We start with encyclopedia words and meanings.
At the moment of conception and the first weeks we have a ball of cells called a blastocyst. Its not a baby, at best it has potential to be one.
After about 10-12 weeks its called an embryo, placenta is formed. That assumes successful implantation in the uterus, anywhere else in the woman's body has fatal consequence without intervention. NOTE: we do not have science, surgery, or drugs, that can correct (relocate) an ectopic pregnancy.
A few weeks later its called a fetus. we need many more months to be even viable.
It is not a baby until it is born, as in outside the uterus, and external to the woman's body.
To survive outside the womb at all the fetus must be 23 weeks and born to a NICU where for the next 5 months the baby will hopefully develop. At 23 weeks that's currently 50-50 chance of surviving. Usually if the premie (premature birth) survives it will have behavioural and learning delays or deficiencies. Many problems early on concern brain, eyes, and lung development as well as status of other organs. That and availability of highest tech NICU.
Any tech that get us viability before 19 to 20 weeks requires the science level that is currently fiction and it would be a test tube baby as its outside the uterus Right now there are many issues with test tube babies. Science will get us there but really the same religions that claim life beginning at conception would have hissy fits with test tube babies. Oh by the way, if fertilization occurs in a test tube that's a blastocyst not even an embryo or a fetus. The ethics of that is still debated and may go to the banned column.
With basic human development we need typically 39-40 weeks for a normal birth.
All that said:
Religion may have life beginning at birth but science screams not remotely possible with even unforeseen tech to get earlier than where we are maybe 20 weeks (~8 out 100 may make it to 23 weeks).
Bang that against the first amendment:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances. END QUOTE
Specifically no law establishing a religious views or opinion. That means prohibiting abortion based on the religions that says life begins at birth is now federal law based on religion and not science. That to me means the justices acted against the Constitution and its prohibitions of this country and are promoting religion. At a minimum they need to be impeached, disbarred, and potentially higher crimes of obstruction. The last court that made grievous errors and removed or denied right was the one that gave us Dred Scott. Like that one, the current court will be known to history for their crimes.
We The USA are not a theocracy. While our founders respected religion and they were diverse in their beliefs they knew from our English and other forebears religion has no place in government. They also believed the government has no say in any religion or the support thereof. Their knowledge of that is their own experience or their predecessors fled other countries on that issue alone!
For this keep your powder dry and well hidden. For surely the redcoats will come for your cannon and shot.