Orphic Hymn I to Prothyrea ("Προθυραία"), identifies Artemis as the goddess of childbirth, and relegates Eileithyia to the role of "assisting goddess":
O venerable goddess, hear my pray'r,
For labour pains are thy peculiar care;
in thee, when stretch'd upon the bed of grief,
The sex as in a mirror view relief.
Guard of the race, endued with gentle mind,
To helpless youth, benevolent and kind;
Benignant nourisher; great Nature's key
Belongs to no divinity but thee.
Thou dwell'st with all immanifest to sight,
And solemn festivals are thy delight.
Thine is the talk to loose the virgin's zone,
And thou in ev'ry work art seen and known.
With births you sympathize, tho' pleas'd to see
The numerous offspring of fertility;
When rack'd with nature's pangs and sore distress'd,
The sex invoke thee, as the soul's sure rest;
For thou alone can'st give relief to pain,
Which art attempts to ease, but tries in vain;
Assisting goddess, venerable pow'r,
Who bring'st relief in labour's dreadful hour;
Hear, blessed Dian, and accept my pray'r,
And make the infant race thy constant care.
The Hymns of Orpheus, translated by Thomas Taylor
Why would the Greeks associate a virgin goddess with childbirth? Is the association limited to the Orphic tradition?