Wa'alaikumassalam sis! I haven't done it myself, tapi a few of my mum friends kena suggest by their doctors sebab ada concerns during pregnancy, dari what they shared, it's basically a needle through the belly to get amniotic fluid for testing, and yes ada small risks so doctors only suggest when really needed. Best talk to your doctor about why they're recommending it, what it can show, and what the actual risks are for your situation, sebab setiap pregnancy different. Mana tahu ada alternative screening dulu? Anyway, if you proceed, ramai moms say the waiting period for results yang paling stressful. Hope everything turns out okay for you, mama!