פירוש על נדה 3:3

שפיר (sac of a fetus) – a piece of flesh. If it has the form of a human being, it is called a fetus having an articulated shape. But I heard that it is like an egg-shell, therefore it is called a sac.

If a woman aborted a sac full of water, full of blood, or full of pieces of flesh, she need not be concerned that it was a birth. These sacs do not count as births (see Bekhorot 8:1). We don't assume that there was a fetus in them.

מלא גנינים ( see Tractate Niddah 24b) – [an abortion consisting of] a bag full of many-colored substance. Another explanation: גנינים are worms, that the piece of flesh is cut into many thin pieces similar worms.

But if its limbs were fashioned she must sit for both male and female. If limbs are noticeable in the shape within the sac, then we must be concerned that this was actually a fetus. Assuming that the gender is unknown, the woman must act stringently in both directions, as we explained in yesterday's mishnah.

אינה חוששת לולד – she is not defiled by giving birth. But if there is no blood with them, she should not worry even because of being a menstruating woman.

תשב לזכר ונקבה impure for two weeks like a woman who gives birth to a female. But she doesn’t have blood of purity (i.e., vaginal bleeding experienced by a woman from eight to forty days after giving birth to a boy and from fifteen to eighty days after giving birth to a girl), other than thirty-three days like a woman who gives birth to a male, for since it is not known/recognized if it is a male or a female, we place upon her the stringencies of the male and the stringencies of a female.