Ukufakwa Kwembryo: Ukuqonda Inqubo Nohlelo Lwesikhathi

Ukutshalwa kwe-embryo kungesinye isinyathelo esibalulekile ekukhulelweni, okuwuphawu okuqalisa ukukhulelwa. Le nqubo yenzeka lapho iqanda elivundisiwe, manje elibizwa nge-blastocyst, linamathela kumcamelo wangaphakathi wesibeletho (i-endometrium), okulimvumela ukuba liqale ukuthuthuka libe i-embryo bese ekugcineni libe yisisu. Ukutshalwa kwe-embryo kuyinqubo eyinkimbinkimbi kakhulu nenozwelo, edinga ukuvumelana okunembayo phakathi kokuthuthuka kwe-embryo nendawo esesibelethweni.

Inqubo Yokutshalwa Kwe-Embryo

Inqubo yokutshalwa kwe-embryo ingahlukaniswa ibe yizezigaba eziningana. Iqala ngokuthi i-embryo iqhamuke ungqimba lwayo lokuzivikela lwangaphandle, i-zona pellucida. Lokhu “kuqandusela” kwenzeka cishe ngosuku lwesihlanu noma lwesithupha ngemva kokuvundiswa. Uma isikhululiwe ku-zona pellucida, i-blastocyst iqala ukusebenzisana ne-endometrium, ifune indawo efanele yokutshalwa. Lesi sigaba sibizwa ngokuthi “i-apposition,” lapho i-blastocyst inamathela kancane kumcamelo wangaphakathi wesibeletho, izilungiselela ukunamathela okujulile [1].

Okulandelayo kuza isigaba sokunamathela, lapho amaseli angaphandle e-embryo (ama-trophoblast) ebopha ngokuqinile kumaseli e-endometrium ngokuhlanganiswa kokusebenzisana kwamangqamuzana. Ekugcineni, i-embryo iqala ukungena ngaphakathi komcamelo wangaphakathi wesibeletho esigabeni sokuhlasela, icwila kakhulu ngaphakathi ku-endometrium. Lokhu kubalulekile ukuze i-embryo ikwazi ukufinyelela ekudleni okudingayo ukuze ikhule nokusungula i-placenta, ezoyondla kuyo phakathi nayo yonke inkathi yokukhulelwa.

Kuthatha Isikhathi Esingakanani I-Embryo Ukuthi Itshalwe?

Isikhathi sibaluleke kakhulu enqubweni yokutshalwa kwe-embryo. Itholakala isikhathi esingakanani i-embryo ukuthi itshalwe? Ngokuvamile, ukutshalwa kwenzeka phakathi kwezinsuku ezingu-6 kuya ku-12 ngemva kokuvundiswa, kanti isilinganiso sivamise ukuba usuku lwesi-9. Ifasitela lempumelelo yokutshalwa limncane, futhi izici eziningana kumele zihambisane ngendlela ephelele ukuze lenzeke. Ukulingana kwama-hormone, ikakhulukazi amazinga e-estrogen ne-progesterone, kubalulekile ekulungiseni umcamelo wangaphakathi wesibeletho ukuze wamukele i-embryo [2].

Kwabesifazane abahamba ngenqubo ye-IVF (in vitro fertilization), ukutshalwa kwe-embryo kulandela isikhathi esifana nalena. Ngemva kokudluliselwa kwe-embryo, kuvamise ukuthatha cishe izinsuku ezingu-2-3 ukuze i-embryo iqale ukunamathela esibelethweni, kanti inqubo iphelela phakathi kwezinsuku ezingu-5-8. Lapho i-embryo isisetshaliwe, ukukhiqizwa kwama-hormone kuyanda, kufaka phakathi i-hormone i-hCG, engatholakala ezivivinyweni zokukhulelwa.

Izici Eziwuthintayo Ukutshalwa Kwe-Embryo

Ngenkathi inqubo yokutshalwa kwe-embryo ibonakala ilula, ibucayi kakhulu ezicini eziningi. Ikhwalithi ye-embryo, impilo nokwamukela komcamelo wangaphakathi wesibeletho, kanye nokulingana kwama-hormone konke kudlala indima ebalulekile. Kwezinye izimo, ukucindezeleka nezinye izifo ezifana nokungajwayelekile kwesibeletho noma ukungalingani kwama-hormone kungase kuthinte impumelelo yokutshalwa kwe-embryo. 

Nasezimweni ezinhle kakhulu, akuwona wonke amaqanda afelitheshiniwe afakwa ngempumelelo, yingakho ukukhulelwa kungenzeka ngokushesha ngaso sonke isikhathi ngemuva kwefelitheshini. Kwabafuna ukuthuthukisa impilo yesibeletho nokulungiselela umzimba wabo ukuze ukhulelwe, izithasiselo ezisekela ukuzala eziqukethe amavithamini namaminerali abalulekile zingasiza ukudala indawo esekelayo yokufakwa kwe-embryo.

Izimpawu Nezibonakaliso Zokufakwa Kwe-Embryo

Abanye besifazane baba nezimpawu ngesikhathi sesigaba sokufakwa kwe-embryo, kodwa abanye bangase bangaboni zinguquko neze. Ukufakwa kwe-embryo kungabangela ukuqunjelwa okuncane noma ukopha okuthozekayo, okubizwa ngokuthi ukopha kokufakwa (implantation bleeding), okwenzeka lapho i-blastocyst izijulisa odongeni lwesibeletho. Ezinye izimpawu ezingase zivele zifaka ubuhlungu noma ukuqina kwamabele, ukukhathala okuncane, noma isicanucanu, kanye ubuhlungu bomzimba obufana nomkhuhlane ekuqaleni kokukhulelwa konke ngenxa yezinguquko zama-hormone ezenzekayo njengoba i-embryo iqala ukukhula [3].

Isifinyezo Esiyinhloko

Ekuphetheni, ukufakwa kwe-embryo kuwumsebenzi oyinkimbinkimbi kodwa obaluleke kakhulu enqubweni yokukhulelwa. Kubandakanya izigaba eziningana, ngayinye ebalulekile ekuzibophezeleni okuyimpumelelo kwe-embryo odongeni lwesibeletho. Ithatha isikhathi esingakanani i-embryo ukuthi ifakwe (implant)? Kuvamise ukwenzeka phakathi kwezinsuku eziyisi-6 kuya kweziyi-12 ngemuva kokufelitheshini. Impumelelo yokufakwa incike ekutheni i-embryo inempilo kanjani kanye nendawo yesibeletho injani, futhi yize abanye besifazane bengase babe nezimpawu ezifana nokopha okuncane noma ukuqunjelwa, abaningi abaqapheli lutho. Ukuqonda le nqubo kubalulekile kulabo abazama ukukhulelwa, kungaba ngokwemvelo noma ngokwelashwa kokungabi nenzalo njenge-IVF.

Imithombo:

1. Laura Governini, Francesca P. Luongo, Alesandro Haxhiu, Paola Piomboni, Alice Luddi. Abaqondisi abakhulu abanomthelela ekwamukelekeni kwesibeletho (endometrial receptivity) nasekufakweni kwe-embryo okuphumelelayo. Tissue and Cell, Volume 73. 2021, 101656. ISSN 0040-8166. https://doi.org/10.1016/j.tice.2021.101656.
2. Kim SM, Kim JS. Uhlolojikelele Lwemikhawulo Yokufakwa Kwe-Embryo (Implantation). Dev Reprod. 2017 Dec;21(4):351-359. doi:10.12717/DR.2017.21.4.351. Epub 2017 Dec 31. PMID: 29359200; PMCID: PMC5769129.
3. Ochoa-Bernal MA, Fazleabas AT. Izehlakalo Zomzimba Zokufakwa Kwe-Embryo (Implantation) Nokwakheka Kwe-Decidua Kubantu Naku-Non-Human Primates. International Journal of Molecular Sciences. 2020; 21(6):1973. https://doi.org/10.3390/ijms21061973