“Moshe descended from the mountain to the people. He sanctified the people and they washed their clothing. He said to the people, ‘Be ready for a three-day period; do not approach a woman.”
“Do not approach a woman” – ‘for this entire three-day period, so that the women should be able to immerse themselves by the third day and thereby be Tahor to receive the Torah. For if they were to have relations within the three-day period of the giving of the Torah perhaps the woman would discharge Shichvas Zera (semen) after her immersion and become impure again. But once she has waited three days after having relations, the Shichvas Zera has already become putrid and is not fit to fertilize and is pure regarding contaminating the woman who discharges it.’
Rashi ad. loc. s.v. ‘Al Tigshu’
One of the basic Halachos of Taharas Hamishpacha is that a woman who is a must wait at least four or five days after the onset of her menstrual cycle before she may perform a Hefsek Taharah and begin counting the Shivah Nekiyim. The reason for this waiting period is that the chachamim were concerned that she may have had relations with her husband on the day preceding the start of her menses. If she were to experience an emission of his Shichvas Zera it would cancel her Shivah Nekiyim. By waiting several days before the Hefsek Taharah, any Shichvas Zera would no longer be capable of insemination and would not cancel her Shivah Nekiyim.
This Halacha of waiting four or five days before the Hefsek Taharah is a unique stringency in Hilchos Niddah. Jewish women have taken upon themselves to be exceptionally stringent with regard to this Halacha especially in light of the many reasons for leniency:
- The opinion of the Ra’avad and other rishonim is that the emission of Shichvas Zera is only a concern with regard to Taharos (ritual purity – e.g. Teruma – that is not currently practiced). However, with regard to Taharas Hamishpacha, this would not be an issue and it would not cancel her Shivah Nekiyim.
- Even according to the other rishonim who disagree with the Ra’avad, a woman should really only need to wait for three days (seventy-two hours) before performing a Hefsek Taharah . Nevertheless, the Shulchan Aruch (Y.D. 196:11) rules that four days are required. This is due to a concern that a woman may have had relations with her husband at the beginning of the night preceding the onset of her period. In that case, less than seventy-two hours would have elapsed when the fourth day begins, and an emission of Shichvas Zera would cancel Shivah Nekiyim. Therefore, a woman must wait four days before performing a Hefsek Taharah.
- The Rema (based on the Terumas HaDeshen) takes that stringency even further, ruling that she must wait five full days before the Hefsek Taharah. This is because she may have had relations with her husband during the night but mistakenly think that it was during the day and begin counting a day too early. She must therefore always wait an extra day, just to be sure.
Aside from all of the above, it should be noted that the concern that a woman will emit Shichvas Zera should only exist if she actually had relations with her husband on the night before her period began. If, however, she knows that she did not have relations with her husband in the days leading up to her period, she should be allowed to perform a Hefsek Taharah and begin her Shivah Nekiyim immediately. The Shulchan Aruch in fact appears to rule this way, but the Rema disagrees and says that every woman must wait five days after the onset of her period regardless of how much time had elapsed since the last time she had relations with her husband. The Rema’s psak is widely accepted as normative halacha, and even the minhag of Sefardim today seems to be to follow the Rema in this matter.
There is yet another stringency in that we do not allow a woman to eliminate the waiting period before performing a Hefsek Taharah by performing a thorough internal cleaning to remove any Shichvas Zera. According to many Rishonim, a woman may wash herself or clean the area very thoroughly and then begin counting her Shivah Nekiyim immediately. However, the Gedolei Ashkenaz forbade this practice arguing that women are no longer adept at doing so adequately.
It is evident from the poskim that these stringencies are based upon the customs of righteous Jewish women in earlier generations who took it upon themselves to wait longer than strictly necessary before performing a Hefsek Taharah and beginning to count Shivah Nekiyim in order to avoid any possible risks or doubts in their taharah. The chachamim in turn accepted these customs and made them binding.
One of the possible causes of a couple’s infertility is dysfunctional sperm (e.g. abnormal motility) that is unable to reach or penetrate the woman’s egg. In order to overcome this, doctors may extract the sperm and insert it directly into the uterus via a catheter in a process known as intrauterine (or artificial) insemination (IUI). If a woman were to undergo this procedure after having already performed the Hefsek Taharah, would this cancel the Shivah Nekiyim? Do our concerns about possible emission of Shichvas Zera following normal relations extend to the case where it was implanted directly via a medical procedure?
Rav Shmuel Wosner zt”l (Shevet Ha’Levi, 9:183) ruled that indeed, in the case of artificial insemination, a woman’s Shivah Nekiyim are interrupted. The Rema (cited earlier) ruled that a woman must wait five days to begin her taharah even when she had not had relations with her husband. The case of artificial insemination is surely no better than that, especially as there is actual cause for concern since the procedure implants Shichvas Zera which may later be emitted.
One also cannot contend, argued Rav Wosner, that such a procedure would be considered an ‘unusual circumstance’ (milsa d’lo shechicha) that was not included in Chazal’s original Takana. Since the actual reason for the ruling exists in this case (as mentioned above), we cannot to be lenient in this matter.
In truth there are several circumstances that were considered by the Poskim to be ‘unusual’ and therefore not included in the law of waiting for four or five days. The Me’il Tzedaka ruled that a woman who saw blood immediately following immersion in the mikvah (before having had relations with her husband) does not need to wait before performing a Hefsek Taharah and restarting her count of Shivah Nekiyim since bleeding at that juncture is exceedingly unusual.
Nevertheless, according to Rav Wosner, one may not be lenient in the case of artificial insemination. Since it does introduce Shichvas Zera into the woman, we cannot be lenient even if the circumstances are unusual. Only where there is no actual concern of her emitting Shichvas Zera (as in the case of the Me’il Tzedaka) can we make a distinction between cases that are unusual and cases that aren’t.
On the other hand, the Nishmas Avraham (196:11) quotes Rav Shlomo Zalman Auerbach zt”l as having ruled leniently in this matter. He argued that the law of waiting to begin Shivah Nekiyim out of concern for the emission of Shichvas Zera only applies when the Shichvas Zera is present due to relations with her husband, not artificial insemination. He does however cite several dissenting opinions including Rav Elyashiv, Rav Yehoshua Neuwirth and Rav Ovadia Yosef zichronam l’vracha.
As far as Rav Ovadia’s position is concerned though, Rav Moshe Paniri quotes him as having agreed with Rav Shlomo Zalman. He bases this on a letter that Rav Ovadia wrote on the 17th of Tammuz 5771 to a gynecologist – Dr. Robinson – in which he sided with Rav Shlomo Zalman and supported his position from Tosfos in Maseches Shabbos (86a) who wrote that the Halacha of emission of Shichvas Zera canceling Shivah Nekiyim applies only in the case of relations and would therefore not apply to artificial insemination.
 The reason that an emission of Shichvas Zera would cancel the Shiva Nekiyim is that Chaza”l (Talmud Bavli Niddah 33) consider it analogous to a ‘re’iya’ – a sight (discharge) – of blood. This resembles the law of the zav for whom an emission of shichvas zera also cancels his Shiva Nekiyim.
There are even some authorities who required a woman to wait six or even seven days from the onset of her period! This practice is an attempt to emulate the ‘seven days of a Niddah’ according to Torah law. (See Bach and Taz ad. loc.)
 This however did not apply to the Minhag (mentioned earlier) to wait seven full days. Regarding that the Rema writes ‘there is no reason for the matter. Those who wish to be stringent, may be stringent but those who are lenient will gain in that they will be able to perform the mitzva (of procreation) earlier’. This is also accepted by the consensus of the Poskim. Even though the Acharonim have found a justification for this practice, it is nonetheless overly stringent to be considered normative Halachah and can cause other problems. In addition, as is implied by the Rema, waiting that long may prevent people fulfilling the mitzva of Pru u’revu (procreation) because by delaying the ability to go to the mikvah for so many days after the period (it works out to be at least two weeks), she may find herself forbidden to her husband on the day that she is ovulating.
 Rav Wosner supports his contention by noting that Chaza”l equated the emission of Shichvas Zera with the discharge of a Zav, even though it originated externally from her husband. If so, it should make no difference how the Shichvas Zera was implanted as we are concerned only with its discharge and not its origin.
 R. Yonah Lansdorfer (1678-1712). This ruling is quoted by the Sha”ch (YD 196:23)
 Rav Elyashiv zt”l also concurred.
 Sefer Avnei Shoham, p753