Ziziphi izinto ezibukekayo?
Kukho iimvavanyo ezimbalwa zokuhlola i-serum (iimvavanyo zegazi) ezifumanekayo ngexesha lokukhulelwa ezinokulinganisela amathuba akho okuba nosana olune-Down syndrome.
Nangona le mvavanyo ihluke ngokuphathelele xa ukhulelwe, kunye nobutyebi (amathuba okukunika impendulo echanekileyo), zonke zilinganisa izinto ezenziwa ngumntwana okanye umntwana.
Inzuzo ebalulekileyo kwi-screening ye-serum xa kuthelekiswa nokuvavanywa koxilongo kukuba akukho mngcipheko wokukhulelwa kwesisu ohambelana nawo.
Uvavanyo lokuqala lokuhlola ukuhlola: i-hCG kunye ne-PAPP-A
Ngexesha lekota yokuqala, izinto ezimbini ezibizwa ngokuba yiHCG kunye ne-PAPP-A zifumaneka kwigazi lomama. Ezi zinto zingalinganiswa (ngokuqhelekileyo phakathi kweiveki ezi-10 ukuya kwe-14 zokukhulelwa) kwaye zisetyenziswe ukubonisa ithuba lomfazi lokuba nomntwana onesifo se- Down syndrome (esiyi-trisomy 21).
I-HCG (iGonadotropin yabantu)
I-HCG yi-hormone eyenziwe yi-placenta. Enyanisweni, ekuqaleni kwexesha lokukhulelwa, yinto efunyenweyo kwi-home and doctor doctor urine kunye nokuhlolwa kwegazi lokukhulelwa.
Ukukhulelwa komntwana apho umntwana ophethe i-Down syndrome banamanqanaba aphezulu e-HCG kunezinye ukukhulelwa.
I-PAPP-A (i-Prognancy-Associated Plasma Protein)
Abasetyhini abanamaqondo aphantsi e-PAPP-A kwiiveki ezi-10 ukuya kwe-14 zesigxina banamathuba okwandisa umntwana wabo ukuba abe ne-Down syndrome.
Amanqanaba aphantsi e-PAPP-A angabonakalisa ingozi eyongeziweyo yokukhutshwa kwemithwalo yangaphakathi, ukuhanjiswa kwangaphambi kwexesha, i-preeclampsia, kunye nokuzalwa komntwana.
Iziphumo zovavanyo lokuqala lweSermetic Testing Test for Down Syndrome
Iziphumo zolu vavanyo lwegazi ngenxa ye-hCG kunye ne-PAPP-A zibikwa ngokuthi "i-screen negative" okanye "i-screen positive" kwaye zinika ukuqikelela kwithuba lakho lokuba nomntwana onesi-trisomy 21.
Ngamanye amazwi, lo vavanyo lwegazi lokuhlolwayo aluxilisi i-Down syndrome.
Isikrini esingabonakaliyo
Iziphumo "ezingalunganga" zibonisa ukuba ithuba lakho lokuba nomntwana one-Down syndrome liphantsi. Nangona kunjalo, kubalulekile ukukhumbuza ukuba umphumo "ongenakonakala" awuqinisekisi ukuba akukho ziphoso zokuzalwa. Ukuba unesiphumo "esingenaskrini", awuyi kunikwa uvavanyo lokulandelelwaniswa ngokulandelelana ngeCVS okanye i-amniocentesis. (Ezi mvavanyo ziyakwazi ukuxilonga i-Down syndrome, ngokungafani nokuhlola kwegazi).
Ngakolunye uhlangothi, uya kunikwa esinye isilingo segazi lokuhlola, esenziwa kwi-trimester yesibini, ebonisa into ebizwa ngokuba yi-AFP. Isixa se-AFP esesikhokelo sikhokelo seenambuzane ezivulekileyo ze-neural njenge-anencephaly and spina bifida.
Iziphumo eziPhambili zeSkrini
Iziphumo "ezintle" zibonisa ukuba ithuba lokuba umntwana abe ne-Down syndrome liphezulu kunexesha eliqhelekileyo. Ngoko, ngale miphumo, ukuhlolwa kokulandelelwaniswa kokuhlolwa kunye neCVS kuya kunikwa.
Kubalulekile ukuba uqaphele ukuba isiphumo "esihle" sithethi ukuba umntwana usenayo i-chromosome engavamile. Enyanisweni, uninzi lwabasetyhini abaneempembelelo "ezintle" ziza kuba neentsana eziqhelekileyo eziphilileyo.
Ukuchaneka kweSkrini esifanelekileyo kunye neSkrini Iziphumo ezimbi
Ukucacisa kwakhona, iimvavanyo zokuhlola i-serum akukunikezi ukuxilongwa kodwa ukunika uqikelelo lokuba nethuba lomntwana onesifo se-Down syndrome.
Nangona ukuchaneka kokuvavanya kuyahluka ngokukodwa kwilebhu kwibhulebhu, ngokubanzi, uvavanyo lokuqala lwe-serum yokuhlola i-hcG ne-PAPP-A luya kubona malunga neepesenti ezingama-80 zeintsana ezine-Down syndrome.
Le nqanaba lokufumanisa landa xa usebenzisa le vavanyo ngokubambisana novavanyo lwe-ultrasound uvavanyo olubizwa ngokuba yi-nuchal translucency test, eyenziwa kwinqanaba lokuqala.
Nangona ukuhlolwa kwe-serum yokuqala ye-trimester kufumanisa malunga ne-80 ekhulwini yokukhulelwa nge-Down syndrome, "kuya kuphinda" iipesenti ezingama-20 (malunga no-1 ukuya kwe-5) ukukhulelwa kwezi meko.
Okunye malunga ne-Nuchal Translucency Ultrasound Screening
Ukuhlolwa kwe-Nuchal translucency yi-ultrasound ekhethekileyo eyenziwe kwi-trimester yokuqala eyilinganisela umlinganiselo wetsholongwane emva kwentamo yomntwana (i-translucency ye-nuchal).
Oku kuyimilinganiselo ekhethekileyo kunye nobunzima ukufumana, kwaye i-ultrasound ingenziwa kuphela ngumntu oqeqeshiwe ngokuzeleyo kwaye eqinisekisiwe ekufumaneni lo mlinganiso.
Ngokubanzi, imilinganiselo engaphantsi kwe-3 mm ithathwa njengesiqhelo okanye "i-screen negative" kwaye umlinganiselo we-nuchal we-translucency we-3 mm uthathwa njengento engavamile okanye iskrini esilungileyo.
Ngokuqhelekileyo, imilinganiselo ye-nuchal ye-translucency kunye neyokuqala-sithathu ye-serum yokucima ixabiso ihlanganiswe ndawonye usebenzisa i-algorithm ekhethekileyo okanye ifomula, kwaye unikwe isethi esinye seziphumo zokuhlola.
Ukuba ukuhlolwa kwe-nuchal yakho ye-translucency kulungile, uya kuhanjiswa kumcebisi wezofuzo ukuze uxoxe ngeziphumo zakho zokujonga, oko kuthetha ntoni, kunye neendlela zakho zokuhlola uvavanyo ezifana neCVS kunye ne-amniocentesis.
Olunye Uvavanyo Lokuqala Lokuhlola Isivivinyo: I-DNA ye-Cell-Free Free Test
Kubalulekile ukuba uqaphele ukuba kukho olunye uvavanyo lokuhlola ukuhlolwa kwe-Down syndrome olufumanisa i- DNA engenaselula egazini likaMama. Olu vavanyo lunokwenziwa emva kweeveki ezili-10 zesigxina kwaye lufumana u-99% ekhulwini lokukhulelwa oluchaphazelekayo yi-Down syndrome.
Umphumo wokuvavanya ngowama-5 ukuya kweetesenti okanye ngaphezulu kweesampula zegazi, akukho miphumo enokufumaneka, nangona emva kokuba uvavanyo luphindwaphindwa. Ukongeza, uvavanyo lubiza. Oko kwathiwa, abafazi abasengozini enkulu yokuba nosana abane-Down syndrome ngokubanzi bafumana lo vavanyo (umzekelo, abafazi abaneminyaka engama-35 okanye ngaphezulu kwithuba lokuhambisa).
Ukongezelela, abafazi abanesicinga "esiphumeleleyo" vavanyo lweHCG kunye ne- PAPP-A banokukhetha ukuvavanywa kwe-DNA ngaphandle kweeseli endaweni yokuqhubeka nokuhlolwa kovavanyo. Ukuba ukuhlolwa kwe-DNA engenaselula kulungile, koko i-CVS okanye i-amniocentesis ingenziwa ukuze ihlolwe.
Ngakolunye uhlangothi, ukuba uvavanyo lwe-DNA olungenaselula luyinto engalunganga, ngoko uvavanyo lokuqala lwegazi (i-hCG kunye ne-PAPP-A) ngokuqhelekileyo kuthathwa njengamanga.
ILizwi
Njengoko uyakubona, kukho inamba yeendlela zokuqala zokujonga i-Down syndrome ezinokuqala ezi-trimester eziquka uvavanyo lwegazi lwe-hCG kunye ne-PAPP-A, i-ultrasound, okanye udibaniso lwababini. Ukongezelela, kubafazi abasemngciphekweni, kukho i-DNA yegazi yokuhlolwa kwegazi.
Ukukhetha apho (ukuba kukho) indlela yokuhlola, kwakunye nexesha (abanye besetyhini bakhetha ukulinda de kubekho i-trimester yesibili), kulungile kuwe isigqibo somntu siqu kwaye ufuna incoko esondeleyo kunye nodokotela wakho kwaye ngamanye amaxesha umcebisi wezofuzo.
> Imithombo:
> I-American College ye-Obstetrics kunye neGynecologists. (2014). Uvavanyo lweSkrini zoLwahlulo lokuzalwa.
> Messerlian GM, Palomaki GE. I-Down Syndrome: Uhlolo-nkcukacha lwe-Screening ye-Prerenatal. UWilkins-Huag L, ed. Isemgangathweno. Waltham, MA: UpToDate Inc.
> I-National Down Syndrome Society. (2012). Ukuqonda ukuxilongwa kwe-Down Syndrome.