The below is a discussion of the notion of ritual impurity in the Church from First Things. You might also enjoy this article from Nun Vassa Larin. It was later responded to by Fr. Sergei Sveshnikov here. This is certainly a topic of much discussion in recent years and worth a read.
(First Things) - “O Master, Lord Almighty . . . Do Thou Thyself heal also this handmaid, [Name,] who today has given birth and raise her from the bed on which she lies . . . purify her from uncleanness . . . cleanse her from bodily uncleanness and the various afflictions of her womb.”
“Purify her . . . from every sin and from every defilement . . . and let her to be counted worthy to partake, uncondemned, of Thy Holy Mysteries . . . Wash away her bodily and spiritual uncleanness.”
These words come from the Orthodox Christian childbearing rites contained in the liturgical handbook, the Great Book of Needs. The first few lines are from “Prayers on the First Day after a Woman has Given Birth to a Child,” or the “First Day” prayers, which are prayed by a priest at a new mother’s bedside soon after birth. The last few lines are from “Prayers for a Woman on the Fortieth Day of Childbirth,” or the “Churching” prayers, which are said when a woman first returns to church with her newborn.
The suggestions about the mother—defiled, unclean, unworthy—jar modern ears. They chafe against the developed-world understanding of childbirth as a healthy and natural biological process that has nothing to do with purity. The situation of these rites among the Orthodox in the United States is varied: Often they are abandoned entirely, some priests change them on the fly, sometimes these rites are celebrated in the tongue of the old country so the exclusively English-speaking mother simply does not have to hear them. Occasionally these rites are being explained, but in wildly inconsistent ways.
Rites can and should make demands on the faithful, so those of us who are piqued by this language must determine if the reason for our reaction is our preference for comfort and ease over hermeneutical effort. We must ask, then, is this concept of impurity after childbirth theologically sound?
It is often assumed that these rites are directly linked to the rites after childbirth found in Leviticus that ban a woman from the temple for a certain number of days and dictate the necessary offerings required for cleansing. Ritual impurity in the ancient world did not constitute a sinful state, but rather a special and contagious ritual state from which one must recover by performing dictated actions. Childbirth was understood as impure not because of the sinfulness of childbearing, but because all experiences which brought one into contact with God’s creative powers, especially female blood—both postpartum and menstrual—were taboo. This understanding was part of the strict division in the ancient world, among the Jews and the pagans, between the sacred and the profane, and this sort of impurity demanded ritual remediation not only to cleanse the impurity from the individual, but also to restore order and maintain God’s favor for the community at large.
Mary, the Mother of God herself, underwent the Mosaic rite or purification, as we hear early in the Gospel of Luke. Yet there is no textual link between the Jewish and Christian purification rites. The oldest extant copies of the Orthodox purification rite, or “Churching,” are from the eighth century, and they do not contain any prayers for the mother whatsoever, but are instead focused entirely on the child. It is only later, in the twelfth century, that the prayers for the mother, which include the impurity theme, were incorporated. The First Day rite was an even later addition, first appearing in the fourteenth century.
The introduction of the Levitical concept of impurity to Orthodox childbearing rites was probably spurred by pagan superstitions about childbirth that were in the air in the late Byzantine period. This likely was not a simple resurrection of the Levitical concept, but instead a new and direct association formed between childbirth and sin.