How Increased Contraceptive Use has Reduced Maternal Mortality

9
How Increased Contraceptive Use has Reduced Maternal Mortality John Stover John Ross Published online: 31 July 2009 Ó Springer Science+Business Media, LLC 2009 Abstract It is widely recognized that family planning contributes to reducing maternal mortality by reducing the number of births and, thus, the number of times a woman is exposed to the risk of mortality. Here we show evidence that it also lowers the risk per birth, the maternal mortality ratio (MMR), by preventing high-risk, high-parity births. This study seeks to quantify these contributions to lower maternal mortality as the use of family planning rose over the period from 1990 to 2005. We use estimates from United Nations organizations of MMRs and the total fer- tility rate (TFR) to estimate the number of births averted— and, consequently, the number of maternal deaths directly averted—as the TFR in the developing world dropped. We use data from 146 Demographic and Health Surveys on contraceptive use and the distribution of births by risk factor, as well as special country data sets on the MMR by parity and age, to explore the impacts of contraceptive use on high-risk births and, thus, on the MMR. Over 1 million maternal deaths were averted between 1990 and 2005 because the fertility rate in developing countries declined. Furthermore, by reducing demographically high-risk births in particular, especially high-parity births, family planning reduced the MMR and thus averted additional maternal deaths indirectly. This indirect effect can reduce a county’s MMR by an estimated 450 points during the transition from low to high levels of contraceptive use. Increases in the use of modern contraceptives have made and can continue to make an important contribution to reducing maternal mortality in the developing world. Keywords Family planning Á Birth spacing Á Maternal mortality ratio Introduction Maternal mortality levels remain high in much of the developing world. The decline over the 15 year period from 1990 to 2005 was small—both in terms of the maternal mortality ratio (MMR—the number of maternal deaths per 100,000 live births) and in terms of the absolute numbers of deaths. The MMR declined just 30 points, from 480 in 1990 to 450 in 2005. The absolute number of deaths declined from about 2.91 million in 1990–1995 to about 2.76 million in 2000–2005. General statements of the relationship of women’s health status to family planning recount the sequence of dangers that follow in the train of unintended pregnan- cies—the risks of unsafe abortions, miscarriages, and stillbirths, and the risks of giving birth. As one review states, ‘‘Family planning gives health benefits to the indi- vidual woman by reducing exposure to unwanted preg- nancy, pregnancy complications, unsafe abortions, childbirth complications, and some cancers’’ [1]. The author notes that abortion rates have declined in countries where use of modern contraceptives has increased. The reduction of maternal mortality and high risk births through family planning use was documented in a thorough review in 1984, using international data sets then available [2]. Family planning programs that support increases in the use of modern contraceptives reduce the number of maternal J. Stover (&) Futures Institute, 41A New London Turnpike, Glastonbury, CT 06033, USA e-mail: [email protected] J. Ross Futures Group International, One Thomas Circle, Washington, DC, USA e-mail: [email protected] 123 Matern Child Health J (2010) 14:687–695 DOI 10.1007/s10995-009-0505-y

Transcript of How Increased Contraceptive Use has Reduced Maternal Mortality

Page 1: How Increased Contraceptive Use has Reduced Maternal Mortality

How Increased Contraceptive Use has Reduced MaternalMortality

John Stover Æ John Ross

Published online: 31 July 2009

� Springer Science+Business Media, LLC 2009

Abstract It is widely recognized that family planning

contributes to reducing maternal mortality by reducing the

number of births and, thus, the number of times a woman is

exposed to the risk of mortality. Here we show evidence

that it also lowers the risk per birth, the maternal mortality

ratio (MMR), by preventing high-risk, high-parity births.

This study seeks to quantify these contributions to lower

maternal mortality as the use of family planning rose over

the period from 1990 to 2005. We use estimates from

United Nations organizations of MMRs and the total fer-

tility rate (TFR) to estimate the number of births averted—

and, consequently, the number of maternal deaths directly

averted—as the TFR in the developing world dropped. We

use data from 146 Demographic and Health Surveys on

contraceptive use and the distribution of births by risk

factor, as well as special country data sets on the MMR by

parity and age, to explore the impacts of contraceptive use

on high-risk births and, thus, on the MMR. Over 1 million

maternal deaths were averted between 1990 and 2005

because the fertility rate in developing countries declined.

Furthermore, by reducing demographically high-risk births

in particular, especially high-parity births, family planning

reduced the MMR and thus averted additional maternal

deaths indirectly. This indirect effect can reduce a county’s

MMR by an estimated 450 points during the transition

from low to high levels of contraceptive use. Increases in

the use of modern contraceptives have made and can

continue to make an important contribution to reducing

maternal mortality in the developing world.

Keywords Family planning � Birth spacing �Maternal mortality ratio

Introduction

Maternal mortality levels remain high in much of the

developing world. The decline over the 15 year period

from 1990 to 2005 was small—both in terms of the

maternal mortality ratio (MMR—the number of maternal

deaths per 100,000 live births) and in terms of the absolute

numbers of deaths. The MMR declined just 30 points, from

480 in 1990 to 450 in 2005. The absolute number of deaths

declined from about 2.91 million in 1990–1995 to about

2.76 million in 2000–2005.

General statements of the relationship of women’s

health status to family planning recount the sequence of

dangers that follow in the train of unintended pregnan-

cies—the risks of unsafe abortions, miscarriages, and

stillbirths, and the risks of giving birth. As one review

states, ‘‘Family planning gives health benefits to the indi-

vidual woman by reducing exposure to unwanted preg-

nancy, pregnancy complications, unsafe abortions,

childbirth complications, and some cancers’’ [1]. The

author notes that abortion rates have declined in countries

where use of modern contraceptives has increased. The

reduction of maternal mortality and high risk births through

family planning use was documented in a thorough review

in 1984, using international data sets then available [2].

Family planning programs that support increases in the

use of modern contraceptives reduce the number of maternal

J. Stover (&)

Futures Institute, 41A New London Turnpike, Glastonbury,

CT 06033, USA

e-mail: [email protected]

J. Ross

Futures Group International, One Thomas Circle, Washington,

DC, USA

e-mail: [email protected]

123

Matern Child Health J (2010) 14:687–695

DOI 10.1007/s10995-009-0505-y

Page 2: How Increased Contraceptive Use has Reduced Maternal Mortality

deaths in two ways [3]. The more direct effect comes from

the reduction in the number of births that occurs as contra-

ceptive use increases. With fewer births, a woman’s risk of

maternal death is lower, and the total number of deaths is

fewer. Increasing contraceptive use may also have an indi-

rect effect on the MMR. By averting high-risk births in

particular, rising contraceptive use reduces the average risk

of mortality associated with each birth [3]. This article

considers both effects and estimates their magnitude. Fur-

thermore (although not examined here), by reducing the

number of unintended pregnancies, contraception also can

reduce the number of abortions, which can carry a high

mortality risk when performed unsafely.

Estimating the direct effect of family planning—that is,

reducing the number of births and, thus, maternal deaths—

is relatively straightforward. In contrast, estimating the

indirect effect—that due to the preferential avoidance of

high-risk births—requires data that report maternal mor-

tality by parity and age. The literature that bears directly

upon the age and parity differentials of maternal mortality

is not extensive. Data sets must be large to yield enough

maternal deaths to permit separation into age and parity

categories. Such large data sets are uncommon.

Nevertheless, the basic differentials of mortality risk by

age and parity are relatively well established.1 As early as

1971 Berelson [4] published mortality differentials show-

ing elevated rates at higher ages and birth orders. He

estimated that, if births occurred only at ages 18–35 in the

developing world, maternal mortality might decline by as

much as 20%. A related technical review by Dorothy

Nortman [5] examined historical data (mid-1960s) from 42

countries with reasonably good data, in Europe, North

America, Latin America, and Asia, and found the classic

J-shaped pattern of mortality by age in each of three sub-sets

of countries with high, medium, and low levels of average

risk. For example, New York State data2 for 1936–1938

show sharply rising risk with age. Nortman observed, ‘‘If

women had births only in the age interval 20–34, maternal

mortality would come down by 19% in Mexico, Thailand,

Venezuela, and the United States; by 23% in Colombia and

France; and by 25% in the Philippines’’ [5]. An unusual

series of maternal mortality ratios recorded from 1954 to

1996 in Sri Lanka [6] shows the rising risk of death with

age, a pattern that persisted even as the overall risk

declined from a historic high level in 1947 of over 1000 to

only 24 by 1996. During part of that period the percentage

of married couples using contraception rose to 68%.

National survey data in Bangladesh [7] also show much

higher risks at older ages. Smaller studies in Honduras ([8],

see also footnote no.3), Guatemala (Edgar Kestler with

data for Guatemala and Honduras, personal communica-

tion), and Burkina Faso [9] show similar gradients.

Evidence is scarcer for parity differentials, but the

studies mentioned for New York State (1936–1938), Ban-

gladesh, Honduras, and Guatemala show increased MMRs

as parity rises from two to five and higher. All but Gua-

temala show higher mortality at parity one than at parity

two and the lowest risk at parity 2. Meanwhile, contra-

ceptive use levels have risen to 43% in Guatemala and 65%

in Honduras but to only 14% in Burkina Faso [10].

Methods and Materials

International information on numbers of deaths and on

MMRs have been compiled for 1990, 1995, 2000, and 2005

[11–14]. The most recent estimates, for 2005, also include

a re-estimation of the MMR in 1990. A comparison shows

that, in the developing world, the MMR declined from 480

in 1990 to 450 in 2005.

No national data sets exist for MMRs by both mother’s

age and parity, but. as noted, we located five data sets for

parity-specific MMRs—from Bangladesh [15], Honduras,3

Guatemala,4 Burkina Faso [9], and Sri Lanka [6]—and 13

data sets for age-specific MMRs as well as the MMRs by

age for 42 countries in Nortman’s 1974 compilation [5].

We use data from Demographic and Health Surveys (DHS)

[16] on contraceptive use and the distribution of births by

risk factor. This data set contains 146 surveys from 68

countries: 33 from sub-Saharan Africa, 13 from Latin

America and the Caribbean, 10 from Asia, 6 from North

Africa and the Middle East, and 6 from Eastern Europe.

We use these data to conduct three separate analyses.

First, we look at the direct effect by estimating the number of

maternal deaths that would have occurred if fertility had not

declined between 1990 and 2005 and if the MMR had not

declined. To do this, we use a demographic projection model

[17] to estimate the number of births that would have

occurred if fertility had not fallen between 1990 and 2005.

We apply the 1990 MMR to those births to calculate the

number of maternal deaths averted by the decline in fertility.

1 Differentials by birth intervals, rather than age and parity, are

reviewed in World Health Organization. Department of Making

Pregnancy Safer (MPS) and Department of Reproductive Health and

Research (RHR). Report of a WHO technical consultation on birth

spacing, Geneva, Switzerland, 13–15 June 2005. ‘‘After a live birth,

the recommended interval before attempting the next pregnancy is at

least 24 months in order to reduce the risk of adverse maternal,

perinatal, and infant outcomes.’’ (Note that this produces a birth

interval of 33 months.)2 Excluding New York City.

3 1997 RAMOS study and 2001 Honduras Reproductive Health

Survey (ENESF – Encuesta Nacional de Epidemiologia y Salud

Familiar).4 2000 mortalidad materna segun paridad, courtesy of Edgar Kestler.

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We attribute most of the historic fertility decline to

rising contraceptive use. Among the four primary deter-

minants of fertility identified by Bongaarts, contraceptive

use is the most important to bring fertility down into a low

range [18]. Fertility can decline also from increased abor-

tion, increased breastfeeding, or increased age at marriage.

For abortion the trends are unclear, and we have no reliable

estimate for the developing world as a whole. However, the

abortion rate and the numbers of abortions tend to decline

as rising contraceptive use prevents more unwanted preg-

nancies. Regarding breastfeeding, surveys indicate that the

international trend has been a mix of increases and

decreases, with the net balance being little change. Age at

marriage has risen in most of the developing world but

many unmarried women, especially in sub-Saharan Africa

and Latin America, are users of contraception. This further

dilutes the connection of later marriage to fertility declines.

Data from 135 DHS surveys show that the TFR is highly

correlated with contraceptive use, with an R2 correlation of

0.76 (0.73 between the general fertility rate and the CPR, and

0.69 between the crude birth rate and the CPR). A 10-point

rise in the percentage using contraception is accompanied by

a TFR decline of over half a birth (0.58). Compared with

contraceptive use, change in the percentage married has a

trivial effect in the correlations below. Therefore, we focus

the first part of the analysis on changes in TFR and assume

that changes in the CPR are the major influence.

Crude birth rate General fertility rate

Slope

(beta)

Significance

level

Slope

(beta)

Significance

level

% contracepting -0.33 0.00001 -1.94 0.00001

% married -0.02 0.71 0.0028 0.99

To assess the indirect effect, in a two-stage analysis we

look first at the relationship at the country level between

contraceptive use and demographically high-risk births,

and then at the relationship between demographically high-

risk births and the MMR. It has been shown that births that

are spaced too closely (less than 24 months apart), mothers

giving birth at too young an age (under 18) or too old an

age (35 and over), and high-parity births (parity 4 and

higher) pose an elevated risk of infant and child mortality

[19]. We examine whether these same risk factors also

affect maternal mortality. There is, for example, supportive

evidence from Bangladesh [20]: Matlab data for more than

20,000 births in 1968–1970 show the classic J-shaped

curve for the MMR, with the highest rates at ages 10–19

and 40–44 and, similarly, high rates at birth orders one and

at seven and above. Additional evidence appears below.

To capture all high-risk births, we employ the DHS

variable ‘‘any risk,’’ which includes all births except first

births and births free of the four specific risks named just

above. Births with ‘‘any risk’’ vary from a low of 25% in

Viet Nam in 2002 to a high of 79% in Yemen in 1991–

1992. In the first stage of analysis, we use time trends for

data from countries with more than one survey to compare

the change in the percentage of all births with any demo-

graphic risk with the change in the percentage of women of

reproductive age using contraception (CPR). In the second

stage of the analysis, we look at the relationship between

the percentage of births with a demographic risk and the

MMR. Country-specific estimates of the MMR do not have

enough precision to measure changes over the short periods

between surveys, so we used a cross-section analysis to

compare the levels of MMR with the levels of at-risk

births. We use this two-stage process to relate CPR to

MMR, rather than analyze the direct relationship between

the two, in order to control for social, cultural, and eco-

nomic differences among countries and to focus on a key

pathway by which contraceptive use affects the MMR.

In our third stage of analysis, we used data on variations

in MMR by maternal age and parity to estimate the

expected changes in the MMR if these patterns remained

the same but increasing contraceptive use modified the

distribution of births by age and parity. Data on the rela-

tionship of contraceptive use to this distribution of births

come from the DHS.

Results

Direct Effect Due to Reduced Numbers of Births

According to the United Nations Population Division [21],

the total fertility rate in all developing countries declined

from 3.63 births per woman in 1990 to 2.83 in 2005. The

declining fertility rate countered by the rising numbers of

women of reproductive age meant that the annual number

of births remained roughly constant at about 122 million

from 1990 to 2005. Applying the MMRs of 480 for 1990

and 450 for 2005 to 122 million births annually suggests

that the annual number of maternal deaths declined

slightly, from 588,000 in 1990 to 550,000 in 2005.

As noted above, if there had been no change in the level

of contraceptive use,5 the TFR would have remained

5 For the developing world, weighting country CPRs by population

size, approximately 53% of married/in-union women (or spouses)

were using contraception in 1990, and approximately 61%, in 2005.

Sources: UN Population Division. (1996) Levels and tends of

contraceptive use as assessed in 1994. New York: United Nations.

Also Carl Haub, C. and Kent, M. 2008 world population data sheet.

Washington, DC: Population Reference Bureau. The 2008 data sheet

figure is based on surveys of earlier dates and approximates the 2005

level of use.

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roughly constant from 1990 to 2005. In that case the annual

number of births would have risen to 157 million by 2005,

and the number of maternal deaths in 2005 would have

been 705,000—155,000 more maternal deaths than the

actual 2005 estimate. For the 15-year period 1990–2005,

the drop in TFR resulted in an estimated 1.2 million fewer

maternal deaths (9.73 - 8.50; see Table 1).

If the MMR had remained rather constant over this 15-

year period, there would have been 370,000 more maternal

deaths (8.87 - 8.50). Thus, the combined effect of changes

in both TFR and MMR was 1.5 million fewer maternal

deaths between 1990 and 2005 (10.04 - 8.50).

Indirect Effect Due to Lower Proportion

of Births at High Risk

The relationship between changes in CPR and changes in

the percentage of births with any risk factor within coun-

tries over time is shown in Fig. 1. The data clearly show

that the distribution of births by risk factor changes as the

use of family planning changes. The average slope of all

the survey pairs is -0.55. This means that, for each 10

percentage point increase in CPR, the percentage of births

with any risk drops by 5.5.

At low levels of contraceptive prevalence, around 70%

of all births will have one or more of the demographic risk

factors. As prevalence increases toward 80%, the percent-

age of births with any risk drops to nearly 35%. The main

cause of this drop is the virtual elimination of high-parity

births and births with multiple risk factors, such as high

age/high parity. At very low levels of contraceptive use,

about half of all births are parity 4 and higher. As con-

traceptive use increases to 80%, this fraction shrinks to

almost nothing.

Figure 2 shows the relationship that results from

ordering all the DHS data sets from lowest CPR to highest

and smoothing the curves across surveys. As high-parity

births decline, the share of no-risk births rises, and the

share of first births rises steadily as well. Most of the risk

categories decline accordingly. There is rather little change

Table 1 Estimated number of maternal deaths (in millions) in low-

and middle-income countries under alternative scenarios

Period Actual Constant

TFR

Constant

MMR

Both TFR and

MMR constant

1990–1995 2.91 3.04 2.93 3.07

1995–2000 2.83 3.26 2.91 3.36

2000–2005 2.76 3.43 2.91 3.61

1990–2005 8.50 9.73 8.87 10.04

35

45

55

65

75

85

700 10 20 30 40 50 60 80

Contraceptive Prevalence

Per

cen

t o

f B

irth

s w

ith

An

y R

isk

Fig. 1 The relationship between changes in contraceptive use and

changes in the percentage of births with any demographic risk (36

countries with multiple DHS surveys)

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80

Percent of Births

Contraceptive Prevalence

Short/manyOld/short/manyOld/manyOld/shortYoung/shortManyShortOldYoungFirst birth No Risk

Fig. 2 The smoothed pattern in

the distribution of births by

contraceptive prevalence.

Source: demographic and health

surveys

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in the share of short interval births since many young

couples wish to have one to three children early in their

marriage and then stop.

The cross-section comparison of the percentage of births

with any risk, on one hand, and the estimated MMR for the

date closest to the date of the DHS, on the other, is shown

in Fig. 3. To adjust the relationship for economic and

social factors, we included two control variables in the

regression analysis: female primary school enrollment and

the Gross National Income per capita expressed in pur-

chasing power parity (data from World Bank sources). The

results are shown in Table 2. The coefficient of 11.3 on

high-risk births means that, for each reduction of 10 per-

centage points in the percentage of births with a demo-

graphic risk, the MMR falls by 113 points.

Using both stages of this analysis, we can estimate the

full effects of contraceptive use on the percentage of births

that are high risk and then on the MMR. As a country

transitions from a very low CPR to a high CPR, the per-

centage of births at risk can be expected to drop from

around 75% to nearly 35% (see Fig. 1). As a result of this

change in the percentage of births at high risk, the MMR

can be expected to drop by about 450 points (40 percentage

point decline in high-risk births multiplied by the regres-

sion coefficient of 11.3)—a change due entirely to the

effects of contraceptive use.

Country-Specific Patterns of MMR by Parity

The most important impact of increasing contraceptive use

on at-risk births is the reduction in high-parity births.

Figure 4 shows the relationship between MMR and parity

for four locations: Bangladesh, Guatemala, Honduras, and

New York State (1936–1938) in the United States. The

patterns are similar, except that Bangladesh has such a high

risk at parity 1 that the risks at all other parities are lower.

The elevated MMR at parities 5 and above is important

because, across all the DHS data sets used here, 29% of

births are in this category. Even a partial shift away from

0

200

400

600

800

1000

1200

1400

1600

1800

2000

30 35 40 45 50 55 60 65 70 75 80

% of Births in Any Risk Category

MM

R

Fig. 3 Relationship of the MMR to the percentage of births in any

risk category

Table 2 Regression results to

estimate the MMR

* PPP purchasing power parity

Variable Coefficient Range of coefficient P value

Intercept 202.664 -521, 926 0.578

GNP PPP* per capita -0.067 -0.095, -0.039 0.000

Female primary school enrollment -0.313 -3.973, 3.347 0.865

% births with any risk 11.319 2.108, 20.530 0.017

0

1

2

3

4

1 2 3 4 5+

Ratio of MMR to MMR at Parity 1

Parity

BangladeshHondurasGuatemalaNY State 193638

Fig. 4 The relationship between the MMR and parity, with MMR

values normalized to 1 at parity 1

Table 3 MMR by parity for Honduras, showing current values and

illustrative estimated values for lower and higher levels of contra-

ceptive prevalence

Parity Resulting

MMR1 2 3 4 5?

MMR by parity 62 56 91 77 183

% of births 25% 21% 15% 11% 28% 101

% births if CPR = 10% 20% 17% 12% 14% 36% 110

% births if CPR = 70% 37% 31% 22% 3% 7% 76

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these highest parity births can lead to important reduction

in the overall MMR.

Table 3 illustrates this effect using the Honduras set of

MMR values.6 Some 39% of births are high parity—11%

are parity 4 and 28% are parity 5 or higher. Judging by the

patterns in Fig. 2, 50% of births would be high parity (4?)

if contraceptive prevalence were only 10%, and just 10%

would be high parity if contraceptive use were 70%. If

these illustrative birth distributions applied to the pattern of

MMR by parity in Honduras, the MMR for all births would

fall from 110 at 10% contraceptive use to 76 at 70%—a

drop of 31%.

The 39% of births in Honduras that currently are at

parity 4 or higher is similar to the average percentage

across all DHS data sets, as are the other percents shown.

Thus, increasing contraceptive use from the historically

low levels to a high level in all developing countries par-

allels a 31% decrease in the overall MMR (down from 110

to 76).

The effect of changing parity distributions on the MMR

can also be seen by examining recent trends in DHS data

on births by parity. For 46 countries with DHS data

available from multiple surveys, we calculated the change

in the parity distribution of births between the earliest and

latest surveys. By applying a fixed schedule of MMR by

parity (using the Honduras schedule in Table 3) to these

parity distributions, we calculated how the MMR changed

solely because of the way that the parity distribution

changed. The results—expressed as the expected decline in

a 10-year period—show small increases in MMR for six

5 0 5 10 15 20 25 30 35 40

Mozambique 1997-03Chad 1996-04

Guinea 1999-05Uganda 1988-06

Kazakhstan 1995-99Ethiopia 2000-05

Niger 1992-06Eritrea 1995-02

Mali 1987-01Burkina Faso 1992-03

Togo 1988-98Nigeria 1990-03

Tanzania 1992-04Rwanda 1992-05Zambia 1992-01Ghana 1988-03

Senegal 1986-05Cameroon 1991-04

Bangladesh 1993-04Guatemala 1987-98

Bolivia 1989-03Madagascar 1992-04

India 1992-98Armenia 2000-05

Haiti 1994-05DR 1986-02

Philippines 1993-03Benin 1996-01

Colombia 1986-05Indonesia 1987-03

Turkey 1993-98Malawi 1992-04Kenya 1989-03

Nicaragua 1997-01Peru 1986-00

Zimbabwe 1988-06Jordan 1990-02

Namibia 1992-00Yemen 1991-97

Nepal 1996-06Egypt 1988-05Brazil 1986-96

Cote d'Ivoire 1994-98Vietnam 1997-02

Cambodia 2000-05Morocco 1987-03

Percent Decline in MMR

Fig. 5 Percentage declines in MMRs expected over a 10 year period due to improved parity distributions of births using a fixed (Honduras)

schedule of MMR by parity

-20

-10

0

10

20

30

40

50

-10 0 10 20 30 40 50

Percent Decline in Deaths

Percent Decline in Births

Fig. 6 Comparison of the expected percentage declines in deaths and

in births due to changes in the parity distribution of births between

earliest and latest DHS

6 Parity data and MMR from a survey published in 1997. In 2001 the

CPR in Honduras was 62 (65% in 2005).

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countries and declines for 40 countries, with an average of

7.3% and ranging up to more than 35% (see Fig. 5). These

are reasonably impressive declines, achieved only by

changing the distribution of births by parity. Actual

declines in MMRs can be larger where health system

improvements have lowered the parity-specific risks.

Another way to look at the same phenomenon is to

compare the change in numbers of births that is expected as

the parity distribution changes with the change in the

numbers of maternal deaths. When women begin to have

fewer births, logically the higher parity births, with their

especially elevated risks, are eliminated first. As a result,

the percentage decline in deaths should exceed the per-

centage decline in births. Indeed, that occurs in almost all

countries (see Fig. 6). Most countries lie above the diag-

onal line, meaning that the shift in parity distributions

would cause the number of maternal deaths to fall more

than the number of births would fall. The result is a drop in

the overall MMR.

Finally, regarding mortality patterns by age rather than

by parity, we compiled the schedules of MMR by the age

of the mother at the time of birth from the few examples

available (see Fig. 7 and Appendix 1). The risk at ages

above 35 is at least double that at ages 20–24 in most

data sets. In fact, in half of the data sets the risk rises to

4.5–8 times higher. We conducted analyses parallel to

those above—for the impact on mortality of changing age

distributions of births between two surveys—and found the

impacts to be much smaller than those for changing parity

distributions. The reasons are two-fold. First, as contra-

ceptive use increases, the changes in age distribution are

much less than changes in parity distribution. Second,

births at older ages are always relatively few, whereas

births at the higher parities are numerous, many occurring

at younger ages, before contraceptive use starts to rise from

low levels.

Conclusion

This article has explored the effects that increasing con-

traceptive use has had on maternal mortality. The direct

effects are clear and large. The drop in the TFR from 1990

to 2005, due primarily to increasing contraceptive use,

resulted in 1.2 million fewer maternal deaths—15% fewer

than would have occurred with no fertility decline. These

1.2 million additional deaths averted between 1990 and

2005 can be added to those that were already being averted

by the level of contraceptive use in 1990. Future increases

in contraceptive use will further reduce women’s exposure

to the risks associated with pregnancy and will keep many

more mothers alive.

There is strong evidence that contraceptive use also

affects the maternal mortality rate. Time-series survey data

show a clear pattern of smaller percentages of high-risk

births as contraceptive use increases. The greatest effect is

the reduction of high-parity births, which are virtually

eliminated at high levels of contraceptive use. Cross-

national data show that the MMR is highly correlated with

the percentage of high-risk births, even with controls for

differences in economic and social conditions. In addition,

declines in maternal deaths are greater than the corre-

sponding declines in births in nearly all countries, due to

the selective effect of increasing contraceptive use averting

6

7

8

9

Ratio of maternal mortality at each age to

maternal mortalityat 20-24

Bangladesh

Honduras

Guatemala

Burkina Faso

Nortman Low

0

1

2

3

4

5

15-19 20-24 25-29 30-34 35-39 40-49

Nortman Medium

Nortman High

Sri Lanka 1954

Sri Lanka 1960

Sri Lanka 1970

Sri Lanka 1980

Sri Lanka 1996

NY State 1936-38

Fig. 7 Age-specific MMR

values in relation to the MMR at

ages 20–24

Matern Child Health J (2010) 14:687–695 693

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the high-parity/high-risk births first. Together, all this

evidence suggests that the reduction in high-risk births

brought about by contraceptive use lowers the MMR.

Other interventions also reduce maternal mortality by

directly addressing the medical causes of maternal mor-

tality—primarily severe bleeding, infection, abortion

complications, hypertensive disorders such as pre-

eclampsia and eclampsia, and obstructed labor—through

better and more widely available prenatal care and emer-

gency obstetric services. Clearly, there is a need to improve

the coverage and quality of all safe motherhood services to

save as many women’s lives as possible. This paper has

tried to bring attention to the role that family planning can

play in the broader effort to reduce maternal mortality in

developing countries—not only through a reduction in the

number of births but also through a reduction in the MMR

as a result of better distributions of births to lower risk

categories, primarily lower parities.

Acknowledgments Thanks to Mary Ellen Stanton and Marge

Koblinsky for their assistance in identifying relevant literature and

data sources and to Jacqueline Bell for providing data for Burkina

Faso, Kim Streatfield for Bangladesh, and Edgar Kestler for Guate-

mala and Honduras. This research was funded by the U.S. Agency for

International Development (USAID) | Health Policy Initiative, Task

Order 1. The views expressed do not necessarily reflect the views of

USAID or the U.S. Government.

Appendix I

See Table 4.

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Table 4 MMR values and patterns, by age

MMR by age

15–19 20–24 25–29 30–34 35–39 40–49

Bangladesh 170 237 358 516 492 2000

Honduras 76 74 75 144 207 263

Guatemala 110 107 122 185 280 436

Burkina Faso 317 271 487 601 714 1262

Nortman low 13 12 16 31 65 99

Nortman medium 34 34 41 70 136 200

Nortman high 134 91 119 192 289 434

Sri Lanka 1954 440 365 370 500 800 900

Sri Lanka 1960 250 260 250 300 450 650

Sri Lanka 1970 95 100 140 150 225 230

Sri Lanka 1980 50 40 50 60 160 110

Sri Lanka 1996 20 20 20 20 25 90

NY State 1936–1938 156 166 234 329 499 747

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20. Chen, L. C., Gesche, C. M., Ahmed, S., Chowdhury, A. I., &

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