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Planned caesarean section versus planned vaginal birth for severe
pre-eclampsia (Review)
Amorim MMR, Souza ASR, Katz L
Amorim MMR, Souza ASR, Katz L.
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia.
Cochrane Database of Systematic Reviews 2017, Issue 10. Art. No.: CD009430.
DOI: 10.1002/14651858.CD009430.pub2.
www.cochranelibrary.com
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia (Review)
Copyright © 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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TABLE OF CONTENTS
HEADER.........................................................................................................................................................................................................
ABSTRACT.....................................................................................................................................................................................................
PLAIN LANGUAGE SUMMARY.......................................................................................................................................................................
BACKGROUND..............................................................................................................................................................................................
OBJECTIVES..................................................................................................................................................................................................
METHODS.....................................................................................................................................................................................................
RESULTS........................................................................................................................................................................................................
Figure 1..................................................................................................................................................................................................
DISCUSSION..................................................................................................................................................................................................
AUTHORS' CONCLUSIONS...........................................................................................................................................................................
ACKNOWLEDGEMENTS................................................................................................................................................................................
REFERENCES................................................................................................................................................................................................
CHARACTERISTICS OF STUDIES..................................................................................................................................................................
APPENDICES.................................................................................................................................................................................................
CONTRIBUTIONS OF AUTHORS...................................................................................................................................................................
DECLARATIONS OF INTEREST.....................................................................................................................................................................
SOURCES OF SUPPORT...............................................................................................................................................................................
DIFFERENCES BETWEEN PROTOCOL AND REVIEW....................................................................................................................................
INDEX TERMS...............................................................................................................................................................................................
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia (Review)
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[Intervention Review]
Planned caesarean section versus planned vaginal birth for severe preeclampsia
Melania MR Amorim1, Alex Sandro R Souza1, Leila Katz1
1Instituto de Medicina Integral Prof. Fernando Figueira - IMIP, Recife, Brazil
Contact address: Melania MR Amorim, Instituto de Medicina Integral Prof. Fernando Figueira - IMIP, Rua dos Coelhos, 300, Recife,
Pernambuco, 50070-050, Brazil. profmelania.amorim@gmail.com, melania.amorim@gmail.com.
Editorial group: Cochrane Pregnancy and Childbirth Group.
Publication status and date: New, published in Issue 10, 2017.
Citation: Amorim MMR, Souza ASR, Katz L. Planned caesarean section versus planned vaginal birth for severe pre-eclampsia. Cochrane
Database of Systematic Reviews 2017, Issue 10. Art. No.: CD009430. DOI: 10.1002/14651858.CD009430.pub2.
Copyright © 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
ABSTRACT
Background
Pre-eclampsia is a very frequent complication of pregnancy, and anticipation of birth is often necessary. However, the best mode of giving
birth remains to be established, although observational studies suggest better maternal and perinatal outcomes with vaginal birth.
Objectives
To assess the effects of a policy of planned caesarean section versus planned vaginal birth for women with severe pre-eclampsia on
mortality and morbidity for mother and baby.
Search methods
We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International
Clinical Trials Registry Platform (ICTRP) (6 September 2017) and reference lists of retrieved studies.
Selection criteria
We planned to include all randomised trials of planned caesarean section versus planned vaginal birth for pregnant women with severe
pre-eclampsia. Quasi-randomised and non-randomised studies are not eligible for inclusion in this review.
The focus of this review is severe pre-eclampsia; studies of planned caesarean section versus planned vaginal birth in pregnant women
with eclampsia are not eligible for inclusion.
Data collection and analysis
We identified no studies that met the inclusion criteria. We excluded two studies.
Main results
There are no included studies in this review.
Authors' conclusions
There is a lack of robust evidence from randomised controlled trials that can inform practice regarding planned caesarean section versus
planned vaginal birth for women with severe pre-eclampsia. There is a need for high-quality randomised controlled trials to assess the
short- and long-term effects of caesarean section and vaginal birth for these women and their babies.
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia (Review)
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PLAIN LANGUAGE SUMMARY
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia
What is the issue?
To assess the effects of a policy of planned caesarean section versus planned vaginal birth for women with severe pre-eclampsia on
mortality and morbidity for mother and baby.
Why is this important?
Pre-eclampsia is a very frequent problem during pregnancy that affects up to one in 10 pregnant women. Pregnant women with preeclampsia have symptoms such as high blood pressure, headache, problems with vision and swelling of hands, legs or feet. If untreated,
serious pre-eclampsia may lead to poor health or even death both for pregnant women and for their babies. More women in low-income
countries and in difficult economic circumstances suffer and die from pre-eclampsia. The only definitive treatment for this illness is the
birth of the infant. It is therefore very common for doctors and pregnant women with serious pre-eclampsia to discuss delivering the baby
after 34 or 37 weeks of pregnancy, with the timing dependent upon the health of the mother and the baby. We wanted to know whether
planned caesarean section or planned vaginal birth was safest for women with serious pre-eclampsia and their babies.
Serious pre-eclampsia is one of the most common reasons for pregnant women to give birth early. Often the baby needs to be born before
a woman is in labour. Many doctors prefer to perform caesareans for women with serious pre-eclampsia, even when the baby is healthy.
Nevertheless, observational studies have demonstrated that caesarean section may worsen the outlook for mother and baby, with an
increased risk of complications.The best way to deliver the baby for women with serious pre-eclampsia is not yet known.
What evidence did we find?
Randomised clinical trials are considered to be the best way to test different treatment options and decide which treatment is safer and
better overall. We searched for studies on 6 September 2017, but did not find any randomised clinical trials comparing planned caesarean
section versus planned vaginal birth for women with severe pre-eclampsia. There is no evidence from RCTs to help decide which type of
birth is better for pregnant women with serious pre-eclampsia and their babies.
What does this mean?
We do not have any information from randomised clinical trials to assess whether caesarean section or vaginal birth is better for pregnant
women with severe pre-eclampsia, and their babies. Until such time as we have good randomised clinical trials, pregnant women with
severe pre-eclampsia need to talk with their doctors about their options for delivering their baby safely and with the best possible results.
Doctors and pregnant women can then decide together if caesarean section or vaginal birth is best for the short- and long-term health
of mother and baby.
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BACKGROUND
Description of the condition
Pre-eclampsia and eclampsia are among the leading causes of
maternal death worldwide (Duley 2009; Khan 2006; WHO 2011).
They can complicate up to 10% of pregnancies and promote
significant maternal and perinatal morbidity and mortality
worldwide (Roberts 2011; WHO 2011). The incidence of these
conditions varies considerably according to the country or region.
Low-income countries have not only a higher incidence of preeclampsia and eclampsia but also an increased risk (up to 300
times) of maternal death due to these complications (Duley 2009;
Roberts 2011; WHO 2011). Pre-eclampsia is usually diagnosed in
the presence of hypertension and proteinuria after 20 weeks of
pregnancy, while eclampsia is defined as the occurrence in a
woman with pre-eclampsia of seizures that cannot be attributed
to other causes (NHBPEP 2000). Recently, an American College
of Obstetricians and Gynecologists Summary Executive (ACOG
2013) and a revised statement of the International Society for
Study of Hypertension in Pregnancy (ISSHP 2014) recognised that
pre-eclampsia is a syndrome that develops during pregnancy
and is characterised by hypertension in the presence of other
findings, eliminating the dependence of diagnosis on proteinuria.
Furthermore, massive proteinuria is no longer a marker of severity,
and the decision to anticipate the birth should not be based on the
amount or change in levels of proteinuria.
Potentially lethal complications include abruptio placentae,
disseminated intravascular coagulation, cerebral haemorrhage,
hepatic failure, and acute renal failure (Duley 2009; Sibai 2005);
these are frequently associated with the diagnosis of severe preeclampsia. Severe pre-eclampsia is diagnosed in the presence
of one or more of these findings: systolic blood pressure of
160 mmHg or more, diastolic blood pressure of 110 mmHg
or higher on two occasions at least four hours apart while
on bed rest (unless antihypertensive therapy is initiated before
this time); thrombocytopenia (platelet count less than 100,000/
microlitre); impaired liver function, as indicated by abnormally
elevated blood concentrations of liver enzymes (to twice normal
concentration); severe persistent right upper quadrant or epigastric
pain unresponsive to medication and not accounted for by
alternative diagnoses, or both; progressive renal insufficiency
(serum creatinine concentration greater than 1.1 mg/dL or a
doubling of the serum creatinine concentration in the absence of
other renal disease); pulmonary oedema; new-onset cerebral or
visual disturbances (ACOG 2013).
The routine use of magnesium sulfate (MgSO4) for preventing
and treating eclampsia has been shown to have an important
effect on maternal mortality (Duley 2010a; Duley 2010b; Duley
2010c; Ronsmans 2011). The optimal management of severe preeclampsia and eclampsia includes both MgSO4 administration and
anticipation of birth, since birth constitutes the only definitive
treatment (Noronha Neto 2010; Ronsmans 2011; Sibai 2005; Sibai
2007). It is therefore very common that obstetricians face the
need to indicate the interruption of a pregnancy in cases of preeclampsia.
Description of the intervention
Pre-eclampsia is one of the most common reasons for the
therapeutic interruption of pregnancy (Goldenberg 2008). When
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indicating anticipation of birth, it is fundamental to define the route
of birth: planned caesarean section or planned vaginal delivery. As
pre-eclampsia often occurs in preterm pregnancies, interruption is
frequently indicated when labour is absent (Mozurkewich 2009).
The rate of caesarean sections in cases of severe pre-eclampsia is
estimated to be high (around 70% or more in preterm pregnancies),
because many obstetricians prefer performing caesareans in
women with pre-eclampsia, even with a reassuring fetal status
(Alanis 2008; Amorim 2015; Catanzarite 1991; Nassar 1998).
Usually induction is proposed for cases of pre-eclampsia from
37 weeks (HYPITAT 2009), for cases of severe pre-eclampsia from
34 weeks or less, according maternal or fetal conditions, or
both. Interruption of pregnancy at any gestational age is often
recommended for all cases of eclampsia (ACOG 2013, ISSHP
2014). A randomised controlled trial was published comparing
induction of labour versus expectation in women with mild
pre-eclampsia or gestational hypertension at term, with better
maternal outcomes when induction of labour was carried out
(HYPITAT 2009). When immediate birth was performed in women
with non-severe hypertensive disorders at 34 to 37 weeks of
pregnancy, there was a small risk of adverse maternal outcomes
but a significant increase in neonatal respiratory distress syndrome
(HYPITAT II 2015). However, these studies did not compare modes
of birth, and the ideal mode of birth for pregnant women with
severe pre-eclampsia remains to be established (Noronha Neto
2010; Norwitz 2017).
How the intervention might work
The only possible cure for pre-eclampsia is the birth of the baby.
Theoretically, the benefits of faster interruption of pregnancy
through a cesarean section would be greater. Longer inductions
may be expected when severe pre-eclampsia occurs before 34
weeks and cervical conditions are not favourable. In the meantime,
maternal complications may arise or worsen. There is also a
concern for fetal well-being, because of the potential risk of fetal
distress and fetal death due to placental dysfunction (Noronha Neto
2010; Norwitz 2017).
It has yet to be proven that caesareans improve neonatal outcome,
and they may be associated with poorer maternal outcome
(Coppage 2002). Observational studies suggest that vaginal birth
may be better in the long term for premature babies and may offer
maternal advantages, with lower complication rates and a shorter
duration of hospitalisation (Alanis 2008; Blackwell 2001; Nassar
1998; Xenakis 1997). Furthermore, the rate of cerebral palsy of the
newborn remains the same (Alanis 2008; Drife 2006).
Considering the more recent studies evaluating mode of birth
in women with pre-eclampsia, an observational study evaluating
maternal outcomes included 500 participants with severe preeclampsia, and determined the risk of postpartum complications
and severe maternal morbidity (Amorim 2015). The labour was
spontaneous in 22.0% and induced in 28.2%, while 49.8% had an
elective caesarean section. Ninety-five (67.4%) of the participants in
whom labour was induced gave birth vaginally. Total caesarean rate
was 68.2%. The risk of severe maternal morbidity was significantly
greater in women who submitted to caesarean section (54.0%
versus 32.7%), regardless of the presence of labour. Factors that
remained associated with severe maternal morbidity following
multivariate analysis were a diagnosis of haemolysis, elevated
liver enzymes and low platelet count (HELLP) syndrome after
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birth (risk almost four times greater) and having a caesarean (risk
almost two times greater). The authors conclude that caesareans
are often performed in women with severe pre-eclampsia and
are associated with significant postpartum maternal morbidity.
Induction of labour should be considered a feasible option for these
women.
benefits associated with this mode of birth for the mother, namely
the high likelihood of success and lower rates of complications
(ACOG 2002; ACOG 2013; ISSHP 2014; Magee 2008). Women with
pre-eclampsia have a low tolerance for blood loss and a greater
risk of haemorrhagic complications; vaginal birth for this group of
women may therefore confer significant benefits (Kuklina 2009).
A retrospective cohort study was published in August 2017
including 5506 women with pre-eclampsia (mild, severe and
superimposed) at 34 weeks’ gestation and without previous
caesarean section (Kawakita 2017). From these, 5104 (92.7%)
women underwent induction. The rate of vaginal birth was
67.6%, with a rate of caesarean lower than the previous study.
Induction compared with planned cesarean was not associated
with an increased risk of the primary outcome (intensive care unit
admission, thromboembolism, transfusion, and hysterectomy),
but was related to increased risks of maternal intensive care unit
admission and linked to decreased risks of composite neonatal
outcome (asphyxia, arterial cord pH below 7.0, hypoxic– ischaemic
encephalopathy, and five-minute Apgar score below five), neonatal
intensive care unit admission, transient tachypnoea of newborn
and respiratory distress syndrome. The authors conclude that
their study supports the ACOG Task Force on Hypertension in
Pregnancy recommendation that does not necessitate caesarean
section (ACOG 2013).
It is important to determine maternal and perinatal outcomes
according to the route of birth in pregnant women with severe
pre-eclampsia, considering the best level of evidence available in
randomised controlled trials.
Since these are observational cohort studies, the level of evidence
is not as strong as that from a randomised clinical trial. As
the selection of women for vaginal birth or caesarean section
was not randomised but was the responsibility of the team
of attending physicians, various confounding factors may be
involved. For example, the decision to perform a caesarean section
may be associated with the presence of prepartum maternal
complications, and these complications in themselves may be
associated with a greater risk of postpartum maternal morbidity.
Why it is important to do this review
OBJECTIVES
To assess the effects of a policy of planned caesarean section versus
planned vaginal birth for women with severe pre-eclampsia on
mortality and morbidity for mother and baby.
METHODS
Criteria for considering studies for this review
Types of studies
Published and unpublished randomised controlled trials which
compare planned caesarean with planned vaginal birth for
pregnant women with severe pre-eclampsia, including clusterrandomised trials. We exclude studies with a quasi-random design,
such as allocation by alternation, day of the week, or hospital
numbers, as they have a greater potential for bias. We also exclude
studies with a cross-over design, since it is unlikely that cross-over
designs will be a valid study design for pregnancy and childbirth
reviews.
We evaluated studies published only as abstracts, and will include
them only if they contain enough information to meet the inclusion
criteria and to allow us to assess risks of bias; if such information is
not provided, we will attempt to contact trial authors.
It is important to consider the morbidity associated with caesarean
section, regardless of its indication. The general perception is
that caesarean section is safe and without adverse effects, but
the evidence shows otherwise, particularly in terms of future
complications in subsequent pregnancies. In a population-based
case-control study performed in eight Brazilian states, derived
from the large study Birth in Brazil (a 2011 nationwide survey
including 9221 postpartum women), after controlling for indication
bias and confounders, the risk of postpartum maternal death
was almost three-fold higher with cesarean than with vaginal
birth (odds ratio (OR) 2.87, 95% confidence interval (CI) 1.63 to
5.06), mainly due to deaths from postpartum haemorrhage and
complications of anaesthesia (Esteves-Pereira 2016). Among the
long-term complications it is important to emphasise abnormal
placentation, such as placenta previa and placental accretism
(Jauniaux 2017), which can represent a serious concern for those
who want a large number of children.
Types of participants
On the other hand, we have to consider that therapeutic decisions
regarding mode of birth in cases of severe pre-eclampsia are not
easy, since obstetricians often have to deal with pregnancies that
are not at term and with unfavourable cervical conditions (Alanis
2008). Additionally, both maternal clinical conditions and fetal
well-being may be compromised (Nassar 1998). Nonetheless, most
medical society guidelines recommend vaginal birth, due to the
Types of interventions
Women with severe pre-eclampsia, as defined by the National High
Blood Pressure Education Program Working Group (NHBPEP 2000)
with the modifications proposed by the Executive Summary of
ACOG 2013 and the ISSHP 2014 for studies published after this
period. We exclude cases of eclampsia, because it is unlikely that
these women will be included in randomised clinical trials on
type of birth. The ability to decide and sign a consent form is
essential in this type of study, and women with eclampsia are often
confused and drowsy, which can lead to important ethical barriers
to performing randomised controlled trials on type of birth in these
women. Women have the right to freely choose their mode of birth
and the right to be fully aware when deciding to participate in a
randomised trial of type of birth. Moreover, emergent caesarean
section is more likely to be needed in this context. We consider
eclampsia to be an exclusion criterion, but could be a secondary
outcome for our review (after randomisation).
Planned caesarean section compared with planned vaginal birth.
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia (Review)
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Types of outcome measures
Primary outcomes
Maternal
• Severe maternal morbidity, defined as one of the following:
eclampsia, admission to intensive care unit, sepsis,
organ failure, uterine rupture, hysterectomy, major surgical
complication, postpartum haemorrhage, life-threatening event,
renal failure, liver failure, postpartum HELLP syndrome,
disseminated intravascular coagulation, pulmonary oedema,
long-term disability, or any other as defined by trial authors or
using World Health Organization (WHO) criteria (WHO 2009)
• Maternal death
Perinatal/neonatal
• Serious neonatal morbidity, defined as one of the following:
severe birth asphyxia, seizures, neonatal encephalopathy,
serious birth trauma, severe respiratory distress syndrome,
prolonged neonatal intensive care unit admission
• Perinatal or neonatal death, excluding fetal anomalies, where
information available
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•
•
•
•
•
•
•
•
•
•
•
•
Apgar score less than seven at five minutes
Low cord blood pH as defined by trial authors
Need for neonatal resuscitation
Neonatal intensive care unit admission
Neonatal encephalopathy, as defined by trial authors
Birth trauma, as defined by trial authors
Subdural or intracerebral or intraventricular haemorrhage
Neonatal sepsis
Necrotising enterocolitis
Chronic lung disease
Assisted ventilation for 24 hours or more
Use of hospital resources: admission to special care nursery,
length of stay, endotracheal intubation, use of mechanical
ventilation
• Long-term disability: blindness, deafness, seizures, poor
growth, neurodevelopmental delay and cerebral palsy
Economic outcomes
Secondary outcomes
• Costs to health service resources: short-term and long-term for
both mother and baby
• Costs to the woman, her family, and society
Maternal outcomes
Search methods for identification of studies
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Emergency caesarean section
Regional analgesia or general anaesthesia
Instrumental vaginal birth
Abruption of the placenta or antepartum haemorrhage
Any thromboembolic disease: deep vein thrombosis or
pulmonary embolism
Infection: surgical site infection and/or endometritis and/or
sepsis
Amniotic fluid embolism
Oliguria
Haemorrhagic complications, other than postpartum
haemorrhage, such as postpartum haematoma, postpartum
anaemia, blood transfusion
Postoperative procedures: repeat surgery or hysterectomy, or
both
Prolonged hospital stay as defined by trial authors
Postpartum HELLP syndrome as defined by Sibai's criteria (Sibai
2004)
Uncontrolled postpartum hypertension: postpartum severe
hypertension, hypertensive crisis, need for antihypertensive
drugs after birth
Use of hospital resources: admission to intensive care unit,
length of stay, mechanical ventilation, dialysis
Postnatal depression
Breastfeeding, at discharge and up to one year after the birth
Women's experiences and views of the interventions: childbirth
experience, physical and psychological trauma, mother-infant
interaction and attachment, woman not satisfied with care
The following Methods section of this review is based on a standard
template used by Cochrane Pregnancy and Childbirth.
Electronic searches
We searched Cochrane Pregnancy and Childbirth’s Trials Register
by contacting their Information Specialist (6 September 2017).
The Register is a database containing over 23,000 reports of
controlled trials in the field of pregnancy and childbirth. For
full search methods used to populate Pregnancy and Childbirth’s
Trials Register including the detailed search strategies for Cochrane
Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase
and CINAHL; the list of handsearched journals and conference
proceedings, and the list of journals reviewed via the current
awareness service, please follow this link to the editorial
information about the Cochrane Pregnancy and Childbirth in the
Cochrane Library and select the ‘Specialized Register ’ section from
the options on the left side of the screen.
Briefly, Cochrane Pregnancy and Childbirth’s Trials Register is
maintained by their Information Specialist and contains trials
identified from:
1.
2.
3.
4.
5.
monthly searches of CENTRAL;
weekly searches of MEDLINE (Ovid);
weekly searches of Embase (Ovid);
monthly searches of CINAHL (EBSCO);
handsearches of 30 journals and the proceedings of major
conferences;
6. weekly current awareness alerts for a further 44 journals plus
monthly BioMed Central email alerts.
Perinatal and neonatal outcomes
• Intrapartum stillbirth
• Apgar score less than seven at one minute
Search results are screened by two people and the full text of
all relevant trial reports identified through the searching activities
described above is reviewed. Based on the intervention described,
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each trial report is assigned a number that corresponds to a
specific Pregnancy and Childbirth review topic (or topics), and is
then added to the Register. The Information Specialist searches
the Register for each review using this topic number rather than
keywords. This results in a more specific search set that has
been fully accounted for in the relevant review sections (Excluded
studies).
In addition, we searched ClinicalTrials.gov and the WHO
International Clinical Trials Registry Platform (ICTRP) for
unpublished, planned and ongoing trial reports. using the search
terms given in Appendix 1 (6 September 2017).
Searching other resources
We searched the reference lists of retrieved studies.
We did not apply any language or date restrictions.
Data collection and analysis
No studies are included in this review.
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Selection of studies
Two review authors independently assessed for inclusion all the
studies we identified as a result of the search strategy. We resolved
any disagreement through discussion or, if required, we consulted
the other authors.
There are no included studies in this review; further methods of
data collection and analysis for use in future updates of this review
are outlined in Appendix 2.
RESULTS
Description of studies
Results of the search
The search of the Cochrane Pregnancy and Childbirth Group's
Trials Register identified two reports. However, both randomised
trials included pregnant women with eclampsia rather than preeclampsia, and we excluded them from the review. Additional
searches of ClinicalTrials.gov and the WHO International Clinical
Trials Registry Platform (ICTRP) did not identify any other
randomised trial (see: Figure 1).
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Figure 1. Study flow diagram.
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Excluded studies
We excluded two studies (Seal 2012; Tukur 2007).
Both studies were controlled trials evaluating mode of birth in
women with eclampsia. The Seal 2012 trial was conducted in a rural
teaching institution and the women were allocated to either vaginal
or caesarean birth. In the Tukur 2007 study, women were allocated
to induction with misoprostol or emergency caesarean section.
Risk of bias in included studies
No studies met the eligibility criteria for inclusion in this review.
Effects of interventions
No studies met the eligibility criteria for inclusion in this review.
DISCUSSION
Summary of main results
We found no randomised controlled trials assessing route of birth in
women with severe pre-eclampsia for inclusion in this review. The
only trials found included women with eclampsia and these studies
were not eligible for inclusion. There is a lack of robust evidence
to compare risks and benefits of planned caesarean section versus
planned vaginal birth for severe pre-eclampsia.
Overall completeness and applicability of evidence
There are no included studies in this review. Further research is
needed.
Quality of the evidence
There are no included studies in this review.
Potential biases in the review process
We recognise the possibility of introducing bias at any stage of the
review process, but we took steps to minimise this. Two review
authors independently assessed for inclusion all the studies we
identified as a result of the search strategy. We resolved any
disagreement through discussion or, if required, we consulted the
other authors.
Agreements and disagreements with other studies or
reviews
Several observational studies have been carried out which support
a general recommendation favouring vaginal birth over caesarean
whenever possible (Alanis 2008; Amorim 2015; Kawakita 2017). The
American College of Obstetricians and Gynecologists recommends
vaginal birth because of the maternal benefits and the high
probability of success of labour induction for severe pre-eclampsia
(ACOG 2002; ACOG 2013). On the other hand, the National Institute
for Health and Care Excellence (NICE) clinical guideline about
hypertension in pregnancy recommends "choose mode of birth
for women with severe hypertension, severe pre-eclampsia or
eclampsia according to the clinical circumstances and the woman's
preference" (NICE 2011).
A systematic review evaluating the evidence supporting indications
for induction of labour failed to find any randomised controlled
trials comparing planned caesarean section with induction of
labour for severe pre-eclampsia (Mozurkewich 2009), although we
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found a small randomised controlled trial comparing caesarean
section or induction of labour with misoprostol in nulliparous
women with eclampsia (Tukur 2007). The systematic review
addressed the question of failed inductions at various gestational
ages, because induction of labour can lead to caesarean section
in most cases when it is attempted at gestational ages less than
30 to 34 weeks. In evaluating the strength of the evidence using
the GRADE system, the authors classified the quality of evidence
regarding induction of labour for severe pre-eclampsia as very low
and the grade of recommendation as weak (Mozurkewich 2009).
Recently, two randomised controlled trials were published
evaluating mode of birth in pregnant women with eclampsia
(Seal 2012; Tukur 2007); we have excluded these studies from
our review as the women did not have severe pre-eclampsia
and eclampsia was an exclusion criterion of this review. Tukur
2007 was published in 2007 and randomised 50 participants
with eclampsia, 25 allocated to induction with misoprostol and
25 allocated to emergency caesarean section. There were more
maternal complications and admissions of babies into the special
care baby unit in the caesarean section group. Maternal mortality
in the two groups was similar (2% each). Seal 2012 was published
in 2012 and included 200 women with eclampsia in a rural
teaching institution, allocated to either vaginal birth or caesarean
section. Maternal event rate was similar: 10.89% in the caesarean
arm versus 7.07% for vaginal birth (risk ratio (RR) 1.54, 95% CI
0.62 to 3.81). Although the neonatal event rate (a composite
outcome including perinatal death and severe neonatal morbidity
indicated by Apgar score less than seven at five minutes, birth
room intubation, or admission to special care baby unit for more
than seven days) was less in caesarean section (- 9.90% versus
19.19%) (RR 0.52, 95% CI 0.25 to 1.05), the difference was not
statistically significant. The trial authors conclude that a policy
of early caesarean section in eclampsia, at 34 or more weeks, is
not associated with better outcomes. Women with pre-eclampsia
generally have a less severe condition than cases of eclampsia and
it is therefore possible that they may benefit even more from a
labour induction policy or from being allowed the evolution of
spontaneous labour, when present.
We need better evidence for both maternal and perinatal effects
of caesarean section performed routinely in women with severe
pre-eclampsia. This evidence will help clarify any doubts that may
persist following observational studies and the trials that included
cases of eclampsia. Although labour induction may represent a
challenge in women with severe pre-eclampsia, particularly in
cases that are remote from term and in whom cervical conditions
are unfavourable, we believe that it would be possible to perform
a randomised clinical trial to compare planned caesarean section
with planned vaginal birth (including both spontaneous or induced
labour) in these women. The randomisation of pregnant women
with eclampsia in relation to mode of birth is complicated. These
women are often confused and disoriented, which may impact on
autonomy and their ability to consent to participate in a trial. This
is not the case for most women with severe pre-eclampsia, who are
able to decide whether or not to participate in a study. However, it
is important to note that even in cases of eclampsia, vaginal birth
did not result in an increased risk of complications; instead, in one
small study, caesarean section was associated with higher maternal
and perinatal risks.
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia (Review)
Copyright © 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
8
Cochrane
Library
Trusted evidence.
Informed decisions.
Better health.
Cochrane Database of Systematic Reviews
AUTHORS' CONCLUSIONS
ACKNOWLEDGEMENTS
Implications for practice
The authors acknowledge CNPq (National Council for Scientific and
Technological Development) that provided a post-doctoral grant to
Dr Melania Amorim to conduct the observational study cited in this
review and supported her efforts to carry out her own review.
There is no evidence from randomised controlled trials to inform
decisions regarding planned caesarean section versus vaginal birth
for severe pre-eclampsia.
Implications for research
Randomised controlled trials are needed in order to determine
maternal and perinatal outcomes, including long-term effects of
planned caesarean section versus planned vaginal birth for women
with severe pre-eclampsia. Pre-eclampsia is a frequent condition
complicating pregnancy, resulting in around one-third of maternal
deaths worldwide, and is the most common cause of maternal
death in many countries. A multicentre randomised controlled trial
would be feasible and desirable in this context.
Until such time as randomised controlled trial evidence becomes
available, a systematic review of the available observational
studies may be helpful.
As part of the prepublication editorial process, this review has
been commented on by two peers (an editor and referee who is
external to the editorial team), members of Cochrane Pregnancy
and Childbirth's international panel of consumers and the Group's
Statistical Adviser.
This project was supported by the National Institute for Health
Research, via Cochrane Infrastructure funding to Cochrane
Pregnancy and Childbirth. The views and opinions expressed
therein are those of the authors and do not necessarily reflect
those of the Systematic Reviews Programme, NIHR, NHS or the
Department of Health
We thank Carlos Noronha Neto for his contribution to the protocol
for this review (Amorim 2011)
Planned caesarean section versus planned vaginal birth for severe pre-eclampsia (Review)
Copyright © 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
9
Cochrane
Library
Trusted evidence.
Informed decisions.
Better health.
Cochrane Database of Systematic Reviews
REFERENCES
References to studies excluded from this review
Seal 2012 {published data only}
Seal SL, Ghosh D, Kamilya G, Mukherji J, Hazra A, Garain P.
Does route of delivery affect maternal and perinatal outcome
in women with eclampsia? A randomized controlled
pilot study. American Journal of Obstetrics & Gynecology
2012;206(6):484.e1-484.e7.
Tukur 2007 {published data only}
Tukur J, Umar NI, Khan N, Musa D. Comparison of emergency
caesarean section to misoprostol induction for the delivery of
antepartum eclamptic patients: a pilot study. Nigerian Journal
of Medicine 2007;16:364-7.
Additional references
ACOG 2002
ACOG Committee on Obstetric Practice. ACOG practice bulletin.
Diagnosis and management of preeclampsia and eclampsia.
Number 33, January 2002. American College of Obstetricians
and Gynecologists. International Journal of Gynecology &
Obstetrics 2002;77(1):67-75.
ACOG 2013
American College of Obstetricians and Gynecologists.
Hypertension in Pregnancy. Report of the American College of
Obstetricians and Gynecologists' Task Force on Hypertension in
Pregnancy. Obstetrics and Gynecology 2013;122(5):1122-31.
Alanis 2008
Alanis MC, Robinson CJ, Hulsey TC, Ebeling M, Johnson DD.
Early-onset severe preeclampsia: induction of labor vs elective
cesarean delivery and neonatal outcomes. American Journal of
Obstetrics and Gynecology 2008;199(3):262.e1-262.e6.
Amorim 2015
Amorim MM, Katz L, Barros AS, Almeida TS, Souza AS,
Faúndes A. Maternal outcomes according to mode of delivery
in women with severe preeclampsia: a cohort study. Journal
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Blackwell 2001
Blackwell SC, Redman ME, Tomlinson M, Landwehr JB Jr,
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Catanzarite 1991
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Coppage 2002
Coppage KH, Polzin WJ. Severe preeclampsia and delivery
outcomes: is immediate cesarean delivery beneficial?. American
Journal of Obstetrics and Gynecology 2002;186(5):921-3.
Drife 2006
Drife J. Mode of delivery in the early preterm infant (
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