Kay angrily confronted Michael with aborting her male fetus, sending him into a violent rage. An abortion was credible, even though abortion was illegal in the US until after Roe v. Wade (1973). Any woman with some money (probably ~$500 in 1958-59) could have gotten an abortion by a real doctor in a clinical setting—and Kay had plenty of money. But, I’m wondering if Kay really did have an abortion—or if she had a miscarriage, and called it an abortion to get back at Michael for all the lies and disappointments he’d inflicted on her:

--Any doctor performing an abortion on Mrs. Michael Corleone knew he’d be putting himself in mortal danger. And, there’d be no way he could hide his identity. Kay was confined to the Tahoe compound, so he’d have to do it there; or, if Kay insisted on going to her doctor’s office or a hospital, she’d have been accompanied by Tom and/or an army of bodyguards.
--“It was a boy!” Kay hissed at Michael, adding that she would never “bring another one of your sons into this world.” Kay was only three months pregnant, as Tom told Michael, and amniocentesis was unknown in the US at the time. There is no way Kay could have known for sure that the aborted fetus was male.
--She also said she did “an unholy thing,” perhaps mocking the Catholic faith that she had converted to after marrying Michael.

What do you think: abortion? Or miscarriage, vengefully misrepresented by Kay as abortion?

I think it was a miscarriage. Kay's resentment (livid anger) over Michael's endangering the family was definitely manifest on the night of the assassination attempt. When they were dancing that night she reminded him about his failed family legitimacy plan. He asked about the baby's gender and she answered him. So, she knew just how to hurt him. She miscarried and drove the knife home with the abortion claim.

Great argument, Turnbull. Strong enough to convince me you are correct.

One other point in favor of it being a miscarriage is that something truly egregious needed to happen in order for Michael to "allow" her to leave. In fact, it is not out of the question that Kay came up with the abortion story then and there, during that very conversation, when Michael said he could never allow Kay to leave. His exact words were "Kay what do you want from me? Do you expect me to let you go? Do you expect me to let me take my children from me? Don't you know me? Don't you know that that's an impossibility -- that that could never happen. That I would use all my power to keep something like that from happening -- don't you know that?" At that point, she may have seen a ruse as her only way out.

The only arguments to the contrary I immediately see are;

Falsifying an abortion when divorce was imminent could easily negatively affect her in a divorce court of that era in regards to child custody. It shouldn't, but it could be an indicator of one not being a safe custodian through the antiquated reasoning of the day. Plus, an abortion then was an illegal act (preposterous, I know, to contrast that with the actions of a mafia don) and could be held as further grounds to deny her custody.

A lesser argument is at no time did she ever admit to the deception. This, while noteworthy, does not convince me of much. What good would it have done to admit it, either shortly after the statement was made or decades after the fact? She may not be believed, it would reopen old wounds, and would not serve any positive purpose.

Well said, Mr. B.

In fact, Kay did lose custody--we saw that near the end of GFII, when Connie was rushing her out of her visitation with the kids, and she ran into the Dreaded Corleone Stare. The divorce may already have been final by that time--Nevada was one of only two states that granted quickie divorces at that time (Idaho was the other). Divorce courts then and now routinely grant custody to the mother, except if the mother can be proven to be mentally, physically or morally "deficient." Kay's divorce would have been grounds for "moral deficiency" in those days, and given Michael's money, influence and fear factor, a judge would have readily granted him custody.

The children were in the New York hotel hallway; she's arguing with Michael. She leaves and takes the kids. Where do they go? Nevada? New Hampshire? Where did she file for divorce? Nevada? Probably not. Michael's face was center stage during the Senate hearings and there's no evidence that Kay had an abortion. She had a miscarriage. It's confusing as usual.

I can't imagine that Michael would ever have allowed his personal business to be aired in divorce court, and Kay surely knew that.

They must have made a private arrangement - something along the lines of Kay being granted a divorce in exchange for Michael getting primary custody (at least for a while - they did end up with Kay eventually).

Kay might not have really objected to that. As much as she wanted them out of the Mafia environment, there was always the chance the children would be targets for Michael's enemies. They would be safer on the compound.

While the miscarriage angle makes for an interesting theory, I think Kay really had an abortion.

While it might not have been possible to tell the sex of a baby at three months, that can be chalked up to director's license. It would be uncharacteristically foolish for Kay's to rely on something medically impossible for her coup de grace against Michael.

As for logistics, in an earlier version of the script, Kay is able to escape (under the guise of boating with a neighbor) and return to her parents' home in New Hampshire. On her home turf, it wouldn't be hard for her to find a doctor either unaware of who she is or willing to take a risk for her.

Also, if it's just a miscarriage, that denies Kay much of her agency. Rather than a strong character taking control of her situation, she would just be a vengeful, opportunistic liar. Kay is a strong character and I think the abortion scenario better fits her story arc.

I'm doubtful that Kay had an abortion. If she was trying to end "this Sicilian thing," logically she would also have to murder her first son, whose closest companions were all gangsters.

This would have made for a marvelous alternate ending: Kay induces Michael to serve as patron of the fledgling Reno Opera Society. For their gala premier, a performance of Cherubini's "Medea," Michael quietly arranges for Kay to sing the title role to rave reviews. He is quite surprised when, in the third act, Kay murders his children onstage to thunderous applause, as the audience all think that it's part of the show.

Just throwing this out there- Kate wouldn't have necessarily needed a doctor to do the abortion.

Women have been performing various methods of self abortion since there have been people on this planet. While dangerous, they were once fairly common, i.e. botanical abortifacients, insertion of objects in to the uterus, etc.

So, Kay doesn't know if her child is male or female, right? But because she wants to end the Sicilian thing, she takes a chance that it's a son?

Why do you assume she didn't know? In the film she makes very clear that she did know, and it's very clear that Michael believed her.

Just because Tom makes an offhand comment about "three and a half months" doesn't seem to me to be a strong argument in favor of a miscarriage.

Maybe Tom was wrong about when the baby was conceived. Maybe one of Michael's forays into the legitimate world was in cutting-edge obstretrical technology. Maybe FFC didn't really think obsessed fans like us would parse the films to this extent to come up with theories.

All of those make more sense than Kay making up a medically impossible story and Michael buying it. (OK, my second theory makes less sense.)

She commented to Michael while dancing that it felt like a boy.

Biggest hypocrite

I reckon Kay never lost the baby!
The baby was born away from Michael and turned up as Vincent in Godfather 3
No wonder he was readily accepted and fast-tracked to Don Corleone

Ref: my above post in the below thread
Did anyone else notice that .......
Michael didn't ask the tough question! - How did Kay get the abortion?

What is even more ridiculous! than Kay getting the supposed 'abortion'....Michael buying Kay's "impossible" story
And a man in Michael's position can't afford to be made to look ridiculous!

It seems the abortion angle was suggested by Talia Shire (edit: at around 1:10:00):

https://youtu.be/Xd71uVNlbLs

It may explain why the idea doesn't seem completely explored by Coppola and Puzo.

Nobody Pete nobody! “completely explores” Godfather like we do!

As dramatic effects go, the 'abortion' is up there indeed and we would have missed out on -

Did anyone else notice that .......
and Talia Shire's reward Godmother! in Godfather III

I always wondered how in the hell could she have gotten an abortion without Tom or somebody else knowing. You KNOW Michael had to have done some kind of investigation into that.

Knowing Michael's lust for vengeance, I'm surprised he didn't have the person that performed the abortion, the murder of his child, eliminated.

I’ve always felt it was a miscarriage but Kay knew the only way to truly end it with Michael was to claim it was an abortion. I’m sure she also knew it would be difficult to find a doctor willing to do it as well as being basically under house arrest at the compound. The only way is if she did it herself which would be extremely dangerous