The moment of conception is the key, everything else is development, and for several mammal species can even be done outside the womb in an artificial environment. Your DNA does not change as your develop. Your sex, race, size, hair and eye color and many other things are determined right at that moment, and they will never change for the next 80 years or more. We were fully human at that moment, and only became larger and stronger and more developed, but never more human.
As for abnormalities you are just has human with a disease as you are when you are well. Would you tell the person working at a fast food restaurant clearing tables they are less human than you are because they have Down’s Syndrome? Would you say someone who has Sickle Cell Anemia or Tay Sachs Disease they are less human than you are, because they have a genetic condition? Should we stop the Labor Day Telethon and tell all those people with Muscular Dystrophy they are not really humans so we are just going to put them down like dogs because their DNA is imperfect? In Communist China women are aborted because families want boys to carry on the family name.There are people waiting in line for years in the USA to adopt any child, even those who are severely disabled. Thousands of Americans go to Korea, Ukraine and all over the world to adopt children because we murder almost half of our babies. You can legislate morality. Theft, rape, kidnapping and murder are all illegal because they are immoral. The secular humanist leftists have tried to convince us that children are not humans, old people are not human, and the disabled are not human. Every place that legalized abortion on demand eventually legalizes assisted suicide, and infanticide, and finally, murder by the state. Abortion is wrong, it is unethical, there is no excuse for abortion; that’s the view from the Hysterical Right Wing.