Decadal change in the association between the status of young mother’s Body Mass Index and anaemia with child low birth weight in India

Young mothers in India are disadvantaged in terms of their nutritional health and co-morbidities associated with their reproductive health [1, 2]. Biologically, about 50% of the adult body weight and 15% of the final adult height is attained during this adolescence, along with changes in body shape and composition. As a result, nutrition during this period is very important for overall growth. Poor nutrition starts before birth and generally continues into young and adult life and can span through the generations. It has been found that chronically malnourished women are more likely to remain undernourished during young and adulthood and when pregnant, are more likely to deliver low birth weight (LBW) babies [3]. An inadequate supply of nutrients during gestation is probably the single most important environmental factor affecting pregnancy outcomes. Previous studies suggest that the group of young girls, who conceive within two years of menarche and who get pregnant with low nutrient reserves and a short inter-pregnancy gap, tend to be at higher risk of having LBW babies which eventually become risky for mothers [4, 5].

Maternal undernutrition is prevalent in many regions, especially in south-central Asia, and in some countries, more than 10% of the women are shorter than 145 cm. Maternal undernutrition i.e., body-mass index (BMI) of less than 18·5 kg/m²—ranges from 10 to 19% in most of the countries from this region [6]. Similarly, a serious problem of maternal undernutrition is evident in most of the countries in Sub-Saharan Africa, South-Central and South-Eastern Asia, and in Yemen, where more than 20% of women have BMI which is less than 18·5 kg/m².

In India, the prevalence of low BMI among women is 40% which is higher than in many developing nations. Studies revealed that the low BMI of mothers along with poor nutrition and maternal short stature are the potential risk factors for adverse birth outcomes and child’s LBW in particular [6]. Another study also found that the poor nutritional status among young women has important implications for physical work capacity and adverse reproductive outcomes and when those women enter with a large iron deficit and are subjected to the added demands for iron during pregnancy, it may be too late to address the problem [7].

Studies have confirmed that the nutritional status of Indian women is inadequate. For instance, at least 20% of women are thin (BMI < 18.5) and an equal proportion are overweight (BMI ≥ 23), 53% anaemic and 8% enter pregnancy as adolescents [8]. On the other hand, overnutrition has increased by 4 percentage points [9]. According to the National Family Health Survey (NFHS), the reported prevalence of anaemia among pregnant women ranges from 45 to 70% [8]. A study revealed that anaemia among mothers is highly associated with undernutrition and in turn resulting in LBW babies [10]. The young mother’s nutritional status is one of the most important determinants of child birth weight and BMI is a more pervasive factor across India [10]. Although the prevalence of young pregnancy has been reduced over time in India, still the number of pregnancies remain high. Mainly the young mothers of age groups 15 to 24 years are highly susceptible to LBW [11, 12]. The birth weight of a child is a reliable index of intrauterine growth retardation (IUGR) and a major factor determining a child’s survival, future physical growth, mental development and disease-free life [13]. LBW is found to be one of the major causes of high mortality and morbidity rate among infants [14]. Worldwide, more than 20 million births are counted as LBW every year, which accounts for 15 to 20% of the total live births [15]. In India, the prevalence of LBW infants has decreased from 20% in 2005–06 to 16% by 2015–16 [16]. The risk of perinatal mortality among LBW infants is several times higher than the infants with normal or higher birth weight [14].

Poor nutrition is one of the known facts behind the LBW of children in developing countries. Several other factors also affect the birth weight such as the age of the mother, economic status, birth order of the child, birth gap, smoking and drinking behaviour of the mother, antenatal care utilization [17]. LBW has several adverse consequences on an infant’s health. LBW babies are more likely to suffer from long term handicapping conditions, poor mental health, non-communicable diseases in later life [18, 19]. However, the main focus of this study is to examine the effect of nutritional health indicators of the mother i.e. BMI and anaemia on the child birth weight and how the association between these two factors and LBW has changed over nearly two decades.

This paper examined the association of young mothers’ nutritional status with childbirth weight. In this study, those mothers were considered who became pregnant quite early between 15 to 24 years of their age and were exposed to deliver LBW children. The major findings of this study are as follows.

First, the prevalence of low BMI and severe anaemic mothers have decreased over the decades. Second, the birth weight of the infants is directly related to BMI but inversely related to the anaemia level of the mothers. Third, over the decade, the prevalence of LBW babies has decreased and a higher reduction has taken place for mothers within the age of 15 to 19 years. Fourth, the odds of having LBW babies was significantly higher for mothers with low BMI, moderate and severe anaemia. However, mild anaemic mothers do not show any significant association. Moreover, the association between BMI, anaemia and child birth weight has decreased over the decade. Fifth, BMI can explain about one-fifth of the difference in child birth weight between mothers with low and normal BMI whereas more than one-third of the difference can be explained by anaemia between mothers with severe and non-severe anaemia.

Some possible explanations of these findings have been provided. Women with abnormal BMI are at risk of LBW outcomes [22]. The decrease of low BMI and severe anaemic women over the decade can be explained by the increase in educational attainment and standard of living which in turn improved the dietary intake of the young mothers. Education is one of the most important and significant factors which plays a substantial role to improve the nutritional status of women [23, 24]. Along with educational attainment, a household’s wealth status shows high association with BMI and anaemia [25, 26]. Our study results show a similar pattern as the studies conducted in other developing countries. A study in a Sudan hospital found that lack of antenatal care and anaemic mothers were the significant determinants of LBW [27]. Another study in Nepal revealed that normal BMI was the protective factor against the child's LBW [28]. In Ethiopia, a study by Betew et al. in 2014 analyzed the determinants of LBW by using the same Demographic and Health Survey data. They concluded that the children born from lower education, low income, anaemic, low BMI and teenage mothers had a higher risk of delivering children with LBW [29]. Though the pattern of the association between mother’s BMI and anaemia with child's LBW remained the same over time but the intensity of association has reduced. There also exists regional variation in BMI and anaemia status of women. For instance, women residing in villages are more likely to have low BMI and suffer from anaemia. In this study, it is found that the prevalence of LBW babies has decreased over the decade. Increased educational status through programs in TV and newspaper articles have a significant role in reducing LBW babies [30]. Another study has found that regular antenatal check-ups and balanced diet intake during the antenatal period have a larger impact on the reduction of LBW infants [31].

Since the implementation of the National Health Mission (NHM) in 2005, the improvement in maternal and child health has been accelerated [32]. The effects of the introduction of such programs have major impacts on maternal and child health. Though public health interventions are making efforts to improve maternal health by reducing maternal mortality but still a large proportion of the women are suffering from poor health and young mothers are at more risk. BMI status of the mother is a major predictor of foetal growth and maternal poor health increases the risk of stillbirth and neonatal death [33]. To combat the situation of low BMI and anaemia among young mothers and pregnancy at a very early stage of their life, India needs to employ multidimensional intervention programmes based on identified individual, household and community-level socio-demographic and economic risk factors that affect maternal nutritional status. Schemes like National Rural Health Mission, Reproductive Maternal Newborn and Child Health + Adolescent (RMNCH + A) in India are working on maternal and child nutrition care. Mother and Child Protection cards of the Ministry of Health and Family Welfare and Ministry of Woman and Child Development are being used by all states as a tool for monitoring and improving the quality of maternal and child health and nutrition interventions. In India, there are some schemes and programs which have the following interventions to promote women’s nutrition: counselling on adequate nutrition during antenatal and postnatal contacts; and provision of iron-folic acid supplements to pregnant women. India may consider replacing iron-folic acid with multiple-micronutrient supplements to all pregnant women, provision of calcium supplementation to those at risk of low intake and provision of balanced energy–protein supplementation to pregnant women as needed, as recommended in the second Lancet series on maternal and child nutrition [34]. Regular systematic monitoring and surveillance of the social trajectory of the nutritional status of young women are essential to develop an appropriate strategy to reduce the burden of LBW outcomes in India.

This study has the following limitation. As the data was taken from a cross-sectional survey which provides only a snapshot of any current situation, the BMI and anaemia level of the mother was captured at the time of interview and not during their pregnancy period.