Cohort profile: the Maharashtra Anaemia Study 3 (MAS 3)-a maternal-child cohort study up to age 18 years in India

The Maharashtra Anaemia Study 3 (MAS 3) aims to (1) Investigate the nutritional, environmental, and economic impacts on haemoglobin concentration/anaemia, (2) Identify the underlying micronutrient causes of anaemia and (3) Investigate the association between anaemia and physical and cognitive development of Indian children during their first 18 years of life. This paper introduces the MAS 3 cohort, which consists of data collected from the participants in the prospective Pune Maternal Nutrition Study from the antenatal period to children at 18 years of age (1996-2014) in the Maharashtra state, India.

Recruitment of 2466 married non-pregnant women, and their husbands, took place between June 1994 and April 1996 in six villages, approximately 50 km from Pune city in India. Women were followed up monthly to identify those who became pregnant. A total of 797 pregnant women were followed up for data collection at or near gestational week 18 and 28, with further data collection for women and children occurring within 72 hours of delivery, for both live and stillbirths. Of the 797 women, 710 were included in the MAS 3 cohort, and long-term follow-up of children occurred at 6 years, 12 years and 18 years of age.

In the MAS 3 cohort, most mothers (73%) were aged between 18 and 25 years at the time of their final prepregnancy visit (baseline), and half (55%) belonged to families of middle-upper socioeconomic status (SES). At the children's baseline (birth) visit, children had a mean birth weight of 2630 g (SD: 376), with one third (31%) of low birth weight. At the 6-year, 12-year and 18-year follow-up visits, data were available for 706 (99%), 689 (97%) and 694 (98%) children.

MAS 3 will be used to address a number of research objectives, including (1) Trends of haemoglobin and anaemia-related micronutrients from age 6 to 18 years, (2) Micronutrient causes of anaemia during childhood, (3) Prevalence and risk factors for maternal anaemia and childhood anaemia, (4) Impact of maternal anaemia on immediate birth outcomes and (5) Intergenerational risk factors associated with anaemia.