F.Management of placenta previa
1.In a pregnancy >36 weeks with documented fetal lung maturity, the neonate should be immediately delivered by cesarean section.
2.Low vertical uterine incision is probably safer in patients with an anterior placenta. Incisions through the placenta should be avoided.
3.If severe hemorrhage jeopardizes the mother or fetus, cesarean section is indicated regardless of gestational age.
4.Expectant management is appropriate for immature fetuses if bleeding is not excessive, maternal physical activity can be restricted, intercourse and douching can be prohibited, and the hemoglobin can be maintained at >10 mg/dL.
5.Rh immunoglobulin is administered to Rh-negative- unsensitized patients.
6.Delivery is indicated once fetal lung maturity has been documented.
7.Tocolysis with magnesium sulfate may be used for im-
mature fetuses.
IV. Cervical bleeding
A.Cytologic sampling is necessary.
B.Bleeding can be controlled with cauterization or packing.
C.Bacterial and viral cultures are sometimes diagnostic.
V. Cervical polyps
A.Bleeding is usually self-limited.
B.Trauma should be avoided.
C.Polypectomy may control bleeding and yield a histologic
diagnosis.
VI. Bloody show is a frequent benign cause of late third trimester bleeding. It is characterized by blood-tinged mucus associated with cervical change.
References: See page 155.
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.
I.Clinical evaluation
A.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.
B.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).
C.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
Hepatocellular injury: Serum transaminase concentration at least twice normal
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 Proteinuria: Over 5 grams in 24 hours or 3+ or more on two random samples four hours apart
Oliguria <500 mL in 24 hours Intrauterine fetal growth restriction Pulmonary edema or cyanosis Cerebrovascular accident Coagulopathy
D.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.
1.Hypertension should be confirmed by at least two measurements at least several six hours apart.
2.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).
E.Eclampsia refers to the development of grand mal 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.
F.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.
G.Hematologic changes. Increased platelet turnover is a consistent feature of preeclampsia. The most common coagulation abnormality in preeclampsia is thrombocytopenia.
H.Liver involvement may present as right upper quadrant or epigastric pain, elevated liver enzymes and subcapsular hemorrhage or hepatic rupture.
I.Central nervous system. Headache, blurred vision, scotomata, and, rarely, cortical blindness are manifestations of preeclampsia; seizures in a preeclamptic woman are defined as eclampsia.
J.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.
II.Management of preeclampsia
A.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.
B.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 |
Daily fetal movement counting |
preeclampsia |
Ultrasound examination for estimation of |
|
fetal weight and amniotic fluid determi- |
|
nation at diagnosis. Repeat in three |
|
weeks if the initial examination is nor- |
|
mal, 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 |
Daily nonstress testing and/or biophysi- |
preeclampsia |
cal profile |
C.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. Betamethasone (two doses of 12 mg given intramuscularly 24 hours apart) or dexamethasone (four doses of 6 mg given intramuscularly 12 hours apart) may be used.
D.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.
E.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 mem-
branes, or uterine contractions should be reported immediately.
F.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.
G.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).
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 func- |
|
tion |
|
Abruptio placentae |
|
Persistent severe headaches or visual |
|
changes |
|
Persistent severe epigastric pain, nau- |
|
sea, or vomiting |
|
|
Fetal indications |
Severe fetal growth restriction |
|
Nonreassuring results from fetal testing |
|
Oligohydramnios |
H.Laboratory
1.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.
2.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.
III.Severe preeclampsia
A.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:
1.Severe proteinuria (greater than 5 g in 24 hours).
2.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.
3.Severe hypertension with blood pressure reduction after hospitalization.
4.Asymptomatic laboratory abnormalities that quickly resolve after hospitalization.
B.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).
C.Timing and indications for delivery
1.Timing of delivery is based upon the maternal and fetal condition and gestational age.
2.Women who develop severe preeclampsia at or beyond 32 to 34 weeks of gestation should be delivered.
3.Women with mild disease remote from term can be managed expectantly to enable fetal growth and maturation.
4.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.
5.Women with stable, severe disease under 32 to 34 weeks may be managed expectantly with daily maternal and fetal monitoring. Delivery can be delayed until either a course of glucocorticoids to accelerate fetal lung maturation can be completed or there is evidence of fetal pulmonary maturity or 34 weeks of gestation are completed.
6.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).
7.Eclampsia is also an indication for delivery.
D.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.
IV.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.
A.Magnesium sulfate is given as a loading dose of 6 g intravenously, followed by 2 g per hour as a continuous infusion. Magnesium sulfate should be considered for prevention of
eclampsia in all women with preeclampsia.
B.Magnesium toxicity is related to serum concentration: loss of deep tendon reflexes occurs at 8 to 10 mEq/L, respiratory paralysis at 10 to 15 mEq/L, and cardiac arrest at 20 to 25 mEq/L. Calcium gluconate (1 g intravenously over at 5 to 10 minutes) is administered to counteract magnesium toxicity.
V.Treatment of hypertension in preeclampsia
A.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.
B.Intravenous labetalol is both effective and safe (beginning with 20 mg intravenously followed at 10to 15-minute intervals by 40 mg, then 80 mg up to a maximum total cumulative dose of 220 mg).
C.Occasionally, preeclamptic women with severe hypertension are stabilized and not delivered. In these patients, oral antihypertensive therapy is often indicated. The only oral drugs that have been proven to be safe in pregnant women are methyldopa (250 mg twice daily orally, maximum dose 4 g/day), and beta-blockers, such as labetalol (100 mg twice
daily orally, maximum dose 2400 mg/day). D.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.
Treatment of Severe Hypertension in Preeclampsia
The goal is a gradual reduction of blood pressure to a level below 160/105 mm Hg. Sudden and severe hypotension should be avoided.
Hydralazine: 5 mg IV, repeat 5 to 10 mg IV every 20 minutes to maximum cumulative total of 20 mg or until blood pressure is controlled.
Labetalol (Trandate): 20 mg IV, followed by 40 mg, then 80 mg, then 80 mg at 10 minute intervals until the desired response is achieved or a maximum total dose of 220 mg is administered.
Methyldopa (Aldomet) 250 mg BID orally, maximum dose 4 g/day
II.Management of eclampsia
A.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.
B.Control of convulsions. Magnesium sulfate, 2 to 4 g IV push repeated every 15 minutes to a maximum of 6 g. Maintenance dose of magnesium sulfate: 2 to 3 g/hour by continuous intravenous infusion. Diazepam may also be given as 5 mg 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.
C.Postpartum course. Hypertension due to preeclampsia resolves postpartum, often within a few days, but some-
times taking a few weeks. Severe hypertension should be treated; antihypertensive medications can be discontinued when blood pressure returns to normal.
III.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.
A.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.
B.Angiotensin converting enzyme (ACE) inhibitors, betablockers, and calcium channel blockers are suitable choices for nonbreastfeeding mothers. ACE inhibitors should be avoided during lactation. Diuretics may reduce milk volume
and should be avoided.
IV.Pre-existent hypertension
A.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.
B.Maternal evaluation
1.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.
2.Periodic reassessment of serum creatinine and quantitative testing for urine protein is recommended every trimester.
C.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.
1.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 endorgan damage.
2.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.
D.Choice of drug
1.Methyldopa and hydralazine have been most widely used in pregnant women and their long-term safety for the