Abstract

BACKGROUND: Birth weight is an important component of pregnancy outcome as well as an
indicator of the newborn’s chances for survival, growth, long-term health and psychosocial
development. In addition, it is an indirect indicator of the mother’s health and nutritional
status. Previous research reported the influence of maternal sociodemographic factors and
haemoglobin level on birth weight independently. .
OBJECTIVE: This study was aimed at assessing the impact of sociodemographic factors and
maternal haemoglobin level on birthweight of term pregnancies in University of Ilorin Teaching
Hospital (UITH), Ilorin, Nigeria.
METHODS: This was a prospective cohort study conducted at the Department of Obstetrics
and Gynaecology of the University of Ilorin Teaching Hospital (UITH) Ilorin from 1st July to 14th
of January, 2013(28.1weeks period). The data were collected from 180 pregnant women whose
social class ranged between III-V (low social class) and standardized by 180 pregnant women
with social class I-II (high social class). Recruitment of participants was by purposive sampling
selection at 20weeks gestation in the antenatal clinic and they were subsequently followed up
till delivery. The data were analysed using Statistical Package for Social Science version 16.
RESULTS: The mean birthweights in subjects and controls were 2.644kg ±0.267 vs 2.924kg
±0.341 with average maternal haemoglobin level of 10.75g/dl ±0.691 and 11.34g/dl±0.9103
respectively. The mean birth weight was 2.78 kg±0.336 and mean maternal haemoglobin level
11.05±0.86g/dl for all participants in the study. A total of 328patients (91.1%) had haemoglobin
concentration level of ≥10g/dl, out of which 241(73.5%) had babies with birthweight ranging
between 2.5kg to 4.2kg. None were found to have birthweight of ≥4.3kg or ≤2.1kg or maternal
haemoglobin level of < 9.0g/dl or >15g/dl at birth. The subjects were significantly more anaemic
(<10g/dl) at 20weeks than controls (54.4% vs 20.6%; p-0.001), and by the 30th week the
maternal haemoglobin level improved more in the controls than the subjects (83.9% vs 52.2%;
p-0.001). While 82.2% of the controls (social class I-II) had birth weight≥ 2.5kg with
haemoglobin level of at least 10g/dl, the subjects (social class III-V) had only 51.7% of such
cases (p-0.001).
Among the sociodemographic factors studied, age, educational status of the couple and
occupational status of the husband were found to be significantly related to birthweight
(p<0.05). Also, both the women and their partners’ educational levels had significant effect on
maternal haemoglobin level in both groups (p-0.0001 vs 0.0001). Most of the patients (55.0%)
were multipara (2-4), parity was found to contribute to normal maternal haemoglobin level at
birth (P-0.010). There was no significant statistical relationship between parity and birthweight
in both groups when social class was considered (<2.5kg; p-0.266, ≥2.5kg; p-0.070).
The mean pattern of change in maternal haemoglobin concentration and birthweight showed
rate of change in fetal weight to be 92.2±13.03g/week between 20th week and 30th week of
gestation and 161.7±15.6g/week between 30th week and at birth with change in haemoglobin
level of 90±20mg/dl/week and 30±10mg/dl/week respectively.
CONCLUSION: The results showed that birthweight is affected by many factors and maternal
haemoglobin is a major determinant. Fetal weight tends to increase more from late second
trimester to birth, although rate of increase in maternal haemoglobin level during this period is
relatively lower, it showed that other factors especially sociodemographic may play an
important role. It also showed that maternal haemoglobin level at 20th week may not have a
profound effect on birthweight than rate of change of haemoglobin over the period of
pregnancy. It is therefore important to monitor not only the maternal haemoglobin level but
also adjustment of sociodemograhic factors that influence birthweight such as parity, age,
educational status occupation and social class for optimum pregnancy outcome.

IMPACT OF SOCIODEMOGRAPHIC FACTORS AND MATERNAL HAEMOGLOBIN CONCENTRATION ON BIRTHWEIGHT AT TERM IN UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN