Abstract: Halachic infertility (also called religious infertility) occurs when a woman ovulates too long before mikveh immersion (and thus intercourse) to allow for conception. When evaluating the cause of infertility problems, it is very important to determine when she has used the mikveh each cycle. If she reports that she is not able to use the mikveh early enough in the cycle, she should be referred to her rabbi prior to additional medical intervention.
Discussion: A woman becomes niddah with the onset of her menses. After she stops bleeding, she must count seven clean days before immersing in a mikveh. In Jewish law, these seven days cannot start before the sixth day from the onset of the niddah status. Therefore, a woman generally cannot immerse in the mikveh until day 12 of her cycle at the earliest. In the idealized cycle of 28 days, ovulation would take place on day 14. However, for women with shorter cycles, missing ovulation is a real possibility . Since women's cycles tend to shorten when they reach their mid-thirties , halachic infertility is more common in older women and is a common cause of secondary infertility in this population.
It is important to make sure that the woman cannot in fact immerse in the mikveh earlier. Some women are embarrassed to approach a rabbi with intimate questions about their staining, and may delay their immersion to avoid bringing stains to a rabbi for evaluation. Women may also be unaware that rabbis are able to rule leniently regarding certain shades of brown, for example. There are many ways to ask these questions anonymously, and the woman should be encouraged to ask prior to embarking on any medical intervention.
Couples may also have difficulty conceiving if the woman ovulates significantly later than mikveh immersion. Traditional premarital education stresses the ideal situation, where a woman is most likely to conceive by having relations on the night she used the mikveh. Not all women will fully comprehend the workings of the menstrual and ovulatory cycles. They may not be aware that ovulation takes place 12-16 days prior to the next menses, so that women with longer cycles could also be ovulating later that cycle. While trying to conceive, they may be putting the stress on relations at the incorrect time of the month. Therefore, it is important when searching for ovulation difficulties to not only test for the time of ovulation, but also to determine time of mikveh immersion.
Treatment of halachic infertility is discussed in a separate article.
Implications for Patient Care: Couples with no physical cause for infertility may at times have difficulty conceiving when intercourse is halachically prohibited prior to ovulation.
Determining the timing of mikveh use should be part of evaluation of difficulty with conception.
Prior to embarking on medical intervention, a woman who ovulates before mikveh should be referred to a halachic authority to determine if she is halachically permitted to immerse earlier than she had thought.
 SK Gardin, 'The laws of Taharat HaMishpacha: potential effects on fertility' Journal of Biosocial Science, 1988 Jan; 20(1):9-17.
 Treloar, AE, Boynton, RE, Behn, BG, Brown, BW. Variation of the human menstrual cycle through reproductive life. Int J Fertil 1967;12:77.
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