The law of a Mesulekes Bedamim:[1]

There are certain women who are presumed to not release menstrual blood, and thereby carry certain Halachic leniencies and Halachic ramifications in the laws of Nidah. This is known as a woman who is Mesulekes Bedamim.

A nursing and pregnant woman:[2] A woman who is within 24 [lunar[3]] months of giving birth retains the Halachic status of a Mesulekes Bedamim, as she is assumed to not menstruate during this time. This applies even if she is no longer nursing.[4] Likewise, a woman who is pregnant is considered a Mesulekes Bedamim, being that a woman does not menstruate during pregnancy. Nonetheless, a pregnant woman is only considered to retain the Halachic status of a Mesulekes Bedamim from after three months [i.e. 90 days[5]] of pregnancy, which is from the start of the second trimester, from the start of the 4th month and onwards. However, during the period of the first trimester, she is not considered to be a Mesulekes Bedamim [even if she has medically determined that she is pregnant[6]]. [The three months are counted starting from her last night of Miveh.[7]]

The Halachic ramifications: As stated above, there are various Halachic ramifications to a woman who is defined as a Mesulekes Bedamim, including the following subjects that will be discussed below:

1. Yom Chashash-Veses Laws by a Meuberes/Pregnant.
2. Internal exams.
3. The law of Bedikos by a Hargasha of a pregnant woman.
4. Bedikos required before and after Tashmish.

[1] See Michaber Y.D. 189:33 [regarding Kevius Veses]; Taharah Kehalacha 1:8; Nitei Gavriel 103:3-105

[2] Michaber 189:33

[3] See Michaber E.H. 13:11; Tzemach Tzedek E.H. 316:11; Taharah Kehalacha 1:8 footnote 21

[4] Michaber ibid; Maharsham 3:214 based on Tosafus and Ran; Taharah Kehalacha 1:8; All Poskim who hold that even a Mapeles has the status of Mesulekes Bedamim

Other opinions: Some Poskim rule that if she has stopped nursing then she no longer has the status of a Mesulekes Bedamim. [Chasam Sofer 164; Pischeiy Teshuvah 189:29; Mahrshak in Shiyurei Taharah] Furthermore, some of today’s Poskim rule that since in todays times even nursing women menstruate, it is therefore proper to be stringent in today’s times to not give her the status of a Mesulekes Bedamim. [Chut Shani p. 138; Shiureiy Shevet Halevi p. 32] Other Poskim, however, completely negate this statement. [Taharah Kehalacha 1:8 footnote 21; 24 footnote 157]

[5] Tzemach Tzedek E.H. 316:11; Shoshanim Ledavid 184; Taharah Kehalacha 1:8 footnote 20; 24 footnote 152; Nitei Gavriel 103 footnote 5

Other opinions: Some Poskim rule that it is counted in calendar months and not days, and hence once majority of the third calendar month has passed, she is Mesulekes. [See Mei Nida 189:28; Darkei Tehsuvah 189:127; Nitei Gavriel 103 footnote 5]

[6] Sidrei Taharah 194:7 in name of Pleisi; Rav Akiva Eiger 1:128; Noda Beyehuda 1 E.H. 69; Avnei Nezer 238; Shoel Umeishiv Tinyana 3:81; Daas Torah 189:33; Pardes Rimonim 184 Miksheh Zahav 10; Chazon Ish 101:2; Shevet Halevi 4:99; Mishneh Halachos 5:148; Igros Moshe 4:17-1, unlike his ruling in 3:52; Taharah Kehalacha 1:8 footnote 20; Nitei Gavriel 103:3 footnote 6 in length

Other opinions: Some Poskim rule that in today’s times she is considered Mesulekes as soon as she is determined to be pregnant, even within three months. [Igros Moshe 3:52, unlike his ruling in 4:17-1; Orchos Rabbeinu 4:43 in name of Chazon Ish, unlike ruling of Chazon ish ibid; See Nitei Gavriel 103:3 and 9 footnote 6; See Shvus Yaakov 1:71; Avodas Hagershoni 21]

[7] See Avodas Hagershoni 21; Shvus Yaakov 1:71; Chochmas Adam 115:20; Teshuvah meahavah 70; Meiy Nida Kuntrus Achron Tinyana 194; Taharah Kehalacha 1:8 footnote 20; 24 footnote 22; Poseiach Shaar Miluim 4:1; Nitei Gavriel 103:8 footnote 15