I-trisomy kwi-chromosome engama-21, noma i-Down's Syndrome, iyindlela ejwayelekile kunazo zonke yokukhubazeka kwezemvelo ezenzeka ezinganeni ezingaba ngu-1 kwabangu-800 ezizalwa. Ososayensi bathole ukuthi lesi sifo ngenxa yokusabalalisa okungalungile kwama-chromosomes, okwenza isiguli, esikhundleni samakhophi amabili we-chromosome engama-21, kunezintathu. Ukulindela ukubonakala kwe-pathology akunakwenzeka, kusobala ukuthi i-trisomy eyodwa kwi-chromosome engama-21 ayisho lutho ngaphandle kochungechunge lwezinkinga ezingokwengqondo, zomzimba nezokuziphatha eziphazamisa ukuthuthukiswa okuvamile nokuphila komntwana ogulayo.
Ngokuphathelene nalokhu okungenhla, kunzima ukugcizelela ukubaluleka kokuthola isifo sokubeletha ngaphambi kokubeletha, okuvumela utero ukuba ubone ukuthi ubungozi be-trisomy 21 bunezinkomba zezici.
Ukuhlolwa kokuqala kwe-trimester
Ikhuluma ngezindlela ezingenasidingo futhi iqukethe i-ultrasound nokuhlaziywa kwegazi ngamama. Isikhathi esifanele sokuhlolwa kokuqala kokubeletha kungamaviki angu-12-13.
Phakathi nokuxilongwa kwe-ultrasound, ochwepheshe balinake ubukhulu bendawo ye-collar, okuyi-marker ephawulekayo yokuba khona kwezinto ezingavamile. Ngokufanayo, kuye ngokuthi yikuphi isonto lokukhulelwa kanye nesimiso esivumelana nalo, isibonakaliso se-trisomy 21 singase sibe ukwandiswa kwesikhala sekhalenda esingaphezu kwama-5 mm.
Kanti igazi le-wesifazane lihlolwe ngamahomoni amabili: mahhala i-HCG ne-RARR-A. Ngoba i-unit of measure yezinkomba ezifundwayo zithatha - i-MoM. Amagugu atholakalayo afaniswa namanani ajwayelekile: I-Trisomy 21 ingabonisa izinga elengeziwe le-b-hCG mahhala - ngaphezu kwama-2 M0Ma, futhi ukuhlushwa kwe-PAPP-A kungaphansi kwe-0.5MoM.
Kodwa-ke, ngokusekelwe emiphumeleni yokuhlolwa kokuqala kokubeletha, akunakwenzeka ukudweba iziphetho ezicacile, ngoba lokhu kuyisibonakaliso esiyingozi kuphela esingacabangi ezinye izici ezithonya izinga lama-hormone. Kuzokwazi ukuthwala kubo: isikhathi esibekiwe sokukhulelwa, isisindo somama, ukugqugquzelwa kwe-ovulation, ukubhema.
Ukuhlolwa kokubili ngaphambi kokubeletha
Esikhathini esiphakathi kwamasonto angu-15-20, kwenziwa umzamo wesibili ukuxilonga isifo se-genomic. Le nkathi ibhekwa njengolwazi oluthe xaxa, ngoba ukwephula okuningi kungabonakala ngesikhathi se-ultrasound. Isibonelo, emntwaneni ophethe i-trisomy kuma-chromosomes angu-21 ahluke ngokujwayelekile: ubude be-humerus ne-femur, ubukhulu bhuloho ekhaleni, ubukhulu be-renal pelvis, futhi ngezinye izikhathi ukukhubazeka okubonakalayo kwenhliziyo, umgudu wamathumbu noma i-cyst ye-plexus ye-vascular of the brain.
Igazi lomama okhulelwe lihlolwe ngezinga le-AFP, eliyimpawu ecacile ye-pathology ye-fetus yokuzalwa. Uma, ngenxa yokuhlolwa kwesibili, i-AFP itholakale ingajwayelekile, lokho kungabonisa ukuthi kukhona i-trisomy kuma-chromosomes angu-21.
Imiphumela etholakalayo iqhathaniswa nemiphumela yocwaningo lokuqala, uma izingozi ziphezulu, owesifazane okhulelwe unikezwa ezinye izindlela zokuhlolwa.
Izindlela ezivelele zokunquma okungavamile kwe-chromosomal
Kunembile kakhulu, kodwa futhi nezindlela eziyingozi kakhulu zokuthola ukukhathazeka ngokobulili yizi:
- amniocentesis - kusho ukubhoboza odongeni lwesisu ngesinaliti esincane nomcingo we-amniotic fluid, okuphenywa esikhathini esizayo;
- I-chorion biopsy iyindlela enhle yokwazisa. Njengomthetho, isampuli yamaseli e-villi ne-placenta kwenziwa emasontweni angu-11-12, ngokubhoboza isisu esiswini, noma ngokusebenzisa i-catheter ngokusebenzisa isisu;
- isampuli yegazi ye-cord umbilical, akwenziwanga ngaphambi kweviki le-18 lokukhulelwa.
Izindlela ezimangalisa, nakuba zivumela ukuzimisela okunembile kokutholakala kwe-anomaly anomaly, kodwa ngesikhathi esisodwa sinomngcipheko wokuqeda ukukhulelwa okungahambi kahle.