Objection 1. It would seem that it was proper for the Blessed Virgin, after Christ, to be sanctified in the womb. For it has been said (4) that the Blessed Virgin was sanctified in the womb, in order that she might be worthy to be the mother of God. But this is proper to her. Therefore she alone was sanctified in the womb.
Objection 2. Further, some men seem to have been more closely connected with Christ than Jeremias and John the Baptist, who are said to have been sanctified in the womb. For Christ is specially called the Son of David and of Abraham, by reason of the promise specially made to them concerning Christ. Isaias also prophesied of Christ in the most express terms. And the apostles were in converse with Christ Himself. And yet these are not mentioned as having been sanctified in the womb. Therefore it was not befitting that either Jeremias or John the Baptist should be sanctified in the womb.
Objection 3. Further, Job says of himself (Job 31:18): "From my infancy mercy grew up with me; and it came out with me from [my mother's] womb." Nevertheless we do not for this reason say that he was sanctified in the womb. Neither therefore are we bound to say that Jeremias and John the Baptist were sanctified in the womb.
On the contrary, It is written of Jeremias (Jeremiah 1:5): "Before thou camest forth out of the womb I sanctified thee." And of John the Baptist it is written (Luke 1:15): "He shall be filled with the Holy Ghost, even from his mother's womb."
I answer that, Augustine (Ep. ad Dardan.) seems to speak dubiously of their (Jeremias' and John the Baptist's) sanctification in the womb. For the leaping of John in the womb "might," as he says, "signify the great truth," viz. that the woman was the mother of God, "which was to be made known to his elders, though as yet unknown to the infant. Hence in the Gospel it is written, not that the infant in her womb believed, but that it 'leaped': and our eyes are witness that not only infants leap but also cattle. But this was unwonted because it was in the womb. And therefore, just as other miracles are wont to be done, this was done divinely, in the infant; not humanly by the infant. Perhaps also in this child the use of reason and will was so far accelerated that while yet in his mother's womb he was able to acknowledge, believe, and consent, whereas in other children we have to wait for these things till they grow older: this again I count as a miraculous result of the divine power."
But since it is expressly said (of John) in the Gospel that "he shall be filled with the Holy Ghost, even from his mother's womb"; and of Jeremias, "Before thou camest forth out of the womb, I sanctified thee"; it seems that we must needs assert that they were sanctified in the womb, although, while in the womb, they had not the use of reason (which is the point discussed by Augustine); just as neither do children enjoy the use of free will as soon as they are sanctified by baptism.
Nor are we to believe that any others, not mentioned by Scripture, were sanctified in the womb. For such privileges of grace, which are bestowed on some, outside the common law, are ordered for the salvation of others, according to 1 Corinthians 12:7: "The manifestation of the Spirit is given to every man unto profit," which would not result from the sanctification of anyone unless it were made known to the Church.
And although it is not possible to assign a reason for God's judgments, for instance, why He bestows such a grace on one and not on another, yet there seems to be a certain fittingness in both of these being sanctified in the womb, by their foreshadowing the sanctification which was to be effected through Christ. First, as to His Passion, according to Hebrews 13:12: "Jesus, that He might sanctify the people by His own blood, suffered without the gate": which Passion Jeremias foretold openly by words and by symbols, and most clearly foreshadowed by his own sufferings. Secondly, as to His Baptism (1 Corinthians 6:11): "But you are washed, but you are sanctified"; to which Baptism John prepared men by his baptism.
Reply to Objection 1. The blessed Virgin, who was chosen by God to be His Mother, received a fuller grace of sanctification than John the Baptist and Jeremias, who were chosen to foreshadow in a special way the sanctification effected by Christ. A sign of this is that it was granted to the Blessed Virgin thence-forward never to sin either mortally or venially: whereas to the others who were thus sanctified it was granted thenceforward not to sin mortally, through the protection of God's grace.
Reply to Objection 2. In other respects these saints might be more closely united to Christ than Jeremias and John the Baptist. But the latter were most closely united to Him by clearly foreshadowing His sanctification, as explained above.
Reply to Objection 3. The mercy of which Job speaks is not the infused virtue; but a certain natural inclination to the act of that virtue.
Source: Summa Theologica (New Advent)