TT #54 · Parshas Tazria · Aliyah 1 · Passuk 7
English: He shall offer it before GOD and make expiation on her behalf; she shall then be pure from her flow of blood. Such are the rituals concerning a woman who bears a child, male or female.
Chabad.org — Chumash, English translation + Rashi for Vayikra 12:7
Torah Temimah cites Sifra (Toras Kohanim) for the included miscarriage cases: a sandal-shaped fetus, a placenta, or a formed sac.
Sifra — Vayikra 12, Midrash Sefer
English: This includes a woman who miscarries a sandal-shaped fetus, a placenta, or a developed amniotic sac.
Textual inclusion
This unit states the included cases directly: a miscarriage involving a sandal-shaped fetus, a placenta, or a formed sac falls within the passage’s childbirth law.