Download Complications of Late Pregnancy (Editors` note: In the absence of

Complications of Late Pregnancy
(Editors’ note: In the absence of qualified obstetrician/gynecologists, surgeons in lowincome countries are obliged to treat the surgical complications of pregnancy and the
female genital tract. It has been estimated that, in the district hospital, these conditions
may comprise at least 40% of the workload.(1) For this reason Surgery in Africa will
continue to post reviews on these important and relevant topics.
(1) Lavy C, Tindall A, Steinlechner C, Mkandawire N, Chimangeni S. Surgery in Malawi - a
national survey of activity in rural and urban hospitals. Annals of the Royal College of Surgeons
of England 89(7):722-4, 2007.
http://simplelink.library.utoronto.ca.myaccess.library.utoronto.ca/url.cfm/42452)
1.0 Introduction
2.0 Placental Abruption
2.1 Introduction
2.2 Clinical Importance
2.3 Risk Factors
2.4 Pathophysiology
2.5 Clinical Presentation
2.6 Diagnosis
2.7 Management
3.0 Placenta Previa
3.1 Introduction
3.2 Incidence
3.3 Risk Factors
3.4 Pathophysiolog
3.5 Clinical Presentation
3.6 Neonatal Outcomes
3.7 Management
3.8 Placenta accreta associated with
placenta previa
4.0 Vasa Previa
4.1 Introduction
4.2 Diagnostic approach
4.3 Therapeutic approach
5.0 Antepartum Bleeding of Unknown Origin
(ABUO)
5.1 Overview
5.2 Incidence and management of ABUO
6.0 Hypertensive Disorders of Pregnancy
6.1 Introduction
6.2 Definition and classification
6.3 Etiology and pathology
6.4 Prediction and prevention
6.5 Antepartum management
6.6 Intrapartum management
6.7 Postpartum management
6.8 Management of eclampsia
7.0 Recommendations
References
1.0 Complications of Late Pregnancy
The purpose of this review is to address two common complications of late pregnancy, abnormal
vaginal bleeding and abnormally high blood pressure. The possible causes of bleeding will be
discussed and a review of hypertensive disorders of pregnancy will be presented.
The initial management of significant bleeding in late pregnancy is similar no matter what the
cause of the bleeding may be. An initial survey should attempt to estimate the amount of blood
loss, although this may be difficult due to concealed hemorrhage. Quick attention to the
presenting vital signs looking for hypotension, tachycardia, confusion, or breathlessness can alert
the clinician to hemodynamic instability. In cases of hemodynamic instability immediate
intravenous access, fluid resuscitation, and availability of blood products is necessary. Baseline
laboratory tests include hematocrit or hemoglobin, blood type, platelet count, fibrinogen level,
and coagulation studies. An assessment of the fetal condition through auscultation of fetal heart
tones or continuous fetal monitoring should be done as soon as possible. (1)
2.0 Placental Abruption
2.1 Introduction
Placental abruption is defined as premature separation of a placenta that is normally located in
the fundus of the uterus. Abruption may be referred to as “revealed” or “concealed.” When blood
tracks between the membranes and the decidua and escapes through the cervix into the vagina
the bleeding from the abruption is revealed. A “concealed” abruption occurs when blood
accumulates behind the placenta, and there is no obvious external bleeding. A total placental
abruption results in fetal death as all blood supply to the placenta is lost. A partial abruption,
with only a portion of the placenta detached from the uterine wall, results in various degrees of
fetal compromise. (2)
Types of Placental Abruption – A- Revealed, B-Concealed
The management of abruption should be individualized on a case-by-case basis depending on the
severity of the abruption and the gestational age at which it occurs. When abruption occurs at or
near term and the fetal and maternal status are good, the goal of a vaginal delivery can be
pursued. In the presence of fetal or maternal compromise, a prompt cesarean is often indicated.
(2)
The incidence of placental abruption is 0.5% to 1.0% and seems to be increasing. This condition
is a leading cause of perinatal mortality and accounts for 10 to 15% of all perinatal deaths. (4)
2.2 Clinical Importance
Placental abruption has a wide range of clinical significance. A small area of abruption may have
minimal bleeding and little or no consequences to the fetus or the mother. A massive abruption
may cause fetal death in utero and severe maternal morbidity. The danger to the mother is based
mainly on the severity of the abruption. The risk to the fetus is based both on the severity of the
abruption and the gestational age at which the abruption occurs. (2)
2.3 Risk Factors
Major risk factors for placental abruption include cocaine and drug use, multiple gestation,
chronic hypertension, mild and severe preeclampsia, cigarette smoking, and premature rupture of
membranes. Other lesser risk factors are maternal trauma, thrombophilias, hydramnios, advanced
maternal age, and intrauterine infections. (3)
2.4 Pathophysiology
In many cases of placental abruption the precise pathophysiology is unknown. Hemorrhage at the
decidual-placental interface causes the abruption. (4) Abruption, which occurs when there is a
sudden uterine decompression resulting from rupture of the membranes with hydramnios, or
after delivery of a first twin, may be caused by shearing forces. (1) In the majority of cases, it
seems that abruption may be the consequence of a long-standing process that probably dates
back to the first trimester. (2)
Acute separation of the placenta may deprive the fetus of oxygen and nourishment, with the fetus
dying. If the coagulation cascade is activated with consumption of coagulation factors,
disseminated intravascular coagulopathy (DIC) may ensue. The risk is highest when there is a
large placental detachment as to cause fetal death. Continuing hemorrhage associated with DIC
may lead to further consumption of coagulation factors, setting off a vicious circle. Bleeding into
the uterine myometrium can lead to a beefy boggy uterus, called a Couvelaire uterus. (5)
2.5 Clinical Presentation
The classical presentation of abruption is vaginal bleeding accompanied by abdominal pain. A
severe abruption may occur with neither or just one of these signs. The amount of vaginal
bleeding correlates poorly with the degree of abruption, because of the possibility of concealed
bleeding. There is a positive correlation between the extent of placental separation and the risk of
stillbirth, with stillbirth occurring in most cases in which there is greater than 50% placental
separation. (1) Typically, the uterus is tense and tender. Backache may be the only symptom. (4)
2.6 Diagnosis
The diagnosis of abruption is a clinical one and should be suspected in women who present with
vaginal bleeding or abdominal pain or both, a history of trauma, and those who present in
otherwise unexplained preterm labor. Common symptoms include vaginal bleeding, uterine pain,
a tetanic contraction of the uterus, and fetal heart rate abnormalities, including a sinusoidal
pattern with continuous fetal heart rate monitoring. (4) The ultrasonographic appearance of
abruption depends on the size and location of the bleed, as well as the duration between the
abruption and the time of the ultrasound. In cases of acute revealed abruption the ultrasound may
show no abnormalities. Ultrasonography will fail to detect at least one half of cases of abruption.
When the ultrasound seems to show an abruption, the likelihood that there is indeed an abruption
is high. (2)
2.7 Management
The management of placental abruption depends on the presentation, the gestational age, and the
condition of the fetus and the mother. It is important to make decisions about management on a
case-by-case basis.
It is reasonable in cases of fetal death, regardless of gestational age, to allow the mother to
attempt a vaginal delivery as long as the mother is stable and there are no other
contraindications. In cases of abruption the uterus usually contracts vigorously and labour
progresses rapidly. Amniotomy frequently speeds up delivery.
Placental abruption carries a significant risk of coagulopathy and hypovolemic shock. Adequate
intravenous access, attention to the amount of blood loss, and replacement of volume, red blood
cells, and coagulation factors is important. Blood should be taken for complete blood count,
coagulation factors and type and crossmatch. (2)
2.8 Trauma in Pregnancy
In cases of blunt abdominal trauma during pregnancy, more than 70% of fetal losses result from
placenta abruption. The mechanism of the abruption in cases of blunt trauma is partially based on
the elasticity of the uterus which allows deformation of its shape with trauma, and the nonelasticity of the placenta, which does not deform with trauma. This mechanism creates a shearing
effect at the uteroplacental interface. (6)
All women beyond 20 – 24 weeks of gestational age who suffer blunt trauma should be
monitored for a minimum of four hours. With any non-reassuring finding such as frequent
uterine contractions, abnormal fetal heart tones, or any serious maternal signs or symptoms, the
mother should be observed longer. In three separate studies, the presence of frequent uterine
contractions has been the most sensitive predictor of placental abruption. (6)
Management decisions in the care of a mother suffering from blunt trauma must be based on
maternal condition, gestational age of the fetus and careful monitoring of clinical signs, keeping
in mind the possibility of placental abruption. (6)
3.0 Placenta Previa
3.1 Introduction
Placenta previa is an implantation of the placenta that overlies or is within 2 cm of the internal
cervical os. The condition is described as a complete previa when it covers the os and as a
marginal previa when the edge lies within 2 cm of the os. Any suspected low-lying placenta seen
by transabdominal scan should be evaluated by a transvaginal scan. (1)
When the cervix has not dilated and the placental edge is located within one cm of the internal
os, bleeding usually occurs with labor and a cesarean section must be done. When the placental
edge is located one to two cm away from the undilated cervical os, the clinical course cannot be
definitely predicted. When the edge is at least two cm away from the os, it is not considered a
placenta previa. (4)
Types of Placenta Previa
3.2 Incidence
Placenta previa is found in approximately 0.5% to 1% of all pregnancies. It can be fatal in 0.03%
of cases. It is more common in multiparous than in nulliparous women occurring in one in 1,500
nulliparous women and as many as one in 20 grand multiparous women. (4)
3.3 Risk Factors
Several risk factors have been found in association with placenta previa. A prior cesarean section
is the most significant risk factor. The risk is one in 200 deliveries after one previous cesarean
section, and even higher after repeated cesarean sections. Other risk factors include pregnancy
termination, intrauterine surgery, smoking, multifetal gestation, increased parity, and increasing
maternal age. (7)
3.4 Pathophysiology
The exact pathophysiology is unknown but it is thought to result from scarring in the
endometrium because placenta previa is more frequent in women who are older, multiparous or
who have had prior cesarean sections or uterine curettage. This prior experience of the
endometrium can lead to poor vascularity of this tissue and a thinner myometrium. The embryo
implants in healthier tissue which would be the healthier tissue of the lower uterine segment. The
fact that there is a six-fold increase in implantation at the site of a previous lower uterine
segment incision is not explained by this theory. (4)
3.5 Clinical Presentation
Placenta previa is commonly seen as an incidental finding on transabdominal ultrasounds
performed at 20-24 weeks gestation. It is present in only 0.4% of pregnancies at term. The
migration of the placenta away from the lower uterine segment is caused by growth of placental
trophoblasts toward the fundus with its richer blood supply. The lower uterine segment also
elongates over time. (1)
Smith performed a prospective ultrasound study comparing findings with transabdominal
scanning and transvaginal scanning. In this study landmarks such as the cervical os and the edge
of the placenta were poorly seen 50% of the time with transabdominal scanning. Also, the
assessment of placental localization was changed in 26% of cases when transvaginal scanning
was done after transabdominal scanning. (8)
Placenta previa which is symptomatic usually presents as vaginal bleeding in the late second or
third trimester, often occurring after sexual intercourse. This bleeding is painless unless labor or
placental abruption has occurred. The first sign of bleeding is usually not sufficient to produce
hemodynamic instability or to threaten the fetus in the absence of digital examination or cervical
instrumentation. (1)
3.6 Neonatal Outcomes
Neonatal complications significantly associated with placenta previa include major congenital
anomalies (odds ratio [OR] 2.48), respiratory distress syndrome (OR) 4.94, and anemia (OR)
2.65. The perinatal mortality rate associated with placenta previa was 2.3% (compared with
0.78% in controls) and was explained by gestation age at delivery, occurrence of congenital
anomalies, and maternal age. (9)
3.7 Management
In general women bleeding from placenta previa are admitted to the hospital for an initial
assessment. Transabdominal and, if possible, transvaginal ultrasonography are important steps in
the assessment, as well as estimation of blood loss, complete blood count, and typing and
crossmatching of blood. Decisions about management are based on gestational age of the fetus,
amount of blood lost or being lost, and the condition of the mother and her fetus. Since most
neonatal morbidity and mortality associated with placenta previa results from complications of
prematurity, an important goal is to prolong the pregnancy until fetal lung maturity is achieved if
possible.
If the evaluation of an antepartum hemorrhage has to be done in a setting where there is no
ultrasonography available, a double setup can be arranged. In the face of significant bleeding and
uncertainty about the location of the placenta, the patient can be taken to the operating theatre
where all is in readiness for an emergent cesearean section. A useful sign is a high presenting
part by abdominal palpation. The high presenting part is due to the placenta filling the lower
uterine segment. A digital exam in the case of a central placenta previa may provoke an
uncontrollable hemorrhage. After inserting a large bore intravenous catheter, a gentle digital
exam can be performed in the theatre to determine if the presenting part is the placenta. If the
examiner feels that a central placenta previa is present, an immediate cesarean section can be
done, especially if significant bleeding is provoked. (18) If placenta previa is ruled out with this
digital exam a cesarean section may not be necessary. If the cervix is fully dilated with cephalic
presentation a vacuum extraction or obstetrical forceps delivery may be possible.
A Cochrane review by Neilson in 2007 examined the question of what effect any clinical
intervention had in cases where it was likely that a pregnant woman had placenta previa. His
results showed there was no clear advantage or disadvantage to a policy of home versus hospital
care. Cervical cerclage may reduce the risk of delivery before 34 weeks or the birth of a baby
weighing less than two kgs. (10)
If vaginal bleeding is occurring with preterm contractions, tocolytic agents may be used safely to
prolong gestation. Corticosteroids should be given to women with pregnancies of 24 – 34 weeks
gestation to accelerate fetal lung maturity. The regimen for corticosteroids is either
betamethasone, 12 mg intramuscularly once in 24 hours for 2 doses, or dexamethasone 6 mg
intramuscularly repeated every 12 hours for a total of four doses.(20)
In the majority of cases a transverse lower uterine segment incision can be used for delivery
especially when the placenta is posterior and with a well-developed lower uterine segment. In
instances where the placenta is anteriorly located, the surgeon must make the incision through
the uterus and deliver the presenting part expeditiously in order to avoid excessive blood loss for
the fetus. Placenta previa is often associated with fetal malpresentation especially transverse lie.
In these cases the uterine incision should be low vertical or classical. (4)
Regional anesthesia has been successfully used for operations for placenta previa. It has been
reported that controlling the blood pressure during the operation has not been a problem.
However, the anesthetist may prefer general anesthesia in cases of heavy blood loss before
proceeding to the theatre. (4)
3.8 Placenta accreta associated with placenta previa
Placenta accreta is an abnormally firm attachment of placental villi to the uterine wall
accompanied by an absence of the normal intervening decidua basalis and a fibrinoid layer called
the layer of Nitabuch. Three types of placenta accreta are recognized: (a) accreta – the placenta is
attached directly to the myometrium (b) increta – the placenta extends into the myometrium and
(c) percreta – the placenta extends through the entire myometrial layer. (7)
The average incidence is approximately 1 in 7000 pregnancies and is highest among women with
placenta previa or a previous cesarean section. The presence of placenta previa in a patient with a
prior cesarean section is associated with accreta in 10% to 35% of cases. With multiple cesarean
sections, the risk may be as high as 60% to 65%. Other risk factors include advanced maternal
age, multiparity, and previous uterine curettage. The incidence of placenta accreta is rising,
mainly due to the rise in cesarean sections. (11)
In most cases of placenta accreta the principal concern is control of hemorrhage at the time of
delivery of the placenta. In the majority of reported cases this has been achieved by
hysterectomy. Fox reported maternal mortality of 5.8% to 6.6% among women who underwent
immediate hysterectomy. Attempts at conservative management were associated with maternal
mortality of 12.4% and 28.3%. (12)
Reported approaches to conservative management of placenta accreta include curettage of
placental fragments, oversewing of the placental bed, ligation of the uterine arteries, or ligation
of the anterior divisions of the internal iliac arteries. (12)
The definitive diagnosis of placenta accreta can only be made by histological examination. The
clinical diagnosis made after or during delivery of the placenta is based on symptoms of
bleeding, retained placenta and unsuccessful manual removal of the placenta. (12)
Komulainen describes two cases of conservatively managed placenta accreta in Finland. One of
these cases will be described for the purposes of illustration. In this case the patient was a 40year old women, G8P7, who had a forceps delivery of a healthy baby girl with 6/8 Apgar scores.
Manual removal of the placenta was attempted but it was firmly attached and only partially
removed. An immediate blood loss of 2000 ml was observed. The bleeding stopped after more of
the placenta was “partly torn out.” Total hysterectomy was considered but not done because of
religious reasons. The ensuing treatment included 12 hours of intravenous oxytocin and
antibiotics. Hospital stay lasted for three weeks. The patient went home well, had weekly
checkups, and a dilatation and curettage were performed 4 months after delivery. The uterine
cavity at that time was normally shaped and the histopathology revealed some remnants of
residual placenta. At the age of 45 this patient again conceived and delivered a ninth time. At the
time of cesarean section a recurrent placenta accreta was diagnosed and total hysterectomy was
required. (12)
The subject of placenta accreta is discussed in this section to alert the doctor faced with
managing placenta previa of the possibility of continuing hemorrhaging after removal of a
placenta previa due to placenta accreta.
4.0 Vasa Previa
4.1 Introduction
The term vasa previa denotes the condition where fetal vessels course through placental
membranes unprotected by placenta or umbilical cord. A velamentous insertion of the umbilical
cord describes a condition where the cord inserts into the membranes rather than its normal
insertion directly into the placenta. This velamentous insertion is the most common cause of vasa
previa. Vasa previa can also occur when fetal vessels course between lobes of the placenta with
one or more accessory lobes. Vasa previa is clinically important because of the high risk of fetal
exsanguination and death that occurs when the membranes rupture, spontaneously or artificially,
and the fetal vessels running through the membranes also are disrupted. Loss of even small
amounts of blood from the fetal vessels can prove disastrous to the fetus because the fetal blood
volume is only about 80 – 100 mL/kg. (7)
The estimated incidence of vasa previa is approximately 1 in 2,500 deliveries. The following are
risk factors for vasa previa: a second-trimester low-lying placenta, pregnancies in which the
placenta has accessory lobes, and multiple pregnancies. (7)
4.2 Diagnostic approach
Vasa previa is most commonly suspected when rupture of the membranes is accompanied by
vaginal bleeding and fetal distress or death. The diagnosis is often confirmed only when the
placenta is inspected after delivery and the position of the fetal vessels is confirmed. Rarely the
diagnosis can be made when the examiner's fingers palpate fetal vessels running through the
membranes. Numerous reports and studies have demonstrated that vasa previa can be diagnosed
prenatally with ultrasonography. (7)
4.3 Therapeutic approach
Good outcomes in the presence of vasa previa depend on diagnosis and delivery by cesarean
section before rupture of membranes. In a multicenter study by Oyelese and colleagues of 155
cases of vasa previa, 61 of the cases were diagnosed prenatally. Perinatal mortality was 56% in
the undiagnosed cases, and only 4% in the cases diagnosed before rupture of membranes. Twothirds of the women had a low-lying placenta in the second trimester, whereas, by the time of
delivery, only one third (20%) of these had a low-lying placenta. In women with a diagnosed
vasa previa, the optimal gestational age for cesarean delivery is 35 to 36 weeks. (7)
5.0 Antepartum Bleeding of Unknown Origin (ABUO)
5.1 Overview
The most common significant reasons for bleeding after the twentieth week of pregnancy are
placenta previa and placental abruption. However, bleeding can also be caused by other
conditions of the cervix, such as cervical ectropion, cervical polyp, cervicitis, or cervical cancer.
The onset of normal labor is often accompanied by a small amount of bleeding, or blood-tinged
mucus, (bloody show). Many pregnant women experience some bleeding after sexual intercourse
or a digital vaginal exam. A history, a physical examination, and ultrasonography are important,
initial first steps in evaluating. A gentle, sterile speculum exam can be safely done in instances
where ultrasonography is not available. A digital exam should not be done before
ultrasonography can be done to exclude placenta previa. (1)
Despite an exhaustive search for the cause of antenatal bleeding the reason for the bleeding will
remain unknown in 2% to 3% of women. Magann and colleagues undertook a study to determine
the incidence and adverse pregnancy consequences of bleeding of an unknown etiology in the
second half of pregnancy and proposed a strategy for management of these pregnancies. (14)
5.2 Incidence and Consequences of ABUO.
One subgroup of women studied by Magann with bleeding before 20 weeks or bleeding in the
first and second trimester had an incidence of ABUO of 8%. In the second subgroup studied the
bleeding was confined to the second and third trimester and the incidence was 2%. (14) Current
management of pregnancies with ABUO requires a careful physical examination and an
ultrasound to evaluate the origin of bleeding. A second trimester ultrasound for the detection of
fetal congenital anomalies should be done if the bleeding occurs in the second trimester. If the
bleeding is accompanied by contractions, then the risk of delivery is high. Corticosteroids should
be administered if the pregnancy is between 28 and 34 weeks. (14)
6.0 Hypertensive Disorders of Pregnancy
6.1 Introduction
Hypertension is the most common medical disorder occurring during pregnancy. Approximately
70% of women diagnosed with hypertension during pregnancy will have gestational
hypertension-preeclampsia, which describes a spectrum of hypertensive disorders, each of which
requires specific thought and management. In the face of hypertension late in pregnancy the
decision between expectant management and delivery depends on fetal gestation age, fetal status,
and severity of the maternal condition at the time of evaluation. (15)
6.2 Definition and Classification
Gestational hypertension is defined only in women who are known to be normotensive before
pregnancy and before 20 weeks’ gestation. A systolic BP of at least 140 mm Hg and/or a
diastolic BP of at least 90 mm Hg on at least two occasions at least 6 hours apart after the 20th
week of pregnancy make the diagnosis of gestational hypertension. This condition is considered
to be severe if there is sustained elevation in systolic BP to at least 160 mm Hg and/or in
diastolic BP to at least 110 mm Hg for at least 6 hours. (15)
Preeclampsia is defined as gestational hypertension plus proteinuria. The proteinuria is usually
documented by a concentration of at least 30 mg/dL (1+) on a urinary dipstick test. At least two
random sample urine specimens collected at least six hours apart further reinforce the presence
or absence of proteinuria. The concentration of urinary protein in random urine samples is highly
variable. (15)
6.3 Etiology and pathophysiology
The etiology of preeclampsia is unknown. Some of the potential etiologies under investigation
include abnormal trophoblast invasion of uterine blood vessels, immunological intolerance
between fetoplacental and maternal tissues, dietary deficiencies, and genetic abnormalities. (15)
Preeclampsia causes numerous pathophysiologic abnormalities including placental ischemia,
generalized vasospasm, abnormal hemostasis, vascular endothelial dysfunction, leukocyte
activation, and changes in various cytokines as well as in insulin resistance. (15)
One of the pathogenetic explanations for the development of preeclampsia is a maladaptation of
the immune system to paternal antigens. Some researchers feel that a local immune
hyperreactivity may cause incomplete trophoblastic invasion of the uterine spiral arteries. This
incomplete trophoblastic invasion could expose the placental site to vasoconstriction and the
eventual development of preeclampsia. Immune deficiency, whether induced by HIV or any
other cause, could therefore inhibit a tendency to immune hyperreactivity and thus prevent the
development of preeclampsia. (17)
A study was carried out in Soweto, South Africa, where HIV seroprevalence was 29.3%, and the
prevalence of preeclampsia/eclampsia was 7.8%, to investigate the relationship between HIV and
preeclampsia. A total sample of 2,600 women was studied. The HIV seroprevalence rate was
27.1%. Hypertension was found in 17.3% of women, with 5.3% having preeclampsia-eclampsia.
The rate of preeclampsia-eclampsia was 5.2% in HIV-negative and 5.7% in HIV-positive
women. Thus, HIV seropositivity was not associated with any reduction in the risk of developing
preeclampsia-eclampsia. (17)
6.4 Prediction and prevention
There is no single screening test at the present time that is reliable and cost-effective for
predicting preeclampsia. There has been a lively interest in clinical reports and randomized trials
describing the use of various methods to reduce the rate and/or the severity of preeclampsia over
the past two decades. At the present time there is no known supplementation or medicine that
can be routinely prescribed for the prevention of preeclampsia in nulliparous women. (15)
6.5 Antepartum management of preeclampsia
The management of women with mild gestational hypertension or mild preeclampsia depends on
maternal and fetal evaluation. Sibai recommends induction of labor for delivery in these women
at 40 or more weeks gestation, in women at 37 weeks with a favorable cervix who are
noncompliant, and in women with labor or rupture of membranes, abnormal fetal testing or
intrauterine growth restriction.
The maternal and fetal condition should be closely followed in women who remain undelivered
with mild preeclampsia. Sibai recommends a regular diet with no salt restriction, reduced activity
but not strict bedrest, nor using diuretics or antihypertensive medications. The nonuse of
antihypertensives is based on the potential of these medicines to mask the diagnosis of the onset
of severe disease. Also, the current data suggest that antihypertensive therapy in women with
mild gestational hypertension or preeclampsia does not improve perinatal outcome. (15)
The definition of severe preeclampsia implies various organ dysfunctions including evidence of
hemolysis, elevated liver enzymes, and low platelets, which is known as the HELLP syndrome.
The clinical course of severe preeclampsia may lead to progressive deterioration in both the
maternal and fetal conditions. Because of the increased rates of maternal morbidity and mortality
and significant risks to the fetus, there is universal agreement that all patients with severe
preeclampsia developing after 34 weeks gestation should deliver. (15)
There is disagreement about management of patients with severe preeclampsia before 34 weeks
gestation where the maternal condition is stable and the fetal condition is reassuring. Friedman
and colleagues reviewed the expectant management of severe preeclampsia remote from term
and found that in some cases delaying delivery was beneficial to the fetus and not harmful to the
mother. The final conclusion of their study was that expectant management of severe
preeclampsia should be undertaken only at tertiary care facilities. (16)
6.6 Intrapartum management
The goals of management of a patient in labor with any degree of preeclampsia include early
detection of any fetal heart rate abnormalities, early detection of any deterioration in the
condition of the mother, and prevention of any maternal complications. Continuous fetal heart
rate monitoring or at least frequent intermittent heart rate monitoring should be used to monitor
the condition of the fetus. Blood pressure recordings and urine output should be watched closely.
A normal progress in labor can result in a vaginal delivery. Cesarean section should be done for
the usual obstetrical indications. The methods of choice for anesthesia in cases of cesarean
section include either epidural, spinal, or combined techniques or regional anesthesia. General
anesthesia increases the risk of aspiration and failed intubation due to airway edema and is
associated with marked increases in blood pressures during intubation and extubation. (15)
The drug of choice for the prevention of convulsions in severely preeclamptic patients is
magnesium sulfate. The benefit of magnesium sulfate in preventing convulsions in women with
mild preeclampsia remains unclear. (15)
The objective of treating acute severe hypertension is to prevent potential cerebrovascular and
cardiovascular complications for the mother. The most commonly used antihypertensive
medicine is intravenous hydralazine given as bolus injections of 5 – 10 mg every 15 – 20
minutes for a maximum dose of 30 mg. Rapid decreases in blood pressure in labor are not
desirable because of the risk of fetal compromise. (15)
As mentioned the drug of choice in preventing the onset of a convulsion in severe preeclampsia
as well as recurrent convulsions in eclampsia is magnesium sulfate. Sibai recommends giving a
loading dose of magnesium sulfate of 6 grams over 15 – 20 minutes, followed by a continuous
infusion of 2 gm/hour intravenously. Sibai does not recommend monitoring serum magnesium
levels during the infusion because there is no established serum magnesium level that is
considered “therapeutic.” Serum magnesium levels are recommended in a patient with renal
dysfunction and decreased or absent reflexes. (19) Magnesium sulfate infusion should be stopped
in a patient with absent reflexes because this may indicate a toxic level of magnesium.
Approximately 10% of elamptic women will have a second convulsion after receiving
magnesium sulfate. In these women, another bolus of 2 grams of magnesium sulfate can be given
intravenously over 3 – 5 minutes. Occasionally a patient will continue to have convulsions while
receiving adequate doses of magnesium sulfate. Sibai recommends giving sodium amobarbital,
250 mg intravenously over 3 – 5 minutes for a recurrent seizure. (19)
Women receiving magnesium sulfate should have a Foley catheter and their urine output should
be monitored every four hours. Deep tendon reflexes should also be checked every four hours
while magnesium is being infused.
6.7 Postpartum management
The blood pressure, urinary output, and fluid intake should be carefully monitored during the
immediate postpartum period. Women who have received large amount of intravenous fluids
during labor are at risk for developing pulmonary edema. In most women with gestational
hypertension the blood pressure normalizes during the first week postpartum. Severe
preeclampsia and eclampsia may develop postpartum for the first time. Women with severe
headaches, visual changes, epigastric pain with nausea or vomiting require hospitalization and
evaluation. Many authorities give women with these symptoms 24 hours of magnesium sulfate
even postpartum. (15)
6.8 Management of eclampsia
The diagnosis of eclampsia is secure in the presence of generalized edema, hypertension,
proteinuria, and convulsions. The first priority in managing eclampsia is to prevent maternal
injury and to support the respiratory and cardiovascular functions of the mother. Immediately
after an eclamptic convulsion the airway of the mother must be secured and maternal
oxygenation supported. The women should be in a bed with padded siderails and she should be
in lateral decubitus position to minimize the risk of aspiration.
As mentioned previously the woman should receive a loading dose of magnesium sulfate
followed by a maintenance dose to prevent recurrent seizures. The next step in management is to
reduce the blood pressure to a safe range avoiding at the same time significant hypotension.
Sibai’s recommendation is to keep the systolic blood pressure between 140 and 160 mm Hg and
the diastolic blood pressure between 90 and 110 mm Hg. The rationale for these ranges of blood
pressure is to avoid potential reduction in either uteroplacental blood flow or cerebral perfusion
pressure.
The presence of eclampsia is not an absolute indication for cesarean section. Sibai recommends
cesarean section for eclamptic mothers with a gestational age before 30 weeks who are not in
labor. Patients having labor or rupture of membranes are allowed to deliver vaginally in the
absence of obstetric complications. Labor is usually induced with diluted intravenous
pitocin.(20)
7.0 Recommendations
1. Placental abruption, or prelabor separation of a placenta, normally located in the uterine
fundus, presents in a variety of ways late in pregnancy, but almost always accompanied by
uterine pain and uterine irritability.
2. A large area of abruption presents as a life-threatening emergency, often but not always
accompanied by vaginal bleeding. A mother with signs of shock, anemia, irritable or hypertonic
uterus, and vaginal bleeding must be investigated for placental abruption.
3. A small abruption may have minimal bleeding and little or not consequences for the mother or
the fetus.
4. Placenta previa is an implantation of the placenta that overlies or is within 2 cm of the internal
cervical os. Ultrasonography is a useful diagnostic tool to localize the position of the placenta.
5. Management of placenta previa is based on the severity of the bleeding, the condition of the
mother and fetus, and the gestational age of the pregnancy.
6. Placenta accreta is an abnormally firm attachment of placental villi to the uterine wall.
Placenta accreta may result in incomplete separation of the placenta postpartum and serious
portpartum hemorrhage. The majority of reported cases of placenta accrete have been managed
by postpartum hysterectomy.
7. Vasa previa is a condition where fetal vessels course through placental membranes
unprotected by placenta or umbilical cord. Vasa previa should be suspected when rupture of the
membranes is accompanied by important vaginal bleeding, fetal distress, or fetal death. A prompt
cesarean section can sometimes save the life of the fetus.
8. Hypertensive disorders of pregnancy include chronic hypertension present before pregnancy,
chronic hypertension with superimposed preeclampsia, gestational hypertension without
proteinuria, preeeclampsia with proteinuria, and eclampsia.
9. Severe preeclampsia implies multiple organ dysfunction and is best managed by delivery no
matter what the gestational age of the pregnancy, except for conservative management at a
tertiary care center. The drug of choice to prevent seizures in severely preeclamptic patients is
magnesium sulfate.
Sue Makin MD, FACOG, Diplomate ABOG
Mulanje Mission Hospital
Mulanje, Malawi
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