Rabbi Menachem Schneerson in his Igrot Kodesh discouraged abstaining from the midras of a niddah in modern times.
Across the spectrum of Orthodoxy, myriads of people meticulously keep Shabbat (the Sabbath), Kashrut (the Dietary Laws), Taharat ha-mishapahah (the Laws of Family Purity) and pray three times a day.
Fertility awareness methods (modern improvements over the rhythm method) are difficult to use, because many infertile days coincide with the ritually impure days of niddah.
This was the synagogue called "Shaf we-Yatib," to which there are several references dating from the third and fourth centuries (R. H. 24b; Avodah Zarah 43b; Niddah 13a), and which Abaye asserts (Meg. 29a) was the seat of the Shekhinah in Babylonia.
# Ḥiddushe ha-Rashbaẓ, novellæ on and elucidations of Niddah, Rosh ha-Shanah, Kinnim, Leghorn, 1744.