About half of the world’s population is affected by maternal and child under-nutrition [1, 2]. Undernourishment of women in reproductive age is more common in South Asia than any other region . In the South Asian region, prevalence of maternal undernutrition varies between 10 and 40% . Particularly in Bangladesh, the prevalence of undernutrition among females is much higher than any other developing country,  with more than 30% women of reproductive age reported to be malnourished . Maternal under-nutrition has persistently been reported to be a major contributor to morbidity, mortality and poor birth outcomes including low birth weight (LBW), neonatal mortality, and subsequent childhood undernutrition . Maternal undernutrition alone accounts for about 25-50% of intrauterine growth restriction . In such a way, undernutrition can transfer from one generation to other.
Globally, about 20.6 million children are born with a low birth weight (LBW) each year. Among them, 96.5% are from low and middle income countries (LMICs) and the global estimate of LBW prevalence is 15.5% . The prevalence of LBW significantly varies across the United Nations regions, such as South-central Asia has the highest incidence of LBW (27%) and the lowest in Europe (6.4%) . In rural Bangladesh around 55% babies are born with LBW . However, the national survey of Bangladesh reported the prevalence of LBW as 36% . The consequences of LBW are universally recognized. For example, it reportedly contributes to child mortality,  undernutrition,  long term disability and impaired development,  shorter adult height,  delayed motor and social development,  having a lower IQ . Consequently, LBW incurs enormous economic costs, higher medical expenditures, special education and social service expenses and decreased productivity in adulthood.
Maternal undernutrition is caused by multiple factors in developing countries. Women from the developing countries lag behind men in having access to food, health care and education . A study from Bangladesh reported that women’s education, exposure to media, and domestic decision-making status significantly influenced the nutritional status of women . Another study reported similar results: female literacy, poverty and lack of empowerment were the major barriers to improving maternal nutrition in South Asia . Other variables that also increase the likelihood of maternal undernutrition, include various biologic and social stresses such as, food insecurity and inadequate diet, recurrent infections, poor health care, heavy work burdens, and gender inequities [14, 15].
Women’s empowerment, which is believed to be one of the key factors for attaining maternal and child health and nutritional goals , can influence all the factors associated with maternal nutritional status to some extent. The pathway of how the empowerment of women affects maternal nutritional status and birth weight is described in Figure 1. Empowered women have the ability to control decision-making in different aspects of life which include socio-cultural, familial and interpersonal and legal dimensions [17, 18]. They can independently make decisions about their own health as well as their children’s health. As a result, women’s empowerment can ensure better maternal care, improved maternal nutrition, and provide freedom in choosing healthy family planning methods. Empowered women have control over finances. Thus, they can change the composition of household purchases, which improves household food security as well as the diet diversity and nutritional status of both themselves and their children [19-22]. They can also allocate more money for the education and health of their family . Empowered women have higher mobility, which increases their freedom to visit food markets and attend health center appointments for both herself and for her children and visit friends or relatives. As a result, they acquire resources such as information and support  which help to improve maternal and child health care. Finally, empowerment of women has been reported to lessen the risk of domestic violence  which contributes to improving maternal mental health  and lowering maternal nutritional deprivation . Studies from LMICs report that women’s empowerment has a significant influence on child nutrition, [27-29] infant and young child feeding, [24, 28] reproductive health, [17, 30] health seeking behavior  and maternal health service utilization . Therefore, the impact of maternal undernutrition on the health of children throughout their life is considered irreversible [32, 33].
While many studies have been conducted in LMICs to investigate the association between women’s empowerment and various health outcomes, the indicators used to define empowerment remain elusive. There are many different indicators, used to define women’s empowerment, available in the literature [18, 19, 24, 34, 35] which entail that empowerment is a dynamic process of change by which “those who have been denied the ability to make choices acquire such an ability” . However, a comprehensive measure of women’s empowerment is lacking. Due to its latent phenomena, different studies used different indicators to measure women’s empowerment . A recent study suggested some indicators to construct a survey-based women’s empowerment index (SWPER) in Africa  to measure progress towards the Sustainable Development Goal 5: achieving gender equality and empower all women and girls . However, there is no scientific consensus on which indicators should be used or how to weigh them to construct a women’s empowerment index. Studies conducted to date using Demographic Health Surveys (DHS) to measure women’s empowerment have generally used two types of indicators: household decision-making and attitudes to wife beating [24, 39]. However, there are other potentially important indicators in the DHS data set that could be used, as proposed in other studies  such as participation in a microcredit programme (membership of Non-Government Organization, NGO) and education. To our knowledge a very few studies investigating women’s empowerment have taken into account the covariation among the indicator variables when constructing a women’s empowerment index [23, 24, 31, 36, 39]. Furthermore, the few studies examining the association between women’s empowerment and maternal and child undernutrition are not consistent . For example, a study from Benin  and other one from Nepal  suggested that women’s empowerment is significantly associated with maternal nutritional status, however, another study from Ghana  found no association. Similarly, Begum and Sen (2009)  found no association between women’s empowerment and child’s nutrition in Bangladesh, but another study from India  reported a significant association. Another study reported that there is a direct link between women’s empowerment and premature delivery,  which is one of the key factors affecting birth weight. However, there is an inadequate number of studies to investigate the association between women’s empowerment and birth weight. Therefore, we aimed to develop a comprehensive indicator for empowerment of women using principal component analysis (PCA) methods to account for the covariation among the indicator variables and assess the association of the index with maternal undernutrition and LBW using Bangladesh Demographic Health Survey (BDHS) data.