are you serious???
You think that john the Baptist got saved in the WOMB???
HAHAHAHAHAAHahahahahahahahahahahahahaahahahahahahahaha
You sure got some funny doctrine, this conversation ended!
What happened to Jeremiah, to John, and to Mary were three separate, distinguishable, prenatal events: which is why I said "analogously similar" and not "precisely the same." The point is that God can save a soul from from the stain of Original Sin and convey outstanding blessings on a person before birth --- not that one can be once-and-for-all "saved" before birth (in the sense of irreversibly destined for heaven.)
That's not how Catholics understand "saved"--- we don't see it as a permanent, irreversible destiny that cannot be altered by subsequent choices.
So I invited your misunderstanding by not first defining "saved."
At no point were Jeremiah, John, or Mary deprived of their free will, their ability to make moral choices. They did not at that point become automatons for the Lord. They were never more or less than human.
The scripture indicates that Elisabeth herself was filled with the Holy Spirit, when John the Baptist was yet in the womb himself.
Luke 1:41 (NKJV)
Previously in the same chapter, in verse 15 speaking of the one who come to be known as John the Baptist, before he was yet conceived, is included this information;
Putting things together it does seem safe to assume that it is possible that John the Baptist first received the Spirit at the time of Mary's own visitation to Elisabeth, when Mary herself was still early in early stages of pregnancy with the Messiah.
Now whether or not John the Baptist in some way had the Spirit of the Lord within his own body before Mary even had visited, the texts do not indicate one way or another, yet only that John's father was told by an angel what the child's name would be, and that he would be filled with the Holy Spirit "even from his mothers womb".
I do not believe there is clear apostolic teaching further on this that can be assuredly traced back to the Apostles themselves.
Later speculations, additions, subtractions, commentary etc., don't automatically cut the mustard (becoming then "apostolic" for reason some noteworthy Bishop or another said or wrote blah, blah, blah, unless there is indication it was directly apolitically received, and can survive painstaking chain-of-custody examination.