Pergamon
IntaMhbnalJorvnol for Qucrliry in Hmlth Cur,Vol. 8, NO.2. pp. 15%165, 1996
W g h t IQ
1996 Elscvicr Science Ltd. An rights reserved
Printed in Great Britain
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Are Operative Delivery Procedures in Greece Socially
Conditioned?
twice as often in the public teaching hospital as in
a private maternity hospital, and operative
PETRIDOU, * t EUGENIA
vaginal
delivery was several times more common
PAPATHOMA, * KATHARII@
in
the
former
than in the latter, after controlling
REVINTHI,* D O N A L D T O N G t and
for biomedical risk factors. The unequal dlstriDIMITRIOS TRICHOPOULOSt
bution of operative delivery procedures between
the
public and the private hospital raises ques'Department of Hygiene and Epidemiology,
tions
about the justification of their performance
University of Athens Medical School, Goudi, 115-27
in a substantial fraction of deliveries, and indiAthens, Greece
cates that social factors condition their use.
tDepartment of Epidemiology, Harvard School of Copyright @ 1996 Elsevier Science Ltd.
YANNIS SKALKIDIS,* E L E N I
Public Health, 677 Huntingdon Avenue, Boston,
MA 02115,USA
Key words: Caesarean section, operative vaginal
delivery, risk factors, time trends, public vs. private
hospital delivery.
Caesarean section rates have increased in
Greece by almost 50% during the last 13 years.
We conducted a study in Athens, Greece, to
INTRODUCTION
assess the importance of a series of medical and
An increasing rate of many radical prosodoeconomic factors in the use of Caesarean
section or operative vaginal procedures, rather cedures including Caesarean section (CS) and a
than a non-operative process, for the delivery of decreasing trend of forceps delivery has been
singleton, liveborn babies of primiparous noted since the early 1960s in most developed
mothers. We used a case control approach to countries [I-91. In 1968, the proportions of CS
compare 444 babies delivered through a Caesar- in USA, UK and the Netherlands were 5.3%,
ean section and 130 delivered through operative 4.0% and 1.8%, respectively, whereas 14 years
vaginal delivery with 1235 normally delivered later, the corresponding figures were 18.5%,
babies in a public and a private hospital. Data 10.1% and 5.3% [1,10]. In addition to the
were analysed through multiple logistic re- striking time trends and intercountry differgression. Caesarean section was more commonly ences, a remarkable variability has been obperformed in older, shorter or overweight served among institutions [4,11] and among
mothers and for high and low birth-weight geographical regions [6,12-141 within the same
babies, as well as in response to several obstetric country. There is a concensus that CS and
complications and following i n - v i i m fertiliz- operative vaginal (OV) deliveries can be lifeation. A similar pattern was noted with respect saving for the offspring and occasionally for the
to operative vaginal delivery, except that this mother [15], but several authors have expressed
procedure was not unusually frequent among concern that these procedures may be overused
overweight women and was not encountered in under the influence of socioeconomic factors
this study among children born after in-vitro and a pervading medicalization ethos
fertilization. Caesarean section was performed [12,14,16-231. Variability that cannot be
Received for publication 7 November 1995.
Correspondence: Eleni Petridou, Department of Hygiene and Epidemiology. University of Athens Medical School,
Goudi, 115-27 Athens, Greur. Tel. and Fax: (301) 777 3840.
160
accounted for by medical indications can be
explained in terms of either underuse or overuse, and most authors believe that overuse is
most often responsible [3,17,23,24]. We undertook a case control study in Athens, Greece, to
identlfy risk factors for CS and O V delivery and
to explore whether the use of these procedures
differs between the public and the private sectors after controlling for obstetric and medical
variables.
Y.Skalkidis et al.
We evaluated the importance of various factors as conditional predictors of delivery
through Caesarean section or through forceps/
vacuum extraction rather than normal delivery
in multiple logistic regression models [Z].
RESULTS
Table 1 shows the distribution of 1235 normal, 130forceps and vacuum extraction and 444
Caesarean section deliveries by a series of
maternal
and socioeconomic variables; Table 2
METHODS
shows the corresponding distributions by
According to the study protocol, all mothers obstetric variables. Since the objective of this
delivered from 1January to 31 December 1993 analysis is to generate predictors of alternative
in the maternity clinic of a major teaching public delivery processes conditional on other cohospital and in one of the divisions of a major existing variables, the data in these tables are
private maternity hospital in the Greater Ath- only for descriptive purposes. Table 3 contrasts
ens area were to be interviewed in order to CS with normal deliveries and Table 4 contrasts
identify risk factors for Caesarean section and OV deliveries with normal deliveries. These
operative vaginal delivery. These institutions tables are based on modeling the data through
were chosen because they were thought to re- multiple logistic regression and allow the calcuflect adequately the public and private sectors, lation of mutually adjusted odds ratios (and
respectively, and there was assurance of good corresponding 95% confidence intervals).
cooperation. A review of the data for all women
The odds ratio (OR) for a Caesarean rather
delivered in the maternity clinic of the public than a normal delivery increases significantly
teaching hospital under study and for all women with increase in maternal age by 5 years. A
admitted to any one division of the private taller woman is less likely to undergo a Caesarmaternity hospital on the basis of bed avail- ean section and an extremely overweight pregability indicates that there was little selection nant woman is substantially more likely to do
bias in the sampling process at this stage of the so. The likelihood for Caesarean section instudy. Moreover, there were only 41 refusals creases with maternal education, but it is lower
out of 3811 deliveries (response rate 98.9%). in the private hospital. Small (<2500 g) and
Interviews took place in the maternity wards large (>3500 g) babies are both more likely to
and were conducted by a trained interviewer; of be delivered by Caesarean section, whereas
the 3770 interviewed mothers, 1809were primi- gestational age per se is not a significant predicparae who gave birth to a singleton liveborn. Of tor of Caesarean section after adjustment for
these, 444 were delivered by a Caesarean sec- birth-weight. A number of obstetric complition, 130 by forceps or vacuum extraction, and cations, including hemorrhage during the third
the remaining 1235 were normal deliveries.
trimester, maternal hypertension, diabetes melThe questionnaire covered a series of vari- litus and placenta previa, are significant and
ables addressing the socioeconomic domain, important predictors of Caesarean section, as is
maternal and fetal factors, and obstetric history in-vitro fertilization.
for the index pregnancy. The medical variables
With respect to forceps and vacuum extracconcerning the index pregnancy were ascer- tion (Table 4), maternal age and maternal
tained through the clinical records that were height are, again, significant predictors of O V
available to the interviewer, whereas birth delivery (positively and inversely related, reweight of newborns was measured in quality spectively), but maternal weight does not
controlled electronic scales. The attending appear to play a statistically significant predicobstetricians provided clarifications or addi- tive role. As for CS, the likelihood of OV
tional information as needed, but they were not delivery increases with maternal education, and
informed about the objective of the study.
it is lower in the private hospital. There is
Operative delivery procedures in Greece
TABLE 1. Frequency distribution (%) of 1235 normal, 130 operative
vaginal (OV) and 444 Caesarran section (CS) deliveries for singleton babies
among primiparae by a series of maternal and sociwconomic variables
Type of delivery
Variable
Normal
OV
Age at current pregnancy (years)
0-19
20-34
35+
Maternal height (cm)
0-159
160-164
165+
Maternal weight before pregnancy (kg)
0-64
65-84
85+
Maternal education (years)
0-1 1
12
13+
Maternity hospital
Private
Public
TABLE 2. Frequency distribution ('%) of 1235 normal, 130 operative vaginal (OV) and 444 Caesarean sedfon (CS) deliveries
of singleton babies among primiparae by a series of obstetric
variables
Type of delivery
Variables
Birth-weight (g)
0-2499
250-3499
350-3999
4ooo+
Gestational age (days)
150-259
260-289
290+
Sex
BOY
Girl
Percentages of women wuh:
In-vitro fertilization
Hemorrhage 2nd trimester
Hemorrhage 3rd trimester
Pregnancy hypertension
Diabetes mellitus
Placenta previa
Normal
OV
CS
Y. Skalkidis et al.
evidence that OV deliveries are more frequently performed for larger babies, whereas
there are rarely used for small babies or premature ones. There are no significant relationships
between OV and pregnancy complications, except for a suggestion of increased use of this
procedure in response to placenta previa.
DISCUSSION
Caesarean section and operative vaginal procedures play an important role in obstetriccare.
However, there is widespread concern that the
procedures are used without adequate medical
justification in a certain percentage of deliveries. There have been attempts to identify a
target proportion of deliveries that should be
undertaken under operative prmdures for
optimization of birth outcome [26-281, but no
concensus has been reached. In the absence of
an agreed standard, evidence of overuse of
surgical procedures for delivery has been based
on: (a) the increasing secular trend of the proportion of deliveries by operative procedures
without evidence of a concomitant improvement in indicators of pregnancy outcome; (b)
evidence of supply-induced demand as witnessed by the increasing frequency of performance of operative delivery procedures with the
increasing number of qualified providers; and
(c) the large variability of the frequency of
performance of CS between and within
countries that cannot be explained in terms of
an underlying variability of medical indications
TABLE 3. Multiple logistic regressionderived odds ratios (ORs) and 95% coddence intervals (CI)for
section dellvery of singleton babies among primiparae in relation to a series of maternal, sodoeconomic and
obstetric variables
Variable
Age at current pregnancy
Maternal height
Maternal weight
before pregnancy (kg)
Maternal education
Maternity hospital
Birth-weight (g)
Category or
increment
Maternal variabks
5 years
1.48
5 m
0.84
0-64
Baseline
65-74
1.14
75-84
1.10
85+
2.48
Socioeconomic variables
5 years
1.12
Public
Baseline
0.49
Private
Obstetric variables
0-2499
25M-3499
35W3999
4000+
Gestational age (days)
In-vitro fertilization
Gender
Hemorrhage during pregnancy
Pregnancy hypertension
Diabetes mellitus
Placenta previa
OR
150-259
-269
270-289
2W+
No
Yes
Girl
BOY
No
Yes
No
Yes
No
Yes
No
Yes
1.53
Baseline
1 .36
2.31
1.24
1.10
Baseline
1.31
Baseline
5.50
Baseline
1.19
Baseline
2.94
Baseline
3.68
Baseline
2.26
Baseline
4.04
Operative delivery procedures in Greece
or chance variation. However, few studies have
tried to determine the variation in the frequency
of performance of operative deliveries after
controlling for medical indications. Such indications are maternal age [8,16,29-311, maternal
height [32], maternal weight [I], small or large
birth-weight [3,7-9,16,32,33] and obstetric
complications [33,34].
In Greece, the rate of deliveries by CS has
increased by 4l0/0 over the last 13 years. During
the same period, a 44% increase has been noted
in the number of practising obstetricians, even
though birth rates have decreased by 26%.
These figures concern Greece as a whole, but
there is a consensus that changes in the Greater
Athens area have been even more extreme.
This pattern suggests a phenomenon of supply-
induced demand. The objective of the present
study was to assess the importance of medical
and socio4tural factors for operative deliveries in Greece. The study is based on an unselected population with a high degree of cooperation. Therefore, important selection bias
is unlikely, and there is no reason to suspect
differential information bias. A potential problem in the study could be the inclusion of only
one private and only one public hospital. However, it includes the patients of more than 40
obstetricians who were delivering at each of the
participating institutions. Another concern is
whether the private and the public hospitals are
typical of their categories. There is no guarantee that they are, but the objective of the study
was not to provide generalizable estimates of
TABLE 4. M a p l e logistic regremion derived odds r a t . (ORs) and 95% confidence intervals (CI) for
operative vagtnal delivery d singleton babies among primiparae in relation to a series of maternal sodaeconomic and obstetdc variables
Variable
Maternal variables
Age at current pregnancy
Maternal height
Maternal weight
before pregnancy (kg)
Category or
increment
5 years
5cm
0-64
65-74
75-84
85+
Socweconomic variables
Maternal education
Maternity hospital
OR
1.42
0.64
Baseline
1.27
O.%
0.63
Public
Private
1.40
Baseline
0.03
0-2499
2500-3499
3500-3999
4000+
150-259
260-269
270-rn
290+
Girl
BOY
No
Yes
No
Yes
No
Yes
No
Yes
0.22
Baseline
1.21
1.87
0.62
0.50
Baseline
0.80
Baseline
1.27
Baseline
0.21
Baseline
0.80
Baseline
2.71
Baseline
5.81
5 years
Obstetric variables
Birth-weight (g)
Gestational age (days)
Gender
Hemorrhage during pregnancy
Pregnancy hypertension
Diabetes meUitus
Placenta previa
95% CI
P-value
Y. Skalkidis et al.
medically unexplained variability, but to assess
whether such variability does in fact exist and, if
so, whether it is substantial o r negligible.
With respect to the medical indications and
risk factors for CS, the results of the present
study are in broad agreement with those
reported in the literature. CS is performed more
frequently among older pregnant women
[8,16,2%32], among those with small body
frame [32], and among those who are excessively overweight [I]. CS is also more frequently
performed in high-risk pregnancies on account
of extreme birth-weight prematurity o r obstetric complications [3,7-9,16,32-341. The literature with respect to operative vaginal
procedures is limited, but the indicationlrisk
profile for these operations is similar but overall
less striking than that noted for CS. This is not
surprising since O V as a surgical procedure is
situated between CS and the normal delivery
process, and high-risk situations are switched to
CS, thus eliminating extreme contrasts in the
comparison between O V and normal deliveries.
An increased frequency of CS deliveries among
more affluent o r better educated women has
also been reported in other studies [16-19,331.
The phenomenon could be accounted for by
increased medical attention directed towards
the wealthier women in response either to an
increased demand on their part or to the prospect of differential compensation [14,19,33,
35,361. The higher frequency of operative deliveries in the public teaching hospital could be
due t o the fact that medical indications are
likely to be interpreted more liberally in a public
teaching hospital than in a private institution.
Moreover, in private maternity hospitals, the
obstetrician has attended the woman throughout her pregnancy and is likely to feel sufficiently confident to choose a conservative approach;
by contrast, in the public teaching hospital,
most deliveries are undertaken by the obstetricians on duty at the time of delivery. Financial
considerations may also contribute, but the
multitude of health insurance funds in Greece
and the ways through which regulations are
allegedly bypassed make it difficult to properly
assess their importance [37].
It has been argued that CS should not exceed
15% of all deliveries [30-321, but comparable
figures for O V deliveries are not available. In
the private hospital under study, CS deliveries
were about 20% of all singleton deliveries
among primiparae; the corresponding figure in
the public hospital was about 30%. It appears
that CS is performed in one of the institutions
with an increased frequency of at least 33%,
whereas in the other institution CS is performed
at twice the recommended frequency. Confounding by demographic [38], obstetric and
medical variables [39] does not explain these
differentials. Thus, it may be concluded that
social factors and the medical culture in Greece
change the frequency of CS and to a certain
extent that of O V deliveries and raise them to a
level substantially higher than would be justifiable on obstetrical and medical grounds.
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