I think it is difficult to propose the tools without clearly understanding the packages of the "the first 100 days interventions". so, it is better if you clarify them.

Will be running growth monitoring clinics along with group based health and nutrition educations with target mothers (pregnant and lactating). Mothers/children with growth faltering or risk at acute malnutrition would be treated intensively through Supplementary nutrition program which will include individual educational sessions.

As per your information, it seems that your program is multi year. If this is so, I am assuming that one of the objectives of your program is to reduce stunting in children under two. Moreover, given the nature of the program “1000 days”, plus “supplementary nutrition program for children and mothers”, improving maternal nutrition could be also one of the objectives. In view of this, the impact is measuring undernutrition. As an intermediate result or outcome, you could also assess IYCF practices and other caring practices. So, to capture both impact and the outcome indicators, then I would suggest to conduct baseline and end line survey which is composed of anthropometry + IYCF+KAP. For data collection instruments, you can use the existing guidelines; SMART, WHO IYCF tools and others. However, to understand whether or not your program is making a difference, you need to have a comparable groups. That means, you need to identify areas where there is no similar program. If u are using the control group, the parameters to calculate sample size is different from that of ENA/SMART. Epidemiologists or statistician can further say on this.

Thank you so much for your suggestions Kirhoss. I shall try incorporate all the ideas in planning the assessment. Thank you.