Wing Ta m (Alice) [627642]

Wing Ta m (Alice)
Jennifer Cheng
Stat 157 course project
More Risk in Everyday Life

49. INFANT MORTALITY RATE

LIKELIHOOD
of exposure to hazardous levels

Consequences:
Severity, num ber of victim s

Low Medium High Risk Meter

Infant mor tality rate is defined as the death of an infa nt before his or her first birthday.
It is a useful indicato r on the nation’s health because it is often associated w ith othe r health
factors such as m aternal health, qu ality and acc essibility of medical care, and socioe conom ic
conditions. The leading causes of infant m ortality are dehydration, disease, congenital
malformation, infection, drugs and alcohol, sudde n infant death syndrom e. Other causes and
factors that contribute to infant m ortality are p renatal care, mother’s m arital status, social and
incom e statu s, poverty, race, sm oking and substa nce abuse, air pollution and environ mental
factors.
Infant m ortality rate is d efined as the nu mber of newborns dying under a year div ided by
the num ber of live births during a year and m easur es the rate of infant mortality. It is often
referred to as the infant death ra te. Infant m ortality rate has droppe d sig nificantly in the W est due
to recent healthcare and sanitary im provem ents and high technology m edical advances, but

continues to remain high in undeveloped countries. Infant mortality rate is commonly included as
a part of standard of livi ng evaluations in economics.
THE HAZARD
There are many factors that would increase the risk of infant mortality. One of which is
smoking. When compare nonsmoking women with smoking women, smoking women having
their first birth and smoking less than one pack per day have a 56% greate r risk than nonsmoking
women. Among women having their second or higher birth, smoki ng women have 30% greater
infant mortality risk than nonsmokers.
Air pollution also contributes to the higher risk of infa nt mortality. By studying the
changes in air pollution level before and af ter the implementation of the Clean Air Act
Amendment in 1970 and its effect on infant mortal ity rate, researchers concluded that for an one
percent decline in Total Suspende d Particles which contributes to air pollution, results in a 0.5%
decline in infant mortality rate.
Race is an important factor that influence infant mortality rate due to differences in
socioeconomic status and experiences with raci sm. African Americans, for example, have a
higher risk of infant mortality rate of a bout 2.2 times than non-Hispanic Whites. African
Americans’ infant mortality rate is about 18.6 per 1000 birth while non-Hispanic Whites’ is
about 8.1 per 1000 births.
The differences between infant mortality ri sk could be explained by the differences in
socioeconomics status an experiences with ra cism. For example, African Americans are more
likely to be at the lower ranking in the socioeconomics status a nd are also more likely to be
subjected racial segregat ion and discriminations.

THE RANGE OF CONSEQUENCES
Studies have shown that racism is linked to the accessibility to medical care. Among
Medicare patients, blacks were le ss likely than whites to receive the same treatment. The four
procedures that blacks were more likely to receive than whites are amputation of a lower limb,
removal of both testes, removal of tissue related to decubitus ul cers, implantation of shunts for
rental dialysis. All of these procedures reflect delayed diagnosis a nd poor medical care.
Racism also leads to segregation. Studie s have shown a positive association between
infant mortality and residence in segregated areas and for areas with higher level of segregations
also has a higher mortality rates.
Stress is also associated with racism. S ubtle discrimination increases stress which
increases cardiovascular reactivity which increase the risk for cardiovascular syndromes such as
coronary heart disease. In a national sample of Americans adult, those who reported a high level
of daily discrimination had over twice the odds for major depression and over three times the
odds for generalized anxiety disorders.
Other factors that influence the risk of infa nt mortality rate are socioeconomics status,
maternal health, and birth weights. As menti oned before, African Americans are 2.2 times more
likely than non-Hispanic whites to be subjected to infant mortality. As shown in the table below,
(model 2) when control for socioeconomics status , the risk is reduce fr om 2.2 times to 1.97 times.
Controlling for maternal health and health care, model 3, the risk is further reduced to 1.56, and
when controls for birth a weight, model 4, the risk is reduce to 1.029.

LIKELY I NFLUENCES
Many factors increase or decrease risk of infant mortality. One prim ary factor that
reduces inf ant mortality risk is prena tal care. Ea rly prenatal ca re tends to lead to dec rease in
infant m ortality. Prenatal care i nvolves having norm al birth weight (low birth rate <2500 gram s).
Less than 0.5% of infants with birth weights >25 00 g die during the first y ear of life co mpared to
10.2% of infants with birth weights <2500 g and 45.3% with birth weights <1500 g.

Another factor shown to have influence on infa nt mortality risk is mother’s marital status.
Unmarried motherhood has been associ ated with increased risk of infant mortality. However, the
risk is associated is concentrated among s ubgroups, often vary based on confounding factors,
such as mother’s race and age. For example, risks of infant mortality among married white
woman relative to unmarried white woman are highest among 25-29 year olds. However, being
unmarried did not affect the risk of infant mortality among babies born to college-educated white
woman.
One study that has shown to prove this th eory consists of 10,347,103 women of which
1,656,044 were Black and 8,691,059 were White. The mar ital status was identified using birth
certificates or by comparing pare nts’ and child’s surnames on certificate. The variables studied
were race (Black or White), mother’s age ( <17, 18-19, 20-24, 25-29, 30-34, >35), parity (total
number of live births), maternal education (<12 yrs, 12 yrs, 13-15 yrs, >16 yrs, unknown),
prenatal care (early or delayed), maternal residence (metropolitan or suburban). The sampling
method used was a stratified sample by race and mar ital status. We examined the distributions of
births by those risk characteristic s that have been associated w ith adverse birth outcomes (age,
parity, education, initiati on of prenatal care and urban residen ce). Then infant mortality rates was
calculated by race and marital status for the subg roups defined by these risk characteristics, and
compared ratios of nonmarital and marital infa nt mortality rates across these subgroups. The
results of infant mortality rate acr oss these subgroups are as follow:

The Adjusted Odds Ratio was calculated for the subgroup unm arried versus m arried wom an,
after excluding nonsignificant intera ctions. The results show that there is significant interaction
between m arital s tatus and age am ong Blacks, an d significant interaction between m arital status
and age, m arital status and education, and m arital status and prenatal care am ong Whites. The
adjusted odds ratio result s are shown as follow:

Social and incom e status is another factor that is shown to have influence on infant
mortality risk. The general pattern is that the higher the individua l incom e the lower th e risk of
disease and mortality. T he hypothesis from a study on infant mortality rate in Nicaragua states
that the absolute level of hous ehold poverty in a low-incom e country such as Nicaragua is
associa ted w ith inf ant mortality; may be f urther modif ied by the prev ailing socioecon omic
conditions of the surrounding society. The study ai ms to assess the effect of poverty and social
inequity on infant m ortality rate in Nicara gua fro m 1988 to 1993. The sample consis ts of 10,867
wom en aged 15-49 years in Leon, Nicaragua and 7,073 infants studied. T he sam pling m ethod
used was cluster sam pling. From 208 geographical clusters, fifty were random ly selected with
probability proportional to num ber of inhabitan ts in each clus ter. All hous eholds (n=7 840) in

selected clusters were included; 51 (0.6%) re fused to take part. A total of 10,867 women
of reproductive age (15-49) were interviewed. Th e following reproductive ev ents were recorded
from each interviewee: date of end of each pregna ncy (births, stillbirths, and abortions), sex of
child, date of child’s death (if applicable). The variables considered in this study were mother’s
age and parity, mother’s position in the househol d, mother’s education, distance to health
services and residence. The inte rviewee’s socioeconomic status estimated via unsatisfied basic
needs (UBN) assessment, based on the followi ng factors: housing qual ity, school enrollment
among minors, dependency ratio, and availability of sanitary servic es (water supply and type of
toilet). Results show an infant mortality rate of 50 per 1000 live births. Poverty, expressed as the
UBN of household, increased risk of infant death. Social inequity, expressed as contrast between
household UBN and predominant UBN of neighborhood, increased risk. The data also shows
that infant mortality rate is associated with moth er’s education, but not associated with mother’s
position in household, distance to health services, urban versus rural residency and the study
period. Infants in poor households (higher scores for UBN) had higher mortality risks than those
in nonpoor households, and infants living in poor environment had higher mortality rates. The
results of this study are shown as follow:

This study links m other’s education to infant mortality rate, w here m ortality risks tend to
be lower am ong infants of educated mother. There is a gradual decrease in infant m ortality rate
from 65 per 1000 in groups without form al education to 30 per 1000 am ong infants of wom en
with secondary education or m ore. However, when stratified a ccording to socioeconom ic status,
the pro tectiv e effect of mother’s education on infant m ortality was de monstrated only in poor
households. Low maternal education (prim ary sc hool or less) in nonpoor households accounted

for 4% of infant m ortality rate, and low m aternal education in poor households accounted for
35% of infant m ortality rate. In fants of m others without any for mal education in poor households
in a predom inantly nonpoor neighborhood had highest risk of infant m ortality, with 130 deaths
per 1000 newborns, as shown in the gr aph below (the tallest colum n).

REDUCING YOUR RISK
Some strategies to reduce infant m ortality rate w ould be focusing on m odifying the
behaviors, lifestyles, and conditi ons that affect birth outcom es, such as smoking, substance abuse,
poor nutritio n, lack of prenatal care, m edical problem s, and chronic illn ess. Furtherm ore, a
network should form between health care ex perts and communities to encourage healthy
behaviors by pregnant wom en and parents of infants.
Health Care Providers should a dvise their patients about factor s that affect birth outcom es,
such as m aternal sm oking, drug and alcohol abus e, poor nutrition, stress, insufficient prenatal
care, ch ronic illness o r other m edical problem s. Communitie s and indiv iduals can als o play an
important role in this effort by encouraging preg nant wom en to seek prenatal care in the first
trimester, w hich will ens ure a be tter birth outcom e than little or no prenatal care.

FOR MORE INFORMATION
Bennett, Trude, et al. "Maternal Marital Status as a Risk Factor for Infant Mortality." JSTOR. Family
Planning Perspectives , Vol. 26, No. 6 (Nov. – Dec., 1994) , pp. 252-256+271. 24 April, 2006.
<http://links.jstor.org/sici?sici=0014-
7354(199411%2F12)26%3A6%3C252%3AMMSAAR%3E2.0.CO%3B2-Y >
Chay, Kenneth, “Air Quality, Infant Mortalit y, And the Clean Air Act of 1970.” October 2003
Hummer, Robert, “Racial Differentials in Infant Mortality in the US : An Examination of Social and
Health Determinants” Social Forces , Vol. 72, No. 2 (Dec., 1993), pp. 529-554.
<http://www.jstor.org/>
Pena, R, et al. "The Effect of Poverty, Social In equity, and Maternal Education on Infant Mortality
in Nicaragua, 1988–1993." American Journal of Public Health , Vol 90, Issue 1 64-69. 24 April, 2006.
<http://www.ajph.org/cgi/content/abstract/90/1/64>