We will begin by outlining an extremely limited sketch of the status of Niddah and Zavah. The Kehati Mishnayot series presents a full introduction to this issue in many places, including Arachin 2:1. The Torah (VaYikra 15:19) states that if a woman becomes a Niddah at an expected time she is Temeiah (impure) for only seven days. If, however, this experience happens at an unexpected time, then she must count seven days after the bleeding has stopped before she may visit the Mikvah (Vayikra 15:25-28). One who experiences this unexpected event is referred to as a Zavah.
The Gemara in numerous places (such as Berachot 31a) records that Jewish women have accepted upon themselves to always consider themselves a Zavah whenever they see blood. Hence, they always count "seven clean days" after seeing blood. The Gemara in Berachot presents this Halacha as an example of "Halacha Pesukah," a straightforward rule. The reason women accepted this stringency (see Rambam Hilchot Issurei Biah 11:1-4) is to avoid confusion in determining what constitutes an expected event and an unexpected event. Thus, Jewish women decided to "play it safe" to avoid violating this extremely serious Torah prohibition and always count seven clean days.
Ramban (in his summary of Hilchot Niddah 1:19) writes, "This stringency that Jewish woman have adopted was approved by Chazal and they accorded it the status of 'Halacha Pesukah' in all locales. Therefore, it is never permitted to be lenient about this matter." The Meiri adopts a similar approach in his commentary to Berachot 31a. The Shach (Yoreh Deah 183:4) similarly writes, "Chazal always required the counting of the seven clean days."
This situation usually works out well as the night of immersion will often be ideal for conception. However, for some couples, ovulation occurs before the night of immersion. The Poskim of the past few decades have addressed the question of whether the requirement of the seven clean days might be waived to permit immersion before ovulation.
Response of the Twentieth Century Poskim
Halachic authorities have unanimously responded that it is forbidden to be lenient. Rav Yosef Dov Soloveitchik (as reported by Rav Aharon Lichtenstein and Rav Yosef Adler), Rav Shlomo Zalman Auerbach (Teshuvot Minchat Shlomo 2:70:1), and Rav Ovadia Yosef (Taharat Habayit 1:27-30) all cite Ramban that we may never waive the requirement for the seven clean days. They believe that Ramban applies even in case of "religious infertility."
One may ask, however, why doesn't the Torah obligation of Peru URevu (the obligation to have children) override the rabbinic requirement for seven clean days, in a case where we are certain that she is not a Zavah? In fact, the Mishnah (Gittin 4:5) records the Halacha that the obligation of Peru URevu overrides the Torah prohibition against freeing a Canaanite slave.
Rav Moshe Feinstein (Teshuvot Igrot Moshe Y.D. 1:93) responds that there is no general Halachic principle that permits violation of a rabbinic prohibition to fulfill a Torah prohibition. The Gemara (Shabbat 130b) teaches that we may not carry a Milah knife on Shabbat, even in an area that is forbidden to carry in only on a rabbinic level, in order to perform a Brit Milah. One may not violate the rabbinical prohibition against sprinkling someone who is Tamei Mait with "Parah Adumah waters" on Shabbat to facilitate fulfillment of the Mitzvah of Korban Pesach (Pesachim 92a and see Rambam Hilchot Korban Pesach 6:6). Rav Feinstein asserts that in most cases Chazal did not condone violation of a rabbinical prohibition to fulfill a biblical obligation.
Rav Ovadia Yosef cites Tosafot (Gittin 41a s.v. Lisa) who ask why Chazal (Gittin 41) forced the part owner of a partially emancipated slave to relinquish ownership of the slave. Chazal made this rule because a partially emancipated slave is forbidden to marry either a female slave or a free woman. Tosafot ask why the Mishnah states that the half-slave does not have the option of marrying a Jewish woman. Tosafot wonder why the obligation of Peru U’Revu does not override the prohibition for a partially freed slave to marry free woman. Tosafot answer that we do not waive the prohibition against his marrying a freed woman since there is an available option to accomplish the goal and violate only a less serious prohibition - freeing a Canaanite slave. Rav Ovadia Yosef argues that similarly we do not sanction the violation of the seven clean days requirement since there are Halachic and medical options that facilitate the couple fulfilling the Mitzvah of Peru URevu without violating the obligation of the seven clean days.
Another answer of Tosafot is relevant to our issue as well. Tosafot explain that since the woman is not obligated in the Mitzvah of Peru U’Revu (Yevamot 65b), there is no override of her prohibition against marrying a slave. Similarly, since the woman is not obligated in Peru URevu, there is no override of her obligation to count seven clean days.
Halacha and Medical Options
Many Halachic authorities permit an early Hefseik Taharah (before five days have passed since the bleeding began) in such circumstances. These authorities include Rav Yosef Dov Soloveitchik (reported by Rav Yosef Adler), Rav Moshe Feinstein (Teshuvot Igrot Moshe Y.D. 4:17:22), and Rav Ovadia Yosef (Taharat HaBayit 2:416). These authorities believe that the custom to wait five days (or four days for Sephardim according to Rav Ovadia Yosef) from the start of the bleeding before beginning to count the seven clean days may be waived (under certain conditions) in order to fulfill the Mitzvah of Peru URevu. We treat a custom with significantly less stringency than a rabbinical prohibition. This approach helps solve the problem in some cases.
Many Poskim also permit artificial insemination using the husband's genetic material before the wife has immersed in the Mikvah. These authorities include Rav Ovadia Yosef (Taharat HaBayit 1:29), Rav Moshe Feinstein (Teshuvot Igrot Moshe Even Haezer 2:18), and Rav Zvi Pesach Frank (an oral tradition reported by Rav Ovadia Yosef ibid). Rav Ovadia and Rav Moshe write that the child will not bear the stigma of a Ben Niddah if it is conceived in this manner. It is important to note that many Poskim strongly urge that this process be performed under strict rabbinical supervision to insure that no tampering or mistakes are made in the process.
Another option might be for an especially competent doctor to prescribe medicine that will adjust her cycle to avoid this problem. Care must be taken to insure that this process does not impinge on the wife's health.
It is important to note that the problem might be a result of the wife thinking that she is a Niddah when, in fact, she is not. Rav Binyamin Forst (The Laws of Niddah p.34) writes, "Many women do not suddenly stop staining on the fifth day. It is very common to find a stain on the Hefseik Tahara cloth." Some women think that every one of these is a prohibited stain and thus do not begin the seven clean days when they are in fact permitted to do so”. A couple should consult with a competent Halachic advisor regarding this issue. This might be the reason why the couple is not having children.
Various sources have reported some limited success in solving this problem using home remedies. Dr. Mordechai Halperin of Jerusalem once stated in a public lecture that he has experienced some successful resolution of this problem, in some cases, simply by instructing the wife to eat breakfast. In fact, I recommended this course of action to a woman who approached me with this problem and a few months later, she reported that she conceived soon after she initiated a daily routine of eating a proper breakfast.
Interestingly, the Gemara (Bava Kama 92b) and Shulchan Aruch (Orach Chaim 155:2) urge us to eat breakfast. The Gemara quotes a folk saying, "sixty people run, but they cannot keep up with one who ate breakfast." Furthermore, the Gemara (Bava Metzia 107b) states that eighty-three sicknesses are related to malfunctioning of the gallbladder and eating breakfast can cure all of them. Rav Menachem Burstein (the head of the prestigious Machon Puah in Jerusalem) suggested (in a conversation with me) that a nutritional imbalance might cause an imbalance in the cycle, and this might account for the success of this approach in some cases.
Other home remedy suggestions include eating estrogen rich food such as sweet potatoes or taking Vitamin K. Rav Burstein told me that he has heard reports of limited success with these approaches. However, Rav Burstein counseled that I should advise the home remedy course only to very young wives, because these home remedies offer only limited success and often take considerable time to take effect. He urged counseling wives to ask their gynecologists to prescribe medicine that will adjust their cycles. One should consult with competent medical professionals regarding these matters.
I have generally shied away from discussing Hilchot Niddah in Kol Torah. However, I have discovered that there is widespread ignorance of this problem and its potential solutions. Since Rabbis and doctors have told me that appropriate Halachic and medical advice can help resolve this problem in almost all cases thus it is imperative that this matter be discussed in this forum, to shed some light on this important subject and urge couples facing such this challenge to discuss this issue with their Rav and physicians. I discuss this topic at greater length in Gray Matter volume two.
Postscript - Machon Puah
Moreover, it is very important to bring to the community's attention a most wonderful resource for the Jewish People throughout the world. Machon Puah in Jerusalem provides Halachic guidance to couples that are experiencing difficulties conceiving a child. They employ rabbis who are available full-time to respond in a variety of languages to questions regarding the interface of Halacha and fertility. Moreover, they are at the forefront of offering rabbinical supervision of fertility procedures. It is highly worthwhile for rabbis and laypeople to consult with Machon Puah in case of need. For more information one may visit their website at www.puah.org.il (click “English” for the English section of the website).