Factors Associated with Low Birth Weight Babies
Introduction
• LBW is Public Health importance because of strong relationship between birth
weight and infant mortality and morbidity.
• The cohort of LBW babies (<2.5 kg) is likely reflect two effect, namely short
gestational age ( preterm babies) and Small for gestational age (SGA).
SGA
Foetal
Foetal abnormalities, Intrauterine
infection, Chromosomal
abnormalities, Multiple gestation
Placental
Placental insufficiency, Placental
abnormalities
Maternal
Social, Nutritional, Health status
IUGR
Introduction
• The incidence of LBW is estimated to be 16% worldwide, 19% in the least
developed and developing countries and 7 % in the developed countries.
• In a study done in Nepal, the LBW rate was found to be 27 % out of which term
LBW babies constitute 70 % and preterm 30%.
• In eastern Nepal, the percentages of LBW babies vary markedly in different
geographical area. It is 4.2% in eastern mountain, 12.8% in eastern hill and 19.2%
in eastern terai.
Objective
• The objective of the study was to assess the risk factors associated with
low birth weight babies (maternal factors, socio-economic and
demographic factors, disease during pregnancy).
Methodology
• Study design:
Hospital based unmatched case-control study
• Study Site:
Two hospitals of eastern Nepal, BPKIHS, Dharan and Koshi Zonal hospital, Biratnagar.
• Study Population:
All the mothers coming to the study site for delivering baby
• Sample size:
159 cases and 159 control by taking control exposed 0.244, Anticipated odds ratio 2, 80% power
and Alpha error 5%. (epi-info)
Methodology
• Inclusion Criteria:
Cases: Mothers delivering live born singleton baby with birth weight less than 2500 gm was
taken as cases.
Control: Mothers delivering live born singleton baby with birth weight 2500 gm or more was
taken as control.
• Exclusion Criteria:
• Mothers delivering babies with congenital anomalies.
• Mothers delivering babies of more than 4 kg.
• Mothers delivering twins or multiple pregnancies.
• Data Collection Techniques:
• Face to Face interview with eligible mothers within 24 hours after delivery.
• Abstraction of ANC and medical records of mothers were also made
• Anthropometric measurement were taken after interview
Methodology
• Reliability and Validity:
• Nepali translated Pre-tested questionnaire were interviewed to mother by researcher self
• Terai Ethnicity mothers were asked in Maithili Language
• Height was measured against calibrated wall while weight was measured using weighing
scale after ensuing zero and standardization.
• Ethical Clearance:
• Ethical clearance to carry out this study will be obtained from the BPKIHS Research
Committee
• Before starting the interview, verbal individual consent to participate will be taken after the
study's aim, methods, benefits and the potential discomfort is adequately explained.
• A printed material (pamphlet) having information about breast feeding, immunization
schedule and care of infant will be given to the subject.
Methodology
• Data Processing and Analysis:
• Data was entered into MS excel 2007 and analysis was done in PASW statistical software
18.0 version. Epi-info 7 version was used for calculating odds ratio.
• Bivariate association: Simple logistic regression, Chi-square analysis
• Based on bivariate analysis, multivariate logistic regression model was constructed
• Entry of exposure variable was forced followed by stepwise entry of potentially relevant
covariates.
• Howmer-Lemeshow test was used to identify and exclude variables that caused poor fit in
the model.
Study Variable
Maternal
Socio-Demographic
•
•
•
•
•
•
•
Ethnicity
Occupation
Socio-Economic
status
Educational status of
parents
Type of Family
Geographical Area
Sex of baby
Low birth
weight
Disease during Pregnancy
• Anaemia
• Night Blindness
• Hypertension
• Heart disease
• TB
• Eclampsia
•
•
•
•
•
•
•
•
•
Age
Weight
Height
BMI
Parity
ANC
IFA tablet
Alcoholism and
smoking
Inter-Pregnancy
interval
Socio-Demographic Description
• Out of 318 subject 70.75% were from rural area while 29.25% were from urban
area.
• Majority of subject are Hindu (94.02%), rest were muslims (5.03%), and
Christians (0.95%).
Socio-Demographic Description
Cases (N): 159
Control(N): 159
Socio-Demographic Description
• Nearly two third (61.32%) of the subjects were of Terai origin while rest
(38.68%) were of hill origin.
• One third (31.13%) of the subjects were Terai middle caste, followed by major hill
caste (22.96%), Terai Natives (16%) abd Gukk Batuves (15.41%). Rest were from
occupational castes of Terai and Hill origin and Muslims.
• Only 17.30% of total respondent mothers were illiterate, while 24.53% of cases
were illiterate. Nearly half 47.17% of the cases but only one fourth of the control
28.3% were illiterate or informally or primarily educated.
Socio-Demographic Description
• More than half 51.26% of the husband of the total respondents were educated up
to SLC and more. Nearly 10% of the husbands of the total respondents were
illiterate.
• More than one fifth 22.01% of the cases were born by teenage mothers, while
teenage mothers gave birth 16.36% of the control.
• More than three fourth of the mothers were housewives while rests worked
outside the home. Only 3.14% of mothers were involved in business while 7.55%
of them were laborers.
Socio-Demographic Description
• More than one third 36.48% of the husbands of the total respondents were
labourers while only 3.46% were unemployed. Rest were involved in the different
occupations like business (13.84%), services(14.78%), Agriculture(12.26%) and
foreign employment (16.66%).
• Nearly two-thirds (63.52%) of the respondent was below poverty level (<$1.25
per day).
• On the basis of Kuppuswami socio-economic scale, nearly half of the mothers
were from upper lower class, but 4.41% of them were also from lower class.
• Only 28.14% of the mothers, who resided in their own house (82.70%) had pucca
house.
Comparison of Basic Variable
Characteristics
Case Group
Control Group
P-Value
Mean
SD
Mean
SD
Monthly Income
(RS)
12627.17
8486.16
16332.7
13786.85
0.03 @
Maternal weight
kg
47.04
9.3
52.11
8.58
<0.001*
Gestational age at
birth (weeks)
39.14
1.52
39.81
1.14
<0.001 *
Total ANC Visit
(No)
3.36
1.47
4.46
1.44
<0.001*
Iron Tablet (No)
98.30
47.40
129.81
48.11
<0.001*
Calcium Tablet
(No)
40.94
54.12
72.64
72.81
<0.001"
• *Significant t-test at (P<0.05)
@Man-whitney U test significant at P<0.05
Comparison of Basic Variable
Characteristics
Case Group
Control Group
P-Value
Mean
SD
Mean
SD
Hb Level (gm/dl)
11.33
1.09
11.33
1.22
0.02*
Birth weight(gm)
2126.73
340.13
3083.65
332.26
<0.001*
Maternal height
(CM)
146.73
7.88
152.77
6.04
<0.001*
Per-capita Income
$
1.10
0.72
1.39
1.09
0.004*
• *Significant t-test at (P<0.05)
@Man-whitney U test significant at P<0.05
Multivariate Regression Analysis for Possible Predictor
Characteristics
AOR
AOR at 95% CI
P value
Maternal Height
≤1.45 meter
1.46-1.55 meter
>1.55 meter
20.377
1.811
Ref
4.872-85.222
0.641-5.115
<0.001*
0.262
Time of Ist ANC visit
First Trimester
Second Trimester
Third Trimester
0.030
0.993
Ref
0.002-0.508
0.438-2.248
0.015*
0.986
ANC visit no
1-2
3-4
>4
• *Significant (P<0.05)
172.787
5.933
Ref
23.570-1266.66
2.258-15.588
0.001*
0.001*
Multivariate Regression Analysis for Possible Predictor
Characteristics
AOR
AOR at 95% CI
P value
Calcium Supplementation
No
1-90 days
91-180 days
1.562
3.567
Ref
0.568-4.293
1.221-10.416
0.338
0.02*
Blood Group
A
AB
B
O
• *Significant (P<0.05)
1.182
0.174
Ref
1.296
0.480-2.914
0.040-0.765
0.716
0.021*
0.505-3.325
0.590
Multivariate Regression Analysis for Possible Predictor
Characteristics
AOR
AOR at 95% CI
P value
Maternal education
Illiterate
Literate
5.693
Ref
1.833-17.685
0.003*
Any Illness during Pregnancy
Yes
No
• *Significant (P<0.05)
4.239
Ref
1.903-9.442
<0.001*
Multivariate Regression Analysis for Possible Predictor
Characteristics
AOR
AOR at 95% CI
P value
Maternal Age
<20
20-29
≥30
0.360
Ref
0.153
0.120-1.082
0.069
0.044-0.533
0.003*
0.130-6.420
0.052-0.704
0.928
0.013*
BMI
Thin (<18.5 kg/m2)
Normal (18.5-24.99kg/m2)
Overweight (≥25kg/m2)
• *Significant (P<0.05)
0.914
0.190
ref
Multivariate Regression Analysis for Possible Predictor
Characteristics
AOR
AOR at 95% CI
P value
House Type
Katcha
Pacca
• *Significant (P<0.05)
2.889
Ref
1.117-7.474
0.0029*
Discussion
Maternal Height:
• In this study, short mothers with height equal to or less than 145 cm were eleven
folds more likely to have LBW neonates than the mothers with height more than
155 cm( OR=11.087,95%CI;2.04 to 8.37). This result is similar to study done by
Mumbare et al 45 and Roy34 . Ojha and Malla19. Documented that association could
not reach significant level(OR=1.87, 95% CI; 0.98-3.75) in mother with short
height.
• Maternal BMI : A study by Nusrat Khan 69 show the importance dof BMI where
higher value of BMI had Protective effect against LBW. Bhattcharya S et al 70,
Mavalankar DV et al61, Han J et al 71 and Borja JB 72 also had same findings that
low maternal BMI was significantly associated with LBW. But in contrast to these
studiesm Low maternal BMI (<18.5Kg/m2) was not found significantly associated
with LBW babies in this study.
Discussion
Time of first ANC Visit
• The association between LBW neonates and the time of First ANC visit was found
be significantly associated in this study and it was in accordance with the study.
By Kercher11 ain Montana and Negi et al 14 in India.
Iron Supplementation
• Intake of iron supplements during pregnancy was found to have a protective effect
with respect to LBW in this study. This is consistent with the finding of some
others studies by SA Rizwi 3 and Christain P et al 75.
Discussion
• Hypertension was found significantly associataed with LBW babies in this study.
Tha same result was documented by Aghamolaei 51, Khan N 69, Fitri et al 42 and
Fatemeh et al 44.
• There was significantly negative association between LBW and maternal blood
group AN which is in accordance with the finding of Fedrick and Adelstein89
Conclusion
• Maternal height Time of first ANC visit, Number of ANC Visit , Iron
supplementation, Calcium Supplementation, maternal education, any illness
during pregnancy and hypertension was found as significant predictors of LBW.
• Maternal blood group AB, Norma maternal BMI, Mother's age of 30 or more
years and starting ANC visit.s earlier were found to be protective for LBW
Recommendation
• Suggested to conduct more comprehensive studies to assess maternal blood groups
as associated factors for LBW Babies
• Strengthen female literacy and income generation program to community level
• Strengthen ANC services
• Calcium and Iron supplementation during pregnancy is suggested
Limitation
• Potential ascertainment bias cannot be ruled out because the researcher had to rely
on charts and records for some sort of data.
• Tendency to hide about original income may underestimate or deviate the findings
of the study.
• Potential information biases cannot be ruled out because weight of mothers wes
taken using bathroom scale and height was taken against calibrated wall.