I-trimester yesithathu yokukhulelwa iqala malunga neeyure ezingama-26-27 zobomi bomntwana ngaphakathi kwesibeleko. Usana sele selunezixhobo ezisemgangathweni ezisebenzayo, nangona zide zingaphelelanga. Namhlanje siza kuthetha malunga nokuphuhliswa komntwana kwiveki yama-27 yokukhulelwa kwaye malunga naluphi utshintsho olwenzekayo ngeli xesha kumzi womfazi.
Umntwana
Ukususela kule veki, izinga lokusinda komntwana xa kuthengiswa kwangethuba kungama- 85%. Ngoku umntwana usenokuba nenene, nangona ukuzaliswa okupheleleyo kuza kugqitywa kuphela emva kweiveki ezi-13 ezipheleleyo. Kwiiveki ezingama-27, umntwana usengumncinci kwaye umncinci, kodwa sele uvele ngaphandle koko kuza kuzalwa. Ubude obude bu malunga no-35 cm, ubunzima-0.9-1 kg. I-crumb isenayo indawo eyaneleyo yokwenza okusebenzayo: iyawa, idibha, ihamba imilenze yayo neengalo, iqeqesha imilenze yayo yokomeleza. Ngamanye amaxesha unokuqikelela ukuba yiyiphi inxalenye yomzimba womntwana ekuphumeni kumama kwisisu.
Amehlo omntwana akwazi ukusabela ekukhanyeni kudlula udonga lwesisu. Umculo wesiqhelo kunye nelizwi lomama, umntwana ulungile ekuboneni. I-reflex yokusondeza iphuhlisiwe kakuhle, ihlala isondeza iminwe. Ngokuqhelekileyo umntwana uhlala emlonyeni, oku kwenzeka embdom kwiveki 27 nangaphezulu. Isizathu se-hiccups singumngcipheko we- amniotic fluid. Oku kuncedisa ekuphuhlisweni kwemiphunga, kuba iimeko ezichanekileyo. Ukususela kwiiveki ezingama-27, ukuphuhliswa kwengqondo yesisu kuqhuba ngokukhawuleza. Ezinye iingcali ziqinisekile ukuba ngeli nqanaba umntwana sele ebonayo amaphupha. Ukuphefumula kwangaphandle kunye nokutya kuyenziwa njengaphambili phambi kwepentecenta. Ukuguqulwa kwe-fetus kwiveki yama-27 kuyimivimbo engu-140-150, ngelixa uqhuba u-40 ukuphefumla ngomzuzu.
Umama
Umbele wesifazane okhulelweyo ekuqaleni kwe-trimester yesithathu iphakame ngaphezu kwenqweno ngo-5-7 cm.