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Reliability and validity scores are significantly high. A
pilot group of 40 subjects were given the questionnaire by
Pitt (1968) at 28 weeks and 34 weeks of pregnancy. Test-
retest reliability was indicated by the correlation between
their scores on these two occasions. The correlation co
efficient, assessed by Pearson Bravai's Product Moment, was
significantly high: + 0.76 (t = 7,2; df * 38; p< 0,001).
In order to test validity, Pitt (19€8) gave 40 subjects the
questionnaire and then interviewed them. The interviewer,
ignorant of their questionnaire score, r.ited them according
to the Hamilton Rating Scale for Depression. Subjects were
then ranked according to their clinical rating and
questionnaire scores. The correlation between their rank
orders on the two assessments was an indication of the
validity of the questionnaire. Spearman's rank correlation
was, in fact, significantly high: + 0,78 (t ■ 7,7; df = 38;
p< 0,001) .
Means and standard deviations wore calculated by Pitt ( 1968)
from the scores of 164 subjects. A moan of 11,89 (SD * 7,7)
was obtained for women tested at 7-10 days postpartum, while
a mean of 11,82 (SD ■ 7,9) was obtained for women tested at
6-8 weeks postpartum.
Pitt's Depression Questionnaire (1968) is v o w e d as one of
the most accurate measures of postpartum depression. It has
109
been successfully used in a number of studies (Brc ;n, 1975).
To date, it remains the only questionnaire designed
specifically to measure postpartum depression.
4 .2.2 Biographical Questionnaire (App< : 4)
A biographical questionnaire, based on that of Chalmers
(1979) was drawn up in order to obtain a detailed sample
description. The questionnaire explored a varying field of
personal information. The areas included nationality,
occupational activities, religious affiliation, marital
history, educational levels, socio-economic status, previous
psychiatric difficulties and treatment, expected abilities to
cope with the baby and the question of whether the baby was
planned or not.
4.2.3 Measurement of S ocial Support (Appenuices 7 and 8)
To date, no measure exists which assesses social support
specifically in the postpartum period. For the purposes of
this study, i special measurement technique was devised. It
was designed to measure both the structure and quality of
social support relationships. Following the majority of
measures in the field, the present scale aimed to assess
suppoit as perceived by the mothers. House (1981) states
that social support is likely to be effective only to the
extent to which it is perceived. This method was considered
110
preferable to unstructured tester rating, which also lends a
subjective bias.
The discussion in Chapter 2.3.1, shows that most
fundamental in the concept of social support is the emotional
aspect. This was the social support quality tapped in the
present scale. According to Kaplan and Blackman (1969) the
most significant support convoys to a mother in the early
postpartum period are, husband, family, doctor and other
hospital staff. To facilitate uniformity and closer control
in the assessment of responses, these four networks were
studied. Paykel et. a K (1980) criticizes many self-rating
social support scales that view only the spouse as a vehicle
of support. The inclusion of 'other patients' as a rating
v a r i a b l e was considered, but subsequently omitted due to the
fact that many patients were in private wards and that the
influx of patients was constantly changing.
The scale was devised to present a complex task in a
simplified form for easy comprehension and self
administration. Subjects were requested to rate the degree
of perceived emotional support from husband, family, doctor
and hospital staff. Thir< rating was according to a Likert-
type rating scale which included the following levels:
i. No jupport.
ii. A little, but not enough
iii. Adequate, but could have been better
111
iv. Good
v. Very good
v i. Excellent
These levels ensured that a wide range of supportive
responses were assessed. The scores ranged from 0 (no
support) to 5 (excellent) with a possible maximum score of 20
and a minimum of 0.
4.2.4 Measurement o f Locus of Control (Appendices 9 and 10)
To assess each individual's locus of control, Rotter's (1966)
S c a l e to Measure Internal versus External Control was used.
The instrument is designed to measure generalized
expectancies for internal versus external control of
reinforcement. The I-E scale consists of a 29-item, forced
choice questionnaire. Six of these items are fillers adapted
from the 60-item Jones Scale (Lefcourt, 1982). The remaining
23 items offer choices between internal and external belief
statements. The scale is scored by summing the number of
external beliefs endorsed. A high score therefore indicates
a high external locus of control, while a low score indicates
a high internal locus of control.
According to Robinson and Shaver (1970), a Kuder-Richardson
internal consistency analysis of the I-E scale yielded
r = 0,70. Test-retest reliabilities of the I-E scale for
females yielded an increase following a one month time lapse
112
between testing, and a decrease in reliability after a two
month interval. According to Rotter (1966), part of this
decrease was due to differences in administration.
Correlations tor validity with the Marlowe-Crowne Social
Desirability Scale (1964) ranged from - 0,07 to - 0,35.
Several factor analyses reported by Katter (1970) support the
assumption of unidimensionality of the scale, and numerous
laboratory and survey studies give evidence for its construct
validity (Robinson and Shaver, 1970).
After evaluating the critical research on the I-E scale,
Lefcourt (1982) suggests that:
"If one wyre now to summarize the current
status of assessment tools used in the study of
locus of control, it would be possible to
conclude that there is enough evidence to
encourage investigators to both continue in
their use of existing devices and to develop
newer, more criterion-specific measures"
(Lefcourt, 1982, p. 179-180).
In the light of the above conclusion, the Rotter Scale was
considered the tool of choice in determining locus of control
in the new mother. Although the Rotter Scale has not been
standardized for a white, South Atrican postpartum sample, it
has been previously successfully used in two South African
research programmes involving White, pregnant, South African
women (Chalmers, 1979; Friedman, 1979).
In order to assess the obstetric birth risk facing the mother
and baby in the light of the occurrence of any complicating
factors in the maternal medical history, Littman and
Parmalee's (1974) scoring methcd was utilized.
The scoring form lists 41 separate items and is based on the
Prechtl (1968) system of optimal scoring, i.e. each category
is believed to be associated with increased risk of infant
mortality and therefore would be likely to have an effect on
development if the infant survived. Scoring involves
attributing a score of one to each optimal condition (i.e.
non-complication condition) experienced by the mother or baby
during the c o u r s e of the pregnancy or delivery. At the
conclusion of scoring, the optimal responses are summed. For
the purposes of the present study information regarding non-
optimal responses was required. This was obtained by
calculating the difference between the maximum optimal score
and the attaint'd optimal score for each subject. This
procedure rendered no violation of the essential nature of
the complication score of Littman and Parmalee (1974).
Chalmers (1979) conducted an extensive factor analysis of
this measure. Her aim was to examine whether:
4.2.5 Measurement of Neonatal Birth Risk (Appendix 11)
"the 'risk' score was essentially a measure of
degree of disorder in pregnancy or a simple
count of the number of complications occurring
in a pregnancy" 'Chalmers, 1979, p. 238).
114
T
The results of thp analysis showed that the 'risk' score did
not constitute a homogenous unitary scale of pregnancy
disorders, but rather reflected a total score of a number of
possible complications arising in pregnancy and delivery.
The twelv ' factors identified by Chalmers (1979) were;
i. 'Maturity' - including estimated gestational age,
placental weight, weight of the infant and an estimate
of maturity of the child.
ii. 'Stage Three' - including length of stage three and
placental measures, viz. delivery by Modified Brandt-
Andrews, normal and manual methods, as well as other
complications of the placenta or its delivery.
iii. 'Method of Delivery' - including normal delivery,
caesarean section and amount of haemorrhage.
iv. 'Apgar Rating' - including the two Apgar ratings of the
baby's well-being taken at one and five minutes after
birth.
v. 'Stage Two' - including length of stage two of the
delivery, the use of forceps during delivery,
episiotomy and normal delivery.
vi. 'Labour Onset' - including spontaneous onset of labour
and the use of oxytocin for induction or assisted
delivery.
115
vii. 'Admissions' - including premature labour, infection or
other complications requiring hospital admission prior
to delivery.
viii. 'Stage One' - including length of the first stage of
labour and artificial rupture of membranes.
ix. 'Metabolic Imbalance' - including ketones and albumin,
both measured by urine tests.
x. 'Membranes' - including only the presence of complete
membranes at delivery.
xi. 'Toxaemia' - including hypertension and oedema.
xii. 'Blood Incompatibility' - including only blood
incompatibility occurring in the pregnancy. Only one
of the variables, 'normal delivery', loaded
significantly on more than one of the 12 factors
(Factors 3 and 5) indicating the presence of a fairly
clear factor structure (Chalmers, 1979).
The choice of Littman and Parmalee's (1974) scoring method
was based largely on its' existance as one of the most
comprehensive, yot least conplox of th<’ frw measures designed
for this purpose, and that it was effectively employed in a
previous South African research programme involving White
mothers (Chalmers, 1979).
116
4.2.6 Measurement of Obstetric Interventions (Appendix
13)
No instrument exists within the field of psychology or
obstetrics to assess women's perceptions of obstetric
procedures.
Three major limitations are apparent in obstetrical research.
The first is that only a few specific procedures have been
assessed with regards to their impact on women. Oakley and
Chamberlain (1981), in assessing affective states and medical
procedures at birth, merely asked women whether instruments
and/or epidural anaelgesia had been utilized. This research
also highlights the second major problem of measurement, i.e.
that generalized statements regarding the effects of
obstetrical procedures are often made on the basis of only a
few interventions under study. Tne third problem, is that
studies have researched obstetric procedures in a global
manner, attributing the same importance to both major and
minor procedures (Grossman et a l . , 1980). To date, no
studies have scientifically measured the varying effects of
different interventions and the degree of stress or ease with
which women respond to them.
In order to allow more accurate comparisons and predictions
to be made as to the effects of obstetric interventions on
postpartum depression, a specific check-list was devised.
The aim of the check-list was to obtain objective mean
ratings as to the stressfulness of each intervention. These
responses could then be summed, to yield a total score of
mothers' attitudes to obstetric interventions. Such a
scientific objective measure would facilitate statistical
calculation as to the contribution of obstetric procedures to
the development of postpartum depression.
To obta in <t stress r a ting to r c ach obstetric technique used,
a separate research programme was conducted. On-' hundred
early postpartum mothers were selected according to the same
criteria as those of the major sample. All were patients at
the Johannesburg General Hospital. These women were asked to
rate n number of interventions on a constructed check-list,
(Appendix 12, Obstetric Interventions Checklist 1) according
to their own experience of the ease, difficulty, stress,
intrusiveness or relief associated with each. The rating
choice ranged from 0 to 10, where 0 indicated no negative
associations, and 10 indicated maximal stress and difficulty
associated with the intervention. In the list given to
mothers, complex technical terminology was simplified.
The check-list comprised antenatal, natal and postnatal
obstetric procedures (Appendix 12). The it«*ms were devised
by consulting hospital records, obstetricians and obstetric
textbooks (Chamberlain, 1980; Llewellyn-Jones, 1971). The
list indexed all possible procedures, both rare and common,
118
which are practiced at birth. The followinq sections were
delineated:
A. Antenatal Interventions
B. First Stage Intervertions
C. Second Stage Interventions
- Maternal
- Foetal
D. Third Stage Interventions
- Placenta
_ Cord
E. Postnatal Interventions
- Infant
- Maternal
F. Other
All ratings from the women were summed, and mean ratings for
each procedure on the check-list were obtained. Table 3
in Chapter 5.2 indicates the objective mean rating weights
and standard deviations obtained for each obstetrical
procedure.
These rating weights represent objective values for each
obstetric intervention. The rating weights obtained from
these subjects could therefore be used as objective measures
for the second group of subjects included in the major
research programme. Holmes and Rahe (1967) argue that this
method is more reliable and valid than obtaining subjects'own
subjectively perceived ratings.
In order to assess the effects of obstetric interventions on
postpartum depression, the author recorded which medical
interventions wore experienced by women (Appendix 13). The
information was obtained from hospital records and nursing
staff and, where necessary, obstetricians and the women
themselves (for example, details of shaving and placement of
the infant, which were not included in records). The lists
were then scored according to the mean rating weights
previously obtained. The scores for each intervention were
then summed and a single total value was acquired. These
final values indicated measures of mothers' attitudes to the
obstetric interventions they experienced.
4.3 Procedure
The names of all primiparous women who were maternity
patients at the Johannesburg General Hospital were located
from hospital files over a period of five months. The tester
briefly interviewed these women in order to assess their
120
suitability for the study according to the criteria discussed
in Chapter 4.1.1, i.e. primiparous, married, no congenital
anomalies in the baby, and no psychiatric history in
pregnancy. The hospital is exclusively for White patients,
therefore this control was already established.
Appropriate subjects w.>re selected and invited to participate
in the study. The language preference (English or Afrikaans)
of each woman was established. All further communications
and questionnaires wore administered according to the stated
preference of each individual. Subjects were told that
research was being carried out by the School of Psychology of
the University of the Witwatersrand, in order to assess how
women felt in the first week after giving birth to their
first oaby. Assuran:e as to the confidentiality of answers
was given. Ail women who agreed to participate in the study,
signed consent forms (Appendices 1 and 2). To prevent the
calculation of expected responses by the subjects, specific
details regarding the aims of the study, i.e. the
assessment of postpartum depression and its relation to the
independent variables, were not explained.
Testing was conducted over a period of five months. All
subjects were tested between the third and seventh day after
birth (32% on the third day; 30% on the fourth; 25% on the
fifth; 11% on the sixth; and 2% on the seventh). In order
to ascertain whether the day of interview influenced
121
me as urement of depression, an analys is of variance procedure
was performed. The results showed no correlat ion oetween the
day of testing and the incidence of post par tuin depression
(F = 1,08; df = 2; p> 0,05).
Subjects were tested in hospital. The tester distributed the
Biographical, Social Support, Locus of Control and Depression
Questionnaires to each subject for self-administration.
Distribution, completion and collection of questionnaires was
carried out on the sam-> day for each woman. Subjects were
asked not to obtain help with the completion of
questionnaires. Separate instructions for the different
measures were given in the respective questionnaires.
The Birth Risk and Obstetric Interventions Checklists were
filled out by the tester. The required information was
obtained from hospital records, staff, and where necessary,
the patients themselves. These lists were completed by the
tester while mothers completed the four self-administered
questionnaires. This ensured that the tester was unaware of
depression scores, rendering a 'blind' rating of risk and
obstetr ics.
Finally, all questionnaires and check-1ists were collated and
scored according to the methods outlined in Section Chapter
CHAPTER FIVE
RESULTS
5.1 Aims of the Data Analysis
The aims of the present, study were stated in Chapter 3 as:
i. To assess the possible contribution of neonatal birth
risk, locus of control, social support and obstetric
interventions to postpartum depression.
ii. To assess the relative importance of these factors in
contributing to postpartum depression.
The aims of the data analysis were therefore to measure the
explanatory and predictive efficacy of neonatal birth risk,
locus of control, social support and obstetric interventions
on the dependent variable of postpartum depression. To
fulfill this aim, a Forward Selection Regression Procedure
was performed.
A further aim of the data analysis was to obtain stress
ratings for each obstetric technique listed in tne
Obstetrics Interventions Checklist 1 used in the preliminary
study. Mean scores and standard deviations were calculated
in order to fulfill this aim.
123
5.2 Mean Scores and Standard Deviations for the Obstetric
Interventions Checklist 1
Table 3 shows the mean scores and standard deviations
obtained for procedures included in the Obstetric
Interventions Checklist 1.
From Table 3 it is evident that the highest mean ratings
obtained were for a "caesarean section under general
anaesthetic" (M = 6,70; SD * 2,95), and for "operative
removal of the placenta" (M = 6,70; SD = 2,60).
"Amniocentesis" followed closely, with a mean rating of 6,67
(M = 6,67; SD = 2,43). The lowest ratings were those of
"childbirth preparation classes" (M = 1,67; SD = 1,24),
and "covering of the infant" (M = 1,61; SD = 1,08).
Further low ratings were located for "natural urinary bladder
emptying" (M = 1,95; SD » 1,07), and "cleaning of the
infant" M = 1,97; SD = 1,03).
124
Mean stress ratings and standard deviations for
Obstetric Interventions Checklist 1.
n = 100
Intervent ion Mean
(Range 0-10)
Standard
Deviation
A. Antenatal
Examination - clinical 2,02 1,47
Examination - laboratory 2,44 1,99
Non-stress test 3,20 3,03
Oxytocin challenge test 5,27 2,84
Sonar 2,11 2,05
X-rays 2,60 1,76
External cephallic version 5,78 2,87
Amn iocentesis 6,67 2,43
Medicat ion 4,76 2,83
Childbirth preparation classes 1 ,67 1,24
B. First Stage
Shaving - pubic 3,07 2,57
- perineal 3,09 2,81
- umbilicus to pubis 3,52 2,82
Bowel preparation
- suppositories 4,05 2,53
- fleet enema 4,52 2,65
Analgaes ic
- Pethidine/Atarax 3,59 2,76
- Gas 4,21 2,38
Table 3 (continued)
Intervent ion Mean
(Range 0-10)
Standard
Deviation
B. First Stage (continued)
Urinary bladder emptying
- natural 1,95 1,07
- catheterization 5,11 3,04
Drip (Dextrose water) 4,98 3,13
Surgical induction of labour 4,86 2,84
(A.R.O.M.)
Pharmacologica1 induction of
labour - oxytocin/syntocinon 5,23 3,15
- intravaginal prosta
glandins (E2/F2) 4,82 2,79
C. Second Stage
Materna1
Position- supine 4,57 3,08
- lithotomy 5,61 2,94
Epis iotomy 5,41 3,21
Forceps - Andersons 6,18 2,63
- Wriggleys 5,95 2,62
- Keillands 6,05 2,66
Vacuum Extraction 6,02 2,62
Caesarian Section
- with local anaesthetic 6,50 2,88
- with general anaesthetic 6,70 2, 95
Breech - delivery 5,82 2,70
- extraction 6,00 2,61
- Pinnard's manoeuvre 6,05 2,61
- Loveset's manoeuvre 5,89 2,50
- other manoeuvres 5,64 2,55
Cervical manipulation 6,45 2,50
126
Table 3 (continued)
Intervent ion Mean
(Range 0-10)
C. Second Stage (cont inued)
Analgesic injections
- Pethidine/Aterax
Local anaesthetics
- local infiltration
- pudendal block
- epidural
- spinal
Other drugs - Syntometrine
- Ergometrine
Antimicrobial agents
- one
- more than one
4,25
4.68
4,93
5,80
5.68
4.45
4.45
3,02
3,61
Standard
Deviat ion
2,75
2, 59
2 , 68
2,83
2,88
3.19
3.19
2,41
2,81
Foeta1
Foetal heart monitor
External pressure monitorinq
Intrauterine pressure monitoring
Third Stage
3,23
3,18
5, 30
2,93
2,76
2,87
Piacenta
Delivery- natural 2,73
- modified Brandt Andrews 3,68
(with cord traction)
- complicated - manual 5,68
- operative 6,70
2,04
2,00
2,47
2,60
Cord
Clamped and cut immediately
Manually slipped over head
Palpation of pulsation of cord
2,43
3,70
3,73
2,28
2,73
2,77
127
Table 3 (continued)
Intervention Mean
(Range 0-10)
Standa rd
Deviat ion
E. Postnatal
Infant
Resusci tat ion
- airways cleared 3,34 2,01
- oxygen mask 4,02 2,96
- manual positive pressure 4 , 34 2,85
vent ilat ion
- intubation 5,20 3,05
- cardiovascular drugs 5,32 3,23
- cardiovascular massage 4,77 3,23
Eyedrops (silver nitrate) 2,80 2,57
Vitamin Kl injection 2,61 2,33
I ncubator 4, 30 2,32
Cleaning of infant 1,97 1,03
Covering of infant 1,61 1,08
Placement of infant
- mothers stomach 1,86 1,04
- table 3,55 2,77
- cot 3,45 2,17
Materna1
Clinical obstetric examination
- by medical team 3,16 2,38
Laboratory examination
- blood, urine tests 2,98 2,37
Suturing of episiotomy or tear 5,34 2,96
Curettage 6, 34 2,45
Examination of placenta 2,20 1,73
Examination of cord 2,02 0,88
128
5.3 Mean Scores and Standard Deviations for the Dependent
and Independent Variables
Mean scores and standard deviations were calculated for the
dependent variable of postpartum depression, and the
independent variables of social support, obstetric
interventions, locus of control and birth risk. The results
are shown in Table 4.
Table 4
Mean scores and standard
independent variables.
deviations for the
n = 87
dependent and
Variable Mean
Standard
Deviat ion
Postpartum Depression 19, 59 11,74
Social Support 14,66 4,76
Obstetric Interventions 117,12 19,93
Locus of Control 10,5 4,2
L
r
5.4 The Forward Selection Regression Analysis
The explanatory and predictive efficacy of the independent
variables of social suoport, obstetric interventions, locus
of control and birth risk on the criterion of postpartum
depression, was assessed within the framework of a Forward
Selection Regression Procedure. Table 5 is a summary of the
results of this analysis.
Table 5
The determinants of postpartum depression: summary of the
Forward Selection Regression Analysis.
n - 87
Independent Vari
able entering
equat ion
Step Multiple R
2 F* in final
R Change equation
(Step 4)
Social Support
Obstetr ic
Intervent ions
Locus of
Cont rol
Birth
Risk
Var iables
Comb i ned
2
3
0,192
0,223
0,229
0,235
0, 235
2
0,037
0,013
0,003
0,004
0,004
15 .07**
3,51
0,72
0,61
6, 30**
*F tests the null hypothesis R
1 1
df /4 - k - 1,
** p < 0,0002.
130
* 0 with
/87 - 4 - 1 / 8 2 .
From Table 5, it is evident that social support was the only
independent variable which made a significant contribution to
postpartum depression (F = 15,07; p < 0,0002). Obstetric
interventions, locus of control and birth risk made no
significant independent contribution to the variance of
postpartum depression. Social support remained a significant
predictor when the effects of obstetric interventions, locus
of control and birth risk had been partialled out, and
appeared therefore to be the best predictor variable.
At the final step of the analysis an optimal linear
combination of the four independent variables accounted for a
significant proportion of the variance of the dependent
variable (F = 6,30; p < 0,0002). Social support, obstetric
interventions, locus of control and birth risk explained 5,7%
of the variance of postpartum depression (Cumulative
CHAPTER SIX
DISCUSSION
The aim of the study was to identify factors at the time of
birth that are predictive of maternal adaptation problems in
the postpartum period. The following discussion integrates
the previously mentioned results and explores the
implications of these findings. The independent variables,
viz., social support, locus of control, obstetric
interventions and birth risk were assessed individually and
in combination against the criterion of depression. In
addition, the mean stress ratings and standard deviations
obtained for items included in the Obstetric Interventions
Checklist 1 are discussed.
6.1 Social Support
Social support was the only variable to make a significant,
independent contribution to the variance of postpartum
depression (F = 15,07; p < 0,0002). Although this result is
significant within the statistically accepted level of 0,05,
it must be interpreted conservatively, since the proportion
of variance explained by social support is in fact, only
3,7% .
132
Author Cooke W L Name of thesis Some determining factors of postpartum depression 1985
PUBLISHER: University of the Witwatersrand, Johannesburg
©2013
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