ID	Search	Items found
#12	Search (#11) AND (“1990”[Date ‐ Publication] : “3000”[Date ‐ Publication])	5,708
#11	Search #9 NOT #10	6,095
#10	Search Editorial[ptyp] OR Letter[ptyp] OR Case Reports[ptyp] OR Clinical Conference[ptyp] OR Comment[sb] OR “pubmed books”[Filter]	3,377,353
#9	Search #8 NOT #7	6,363
#8	Search #1 AND #5 AND #6	6,378
#7	Search ”Animals”[Mesh] NOT (“Humans”[Mesh] AND “Animals”[Mesh])	4,499,401
#6	Search (time[tiab] OR timing[tiab] OR moment[tiab] OR duration[tiab] OR age[tiab] OR month[tiab] OR months[tiab] OR early[tiab] OR week[tiab] OR weeks[tiab] OR year[tiab] OR years[tiab] OR day[tiab] OR days[tiab] OR “Time factors”[Mesh] OR “Age Factors”[Mesh:NoExp])	9,319,237
#5	Search #2 OR #3 OR #4	8,749
#4	Search Exclusiv*[tiab] AND (breastfeed*[tiab] OR breast feed*[tiab] OR breastfed[tiab] OR “breast fed”[tiab] OR lactat*[tiab] OR “breast feeding”[Mesh])	7,687
#3	Search (full[tiab] OR fully[tiab] OR exclusiv*[tiab]) AND (“breast milk”[tiab] OR “human milk”[tiab] OR “maternal milk”[tiab] OR “mother's own milk”[tiab]) AND (fed[tiab] OR feeding*[tiab] OR diet[tiab] OR intake[tiab])	2,171
#2	Search ”fully breastfeeding”[tiab] OR “fully breastfeeding”[tiab] OR fully breastfed*[tiab] OR fully breastfed*[tiab] OR “full breastfeeding”[tiab] OR “full breastfeeding”[tiab]	388
#1	Search ”Infant”[mh:noexp] OR “Child, Preschool”[Mesh] OR infan*[tiab] OR young child*[tiab] OR baby[tiab] OR babies[tiab] OR early childhood[tiab] OR weanling*[tiab] OR “ first year of life”[tiab] OR “early life”[tiab] OR ((“pre school”[tiab] OR preschool[tiab] OR kindergar*[tiab]) AND (child*[tiab])) OR “preschool aged”[tiab] OR “preschool age”[tiab] OR “pre school age”[tiab] OR “pre school aged”[tiab] OR “kindergarten age”[tiab] OR “kindergarten aged”[tiab]	1,461,295