Women's Work in Agriculture and Infant Nutrition
Condition: Malnutrition
MeSH terms: Malnutrition
Study type: Observational

Summary: 
      Background Over the last 10 years there has been an increase in the female agriculture labour
      force, in Pakistan, resulting in a feminisation of agriculture; which could have either a
      positive or negative impact on maternal and young child nutrition. It could have a positive
      impact through increased female wage earnings that improve her bargaining/decision-making
      power within the household. Women are more likely than men to make pro-nutrition choices with
      regards to household expenditure. Conversely, women's involvement in agricultural work may
      have a negative impact on infant or maternal nutrition by reducing time available for child
      care, through increased expenditure of physical energy without compensatory increases in food
      consumption or exposure to harmful toxins present in pesticides and other chemicals used in
      farming. Understanding the dynamics of these pathways, in a specific context, is important to
      ensure agriculture programmes and policies do not disadvantage women or their children.

      Overall aim To provide insights into positive and negative pathways between women's work in
      agriculture and maternal and child nutritional status, in different agriculture workload
      contexts, to inform agriculture interventions and policies in Pakistan.

      Specific Objectives

        1. To determine whether the number of hours a mother participates in agriculture work is
           associated with maternal body mass index and infant nutrition.

        2. To identify factors that modify the influence of maternal participation in agriculture
           work on maternal and infant nutritional status.

      Study Design A cohort study was conducted from September 2015 in irrigated rural areas of
      Pakistan. Infant-mother dyads were recruited when the infant was between 2 and 12 weeks of
      age inclusive. Anthropometric measurements (maternal and infant height / recumbent length and
      weight), interviewer administered questionnaires and spot observations were collected at
      recruitment (Time 1) and again when the infants were between 9-15 months of age (Time 2). The
      interviewer administered questionnaires were collected from each infant's mother (or the
      household head if the father was not present). A one page questionnaire was also completed at
      recruitment to record the numbers of women who agreed to participate in the study, the number
      who were approached but were not recruited into the study and the reasons they were not
      eligible to participate or their reasons for refusal.
    

Detailed description: 
      Study Design This study is an longitudinal observational study which was used to generate
      hypotheses rather than testing them. Mother-infant dyads were recruited between December 2015
      and February 2016; and were followed up between November 2016 and January 2017.

      Sampling The sample size (n=1000) was calculated to detect an increase/decrease in maternal
      BMI of around 0.18 for every additional hour worked with 80% power at a 5% level of
      significance. To estimate it, simulations were run to explore the power we would have to
      detect the relationship between maternal BMI and number of hours worked. It was based on a
      mean number of working hours of 6 and a standard deviation of 4 and a within cluster
      variation of 0.2 . This is a small effect size and suggests that the proposed sample size
      will provide adequate power to allow us to explore proposed relationships and generate
      hypotheses.

      Participants were selected via systematic random cluster sampling. Initially, administrative
      villages with perennial canal irrigation were selected; villages with a population<10% or
      >90% of average village size were excluded, and random sampling was used to select villages
      from the eligible villages (n=2,909). All dyads, in the selected villages (n=62) were invited
      to participate in the study if: (i) the infant was a singleton birth ≥2 weeks and ≤ 12 weeks
      of age on the day of the first interview; healthy without congenital deformations that would
      impact on their ability to eat and (ii) the primary caregiver (i.e. the biological mother)
      intended to reside in the study area over the next 10 months.

      To recruit these dyads, all recent births in the identified village were listed through a
      systematic multi-stage community profiling procedure using local key informants/resource
      persons including: health workers, midwives, doctors and paramedics, and locally
      well-informed individuals. In the first stage, several key informants per village were asked
      to exhaustively list all kinship groups or castes and localities within the village. Then
      they were asked to list all births from within those castes/localities within a given time
      period. Probes were used at both stages to counter exclusions. Afterwards a team of
      recruiters visited each of the listed mothers to confirm eligibility (i.e. correct age of the
      new born). Recruiters also probed for other births within the locality, to identify new cases
      through this snowballing technique. All dyads in the village who fulfilled this condition and
      met the inclusion criteria were recruited and actual date of birth was recorded.

      Procedures and Methodology At each of the two data collection periods, interviewer
      administered questionnaires were collected from the mothers; and included questions related
      to socio-demographic status, health, dietary intakes, maternal agency and nutrition
      knowledge. These questionnaires were pilot tested and modified to ensure each questionnaire
      took less than 60 minutes per respondent to complete. For mothers, questions related to
      infant feeding, immunisation and pregnancy varied between the first and second data
      collection periods to reflect differences in infant age and maternal status. All data were
      entered directly into an android tablet.

      Anthropometric measurements of maternal height and weight and infant weight and recumbent
      length were done in duplicate by trained anthropometrists using high quality equipment. If
      the first and second measurements did not agree to within a specified limit (e.g., 0.5 kg or
      0.5 cm) a third measurement was taken. These data were entered directly into an android
      tablet to allow consistency checks for quality assurance. Spot observations were also done to
      determine housing materials and the hygienic conditions of the environment, which were
      entered directly into an android tablet.
    

Observational model: Ecologic or Community
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Community sample. Mother-infant dyads living in rural Sindh province, Pakistan. They were
        selected from 62 administrative villages with perennial canal irrigation.
      
Keywords: stunting; under-weight; Pakistan; infant; time-use; women; body mass index; growth