Commentary on the Diatessaron 2.6 — as quoted by Pitre (p 135); translation: Carmel McCarthy, Saint Ephrem's Commentary on Tatian's Diatessaron (Oxford, 1993)
How would it have been possible for her…[to] give birth filled with birthpangs, in the image of the primeval curse? If Mary was 'blessed of women' (Luke 1:42), she would have been exempt from the curse from the beginning, and from the bearing of children in birthpangs and curses.
No freely usable English translation of this passage is online, so the note keeps Pitre's quotation and links to the full text. Translation: Carmel McCarthy, Saint Ephrem's Commentary on Tatian's Diatessaron (Oxford, 1993), as quoted by Pitre.
In Jewish Roots of Mary
Why it is cited
If Mary was 'blessed among women,' she was exempt from Eve's curse of birth pangs — Ephrem's reasoning behind the painless birth as a sign of the new creation.