may be a sign of hemolysis. An elevated lactic acid dehydrogenase (LDH) concentration is a better sign of hemolysis, and a marker of severe disease or HELLP syndrome (ie, Hemolysis, Elevated Liver enzymes, Low Platelets). Hemolysis can be confirmed by observation of schistocytes on a blood smear.


Indications for Delivery in Preeclampsia
  • Maternal indications : Gestational age greater than or equal to 38 weeks of gestation
  • Platelet count less than 100,000 cells per mm3.
  • Deteriorating liver function.
  • Progressive deterioration in renal function.
  • Abruptio placentae.
  • Persistent severe headaches or visual changes.
  • Persistent severe epigastric pain, nausea, or vomiting.
  • Fetal indications :
    • Severe fetal growth restriction.
    • Nonreassuring results from fetal testing.
    • Oligohydramnios.

Severe preeclampsia

All women with severe preeclampsia should be delivered or hospitalized for the duration of pregnancy. Prolonged antepartum management may be considered in women under 32 to 34 weeks of gestation who have: Severe proteinuria (greater than 5 g in 24 hours).

Mild intrauterine fetal growth restriction (fifth to tenth percentile), as long as antepartum fetal testing remains reassuring, oligohydramnios is not severe, umbilical artery diastolic flow is not reversed on Doppler velocimetry, and there is progressive fetal growth. Severe hypertension with blood pressure reduction after hospitalization. Asymptomatic laboratory abnormalities that quickly resolve after hospitalization.

Delivery should be initiated, after a course of antenatal corticosteroid therapy if possible, when there is poorly controlled, severe hypertension, eclampsia, thrombocytopenia (less than 100,000 platelets/microL), elevated liver function tests with epigastric or right upper quadrant pain, pulmonary edema, rise in serum creatinine concentration by 1 mg/dL over baseline, placental abruption, or persistent severe headache or visual changes. Fetal indications for delivery include nonreassuring fetal testing, severe oligohydramnios, or severe fetal growth restriction (less than the 5th percentile).


Timing and indications for delivery

Timing of delivery is based upon the maternal and fetal condition and gestational age.

Women who develop severe preeclampsia at or beyond 32 to 34 weeks of gestation should be delivered.

Women with mild disease remote from term can be managed expectantly to enable fetal growth and maturation.

Women with mild disease and a favorable cervix or who are noncompliant may benefit from induction as early as 37 weeks; otherwise, delivery by 40 weeks of gestation should be considered.

Delivery should be undertaken if there are signs of worsening disease (eg, severe hypertension not controlled with antihypertensive therapy, cerebral/visual symptoms, platelet count <100,000 cells/microL, deterioration in liver or renal function, abdominal pain, severe fetal growth restriction, abruption, nonreassuring fetal testing). Eclampsia is also an indication for delivery.


Route of delivery

Delivery is usually by the vaginal route, with cesarean delivery reserved for the usual obstetrical indications. Severe preeclampsia does not mandate immediate cesarean birth.

Anticonvulsant therapy is generally initiated during labor or while administering corticosteroids or prostaglandins prior to planned delivery and continued until 24 to 48 hours postpartum, when the risk of seizures is low. Magnesium sulfate is the drug of choice for seizure prevention.


Treatment of hypertension in preeclampsia

Severe hypertension should be treated. In adult women, diastolic blood pressures >105 to 110 mm Hg or systolic pressures >160 to 180 mm Hg are considered severe hypertension. In adolescents, treatment is initiated at diastolic pressures of >100 mm Hg. Intravenous labetalol is both effective and safe (beginning with 20 mg intravenously followed at 10- to 15-minute intervals by 40 mg, then 80 mg up to a maximum total cumulative dose of 220 mg).


Blood pressure goal

The goal of therapy is a systolic pressure of 140 to 155 mm Hg and diastolic pressure of 90 to 105 mm Hg.


Management of eclampsia

Maintenance of airway patency and prevention of aspiration are the initial management priorities. The patient should be rolled onto her left side and a padded tongue blade placed in her mouth, if possible.


Control of convulsions

Magnesium sulfate, 2 to 4g IV push repeated every 15 minutes to a maximum of 6g.


Maintenance dose of magnesium sulfate:

2 to 3g/hour by continuous intravenous infusion. Diazepam may also be given as 5mg IV push repeated as needed to a maximum cumulative dose of 20 mg to stop the convulsions; however, benzodiazepines have profound depressant effects on the fetus.


Postpartum course

Hypertension due to preeclampsia resolves postpartum, often within a few days, but sometimes taking a few weeks. Severe hypertension should be treated; antihypertensive medications can be discontinued when blood pressure returns to normal.


Postpartum hypertension

A small rise in blood pressure is common, with an average increase in systolic and diastolic pressure of 6 and 4 mm Hg, respectively, in the first four postpartum days.
Preeclampsia-related hypertension usually resolves within a few weeks (average 16 days) and should always be gone by 12 weeks postpartum. Mild hypertension that persists beyond this period should be evaluated and treated. Diuretics may reduce milk volume and should be avoided.


Pre-existent hypertension

There is a threefold increase in perinatal mortality, a twofold increase in abruptio placentae, and an increased rate of impaired fetal growth in pregnant women with preexisting hypertension. There is also a higher rate of preterm delivery before 35 weeks.


Maternal evaluation

Baseline laboratory tests include urinalysis and urine culture, serum creatinine, blood urea nitrogen, glucose, electrolytes, and 24-hour urine collection for total protein and creatinine clearance. An electrocardiogram should be obtained in women with long-standing hypertension.

Periodic reassessment of serum creatinine and quantitative testing for urine protein is recommended every trimester.

Indications for treatment. Women with chronic hypertension who are normotensive or mildly hypertensive on medication may continue their therapy or have their antihypertensive agents tapered and/or stopped during pregnancy.


Mild essential hypertension. Indications for initiating or reinstituting antihypertensive therapy are a diastolic pressure persistently above 100 mm Hg, systolic pressure >150 to 160 mm Hg, or signs of hypertensive end-organ damage.


Severe hypertension (blood pressure >180/110 mm Hg), particularly if associated with signs of early hypertensive encephalopathy, should be treated to protect the mother from stroke, heart failure, or renal failure.

 

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