The Measurement of Maternal Mortality
IRVINE LOUDON
r
^ HERE are, of course, problems in the interpretation
of all historical mortalities, but those surrounding
maternal mortality show some unusual and rather
complicated features, and they illustrate some interesting points concerning what one might call the
"mechanics" of death registration in the past. For
the most part, I deal here with the Registrar General's statistics for
England and Wales.
The easiest way to show a trend in mortality is to display the total
number of deaths. Figure i shows total maternal deaths (and also
total births) in each decade from 1850 to 1980, indexed to 100 in
1850. In round figures there were between 8 and 9 maternal deaths
per day in 1850, rising to a peak of 13 per day in the 1890s and
falling to less than 1 per week in the 1980s. The shape of this graph—
the initial rise followed by the steep fall from the end of the nineteenth
century—resembles the trend in infant mortality, which perhaps is
not surprising. We think of mothers and infants as closely linked and
expect their deaths rates to be shaped by the same sort of determinants
of mortality.
Showing total deaths, however, is acceptable for comparing something like road deaths over two or three years, but it is a misleading
way of showing maternal deaths over a period of 140 years, for it
takes no account of changes in the population at risk, which, in the
case of maternal deaths, is women of childbearing age (15-44). Figure
2 (also indexed to 100 in 1850) corrects for this factor. The figure
shows a huge change in the population of women aged 15—44 a n d
also shows the maternal death rate expressed as the number of maternal
deaths per 1,000 women aged 15—44. The French, incidentally, were
fond of showing maternal mortality in this way. Once again we have
© 1999 OXFORD UNIVERSITY PRESS
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Measurement of Maternal Mortality
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Total Births
100
. Total Maternal Deaths
S
Values for 1850 = 100
Fig. 1. Total births and total maternal deaths, England and Wales, 1851—1860 to
1971—1980. Source: Registrar General for England and Wales, Decennial Supplements
(London: Her Majesty's Stationery Office).
a graph of maternal deaths showing an initial rise and a steep fall,
similar to Figure 1. Figure 2, however, also shows the fall in the crude
birth rate. This should alert us to the fact that the population at risk
is not all women aged 15-44 but only women during the "puerperal
state," which can be defined as during pregnancy, labor, and the
postnatal period. It is obvious that, other things being equal, if women
have fewer babies, there will be fewer maternal deaths.
Thus the correct denominator is not the population of women of
childbearing age, but deliveries or births. The definition of the maternal mortality rate (MMR) is the number of maternal deaths per 1,000
(or 10,000 or 100,000) births. Put simply, the MMR measures the
cost in maternal deaths of producing 1,000 (or 10,000 or 100,000)
babies. Figures 3 and 4 show the trend in the MMR. Figure 3 is
314 Journal of the History of Medicine :
Vol. 54, April iggg
200 -
100
Birth rate
\ ( Maternal Death Rate
1
1
1
1
Values for 1850 = 100
Fig. 2. Birth and maternal death rates for population of women aged 15—44,
England and Wales, 1851—1860 to 1971-1980. Source: Registrar General for England and Wales, Decennial Supplements (London: Her Majesty's Stationery Office).
Loudon
:
Measurement of Maternal Mortality
315
60
50
40
30
20
10
0
Fig. 3. Fig. 3. Annual rates of maternal mortality, England and Wales, 1850 to
1970. Source: Registrar General for England and Wales, Decennial Supplements
(London: Her Majesty's Stationery Office).
based on annual rates. Figure 4 is based on five-year averages, and
the vertical axis is logarithmic to demonstrate comparable rates of
decline. This is a vivid example of the importance of choosing the
correct denominator, for the shape of the graph is now quite different.
Instead of falling steeply from the 1890s, the MMR stayed on a high
plateau (albeit a plateau with spikes on it, deliberately smoothed in
Fig. 4) from 1850 to the mid-i93os. Then it declined steeply, the
first year of the fall being 1937, and continued to fall at a remarkably
constant rate until the present.
This is an extraordinary trend. The decline in infant mortality
began around 1890-1900 in most Western countries. The received
wisdom is that the decline was probably due to better standards of
living, better diet and housing, improvements in hygiene, and so on.
Surely, the same factors should have reduced the MMR? In fact, the
MMR should have fallen even more steeply than the infant mortality
rate because of additional factors such as the introduction of antisepsis
and asepsis (c. 1890), which dramatically lowered the mortality in
lying-in hospitals; the training of midwives (from 1902 in England);
the introduction of antenatal/prenatal care (roughly from the 1920s);
316 Journal of the History of Medicine
1850
1900
Vol. 54, April
1930 1940
1980
80
70
50
40
30
.2 20
15
o 10
i
of
lL
Fig. 4. Maternal mortality rates (five-year averages), logarithmic scale, England
and Wales, 1850 to 1980. Source: Registrar General for England and Wales,
Decennial Supplements (London: Her Majesty's Stationery Office).
and supposedly better medical education. Yet, instead of a decline
there is a plateau; what is more, it was a gently rising plateau from
1900 to the mid-i93Os, the very period -when the additional factors
came into operation.
It was these paradoxical features that awakened my interest in
maternal mortality more than a decade ago. Initially I refused to
believe the graph was accurate. How could one possibly explain the
plateau of mortality from 1850 to the mid-i93Os, which, if correct,
suggested that for those aged 65 or over in 1999, the risk of their
mothers dying in childbirth when they were born was virtually the
same as it had been in the 1850s? Further, what caused the steep
decline from 1937 to the present?
I thought perhaps that the trend shown in Figures 3 and 4 was a
statistical artifact. Not so. Although there are many confounding
factors, some slight, others quite considerable, the trend shown in
London
:
Measurement of Maternal Mortality
317
Figures 3 and 4 is, broadly speaking, accurate. But there are still
considerable difficulties, especially when it comes to international
comparisons.
THE CORRECT DENOMINATOR
I have said the correct denominator is deliveries or births. In fact,
this is not quite true. Because some women died without delivering
during pregnancy, the correct denominator is pregnancies rather than
births. Unfortunately, for England and Wales, the number of pregnancies that end in abortion is (and always will be) unknown, so births
have to be used instead.
Then there is the question of multiple births. Twins are one delivery
but two births. Because twins occur on average in one in 80 births,
triplets in one in 802, and quadruplets in one in 803 (proof that
God is a mathematician?), one can calculate the probable number of
deliveries for any given number of births. But, as shown below, it is
scarcely worth the trouble because it makes so little difference.
A greater problem is stillbirths. Stillbirths were not registered in
England and Wales until 1929. The M M R was therefore based on
live births before that date and total births (live births plus stillbirths)
afterward. This makes some difference but not very much. An even
greater problem is the wide variety of definitions of stillbirths in
various countries, especially in the United States and France. It has
been shown, however, that in practice this makes little difference to
international comparisons.1
The extent of the deviation due to these factors can be shown by
a simple calculation. For this I have arbitrarily chosen England and
Wales in the year 1925. In 1925, the official published maternal
mortality rate per 10,000 live births was 40.80. The maternal mortality
rate if allowance had been made for stillbirths, would have been 38.76,
and for stillbirths and multiple births 39.60. The difference between
an M M R of 40.80 and 39.60 lies well within the range of random
variation (see Table 3).
THE DEFINITION OF MATERNAL DEATHS
Defining a maternal death would appear to be easy, but it is not. If
a woman dies of a cause directly related to childbirth (puerperal fever
1. Elizabeth Tandy, Comparability of Maternal Mortality Rates in the United States and Certain
Foreign Countries, Children's Bureau Publications, no. 229, U.S. Dept. of Labor (Washington,
D.C.: Government Printing Office, 1935).
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Vol. 54, April lggg
or obstetric hemorrhage, for example), it is clearly a maternal death.
Such deaths used to be called "true" maternal deaths; they are now
called "direct." If a woman who happened to be pregnant was run
over and killed by a horse and cart or automobile, it would be silly
to include the case as a maternal death; it would be an accidental
death. The fact of pregnancy, however, may be noted. Such deaths
are now recorded as "fortuitous [maternal] deaths."2 But what if a
woman died during pregnancy, in labor, or after delivery from influenza, heart disease, smallpox, or tuberculosis? Such deaths, now called
"indirect maternal deaths," used to be called "associated maternal
deaths." Should they be included as maternal deaths in the published
records of a nation's MMR, or should they be excluded? (They
can always be counted and delegated to a footnote for comparative
purposes.)
According to one view, pregnancy was a delicate state which weakened the resistance of women and made them more liable to die
from the general diseases that afflict the human race. In this sense
they were true maternal deaths and should be counted as such.
Countries in which this view prevailed (United States, Denmark,
Australia, and Scotland) therefore included associated deaths in their
calculations of maternal mortality.3 Statistics for these countries
showed a high peak of maternal mortality in 1918—1919 corresponding
to the pandemic of influenza.
In other countries it was held that pregnancy is a healthy state in
which women are no more liable to die of incidental disease than
they would have been if not pregnant. This was the English view,
and in 1933 the Registrar General for England and Wales appeared
to prove the point. He calculated the maternal deaths due to various
diseases such as influenza, pneumonia, heart disease, and so on, and
compared the result with the death rate from the same diseases in a
matched cohort of women of the same age structure and social class
who were not pregnant or had not recently delivered. There was no
2. Report on Confidential Enquiries into Maternal Deaths in England and Wales, Report on
Health and Social Subjects 29, Department of Health and Social Security (London: Her
Majesty's Stationery Office, 1986).
3. Robert M. Woodbury, Maternal Mortality. Tlie Risk of Death in Childbirth and from All
the Diseases Caused by Pregnancy and Confinement, Children's Bureau Publications, no. 152,
U.S. Dept. of Labor (Washington, D.C.: Government Printing Office, 1926), p. 32.
Loudon : Measurement of Maternal Mortality
319
difference. He concluded that "this group of deaths [i.e., associated
deaths] should not be laid at the door of childbearing."4
In fact, recent work has shown that childbearing women have
reduced immunity. They are more likely to die of infective disorders
during the process of childbearing. Technically, the Registrar General
was wrong in 1933, but the point at issue is the effect on international
comparisons of maternal mortality. How much were comparative
rates affected by the fact that some countries published associated
deaths as maternal deaths while others did not?
In the United States, which, during the first half of this century,
had the highest national rate of maternal mortality in the Western
world, it was often said that international comparisons were meaningless precisely because of this factor.5 It was all a question of the
inclusion or exclusion of "associated deaths." Were they right?
Elizabeth Tandy, a member of the U.S. Children's Bureau, tackled
this problem in 1935. She collected a number of case histories —a
mixture of true (direct) and associated (indirect) maternal deaths — and
sent them to the vital statistics authorities in various countries. She
asked them to see how many of these deaths they would have assigned
to maternal deaths according to their own rules. The results can be
seen in Table 1. Then she calculated what the mortality rates for
each country would have been if they had all used the method of
assigning maternal deaths used by the United States. The results are
shown in Table 2.6 Certainly there is a difference between columns
"1927 (A)" and "1927 (B)," but the United States still occupied the
unenviable position of having the worst MMR in the world.
But there is more to this than meets the eye. As Table 1 shows,
the difference between countries that included associated deaths and
those that did not was not clear cut. Countries differed in which
associated deaths they included. It is important to remember that in
spite of guidance in the form of international publications on the
classification of causes of death, each country was to some extent
4. Annual Report of the Registrar General for England and Wales for 1933 (London: His
Majesty's Stationery Office, 1934), pp. 97-8.
5. Woodbury, (n. 3) Maternal mortality, p. 57; SJ. Baker, "Maternal mortality in the
United States,"/ Am. Med. Assoc, 1927, 8g, 2016-17; J-G. Marmol, A. L. Scriggins, and
R. F. Vollman, "History of the maternal mortality study committees in the United States,"
Obstet. Gynaecoi, 1969, 34, 123-38.
6. Tandy, (n. 1) Comparability of Maternal Mortality.
320
Journal of the History of Medicine
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TABLE 1
The Assignment of 447 Maternal Deaths according to
the Methodology Used in Various Countries for
the Classification of Maternal Deaths
Puerperal
causes (%)
Country
Denmark
USA
New Zealand
Australia
Scotland
Netherlands
France
Sweden
England and Wales
Norway
Non-puerperal
causes (%)
99-4
92.9
92.8
92.7
92.3
91.9
82.7
80.5
78.7
76.9
0.6
7-i
7-2
7-3
7-7
8.1
17-3
19-5
21.3
23-1
Source: Elizabeth C. Tandy, Comparability of Maternal Mortality
Rates in the United States and Certain Foreign Countries, Children's
Bureau Publication, no. 229 (Washington, D.C.: Government Printing Office, 1935).
guided by its own conventions, its own "house rules." The same
applied to individual American states. Some of the published statistics
of maternal mortality included only true or direct maternal deaths,
others included associated deaths as well. In England and Wales,
inclusion of associated deaths would have raised the MMR by between
15 and 20 percent. Note that Scotland and Australia used the same
methodology as the United States, whereas Denmark appeared to
include even more associated deaths than Scotland and the United
States.
REGISTRATION EFFECTS
Changes in the methodology of death registration had only minor
effects on the records of maternal mortality. In England and Wales
the Births and Deaths Registration Act of 1874 made the certification
of the cause of deaths by doctors compulsory in England and Wales
London
:
Measurement of Maternal Mortality
321
TABLE 2
The Effect of Differences in Methodology on the Reported
Maternal Mortality Rates (MMR) in Certain Countries, 1927
Maternal deaths per 10,000 births"
Country
USA
Scodand
Belgium
Australia
New Zealand
England and Wales
Norway
The Netherlands
Sweden
Denmark
b
19io
1920
1927 (A)' 1927 (Bf
69
57
78
62
65
64
52
61
61
51
59
49
27
50
65
44
35
25
24
25
45
36
65
64
—
41
59
59
48
24
28
29
28
30
26
24.
31
20
32
"To nearest whole number.
TData for 1910 and 1920 are included to demonstrate the constancy of
the rank order.
c
Column 1927 (A) shows the actual MMR published by each country
in 1927.
In column 1927 (B) the values represent the mortality rate which would
have been recorded in each country if the method of assigning maternal
deaths which was used in the U.S. had been applied uniformly.
Source: The published vital statistics of various countries and Children's
Bureau Publications, U.S. Department of Labor, Washington, D.C.: Grace
Meigs, Maternal Mortalityfrom All Conditions Connected with Childbirth in the
United States and Certain Other Countries. Children's Bureau Publications,
no. 19 (1917); R. M. Woodbury, Maternal Mortality: The Risk of Death in
Childbirth and from All the Diseases Caused by Pregnancy and Confinement,
ibid., no. 152 (1926); Elizabeth C. Tandy, Comparability of Maternal Mortality
Rates in the United States and Certain Foreign Countries, ibid., no. 229 (1935).
and allowed a longer time for the registration of births, but this made
little difference to the registration of maternal deaths.
The introduction ofvarious editions of the International Classification
of Diseases (ICD) was more important. Britain adopted this system
in 1911 and it had one important effect. Before 1911 deaths due to
toxemia of pregnancy (but not deaths due to eclampsia) were allocated
to diseases of the kidney. They are lost to posterity in a "dustbin"
category which contained an undifferentiated collection of actual and
322 Journal of the History of Medicine :
The Periods in which Mates were
admitted to (he death registration
area of the USA
States admitted before 1000
States admitted between 1900 and 1915
I
I States admitted between 1916 and 1923
|
| States admitted between 1924 and 1933
Vol. 54, April iggg
i Miss.
! Conn.
>NJ
• Del.
I Md.
. W. Vi.
:DC
Fig. 5. The periods in which states were admitted to the United States Death
Registration Area. Source: Maternal Mortality in Fifteen States, Children's Bureau
Publication, no. 213, U.S. Department of Labor (Washington, D.C.: Government
Printing Office, 1934).
supposed renal disease. From 1911 deaths from toxemia were placed
where they belonged, in with the true or direct maternal deaths.
But, again, the addition made relatively little difference.7
In the United States the situation was confused by the slow introduction of the death (and the birth) registration areas to which states
were admitted when their statistics were judged to have reached a
high degree of reliability (see Fig. 5). Nine states (or large cities) were
admitted before 1900, mostly in New England. Between 1900 and
1915 another 18 states were admitted, and the total of 27 states,
known as the 1915 death registration area, was often used for national
statistics. Constructing the time trend of maternal mortality in the
7. Irvine Loudon, Death in Childbirth: An International Study of Maternal Care and Maternal
Mortality 1800-1950 (Oxford: Oxford University Press, 1992), pp. 19-39, discusses at greater
length the points raised in this paper.
London
:
Measurement of Maternal Mortality
323
Miunul Deaths per 10.000 Births
50 or more
I*^M 30-9
Fig. 6. Interstate variations in maternal mortality rates in terms of four categories
of maternal mortality, 1938 to 1940. Source: Births, Infant Mortality, and Maternal
Mortality, Children's Bureau Publication, no. 288, U.S. Dept. of Labor (Washington, D.C.: Government Printing Office, 1945).
United States between, say, 1915 and 1935 was tricky. Some used the
1915 death registration area and ignored later additions in order to
achieve consistency. The trouble with this approach was that the states
added last were mostly in the South which were precisely the states
with the highest level of maternal mortality (see Figs. 5 and 6).
Leaving them out made the national level of maternal mortality lower
than it really was.
The complications of assessing American national trends against
the background of two moving targets, the death and birth registration
areas, are dealt with admirably by Robert Morse Woodbury in Maternal Mortality.9 One of his important conclusions was that although
maternal deaths were under-registered, there was a corresponding
under-registration of births. The two faults tended to cancel each
other out in the calculation of maternal mortality.
8. Woodbury, (n. 3) Maternal Mortality, pp. 45-56.
324 Journal of the History of Medicine :
Vol. 54, April iggg
TABLE 3
The Range of Random Variation (Critical Range of Variation) in
Maternal Mortality Rates in Relation to the Number of Births, assuming
a Rate of Maternal Mortality of 50 Maternal Deaths per 10,000 Births
Assumed
Annual
births
1000
5000
Maternal
deaths
rate of
Critical
maternal
mortality
range of
5
5O
25
5O
10,000
50
50
25,000
125
50
50,000
250
5O
100,000
500
50
variation
Regions with annual
births close to these values
during the lgjos
Doncaster, Darlington
Bristol, Newcastle upon
Tyne
35-65 Manchester, Amsterdam
40-60 Lancashire, Middlesex,
New Zealand
43-57 Paris
45-55 Sweden, Belgium,
Australia
5-95
30-70
The critical range of variation shows the values for the maternal mortality that could
occur through chance if the true value were 50 per 10,000 births. Thus, if it had been
possible to show over a large number of years that the true maternal mortality rate in
Doncaster was exactly 50 per 10,000 births, in any given year the actual rate could vary
by chance alone from 5 per 10,000 to 95 per 10,000 because the total annual number
of births was only 1,000.
One final point will be so obvious to demographers that it scarcely
needs to be made. In the study of maternal mortality, one needs
accurate records of a large number of deliveries to achieve statistical
significance. This is illustrated by Table 3.
HIDDEN MATERNAL DEATHS
The worst problem in assessing maternal deaths is that of "hidden
maternal deaths."9 The accuracy of vital statistics is determined by
the quality of those who certify causes of death. The "old women
searchers" and the London Bills of Mortality is an example. As for
doctors in the nineteenth and twentieth centuries, there are in medicine as in every profession ignorant, careless, and dishonest practitioners as well as well-informed, careful, and honest ones. The
9. Loudon, (n. 7) Death in Childbirth, pp. 519-27.
London : Measurement of Maternal Mortality
325
former played a significant role in the statistics of maternal mortality
by filling out death certificates in such a way that maternal deaths
were allocated to nonmaternal categories, creating the "missing" or,
as I prefer to call them, the "hidden" maternal deaths. Sometimes
this was mere carelessness; more often, I suspect, it was deliberate.
The hidden deaths were almost always deaths from puerperal fever
for the simple reason that a doctor (or midwife) whose patient died
of puerperal fever was liable to be blamed for the death whether
justified or not. No doctors certified a death as due to puerperal
fever unless they felt compelled to do so, and many submitted to the
temptation of cover-up. As a result deaths from puerperal fever were
never exaggerated; they were virtually always an underestimate.
Hidden maternal deaths were created by doctors developing certain
well-recognized strategies while ensuring they could not be accused
of gross lies and distortion, for death certificates were seen by relatives
of the deceased and also by the local Registrar of Births, Deaths and
Marriages who would detect a gross lie. One way to hide a maternal
death due to puerperal fever was to invoke multiple causes and relegate
puerperal fever to a secondary position. For example, if a mother
had a slight postpartum hemorrhage and died a week later of puerperal
fever, "hemorrhage" could be put as the primary cause on the death
certificate, and "puerperal fever" as the secondary cause. Only the
primary cause appeared in the published statistics, and the death
remained in the broad category of maternal mortality.
The mode of death in puerperal fever was either peritonitis or
septicemia or both. Indeed, puerperal peritonitis and puerperal septicemia were both common synonyms for puerperal fever. Another
means of hiding maternal deaths due to puerperal fever was to list
"peritonitis" or "septicaemia" alone, with no mention of childbirth.
The cause of death was, strictly speaking, correct but incomplete.
The deaths so recorded promptly disappeared into one of two
"dustbin" categories in the vital statistics: "peritonitis of unstated
origin" or unspecified "septicemia." This same camouflage was practiced in the United States and was referred to by those two eminent
analysts of maternal mortality, Grace Meigs (1917) and Robert Morse
Woodbury (1926).10 There were also other ways to hide maternal
10. Grace Meigs, Maternal Mortality from all Conditions Connected with Childbirth in
the United States and Certain Other Countries, Children's Bureau Publications, no. 19.,
U.S. Dept. of Labor (Washington, D.C.: Government Printing Office, 1917); Woodbury,
(n. 3) Maternal Mortality, pp. 7-16.
326 Journal of the History of Medicine :
Vol. 54, April iggg
deaths. In the 1890s a Midwestern American doctor noted wryly
that it was amazing how many women appeared to have died from
malaria just after having a baby.11
That such strategies accounted for the large majority of hidden
maternal deaths was shown by William Farr and his successors at the
General Register Office in London.12 Like"detectives, they investigated a large sample of women of childbearing age who had died
but whose death certificates did not indicate childbearing. They
uncovered some hidden maternal deaths, mostly deaths recorded as
peritonitis. But shortage of staff made it impossible to investigate all
the deaths in which such a cover-up had occurred. For this reason,
I decided to try to quantify these hidden deaths, starting with peritonitis.
The favorite hiding place for hidden maternal deaths, "Peritonitis
of unstated origin," was a large but rapidly diminishing category of
death. It contained (in round numbers) 23,000 deaths in the 1890s,
3,800 in the 1920s, and only 1,600 in the 1940s. At first sight it
looks as if peritonitis was a deadly nineteenth-century disease which
gradually disappeared, but this is not so, and the explanation is simple.
Although appendicitis and duodenal ulcer were almost certainly common diseases in the nineteenth century, they only became officially
recognized as registerable causes of death in 1902 and 1911, respectively. Both diseases could cause peritonitis. Having no other place
to go, they were placed in "peritonitis of unstated origin" before
1902 and 1911, swelling that category to a great size. After those
dates they were provided with a classification of their own. But for
several years deaths from these surgical diseases continued to gravitate
into "peritonitis" because doctors are slow to change their ways.
Thus the number of deaths in the category "peritonitis of uncertain
origin" gradually withered away, while those in the categories "appendicitis" and "duodenal ulcer" increased. The apparent changes in
incidence were, in fact, changes in the categorization of causes of
death. For those with an interest in the mortalityfromsurgical diseases,
it would be easy to fall into the trap of believing that appendicitis
and duodenal ulcer suddenly increased in the early years of this
century.
11. C.S. Bacon, "The mortality from puerperal infection in Chicago," Am. Gynecol.
Obstet.J., 1896, 8, 426-46, pp. 430-31.
12. Supplement to the Annual Report of the Registrar General (London: Her Majesty's
Stationery Office, 1895). pp. xxii-xxviii.
London : Measurement of Maternal Mortality
327
What does all this have to do with hidden maternal deaths? As it
happens, the causes of death from peritonitis are virtually all more
common in males than females. Therefore, if one expresses female
deaths from peritonitis of unstated origin as a percentage of male
deaths, the result should always be less than 100. If, however, maternal
deaths were hidden in this category, female deaths should increase
proportionately in the ages of childbearing, even to the point where
they exceed male deaths. This is just what I found (Table 4). (The
features shown in Table 4, incidentally, were found in every decade
from the 1880s to the 1940s.)
Further, as Table 4 shows, the highest percentage of female deaths
occurred in the maximum age of childbearing, 25—35 years, as one
would expect if they were maternal deaths in disguise. Above 45-50
years, after childbearing, male deaths outnumbered female deaths. As
the accuracy of death registration improved steadily through the
twentieth century, one would expect the excess of female deaths in
the "peritonitis" category to decrease in number, as it did. Female
deaths due to peritonitis virtually disappeared after 1950.
I carried out a similar exercise with the category "septicemia" (the
common causes of which were much more common in males than
females), but I found little evidence of a substantial number of hidden
deaths.
Returning to peritonitis, if one assumes that' the excess of female
deaths over male in ages 15-44 were hidden deaths due to puerperal
fever, it is easy to quantify them. The number of hidden maternal
deaths was greatest around 1880-1900, and then decreased.
Although I have not uncovered all the hidden maternal deaths,
the work I have done suggests that although some maternal deaths
were hidden, they were too few to cause serious distortion. Further,
such distortion as there was diminished throughout the first half of
this century. At most, if all hidden maternal deaths had been detected
and added to the published figures, the MMR would have been
raised by about 10 percent in the late nineteenth century and considerably less by the 1920s.
There is some indirect evidence that careless and deceitful miscertification caused relatively little distortion of the published rates of
maternal mortality. In Switzerland, death certification was carried
out by specially trained public health officers who had no clinical
responsibility for mothers who died in childbirth and therefore had no
reason to distort the data. If miscertification had seriously understated
oo
79
86
88
98
96
86
74
65
177
87
196
5O-S4
55-59
60-64
65+
in
56
78
72
78
90
165
68
68
203
43
56
7i
67
74
48
47
no
50
39
46
82
81
68
63
106
100
27
28
104
33
75
17
26
12
72
36
63
93
57
H3
23
300
8
14
16
18
6
200
450
100
90
62
100
277
10
400
219
36
9
5
4
9
10
25
290
29
%
86
58
5
2
120
414
12
29
171
39
21
204
136
9
7
10
10
8
4
20
10
336
50
9
85
17
23
20
70
28
304
140
59
144
64
54
108
100
797
795
226
141
152
237
92
189
82
300
630
M
The third columns in each period show the excess of female deaths as a percentage of male deaths, with the excess
being most prominent in the age of childbearing, especially the age groups 25—34. The excess of female deaths in
children under the age of 15 was due to a condition which has now virtually disappeared, "primary pneumococcal
peritonitis" which occurred in female but not in male children before the onset of puberty. It was most common
between the ages of 3 and 13.
45
3O-34
35-39
40-44
38
43
61
133
56
10-14
15-19
20-24
25-29
5-9
40
387
542
129
59
2137
125
%
F
M
F
%
F
1128
152
M
86
56
64
Total
Under i
1-4
Ages
1940-1950
1941-1950
1931-mo
Deaths Recorded in the Reports of the Registrar General as "Peritonitis of Unstated Origin";
Total Deaths for Both Sexes in Certain Age-Groups, and Female Deaths Expressed as a Percentage
of Male Deaths, England and Wales
TABLE 4
London : Measurement of Maternal Mortality
3 29
maternal deaths in other countries, one would have found the Swiss
figures to be unexpectedly high. They were not. They were of the
same order as those in France, Germany, England, and Wales.
What do we learn from all this? You may remember Sam Weller's
story about the charity school boy who, having learned the alphabet,
expressed serious doubts whether it was worth going to so much
trouble to learn so little.13 The same might be felt about this catalogue
of statistical complications and confounding factors. Is their analysis
worth the trouble?
The answer must be that of course it is. The only available measure
of the effectiveness of maternal care in the past is maternal mortality.
Comparisons of maternal care between countries and regions, between doctors and midwives, or home and hospital deliveries, and
between different obstetrical techniques demand an appreciation of
the reliability and the potential sources of error in the published
statistics of maternal mortality. Without such information one is left
with unsubstantiated assertions based on anecdotal evidence. For
demographers, however, I am preaching to the converted.
13. Charles Dickens, The Pickwick Papers (first published London, 1837).