It's a feeling many soon-to-be or brand new parents experience when given the news that their child has Down's Syndrome. Naturally, specific emotions will differ from person to person, but anecdotally, a sense of finality and loss permeates during a time most people without said bombshell undergo transformative and celebratory changes as they adjust to life with their new son or daughter.
For most, there are two forces at play. One is a sense of grief - the grieving of a life you feel you have 'lost'. A vision of parenthood you neither anticipated nor even particularly wanted, and one you didn't experience in either your own upbringing or that of your friends or family members. The second is a fearful lack of understanding - a pregnancy encourages many to ingest as much knowledge about the brave unknown before the baby arrives, but few look with any discernment into information on disability during that time.
The prospect of doing this should Down's (or any unexpected condition) arise during screening or after the birth can be daunting, and even threaten to ruin what again is traditionally considered a very happy occasion.
Unfortunately, only time can heal such an open and exposed wound. Like any bereavement, the grief will linger simply until it does not.
As a parent, you are aided by your child. Your tremendous, curious, confused, excited and infuriated little baby. They require the continued nourishment of your love and undivided attention until a bond forms. And that's if it didn't already in utero. It is not the end, even if it doesn't particularly feel like much of a beginning.