A STATISTICAL MODEL OF DETERMINANTS OF BIRTH WEIGHT.
1.0 STATEMENT OF THE PROBLEM
More than 20 million infants worldwide representing 15.5% of all births are born
with low birth weight, 95.6% of them in developing countries (United Nations
Children Fund, 2008). Low birth weight is of public health concern because of the
increased morbidity associated with it. The level of low birth weight in developing
countries is 16.5% and it is more than double the level in developed regions which is
7% (United Nations Children Fund and WHO, 2004).
The exact number of deliveries in Nigeria is not known. The percentage of low birth
weight may not be known but the absolute figure is probably enormous. In
developed countries such babies will be a burden on the government but in Nigeria
and other developing countries, they are likely to be a permanent burden on the
families. With the poor resource setting we have in Nigeria, such burden will worsen
the economic fortunes of the poor families.
1.1 SIGNIFICANCE OF THE STUDY
In this era when medicine is emphasizing primary treatment (preventive medicine)
epidemiology becomes a veritable tool. Epidemiology of low birth weight is the
study of the phenomenon, factors that affect it and the use of the knowledge in
managing the phenomenon. Some of the factors known in literature that affect birth
weight are modifiable like the social and environmental factors. They can easily
change. Some factors are not modifiable and may have statistical relationship with
the birth weight as a dependent variable. Gestational age, parity, age of mother and
sex of baby are non-modifiable factors. In-depth knowledge of these factors and
their relationship with birth weight is necessary for Obstetricians, Pediatricians,
Public Health Physicians and Health Policy makers to understand the epidemiology
of low birth weight and reduce its prevalence and associated public health
consequences. Literature is scanty in Nigeria including Anambra State. No statistical
model has been developed yet to address this issue. This study proposes to examine
these factors namely parity, maternal age, gestational age of index pregnancy and
sex of index baby and develop an exploratory model of these determinants of birth
weight that may be useful in epidemiological studies.
1.2 SCOPE AND LIMITATIONS
Method of multiple regression will be used in model specification. All the 1023 life
births obtained in a private hospital between 2000 and 2001 will be used in checking
the adequacy of the proposed model. For financial and time constraints, the scope is
limited to Nkpor, Onitsha and its environs which form the catchment area of the
hospital from which data will be collected.
The general objective of the study is to do a statistical analysis of birth weight and of
the independent variables that affect it. The specific objectives are:
1. To determine the association, if any, between birth weight and any of the
following variables; parity, age of mother, sex of baby and gestational age.
2. To determine the relationship between parity and age of mother
3. To develop an exploratory model of birth weight with parity, maternal age,
sex of baby and gestational age as its determinants.