nangyayari yan pag di po maganda yung sperm or eggcell na nagmeet. ang chromosome po ay yung genetic material na manggagaling sa sperm at eggcell (tig 23 po yan sila para mabuo ang 46 chromososmes yan po ang normal) maraming reasons bakit nagkakadefect pero madalas kulang o sobra yung chromosome- yung iba sa 1st few weeks pa lang ng pregnancy, nawawala na ang embryo, di nagkaheartbeat, yung iba po during 2nd or 3rd tri. kaya po mag nababasa o napapanood kayo na may trisomy, down, edwards syndrome, etc. medyo malawak po kasi na topic ito. na sa OB or expert nyo po talaga mas maiintindihan. read this po https://www.verywellfamily.com/chromosomal-abnormality-2371605#:~:text=Chromosomal%20abnormalities%20occur%20because%20of,also%20have%2046%20chromosomes%20each. also this: https://www.cdc.gov/ncbddd/birthdefects/prevention.html
Google mi.
Anonymous