ititl.

in aço imixquac, in anoço incuexcochtlan, anoço iniollopan, anoço imelchiquipan, anoço imitipan, in anoço vel inxillan = the forehead, the nape of the neck, the heart, the chest, the stomach, or the whole abdomen (Mexico City, sixteenth century)
James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 146.

The phrase "quimati in iiti" is used in the Florentine Codex to describe the pregnant woman's feeling or becoming aware of labor pains. See Book 6, Chapter 28.

qujpachoa in ijti in otztli = she massaged the pregnant woman's abdomen (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 155.

auh in jqujn qujmatizque in ijti, qujlmach mjtoa: qujtlatlaqualizchiuhtoque. Auh in ie qujmati in ijti cioatzintli = And when she was to become aware of the labor pains, they say - it is said - they were to prepare food for her. And when the woman already felt labor pains (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 159.

intla oqujc cioapatli, in joan tlaquatl: intlacamo qujtlacamati in ijti: cenca tlaovicamati in ticitl, ioan in jlamatque = if the woman drank the ciuapatli and the opossum [tail infusion, and] if her labor pains responded not, the midwife and the old women considered it (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 159.

ititl = abdomen
itetl = abdomen
titi = our abdomen
tote = our abdomen
ca pitztic = it is thin
ca pitzauhqua = it is thin
uei = large
ololtic = round
uilanqui = dragging
uilaxtic = dragging
poҫactic = swollen
patztic = soft
papatztic = very soft
xoxoquiuhqui = like an olla
xoxoquiui = it becomes like an olla
papatziui = it becomes very soft
itipoҫaoa = abdomen swells
îtiuilani = abdomen drags
ititlapaniui = abdomen breaks
itiuilaxtia = abdomen drags (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 10 -- The People, No. 14, Part 11, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 121.