The Role of Delayed
Childbearing and Obstetric
Interventions in the Prevention
of Obstetric Fistula
Amy Tsui, Andreea Creanga, and Saifuddin Ahmed
The Gates Institute
Johns Hopkins Bloomberg School of Public Health
July 30, 2005
Questions addressed
z
What impact will
z
z
z
have on the incidence of obstetric fistulas?
What is the relative association of risk factors with
the likelihood of prolonged labor?
z
•
Delaying the age of childbearing
Delaying the start of childbearing
Analysis based on national population survey data for
Niger (1998), Nigeria (1999) and Tanzania (1999)
Proxy measure of prolonged labor with stillbirth
outcome
1
Initiation of Sexual Activity by Age 20 and
Marital Context among Women Aged 20-24:
Three Sub-Saharan African Countries
100
90
80
70
% sexually
60
active before 50
40
age 20
30
20
10
0
Niger
1998
All
Nigeria Tanzania Burkina Mali 1996
1999
1999
Faso
1999
Before marriage
Within marriage
Source: United Nations, World Population Monitoring 2002.
Commonly cited characteristics of
obstetric fistula cases in research
literature
z
Parity 1 (primagravida)
z
z
z
z
z
55% of 1178 cases over 2 year period (Muleta, 1997)
45.8% of 932 cases over 7 years (Wall et al., 2004)
42.7% of 150 cases over 5 years (Danso et al., 2006)
82% of 31 cases (Ibrahim et al., 2000)
Prolonged/obstructed labor
z
z
z
62.5% with 3 days labor (Muleta, 1997)
75.9% of 241 cases over 2 year period (Ampofo et al., 1990)
38% of 42 births (Wall et al., 2002)
z
Short stature (Height <145 cm)
z
Stillbirth or neonatal death
z
z
z
z
51.9% of 241 cases < 150 cm (Ampofo et al., 1990)
91.7% stillbirth and 1.5% neonatal mortality of 932 cases (Wall et al., 2004)
87% stillbirth of 31 cases (Ibrahim et al., 2000)
Young age at fistula occurrence
•
•
•
•
58.8% before age 15 (Ampofo et al., 1990)
60% 13-15 years (Ibrahim et al., 2000)
4.5-5.5% before age 20 (Melah et al., 2003)
21.3% before age 20 (Danso et al., 1996)
2
Malnutrition
Poverty
Illiteracy
Early marriage
Childbearing before pelvic growth is complete
Relatively
large fetus or
malpresentation
Cephalopelvic disproportion
Lack of emergency
obstetric services
Obstructed labor
Harmful
traditional
practices
Fetal death
Fistula formation
Other outcomes related to
obstructed labor injury complex
Other physical
compromises
Social
compromises
Adapted from Worldwide Fistula Fund, “The Obstetric Fistula Pathway”
Malnutrition
Poverty
Illiteracy
Early marriage
Childbearing before pelvic growth is complete
Relatively
large fetus or
malpresentation
Cephalopelvic disproportion
Lack of emergency
obstetric services
Obstructed labor
Harmful
traditional
practices
Fetal death
Fistula formation
Other outcomes related to
obstructed labor injury complex
Other physical
compromises
Social
compromises
Adapted from Worldwide Fistula Fund, “The Obstetric Fistula Pathway”
3
Clinical expert-based estimation of
progression of prolonged labor to
stillbirth and obstetric fistula
development in high-risk SSA countries
Still birth
20-30%
20% Prolonged
labor
(> 12 hours)
Obstructed
labor
80-90%
Fistula
development
20%
.20 x .25 x .20= .001, or 1 per 1,000 deliveries
Danso et al., 1996: 1 per 1,000 deliveries over 5 years in Ghana
Harrison: 3.5 per 1,000 deliveries over 3.5 years in Zaria
Percent of births in past 5 years with
prolonged labor* reported by maternal age:
Three Sub-Saharan African countries,
1998-1999 (*prolonged labor = > 12 hours)
60
50
40
30
20
10
0
<15
15
16
17
18
19
2024
2529
3034
3539
4044
4549
Maternal age
Niger
Tanzania
Nigeria
All 3
4
Percent of births in past 5 years with
reported prolonged labor* by birth order:
Three Sub-Saharan African countries,
1998-1999 (*prolonged labor = > 12 hours)
35
30
25
20
15
10
1
2
3
4
5
6
7
8
9
10+
Birth order
Niger
Tanzania
Nigeria
All 3
Estimates of Stillbirth and Neonatal
Mortality Rates in Three Sub-Saharan
African Countries
Still birth rates
(per 1000
deliveries and
95% CI)
Neonatal
mortality rates
(per 1000 live
births)
% of neonatal
deaths where
labor was
prolonged
Niger
37.6 (29.0-51.3)
39.2
34.7
Nigeria
29.1 (22.0-38.4)
36.6
35.2
Tanzania
29.3 (21.9-39.1)
43.9
26.0
Country
Source: Stillbirth rates from C. Stanton; other estimates from DHS calculations.
5
Multivariate Logistic Regression of
Likelihood of Prolonged Labor
z
Focus on association with woman’s primagravid
status and age ≤ 19
z
z
z
Other maternal physical covariates
z
z
z
Birth order: 1, 2-5, 6+
Age group: ≤ 19, 20-34, ≥ 35
BMI < 18.5 kg/m2
Height <145 cm
Other maternal covariates
z
z
z
Education
Region
Size of place of residence
Results from Logistic Regression of
Prolonged Labor on Parity 1 and Young
Age for Three SSA Countries
Country
Crude OR
Adjusted OR
95% CI
p
Parity 1
1.42
1.58
1.26, 1.97
0.000
Age ≤ 19
1.13
0.90
0.72, 1.13
ns
Parity 1
1.50
1.53
1.16, 2.02
0.003
Age ≤ 19
1.20
1.05
0.79, 1.39
ns
Parity 1
2.04
2.11
1.73, 2.56
0.000
Age ≤ 19
1.54
0.95
0.75, 1.20
ns
Niger (n=4,714)
Nigeria
Tanzania
6
Simulated Proportions of Recent Births
with Prolonged Labor if All Mothers
Primagravids or at Parity 6+
Simulated percentages of PL
Country
No. of
recent
births
(last 5
yrs)
% of births
with
prolonged
labor
If all
births
to
primagravid
women
% point
change
If all
births to
women
parity 6+
% point
change
Nigeria
2616*
18.9
23.8
+4.9
18.5
+0.4
Niger
4714
28.2
34.2
+6.0
28.3
+0.1
Tanzania
6356
19.8
30.6
+10.8
16.8
+2.9
*About 800 cases missing either or both maternal height and weight
Indirect Estimation of Annual
Incidence of Obstetric Fistulas
z
Estimate % of recent births where prolonged labor
(>12 hours) reported, by maternal age/birth order
group
z
z
Estimate % of prolonged labor cases ending in
stillbirth by age/birth order group
z
z
z
z
22% across 3 selected countries
Pr(PL|SB)=0.016
Based on Nigeria DHS (n=3,551 births in past 5 years)
Apply to estimated number of births by age/birth
order group
Derive number of cases with obstetric fistula
potential by age and birth order group
7
Percent of difficult child deliveries in past 5 years
ending in stillbirth by parity: Nigeria 1999
0.04
0.035
0.03
0.025
0.02
0.015
0.01
0.005
0
1
2
3
4
5
6
7
8
9
10+
Birth order
Simulation of Potential Obstetric Fistulas
Prevented in Three Sub-Saharan African
Countries: Nigeria (1999) Example
Age
Annual
number of
births
Incidence of
prolonged
labor
% prolonged # of prolonged
labor cases
labor ending
ending
in still
in still birth
<15
51,171
16,631
.016
266
15
51,171
11,514
.016
184
16
97,225
24,306
.016
389
17
149,675
30,703
.016
491
18
198,288
40,937
.016
655
19
244,342
51,171
.016
819
Total <20
791,874
175,261
.016
2,804
Total 15-49
4,819,502
950,211
.005-.016
11,849
births
8
Estimated Potential for Annual Obstetric
Fistulas in Three SSA Countries: Age
Annual
number of
births
Incidence of
prolonged
labor
% prolonged
labor ending
in still birth
# of prolonged
labor cases
ending in still
births
15-19
143,208
42,913
.016
687
15-49
656,135
185,931
.005-.016
2,344
13-19
791,874
175,261
.016
2,804
13-49
4,819,502
950,211
.005-.016
11,849
15-19
304,560
80,007
.016
1,280
15-49
1,691,912
335,556
.005-.016
4,420
Country/
Age
Niger
Nigeria
Tanzania
Estimated Potential for Annual Obstetric
Fistulas in Three SSA Countries: Parity
Annual
number of
births
Incidence of
prolonged
labor
Primagravid
119,428
39,531
All parities
656,135
183,268
Primagravid
1,007,060
249,751
All parities
4,819,502
939,803
Country
% prolonged
labor ending
in still birth
# of
prolonged
labor cases
ending in still
births
%
primagravid
Niger
.016
632
2,932
21.6
Nigeria
.016
3,996
15,211
26.3
Tanzania
Primagravid
All parities
360,648
80,007
1,691,912
335,556
.016
1,708
5,342
32.0
9
Summary of findings
z
High % of prolonged labor concentrated in women
at parity 1 or < age 20
z
z
z
Relative risk of OL with SB is 1.6 per 1000
pregnancies in Nigeria
z
z
z
RR for 1st birth ranges from 1.53 to 2.11 compared to 2-5th
birth
Point of opportunity for social and public health intervention
Comparable to other clinical case research
Estimated cases with high OF potential in 3 countries
z 6,326 for 1st birth
z 23,485 total
Need replication with pooled DHS data with
maternity indicators
Implied public health interventions to
prevent and manage obstetric fistula
z
z
z
Improve childhood nutrition, especially for preadolescent girls
Pre-nuptial family life counseling
Delay first birth/delivery
z
z
z
z
Delay marriage (where marital status mediates sexual
activity)
Promote contraceptive use prior to 1st birth among very
young women
Improve access to safe abortion
Increase access to emergency obstetric services
10
Percent of births in past 5 years delivered
at home by maternal age group: Three SubSaharan African countries, 1998-1999
100
90
80
70
60
50
40
15-19
20-24
25-29
30-34
35-39
40-44
Maternal age group
Niger
Tanzania
Nigeria
Grounds on which abortion is
permitted in selected countries
Country
Save the
woman’s
life
Preserve
physical
health
Preserve
mental
health
Rape
or
incest
Foetal
impairment
Economic
or social
reasons
On
request
Ethiopia
Malawi
Niger
Nigeria
Tanzania
Source: United Nations, World Population Monitoring 2002
11
Contraceptive Prevalence and Unmet Need
among Female Adolescents (15-19 Years)
in Selected Sub-Saharan African Countries
45
40
35
30
25
20
15
10
5
0
Ethiopia
2000
Malawi
2000
All methods
Niger
1998
Nigeria
1999
Modern methods
Tanzania
1999
Unmet need
Source: United Nations, World Population Monitoring, 2002
Thank you.
12