Mae'r rhaglen sgrinio gynenedigol bresennol yn cynnig nifer o wahanol brofion sgrinio sylfaenol i fenywod beichiog er mwyn canfod rhai o'r cyflyrau a allai effeithio ar y fam neu'r babi. Mae un o'r profion sgrinio hyn yn gallu dangos y posibilrwydd o gael babi sydd â syndrom Down. Os yw'r posibilrwydd yn cyfateb i 1 allan o 150 neu'n uwch, ystyrir bod yna fwy o risg, ond ar hyn o bryd yr unig opsiwn sy’n cael ei gynnig yw prawf mewnwthiol i gadarnhau'r diagnosis. Mae risg bach y gellid colli’r babi drwy gael y profion diagnostig mewnwthiol hyn.
The current antenatal screening programme offers pregnant women a number of different primary screening tests to detect some of the conditions that may affect either the woman or their baby. One of these screening tests shows the chance of having a baby with Down’s syndrome. If this is equal to or higher than 1 in 150, women are considered higher chance but are currently only offered the option of an invasive test to confirm the diagnosis. These invasive diagnostic tests carry a small risk of miscarriage.