Low birth weight: prevalence and associated factors among newborns at hospitals in Kambata-Tembaro zone, southern Ethiopia 2018

Introduction More than 20 million infants were born with low birth weight in worldwide. Low birth weight contributes more than 80 percent of all the neonatal mortality. In Ethiopia, studies have shown that there is a high prevalence of low birth weight among newborns. Thus, this study was aimed to determine the magnitude and associated factors with low birth weight among newborns delivered at term in Kambata-Tembaro zone, Southern Ethiopia, 2018. Methods Institution based cross-sectional study design was used. The sample size was proportionally allocated to each hospital. The total of 341 study participants was enrolled using systematic random sampling techniques. Data were collected by interview-administered questionnaire and entered using Epi-Info version-7 and exported to SPSS version 20 for analysis. Multivariate logistic regression analysis was carried out to identify associated factors with the low birth weight. Results The prevalence of low birth weight was 18% and significantly associated with the mothers’ non-employment [aOR=5.4;95%CI:1.7-17.4], residing in the rural [AOR=5.4; 95%CI:2.1-14.7], unintended pregnancy [aOR=2.0;95%CI:1.2-3.8], not attending antenatal care [aOR=2.3;95%CI: 1.3-2.7], mothers with greater than three births [aOR=1.5;95% CI:1.8-2.6], birth interval less than or equal to two years [aOR=1.9;95%CI:1.6-3.6] and intimate partner violence during pregnancy [aOR=2.1:95% CI: 1.1-3.9]. Conclusion The study finding shown that the prevalence of low birth weight among newborn was high (18%) in the study. Preventing of low birth weight is an important intervention to reduce neonatal death. Therefore, maximizing women economic status, providing quality family planning services, enabling pregnant women to use antenatal care and preventing intimate partner violence during pregnancy via launching women empowering strategies in the community level is highly recommend.


Introduction
Low birth weight is defined as a weight of newborns at birth less than 2500 gram by World Health Organization. More than 20 million infants are born with low birth weight in worldwide [1,2]. Low birth weight is an indicator of a public health problem and also, an important predictor of newborn health and survival [3]. Globally, each year an estimated 2.9million babies die in their first months of life. More than 80% of neonatal mortality occurs among low birth weighted newborns in southern Asia and Sub-Saharan Africa [3,4]. Birth weight is the most important criteria for determining the neonatal and infants morbidity and mortality. Babies with low birth weight are more vulnerable to risks as compared with normal weighted newborns. It continues to be a significant social problem globally and has both short and long term consequences [5]. From low-middle income countries; systemic reviews revealed that those newborns with low birth weight were increased risk of neonatal morbidity and mortality [6].
Low birth weight is not only a predictor of prenatal morbidity and mortality, but studies have found that it also increases the risk for non-communicable diseases such as diabetes mellitus and cardiovascular diseases in later life [7,8]. Studies have shown that newborn with low birth weight demonstrates growth retardation and persistent short stature in their life. In most cases, this is linked with abnormal growth hormone secretion and it is associated with poorer school performance [9,10]. According to Ethiopian demographic health survey 2011, 29.1% newborns were reported as low birth weight and it associated with maternal educational status, lack antenatal care during pregnancy, maternal age at delivery and medical illness during pregnancy [11]. In northwest Ethiopia, studies shown that neonates with low birth weight were two times more likely to die when compared with normal size babies [12,13]. A study conducted on causes of neonatal mortality in southwest Ethiopia shown that low birth weight babies were two times more likely to die when compared to newborns with weight ≥ 2500g [14]. Study findings revealed that low birth weight was resulted from poor maternal health service utilization preconception and during pregnancy. It is important to ensure that every pregnant woman and newborn have access to good quality care and life-saving interventions [15].
To prevent low birth weight World Health Organization recommended evidence-based maternal health care interventions like women   empowerment, women education attainment, appropriate perinatal   care, adequate nutrition for adolescent girls, prevention of malaria   during pregnancy, birth spacing, antenatal care interventions for all   women, iron and folic acid supplements for women during pregnancy daily, interventionist care in severe pre-eclampsia before term and improve linkage and referral for facility births [16,17]. As literatures review revealed that low birth weight at birth was significantly associated with women illiteracy, woman's lack of income, women age at birth, early marriage, birth space, maternal illness, maternal reproductive characteristics, women body mass index, personal behaviors, intimate partner violence during pregnancy [18][19][20][21][22][23]. In Ethiopia, the magnitude of low birth weight among newborns is high and yet, has been contributing a lot to neonatal morbidity and mortality. Even if, much efforts had invested in child health program to tackle the popularity of low birth weight, associated factors and its contribution for neonatal death; still needs further concern and commitments. Moreover, there is still a lack local community-based data on the level of low birth weight and its associated factors that might be vital input for health program designers and all concerned organizations. Addressing factors affecting the birth weight of babies will contribute to the achievement of reducing neonatal mortality in a particular community and nationally. Therefore, the study was aimed Inclusion criteria: all singleton newborns delivered at term, without congenital anomalies were included and newborns from mothers who had diagnosed medical illness during pregnancy were excluded.
Sample size determination: the sample size was determined by a single population formula considering the prevalence of low birth weight in Kersa, southern Ethiopia (p=28%) [24], 95% confidence level, 5% margin of error, and considering 10% non-response rate.
The total sample size was 341.
Sampling technique: the sample size was proportionally allocated to each hospital in the study area and systematic sampling was used to enroll study participants.
Data collection and quality control: structured intervieweradministered questionnaire was used to collect data. A tool was developed in English by reviewing different kinds of literature and translated into local language. Questionnaires contained maternal socio-demographic and reproductive characteristics and health care service utilization. Data was collected from postnatal mothers in the health facility at the time of discharge. To ensure quality data, training was given to data collectors and questionnaires were examined for completeness and consistency during data collection. Additionally, data was thoroughly cleaned and carefully entered for the commencement of analysis.
Data processing and analysis: data was entered using Epi-Info version-7 and transported to SPSS version 20 software for analysis.
Descriptive statistics was done. Multivariable logistic regression analysis was used to identify associated factors with low birth weight newborns at birth and variables with a p-value < 0.05 were declared as significantly associated factors with low birth weight.
Ethical consideration: a research ethical approval was obtained from research ethical review committee of the College of Health Science and Medicine, Wachamo University, Ethiopia. A committed was dedicated to evaluating ethical considerations. Written informed consent was obtained from respondents throughout data collection and confidentiality was maintained.
Ethics approval and consent to participate: ethical approval was gotten from Wachamo University, College of Health Ethical committee which was dedicated to evaluating ethical consideration of researchers and informed written consent was obtained from study participants during data collections.

Results
Socio-demographic characteristics of respondents: from a total of 341, 334 participants have responded the questionnaires (response rate was 97.9%). The mean age of the respondents' was found to be 28.68 (SD+5) years. One hundred forty-four (43.1%) of the respondents were couldn't read and write (Table 1).   [11,26].

Reproductive characteristics of respondents
In contrast, the study finding was higher as compared to other studies result; study done in Northern and southwestern Ethiopia the prevalence of low birth weight was found to be 14.6% and 11.02% respectively [22,27] In this study, the number of birth was significantly associated with the low birth weight of babies delivered at term. Mothers who had number of birth greater than three were nearly two times more likely to have low birth weighted babies at term delivery [aOR=1.5; 95%CI:

1.8-2.6]. This finding is in line with finding of study in Mekelle
Hospital, Ethiopia and Republic of Indonesia [19,21]. But, a study in southwestern Ethiopia, the number of birth was not significantly associated with the low birth weight babies at term delivery [27]. As number of birth increases, there is a high chance of having a large family that might affect family socio-economic status.
In this study, mother who gave birth with birth interval less or equal to two year were two times more likely to have low birth weighed babies as compared to those who have three years and above

Conclusion
The prevalence of low birth weight among newborn was 18% in the study. Prevention of low birth weight is an important intervention to reduce neonatal death. Therefore, to prevent low birth weight among newborns; encouraging women by means of accessing income generating enterprise to maximize their economic status in the community, providing quality and client choose based family planning services, enabling all mothers to use antenatal care during pregnancy by continues and consistent awareness creation and preventing intimate partners violence during pregnancy via empowering women in the community is greatly recommended.

Limitation of study
In this study, contextual and individual life styles factors that affects weight of newborns didn't addressed. We recommend other researchers to do follow up study to come up with finds shown that what effects each covariates have by controlling all potential confounders.
What is known about this topic  Maternal socio-demographic characteristics like education and age already known factors that associated with low birth weight in most of the studies;  Maternal medical illness during pregnancy, preterm, multiple pregnancy were already well known associated factors with the low birth weight at birth in most of the studies.

What this study adds
 In this study, intimate partner violence during pregnancy was significantly associated with the low birth weight among newborns; this was not much revealed by other studies;  The finding of this study supplemented that appropriate family planning service utilization prevent unintended pregnancy and helps to space birth interval. As result of this study showed unintended pregnancy and short birth interval was significantly associated with low birth weight of newborn. Thus, quality family planning service has great contribution to prevent low birth weight among newborns.