SUMMARY To evaluate the perinatal outcome of premature babies according to the mode of delivery. A total of 113 pregnant women and 124 neonates who delivered from 30 to 35 weeks of gestation were enrolled and outcomes of 70 neonates born vaginally were compared to 54 neonates born by caesarean. Neonatal mortality rate was 20 percent for infants in caesarean group as compared to 10 percent for vaginal group. There was no significant difference in the neonatal morbidity among both the groups. Caesarean delivery cannot be routinely recommended, unless there are obstetric indications

MD (Obst &amp

MD (Paediatrics) P Naik

S Sonkusare

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Med J Malaysia Vol 64 No 4 December 2009 303
SUMMARY
To evaluate the perinatal outcome of premature babies
according to the mode of delivery.  A  total  of  113  pregnant
women  and  124  neonates who delivered from 30 to 35
weeks of  gestation  were enrolled and outcomes of 70
neonates born vaginally were compared to 54  neonates
born  by caesarean.   Neonatal  mortality  rate  was  20
percent for infants in caesarean group as compared  to 10
percent  for vaginal group.  There was no significant
difference in the neonatal morbidity among both the groups.
Caesarean delivery cannot be  routinely recommended,
unless  there  are  obstetric  indications.
KEY WORDS:
Preterm vaginal delivery, Preterm caesarean delivery, Premature
baby,  Neonatal  complications,  Perinatal  mortality
INTRODUCTION
Preterm  birth  is  the  most  significant  problem  in  current
obstetric  practice  and according  to  the World  Health
Organization,  is  the  direct cause accounting  for  24%  of
neonatal  deaths1.  Rates  of  preterm  birth  range  between
7-16%  and  are  similar  world wide1.
The optimal mode of delivery for preterm babies is
controversial.   Data from prospective randomized studies are
very limited due to recruitment difficulties2,3.  In practice,
however, the rate of elective caesarean deliveries in preterm
babies  has markedly  increased  over  the last decades.  This
further  strengthens the need to  try  and determine whether
this  practice of elective caesarean deliveries is  justified for a
possibly  better  outcome  of  the  infants,  in  face  of
potential serious morbidities  among the  mothers. 
This  observational  study  is  specifically aimed to determine
the  association  between the  mode  of  delivery (caesarean
versus  vaginal) and morbidity in the neonates  and  the  rate
of  death  prior  to  discharge  in  premature infants  between
30 and 35 weeks of gestation.  In  order  to  do  this,  we  also
studied  the  perinatal  factors associated  with caesarean
delivery of  these infants.
MATERIALS AND METHODS
This study is  based  on  an analysis  of  data  prospectively
collected  after   gaining   approval   from   the   institute
ethical  committee,  from  a  database  comprising maternal
and  neonatal  information  drawn  from  the  medical  charts
on  preterm  infants born  in  Kasturba  Hospital, Manipal,
India (level III centre),  from  01.05.2002  to  30.09.2003.  The
database  was  based  on  file  reviews  and  collected  in  a
uniform, consistent  and  reliable  manner  by  trained
qualified  doctors  with  the  use  of  standard definitions.
Data  included  information on  the maternal  pregnancy
history,  details  of  the delivery, the  infant’s  status  at
delivery,  diagnoses,  procedures and  complications  during
hospital  stay  and  outcome  at  discharge.  Women  with
conditions  potentially  affecting the  likelihood  of  an
adverse  neonatal  outcome  were  noted.
Gestational  age (in  completed  weeks)  was  determined  by
the  best  obstetric  estimate  of  gestational  age  based  on
last  menstrual  period,  obstetric history and examination,
prenatal  ultrasound  and  postnatal  physical  examination.
Antenatal  steroid  treatment was considered  as given  even
if  delivery  occurred  in  less  than  24  hours  after  the  first
dose.   Intravenous antenatal  antibiotic  therapy  was  given
in  the  form  of  Amoxycillin 500mg  6  hourly  and
Metronidazole  500 mg  8  hourly  after  the  patient  got
admitted and  was  maintained  in  intravenous  form  till
delivery.   Premature  rupture of  membranes  was considered
when  membranes  ruptured  more than   6  hours  before  the
onset  of  regular  uterine  contractions.  Failed  induction  was
considered  in  the  absence  of  significant  change  in
Bishop  scoring  with  twice  prostaglandin  E2 gel  instilled
intracervically  6  hours  apart.   Severe  preeclampsia  was
considered  as blood  pressure  above  150/110  mm  Hg
which  remained  uncontrolled  on antihypertensive  drugs,
along  with  proteinuria  of  > 2 +. Oligohydroamnios  was
defined  as  amniotic  fluid  index  of  < 5  as  measured  by
transabdominal  ultrasonography.   All the ultrasonographies
were done  by  the  qualified  personnels.  Neonatal  sepsis
was  defined  as  positive septic  screen  of  the  neonate  and
the  causative  organism  was  demonstrable  in  most  of  the
cases.  Neonatal  hyperbilirubinemia  was  defined  as  the
serum  bilirubin  levels  of   >7 mg/dl  for  a  neonate
weighing  <1500  grams;  >10  mg/dl   for  the infant
weighing  1500 to  2000  grams  and   >13  mg/dl   when  the
infant  weighed  >2000  grams.   Mortality was defined  as
death  occurring  before  discharge  from  the  hospital.
The  total  number  of  deliveries  during  this  period  in  this
center  were  2223, out  of  which  153  were  preterm
deliveries (7 percent). The  overall  caesarean  rate  was  25
percent (%),  which  is  similar  to  the  rate  in other  tertiary
centers  all  over  India .During  this  17 month  period,  out
of  153  deliveries,  there  were  11 antenatal  fetal   deaths
and  8  babies  with  congenital  malformations, which  were
excluded. Out  of  the  rest, 22  births   were  excluded  as  we
Preterm Birth: Mode of Delivery and Neonatal Outcome
S  Sonkusare, MD (Obst & Gynae)*, L Rai, MD (Obst & Gynae)*, P Naik, MD (Paediatrics)**
*Department of Obstetrics and Gynaecology, **Department of Paediatrics, Kasturba Medical College, Manipal - 576104,
Karnataka, India
ORIGINAL ARTICLE
This article was accepted:  19 October 2009
Corresponding Author: Shipra Sonkusare, Department of Obstetrics & Gynaecology, Melaka Manipal Medical College, Jalan Batu Hampar, Bukit Baru,
75150, Melaka, Malaysia     Email: shipra_s18@rediffmail.com
Original Article 
304 Med J Malaysia Vol 64 No 4 December 2009
could  not  get  the complete information  from  their
records. Thus, 113  premature  deliveries  between  30  and  35
weeks of gestation  were  registered  in  the  database. Only
live  births were included in  the  examination  of  the
management  of  preterm  births  because  an  antepartum or
intrapartum  still  birth  is  likely  to  have  a  major  effect on
delivery management  although  there  were  no intrapartum
or  labour  room  deaths  in  this  study. Similarly, cases of
congenital  anomalies  were  also  excluded.  No mothers  or
babies  had  any    complications  other  than  the  ones
mentioned.     
Out  of  113  preterm  births  which  were  analyzed,  58
women  either  went  into  preterm  labour  or  had  preterm
premature  rupture  of  membranes. Five  of  these  had  failed
induction   after  rupture  of  membranes  and  underwent
caesarean delivery.
Twenty  eight  women  were  planned  for  elective  vaginal
delivery,  the  indication  being  severe  pre-eclampsia  in 24
and  abruptio  placenta in 4,  but  only  12  delivered
vaginally  and  rest  16  had  caesarean delivery. Twenty  seven
women  were  planned  for  caesarean,  the  main  indications
being  severe  oligohydramnios,  placenta  previa  and
malpresentation.  Out of  these,  one  delivered  vaginally.
Thus,  a  total  of  66  mothers  delivered  vaginally  and   47
mothers  had  caesarean  delivery.  To  these  113  mothers,
124  babies  were  born,  70  vaginally  and   54  by  caesarean.  
For  analysis , the  mothers  and  the  neonates  were  classified
into  two  groups (1)  those  who  delivered  by  caesarean  and
(2)  those who delivered vaginally.  The following antenatal,
perinatal  and  neonatal  variables  were  included  in the
analyses: mother’s age, parity, pregnancy complications
including  premature  rupture  of  membranes,  antepartum
hemorrhage, severe preeclampsia,  malpresentation, multiple
gestation, antenatal  steroid  treatment,  antenatal  antibiotic
treatment, presence of oligohydramnios, delivery mode,
gestational  age  at  delivery  in  weeks, birth  weight,  gender,
apgar  score,  presence  of  neonatal  complications  like
intraventricular  haemorrhage,  sepsis, respiratory distress
syndrome, neonatal  hyperbilirubinemia  and  intensive  care
unit  admission  days. All  neonatal  diagnoses  were  made  at
the time  of  the  baby’s discharge by an experienced
neonatologist who was not blinded for preterm babies.  
The significant differences in the antenatal and   intrapartum
factors   between   both  the  groups  were  standardized  using
analysis  of  covariance  (ANCOVA)   and  the  adjusted  means
were   finally  analyzed.  The  Odds  ratio  (OR)  and  95%
confidence  interval  (CI)  were  calculated    to  compare   the
proportion  in  the   two   groups  using  the  Confidence
Interval  Analysis.  Testing  for  relationships  between  the
variables  in  the  two  groups  was  done  using  the  Chi-
square  test,   and  Fisher   Exact  test  was  used  for  cell values
of   less  than  5.  P value of  less  than  0.05  was  regarded  as
significant.
RESULTS 
The overall caesarean rate was 42%.  And  it  was  directly
associated with maternal hypertension and
oligohydroamnios. Conversely  caesarean  rate  was  much
lower  among  mothers  with  premature  rupture  of
membranes. Important  indications  for  caesarean  delivery
were:  severe  preeclampsia  (34%), placenta previa  (13%),
malpresentation  (13%),  preterm  premature  rupture  of
membranes  with  failed  induction (11%), oligohydramnios
(17%)  and  multiple  gestation (11%).  Among  124  neonates
recruited,  there were  35  male  infants  in  the  vaginal
delivery  group  and  26  in  the caesarean  delivery  group.
There  was  no  significant  difference  in  the basic  antenatal
profile  except  that  larger  number  of  women  in  caesarean
group  had  received  antenatal  steroid   as  well  as
antibiotics (Table  I).
Antenatal  profile Caesarean group Vaginal delivery Odds ratio p value
[n(%)] group   [n(%)] (95%CI)
Mother’s Age (Years)
18-25 16  (34) 26(39) 0.794 0.56(NS)   
(0.36-1.73)
26-34 25  (53) 33(50) 1.13 0.73(NS)   
(0.53-2.40)
>35 6  (13) 7(11) 1.23 0.72(NS)
(0.38-3.93)
Primipara 33  (70) 37(56) 1.746 0.12(NS)
(0.83.4.07)
Gestational age (weeks) at delivery
<32 17  (36) 28(42) 0.302 0.50(NS)
(0.35-1.66)
>32 30  (63) 38(58) 0.51 0.50(NS)
(0.60-2.80)
Received antenatal 47(100) 61(92) 0.05(S)
Steroid therapy
Received antenatal 47(100) 61(92) 0.05(S)    
Antibiotic therapy
NS: Not significant   S:  Significant
Table I: Antenatal profile of the mothers among caesarean and vaginal delivery group
Preterm Birth: Mode of Delivery and Neonatal Outcome
Med J Malaysia Vol 64 No 4 December 2009 305
But  there  were  more  high  risk  factors  like    oligoamnios
and  severe  preeclampsia  in  the mothers  who  had
caesarean (Table  II).
Neonatal  morbidity  due  to  intraventricular  hemorrhage
and  sepsis  as  well  as  the mortality  was  apparently  higher
in  the  caesarean  delivered  newborns  (Table III) , but  was
not  significant  statistically.       
The  overall  neonatal  mortality  rate  until  discharge  was
14.5%  and  important  factors  associated  were,  sepsis  with
coagulase  negative  Staphylococci  and  Pseudomonas,  severe
prematurity  and  intraventricular  hemorrhage  grade  III.
The  mortality  rates  decreased  significantly  with  increasing
gestational  age  for  infants  delivered  by  caesarean  section.
DISCUSSION
The   main  finding  in  this  study  is  that  caesarean  delivery
did  not  enhance  the neonatal  survival  of  preterm  infants
nor  did  it  decrease  the  morbidity  in  these infants.  This
is further supported  by  the work  of  Malloy  et al.4 and
others5-8.
Though  the  issue  of  how  best  to deliver  is  of importance,
there  is  little evidence from  randomized  studies  on  which
to  base  the  management  of  preterm birth.  Data  in  the
literature  are  so  far  inconclusive  and associated  with
problems  of  randomization,  selection  criteria  and  the
effects  of multiple  confounding  variables4,5,9.   The  largest
metaanalysis  of  six  trials  too  involves  only  a  total  of  122
babies2.   Conducting  an  appropriately controlled  study
designed  to  answer  this  important  clinical  issue  should
be  the  ultimate  goal.  
In  the light  of  lack  of  direct evidence to support  the
management  of  preterm  birth, we  took  a  multivariate
analysis  using  analysis of covariance  of  the  observational
data  based  on  a  significant  population  of  all  preterm
infants  born in  Kasturba  Hospital,  Manipal, which  catered
to  other states of  southern  India  too.  During the study
period, recent technologies  and  treatments  were  widely
used.  The multivariate  analysis attempted  to  control  for
confounding  variables,  such  as  the  fact  that  the  mode  of
delivery  may  be  influenced  by  the  indication, such  as
hypertension  or decreased  liquor.
We  also  have  studied  the incidence  of  morbidity  along
with  the  mortality  rate  in  the  preterm  fetuses,  to  study
the  effect  of  mode  of  delivery.  We  have  taken  into
account  the  specific  circumstances  influencing  the
obstetric  decision- making  process  for  the  individual
deliveries,  and  factors  that might  have  led  the  obstetrician
to  perform  a  caesarean.  Thus,  the  caesarean  group  had
more  number  of  high  risk  mothers  with  compromised
fetal status which mandated  caesarean  delivery.   
The  neonatologist  was  not  blinded  for  the  preterm babies
though  it  does not affect all the variables  of  the  outcome
like  mortality  and  development  of complications,  it will
Risk Factor Caesarean group Vaginal delivery Odds ratio 
[n(%)] group   [n(%)] (95%CI) p value
Preterm premature 5(11) 29(44) 0.15 < 0.0001(S)
Rupture of membranes (0.05-0.43)
Severe preeclampsia 16(34) 8(12) 3.74 0.004(S)
(1.44-9.71)
Oligohydroamnios 8(17) 1 (2) 13.33 0.003(S)
(1.60-110.6)
Antepartum 6(12) 4 (6) 2.26 0.31(NS)
Haemorrhage (0.60.8.53)
Malpresentation 7(14) 3 (5) 2.64 0.09(NS)
(0.89-15.04)
Multiple gestation 5(10) 4 (6) 1.84 0.48(NS)
(0.46-7.27)
NS: Not significant  S: Significant  
Table II: Antenatal risk factors among caesarean and vaginal delivery group
Infant data Caesarean Group Vaginal delivery Odds radio Adjusted
[n(%)] group [n(%)] (95% CI) p value
Birth weight (grams)
<1500 15(28) 23(33) 0.78 (0.36-1.70) 0.54(NS)
1501-2500 39(72) 47(67) 1.27 (0.58-2.76) 0.59(NS)
Apgar <5 at 5 minutes 11(20) 8(11) 1.98 (0.73-5.33) 0.17(NS)
NICU admission days
<5 13(24) 15(21) 1.16 (0.49-2.70) 0.72(NS)
<5-10 18(33) 26(37) 0.84 (0.40-1.78) 0.66(NS)
>10 23(42) 29(41) 1.04 (0.51-2.15) 0.89(NS)
Intraventricular Haemorrhage 2  (3) 1(1.4) 0.41(NS)
Respiratory distress Syndrome 12(22) 13(19) 0.92(NS)
Sepsis 16(29) 13(19) 0.29(NS)
Neonatal Hyperbilirubinemia 23(43) 40(57) 0.10(NS)
Neonatal mortality 11(20) 7(10) 0.33(NS)
Table III: Comparison of neonatal outcome among caesarean and vaginal delivery group
definitely affect the initial  admission days  in  the  intensive
care  unit.  Hence, the  initial  admission days  in  the
neonatal  intensive care  unit  might have  been influenced
by  the  knowledge of  exposure,  and  probably does not
correlate with  the  seriousness  of  the  morbidity ,  though,
persistent  stay in  the  intensive care unit is a better  indicator
of  morbidity.  The malpresenting infants were also included
in the analysis.   Also, we have analyzed singletons, twins or
triplets  together.   Furthermore, data collection, as  much  as
we  tried  to  avoid it,  might  still  have been misclassified  or
subject  to  temporal  changes  in  data  input.  Despite these
reservations,  in  the absence  of  a  prospective randomized
control study,  which  may not  be  feasible, we believe  that
these are  the  reasonably fair  available data. This  study
would  have  been  more  informative if  the follow up  of  the
infants was studied  at  least  for  two  years.
CONCLUSION 
Based  on  our  findings, we disagree  with the assumption
that  caesarean  delivery  may improve  the  outcome  in
preterm  babies.   Our data  is consistent  with  the hypothesis
that  mode  of  delivery  does  not  influence  mortality  and
morbidity in preterm infants,  if  there  are  no  obstetric
indications  favoring  a  particular  mode.  We  believe that
caesarean section cannot  be  recommended  as  the  routine
mode of  delivery  for  preterm  babies  unless there  are  other
recognized  maternal  or  fetal indications.   However, these
conclusions are guarded  due to  the limits of  the
methodology  employed. 
REFERENCES
1. Save the Children.  State of the World’s Newborns, Save the Children,
Washington, DC 2001.
2. Lumley J.  Method of delivery for the preterm infant.  Br J Obstet  Gynaecol
2003; 110: 88-92.
3. Grant A, Glazener CMA.  Elective caesarean section versus expectant
management for delivery of the  small baby.  The Cochrane Database of
Systematic Reviews 2001, Issue 2.   Art. No.: CD000078. DOI: 10.1002 /
14651858. CD000078.
4. Malloy MH, Onstad L, Wright E.  The effect of caesarean delivery on birth
outcome in very low birth  weight  infants.  National Institute of Child
Health and Human Development Neonatal Research  Network.  Obstet
Gynecol 1991; 77: 498-503. 
5. Mattern D, Straube B,  Hagen  H.  Effect of mode of delivery on early
morbidity and mortality of  premature infants  (< or = 34th week of
pregnancy).  Z  Geburtshilfe  Neonatol. 1998; 202: 19-24.
6. Kitchen W, Ford GW, Doyle LW et al. Caersarean section or vaginal
delivery at 24 to 28 weeks’ gestation:  comparison of  survival  and
neonatal and  two- year morbidity.   Obstet Gynecol 1985; 66: 149-57.
7. Melchor  JC,  Aranguren G,  Lopez  JA  et al.  Perinatal outcome of very low
birthweight infants by  mode  of   delivery.  Int  J Gynaecol  Obstet 1992;
38: 181-87.
8. Kato  EH, Yamada  H, Matsumoto Y et al. Relation  between  perinatal
factors  and  outcome  of  very  low birth weight infants. J  Perinat   Med
1996; 24: 677-86.
9. Lumley J, Lester A, Renou P et al. A failed  RCT  to  determine  the  best
method  of  delivery  for   very  low birth  weight  infants.  Control Clin
Trials. 1985; 6: 120-27.
306 Med J Malaysia Vol 64 No 4 December 2009
Original Article 


preterm birth: mode of delivery and neonatal outcome

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