Background: ‘Religious (halachic[1]) infertility’ results from precoital ovulation prior to immersion in a ritual bath (mikveh) 7 days after menstruation, as mandated by Jewish religious law. Previous authors recommended treatment with estradiol to postpone ovulation and enhance pregnancy rates.
Objectives: To evaluate the prevalence of halachic infertility in an ultra-Orthodox Jewish community, and assess the efficacy of estradiol treatment in postponing ovulation and increasing pregnancy rates.
Methods: We reviewed 88 cycles, of which 23 were control cycles and 65 estradiol-treated cycles, and analyzed the files of 23 women who were treated with 6 mg estradiol/day from day 1 for 5 days of the cycle.
Results: The prevalence of precoital ovulation in the infertile population was 21%. Most of the patients (94%) ovulated before day 13 of the cycle. A short follicular phase due to low ovarian reserve or thyroid endocrinopathy was noted in 12% of the patients. While 64% of the women reported consultation with a Rabbinate authority, 68% of the patients sought medical therapy. Estradiol postponed ovulation for at least one day in 89% of the treatment cycles. Ovulation post-mikveh occurred in 73% of estradiol-treated cycles. The pregnancy rate was 12.5% per cycle and the cumulative pregnancy rate 35% per woman. Half the patients reported spotting during estradiol-treated cycles, and this postponed coitus.
Conclusions: Precoital ovulation is a major reason for infertility among observant couples attending fertility clinics. Estradiol treatment is effective in delaying ovulation and restoring fecundity however, it causes some adverse effects that may decrease its effectiveness.

[1] Referring to Halacha, the body of Jewish Law