Footnotes

1. The term "preembryo" is commonly used to describe the stage of cell development from the time an egg is fertilized by sperm until implantation into the uterine wall. Implantation commonly takes place within 10-14 days after fertilization. (Obviously, in the case of an IVF frozen preembryo, implantation can occur only after transfer to a uterus which may and often does occur years later.) At the 10-14 days point, a primitive dark streak begins to appear within the otherwise undifferentiated cells. This dark streak will eventually form the neural tube. In modern medical parlance, the appearance of this streak coupled with uterine implantation mark the transition from preembryonic to embryonic status. [Technically, immediately after fertilization, the fertilized ovum is a single cell known as a zygote. The zygote becomes a true preembryo only after cleavage which occurs shortly after fertilization.] Those who distinguish the preembryo from the embryo justify that distinction on the basis that prior to the embryonic axis being formed, the cell has no developmental individuality; twinning can occur either naturally or experimentally. The embryonic stage lasts for around eight weeks by which time there is at least rudimentary development of differentiated organs. After that point, the organism is termed a "fetus". See generally American Fertility Society, Ethical Considerations of Assisted Reproductive Technologies (Nov. 1994), 29S-31S. This usage is not consistently followed and the terms "embryo" and "preembryo" are often used interchangeably.

2. Many changes and improvements have been made since the first successful IVF was performed in 1978. The two most important developments were the use of medications which stimulate the ovaries to produce multiple eggs (superovulation) and the development of cryopreservation to freeze embryos for future use. Another important development is in egg retrieval. The procedure originally required laparoscopy under general anesthesia. Today, transvaginal ultrasound guidance allows the insertion of a thin probe through the vagina directly into the ovary and the visualized eggs are removed by suction. The procedure requires only mild sedation and recovery is rapid. The IVF-ET Registry for 1985 indicated that 94.2% of oocyte retrievals were performed by laparoscopy. By 1984, 87% were done by ultrasound. See, for the data, Moghissi and Leach, "Future Directions in Reproductive Medicine," 116 Arch. Path. Lab. Med. 436-441 (April 1992).

3. The best chance of achieving an IVF pregnancy involves the transfer of 2-4 embryos. Fewer than two greatly reduces the chance of pregnancy. More than four increases the risk of multiple gestation which may pose risk to mother and fetus. Eight or more eggs are routinely retrieved and recovery of more than 20 is increasingly common. See Wood et al, "Factors Influencing Pregnancy Rates Following In-vitro Fertilization and Embryo Transfer," 43 Journal of Fertility and Sterility 295 (1985).

4. Considerations of space obviously do not permit full discussion of all areas of preembryo technology. One area that will not be extensively discussed is embryo cloning. In October 1993, physicians at the George Washington Hospital were able to separate cells from 2-8 celled preembryos and have them grow into separate entitites. While the new preembryos did not survive, as the technique gets perfected it will allow for the artificial creation of genetically-identical human beings, i.e., identical twins. See Robertson, "The Question of Human Cloning," Hastings Center Report 24, no. 2 (1994), 6-14. Theoretically, preembryos can be split enabling one to be implanted and the other to be transferred. This creates the anomaly of not only siblings but genetically-identical people having different parents. Without addressing all the issues of cloning, it may be said that the existence of an identical genotype is not a halachically relevant factor. Notwithstanding their common genetic structure, twins will not be siblings unless they share common parental bonds. With respect to virtually all the aspects discussed in this paper - destruction, experimentation, donation - there should be no distinction between preembryos that are produced by cloning and those that are produced by a separate sperm fertilizing a separate egg.

Other aspects of preembryo technology that have been regarded by the general public as ethically problematical do not necessarily engender halachic questions. For example, (1) concern has been expressed about persons donating or even selling some of their embryos while using the rest, thereby generating siblings who are unaware of each other's existence. While the possibilities of unknown incest are indeed halachically problematical, the problem existed well before the externalization of the preembryo with the widespread use of artificial insemination, sperm banks etc. (2) Cryopreservation, donation, etc create possibilities that eggs that were fertilized at the same time may be born years apart. While this may raise issues concerning inheritance etc., that is not a circumstance that halacha particularly condemns. (3) Finally, much concern has been expressed about intrafamily sperm or ovum donations, e.g., brother to brother, sister or even mother donating an egg to siblings/daughter. Some clinics have prohibited the practice. See M.V. Sauer et al., "Survey of Attitudes Regarding the Use of Siblings for Gamete Donations," Journal of Fertility and Sterility 49(4):721 (1988) and "Ethical and Legal Issues in Human Egg Donations," Journal of Fertility and Sterility 52(3):353 (1989). From the standpoint of halacha, however, the problems of intrafamily donations are not unique. All sperm donations (from Jews) raise possible adultery and mamzeirut issues even from unrelated parties and all ovum donations even from related parties may not. See text at notes _____. The intrafamily aspect does not appear to be significant.

5. Artificial insemination with husband's sperm (AIH) may be a helpful procedure for men who have low sperm counts since it allows the combination of several ejaculates and may also be indicated when a woman's fertile period around ovulation precedes the date she can go to the mikvah. See generally A. Steinberg, "Artificial Insemination in the Light of Halacha," Sefer Assia 128-141 (1982) and A. Cohen, "Artificial Insemination," 13 Journal of Halacha and Contemporary Society 43 (Spring 1987).

6. The issues raised by AIH included: (1) whether or not the husband had a paternal relationship to the child; (2) whether or not a child conceived through AIH is a fulfillment of the Torah commandment of p'ru v'revu or at least the prophetic edict of lashevet; (3) whether the methods that were employed for the procurement of semen violated the edicts against hashchatat zera and what alternatives could minimize the prohibition; and (4) fear concerning substitution or mixing with donor semen.

7. See, for example, Teshuvot Maharsham III, no. 268; Minchat Yitzchok I, no. 51; R. Shlomo Zalman Auerbach, I Noam at 157 (5718); Seridei Aish III, no. 5; Tzitz Eliezer IX, no. 51; Yabea Omer II, E.H. no. 1. See also the excellent summary in Nishmat Avraham E.H. 1:5.

While the procedure as such has been validated, controversial areas remain. May a woman be inseminated while she is a niddah? This is extremely important for cases of early ovulation. Compare Teshuvot Maharsham III, no. 268 (prohibited) with Igrot Moshe E.H. II, no. 18 and Yabea Omer E.H. II, no. 1 (permitted). See also Minchat Yitzchok I, no. 50 (willing to permit woman to immerse seven days from the onset of her period so that she is no longer a niddah under Torah law but only if other authorities agree). Interestingly enough, the advent of IVF may avoid the need for insemination during niddah since the egg can be obtained during ovulation and fertilized later and in any case would not be fertilized within the niddah's body. [Note too that artificial insemination per se is not treated as a ptichat hakever which would render a woman niddah - R. Auerbach in Noam.] May an AIH child be circumcised on Shabbat? See Nishmat Avraham Y.D. 240:2.

8. See Rabbi Ovadiah Yosef, I Techumim at 287; R. Avigdor Nebenzal, 34 Assia (Tishrai 5743); R. Shmuel Wozner, Shevet Levi V, no. 47 (although one may not desecrate shabbat to save the preembryo because of the low probability of its ever coming to term).

9. Tzitz Eliezer XV, no. 45. Query whether utilization of GIFT would change his view. In GIFT, the egg and the sperm are mixed together but are then placed in the fallopian tube where fertilization takes place. See infra text at notes ___________.

10. Even where the egg donor carries the baby to term and is thus both the gestational and birth mother.

11. Bishevilai HaRefuah, no. 8 (Kislev 5747), p.33.

12. Kol Tzofayich, pp. 361-367; Or HaMizrach (Tishrai 5749).

13. Other aspects of AIH or IVF may be more problematical. First, may AIH or IVF be undertaken by a couple who already have the minimum son and daughter but desire to have more? Compare the views of R. Auerbach (even where he has a son and daughter, a man may be permitted to obtain sperm in order to fulfill the imperative of lashevet or where his wife is in significant psychological distress in not having more children) cited in Nishmat Avraham E.H. 23:1 (however with the qualifying term "yitachen" - it may be possible) with the contrary view of R. Eliyahu Bakshi-Doron, the present Sefardic Chief Rabbi of Israel (then the Rav of Haifa), who ruled that the ban on hashchatat zera can be lifted only for the Torah commandment of p'ru u'revu and not for the lesser mitzva of lashevet. Letter to Joel Wolowelsky, Dec. 15, 1991. Rabbi Moshe Feinstein also seemingly subscribes to this restrictive view. See Igrot Moshe E.H. IV, no. 73. Note, however, that both Rabbi Feinstein and Rabbi Bakshi-Doron are addressing the use of sperm procurement for testing, not actual procreative use. The latter may be considerably more lenient. Note too that any halachic distinction between p'ru u'revu or lashevet must assume that one fulfills p'ru u'revu through AIH or IVF. This too is a matter of controversy. See next note and note ___.

Second, is it permissible for a single person who is undergoing chemotherapy that will probably render him sterile to freeze sperm for later impregnation? The poskim have responded in the negative. See Nishmat Avraham [App. Vol.] E.H. 23(1) quoting R. Elyashiv. See also Letter of Machon Eretz Chemdah, an Israeli "think-tank" specializing in medical halacha (9 Tevet 5754, Dec. 23, 1993) to Dr. Joel Wolowelsky. (The signatories on the letter were Rabbis Yosef Carmel and Moshe Ehrenreich and the conclusions were approved by Rabbi Shaul Yisraeli, the head of the Machon. Dr. Wolowelsky was kind enough to furnish a copy of the correspondence.) Nishmat Avraham quotes R. Auerbach as disapproving of such a practice even for a married man who has not yet fulfilled the mitzva of p'ru u'revu but l'fi aniyus daati, this psak is very difficult to understand.

14. It appears to be unresolved whether one can fulfill the Torah command of p'ru u'revu though either AIH or IVF. R. Auerbach in his Noam article states that the matter is not clear. The Aruch L'Ner to Yevamot 10a explicitly rules that one does not fulfill p'ru u'revu in the absence of a sexual act. On the other hand, Rabbi Bakshi-Doron apparently assumes that p'ru u'revu is fulfilled since he only permits the procedure to achieve this purpose.

The foregoing assumes a paternal bond. If one adopts the views of Rabbis Waldenberg, Sternbach, and Gershuni that sperm contributors do not have paternity in IVF cases, it is clear that there is no mitzva of p'ru u'revu though, as noted, R. Gershuni even here would concede the mitzva of lashevet.

15. One further point concerning IVF needs further elucidation. While the poskim who permit IVF have not been explicit, none of them indicate that the entire seminal ejaculate or sperm be deposited in the vagina or otherwise preserved. R. Yisraeli has expressly so ruled, indicating that surplus sperm should be destroyed to prevent its unauthorized donation to another woman. See Letter of Dec. 1993. In the normal course of events, an egg is fertilized by a single sperm. Even if all fertilized eggs are transferred, there will clearly be much sperm that goes to "waste". (As noted, this is one of the reasons why R. Waldenberg condemns IVF.) This problem does not arise in regular intercourse since all the zera enters the body and is thus not levatala even if only a single sperm fertilizes an egg or indeed even if no pregnancy results at all. (It is axiomatic that marital intercourse with an infertile woman is not hashchatat zera.) Where, however, the sperm is obtained for procreation outside of the woman's body, why isn't the extra "going to waste"? The theory must be that since the sperm was obtained for procreative purposes and the egg was exposed to all the sperm in the dish, the sperm is effect was permitted to perform its natural functions, i.e., compete to fertilize the egg, and, as true for insemination within the body, need not be retrieved or preserved to try again.

This analysis would have major repercussions for certain aspects of AIH or IVF. Could either of these procedures be used for sex selection by separating out the X or Y sperm? Obviously, in the absence of an underlying fertility problem utilization of these procedures would be forbidden but what if there is a fertility problem that justifies the obtaining of semen outside of marital intercourse? Could there then be separation? Based on the above analysis, the answer would still be no. AIH would require that the entire ejaculate be deposited in the woman's vagina or uterus and even IVF would necessitate that all sperm be exposed to the egg and enabled to perform their natural function, although once fertilization took place, the excess sperm could be discarded. (But cf. Nishmat Avraham (App.Vol.) E.H. 1:1 which quotes R. Auerbach as permitting sperm separation in AIH to prevent the conception of a male child that may carry hemophilia.)

A similar problem exists with respect to genetic testing and screening. Individual sperm can now be examined for chromosomal abnormalities and genetic defects and discarded. Is such discarding violative of hashchatat zera? Must all sperm be placed in the petri dish or as long as some sperm is, the emission was not levatala? For a variety of reasons, poskim have permitted selective discard on the basis of genetic defects although they have not permitted it for "mere" sex selection. (As noted, however, R. Auerbach did permit sperm separation where the possibility of a genetic defect was sex linked.) Moreover, at least one posek has permitted such genetic screening not only in cases where the IVF procedure was independently justified for infertility concerns but even in cases where there was no infertility treatment and IVF was being employed as a diagnostic device. R. Yitzchok Silberstein, quoted in Grazi, Be Fruitful and Multiply, pp. 182-184. This is clearly a matter that needs further discussion.

A final problem area is the recently developed medical technique of drilling the outer layer of egg and inserting a specific sperm. Since the other sperm have no chance of penetrating the egg, was the procurement of such sperm an act of hashchata? Presumably not - unlike sex selection or genetic screening, this procedure is specifically calculated to improve the prospects of fertilization . If such drilling is warranted on the basis of fertility considerations, i.e., sperm is not strong enough penetrate, there would then appear to be nothing objectionable to choosing the sperm on the basis of sex or chromosomal makeup. It would appear to be halachically preferable, however, to obtain the single sperm required through testicular biopsy, thereby avoiding the emission of extra sperm that would be levatala.

16. The most complete study of the halachic aspects of abortion appearing in English is Bleich, "Abortion in Halachic Literature," I Contemporary Halakhic Problems 325. See also Nishmat Avraham H.M. 425.

17. One isolated reference in Tosafot, Niddah 44a, s.v. Ihu, seems to suggest that the killing of a fetus may actually be permitted even rabbinically but must commentators have concluded that Tosafot's words cannot be understood literally or that they represent a scribal error. See, e.g., comments of Yaabetz there; Igrot Moshe H.M. II, no. 69. See also Achiezer III, no. 65(14) and Beit Shlomo H.M. 132 who assert that Tosafot's blanket dispensation applies only to the Sages who maintain that feticide is not a capital crime under Noachide law. Since the halacha is in accordance with the view of R. Yishmael that feticide is a capital offense under Noachide law, it would automatically follow that such practice be Biblically prohibited to a Jew based on the general rule that there is nothing that is prohibited to a Noachide that is permitted to a Jew (though the Noachide punishments may be more severe).

18. In cases of abortion, it is not entirely clear who is the technical transgressor. Is it only the physician who actually kills the embryo or fetus or would it also be the woman (and perhaps the husband) who requests the service and, in the case of the woman, makes herself physically available for the service to be performed? If we assume the former, the only transgression the woman would be violating is "lifnei ivair lo titain michshol" - causing another to transgress (equally applicable to causing non Jews to violate the Noachide laws as well); under the second possibility, the woman is a direct and primary transgressor and not merely an aider and abetter of someone else's sin. R. Auerbach seems to rule that the patient is not simply a facilitator but is a direct violator. See Nishmat Avraham O.H. 656:1 at p. 92. Such a characterization is quite logical if abortion is proscribed because of the affirmative obligations of hatzala - conduct facilitating fetal destruction is as inconsistent with this duty as actual destruction is. This result may also follow if abortion is described as noncapital murder since, as Rambam rules, one who hires the murderer is guilty of murder at least in the eyes of Heaven. See Mishna Torah, Hilchot Rotzeach 2:1. It is difficult to regard the woman as a primary offender if the offense be defined as hashchata zera since merely allowing seed to be destroyed does not appear to be an act of hashchatat. (Note too that many opinions rule that a woman is generally not subject to the prohibition of hashchatat zera). The same difficulty arises if abortion is prohibited because of chavala.

It must be reiterated, however, that even if an woman is not a primary violator, she is prohibited from obtaining an abortion from either a Jewish or non Jewish physician because of lifnei ivair.

19. The halacha is clear that a Jew is not permitted to perform an abortion on a non Jew but the reason is uncertain. If Jews are prohibited to perform abortions because feticide is regarded as a species of murder (albeit non capital murder), then just as a Jew is not allowed to kill a non Jew, he is not allowed to abort a non Jewish fetus. If, however, the abortion prohibition of a Jew is subsumed under hashchatat zera, chavala of child or mother, or as a violation of the affirmative obligation to sustain life, none of these are obligations that Jews owe non Jews. Why then cannot a Jew perform an abortion on a non Jew? The answer would be that the Jew would be transgressing lifnai ivair. If we accept R. Auerbach's ruling that the woman is not merely an accessory to the doctor's primary violation (which in this case would be nonexistent) but that she herself committed the equivalent of an act of (capital?) murder, it would be prohibited for the Jewish doctor to facilitate such a transgression. Even if there are other doctors who would willingly perform the abortion if he declines, his assistance is still prohibited because those others are themselves subject to the same proscription. [See Mishna L'Melech, Hilchot Malveh V'Loveh 4:2 - the existence of alternative facilitators removes lifnai ivair only where those facilitators are allowed to extend such assistance].

Thus, if abortion is viewed as retzicha, the Jewish physician performing it on a non Jew is a primary transgressor; if abortion is not viewed as retzicha (from the perspective of a Jew), the physician is an aider and abetter of a primary transgression of Noachide law committed by the patient.

20. Tosafot in Sanhedrin remains in doubt whether the Noachide prohibition against feticide may be set aside even in the event of danger to the mother's life. The various possibilities in understanding Tosafot's doubt are thoroughly catalogued in Bleich, "Fetal Tissue Research: Jewish Tradition and Public Policy," 24(4) Tradition 69, 87-88 n. 47 (Summer 1989). Rabbi Feinstein rules that because of this doubt, the non Jewish doctor should not perform the abortion. [CITE] Two questions R. Moshe does not fully address are: (1) Could a Jewish doctor perform an abortion on a non Jewish woman where her life is in danger? (2) Could a non Jewish doctor perform an abortion on a Jewish woman if her life is in danger?

With respect to the first question, its resolution depends on understanding why the Noachide law of abortion should not be waived to save the mother's life. After all, the Gemara in Sanhedrin concludes that Noachides may even violate idolatry for pikuach nefesh. If the reason pikuach nefesh does not set aside Noachide feticide is because for Noachides abortion is akin to murder and one may not destroy one soul to save another, a Jew could not facilitate a Noachide's committing murder because at the very least the Jew would be transgressing lifnai ivair. If, on the other hand, considerations of pikuach nefesh would permit feticide even under Noachide law but the problem lies only in the use of third party intervention, i.e., a Noachide may commit feticide to save his or her own life, but cannot transgress any Noachide law to save the life of another, the woman herself is not a violator. It would only be the doctor. If the doctor is Jewish and his only sin is causing the woman to transgress, it might be permitted here since the woman is no longer a transgressor. See Minchat Chinuch, no. 296 (a Noachide may transgress Noachide law to preserve his own life but not to save another).

In short, (1) if abortion from a Jewish perspective is treated as (noncapital) murder, under no circumstances could the Jew perform the abortion on a non Jew since there is no affirmative obligation of saving life that would override the prohibition.

(2) If abortion from a Jewish perspective is not murder but a Jew may not abort a non Jewish fetus because it facilitates a transgression on the part of the woman and pikuach nefesh is not a Noachide dispensation for the woman because for Noachides feticide is equated to murder, a Jew once again could not perform the abortion.

(3) If abortion for Noachides is not murder but pikuach nefesh is nonetheless not a Noachide dispensation because illness is not equated to duress, once again a Jew could not facilitate the woman's commission of transgression. See again Minchat Chinuch, no. 296 (a Noachide may violate Noachide law if he is threatened with death by another if he does not do so but may not violate such law to extricate himself from life threatening illness.)

(4) If, however, abortion is not murder for Noachides but pikuach nefesh is not a dispensation solely because of third party violations, the woman herself is no longer a direct transgressor. The Jewish doctor is therefore not the facilitator of a sinful act and could abort.

In sum, there is at least a tenuous basis in halacha to permit a Jewish doctor to abort a non Jewish fetus where the mother's life is at risk.

With respect to the second question, here the poskim clearly indicate a preference for a Jew who is permitted to violate prohibitions in order to sustain life. A non Jew would not be permitted to so act. Nevertheless, from the perspective of the Jewish patient, the only prohibition involved is lifnai ivair and if necessary to save her life, she may certainly transgress lifnai ivair to have the doctor perform although halachically the doctor's proper response would be to refuse.

21. See Beit Shlomo H.M. 132; Torat Chessed E.H. 42 (33); Seridei Aish III, no. 127. See also Achiezer III, end of no. 65 ("perhaps" there is no Torah prohibition). A stricter view is taken by R. Isser Yehudah Unterman, 6 Noam at ___, and Rabbi Moshe Feinstein, Igrot Moshe H.M. II, no. 69.

22. See Ramban, Yoma 82a; Torat HaAdam (Shaar HaSakkana); Noda B'Yehuda II, H.M. 59.

23. This correlation is rejected by Seridei Aish who argues that even according to the Behag abortion within 40 days may be halachically permissible. The dispensation to desecrate the shabbat to save a life does not, in his judgment, automatically imply a prohibition to terminate that life. As noted by Rabbi Weinberg himself, however, his assertion is flatly contradicted by Chavot Yair. See also Bleich at 340.

24. Sanhedrin _________.

25. R. Unterman, 6 Noam, at 4; Shevet M'Yehuda I, 9.

26. For reasons that are not clear to this writer, R. Bleich at 343 limits this dispensation to a Jew "giving advice or rendering indirect assistance."

27. See R. Mordechai Eliyahu (the former Rishon L'Tzion), "Discarding Fertilized Eggs and Fetal Reduction," 11 Techumin (1991); R. Chaim David HaLevi (Ashkenazic Chief Rabbi of Tel Aviv), "On Fetal Reduction." Assia 47-48 (12:3-4) (1990) ("The law of abortion applies only to procedures in the womb but in vitro, there is no prohibition at all."); R. Moshe Sternbuch, Bishevilai HaRefuah no. 8 (Kislev 5747), p. 29 ("The prohibition against abortion is in the woman's uterus for [the embryo] has the potential to develop and become complete in her womb and it is destroyed.") This also appears to be the implicit assumption of R. Shaul Yisraeli in an essay published as an Appendix to the Entzyclopedia Hilchatit Refuit, Vol. 4, where he discusses the Nachmani case, see text at _____, and rules that the embryos should be destroyed.

28. See R. Ezra Bick, "Ovum Donations: A Rabbinic Conceptual Model of Maternity," ____ Tradition _____.

29. To the extent permissibility of preembryo disposition rests on the fact that the embryo is microscopic and less than 40 days old, eventual technological "progress" - if that is the proper term - in allowing the embryo to develop outside of the womb for more than forty days may remove the halachic dispensation. On the other hand, if permissibility hinges on the fact that the embryo is not in an environment in which it can be brought to viability, this would permit disposal even if embryonic development outside the womb went considerably further. Finally, if one accepts R. Bick's definition of human life, one reaches the uneasy conclusions that if science ever produces a totally "test tube" baby, the baby would not be human and would be destroyed, Hashem yishmarenu.

30. Shevet Levi V, no. 47.

31. Two peripheral points that may suggest leniency should be rejected. First, the fact that the preembryos are likely to be destroyed by a non Jew would not in and of itself justify the procedure. Even if the non Jew is free of transgression as Rabbi Unterman argued, the Jewish parents who authorize the embryo destruction are considered in themselves to be primary violators of their halachic obligation to protect and sustain even potential life (according to the views that a Jew may not abort an embryo less than 40 days old). From the perspective of lo taamod, there is absolutely no distinction between acts of commission and sins of omission. Moreover, if we perceive the prohibition against a Jew aborting a "less than 40 day old" embryo as based on a recognition of the embryo's actual life rather than its potential to become life and thus, it too is a form of noncapital murder, Rambam makes clear that at least insofar as Heavenly judgment is concerned, hiring the murderer (even if for him - the Noachide - it is not a murder) renders the hirers culpable. Hilchot Rotzeach 2:1 Second, in many cases, the preembryos will not be physically destroyed but will thawed out or left in storage which will cause their inevitable spoilage and deterioration. Death will occur only via grama (indirect causation). This too should not make a difference. Failure to affirmatively preserve life is implicated whether destruction is active and direct or merely indirect and gradual. The gravamen of "lo taamod" is not how the entity died but that no steps were taken to prevent its death. Even if the concern is with actual retzicha, Rambam rules that indirect homicide violates lo tirtzach even though the perpetrator is not subject to capital punishment. Hilchot Rotzeach 2:1.

32. The Beit Yosef, C.M. 426, quotes the Talmud Yerushalmi that one is obligated to expose oneself to possible danger in order to extricate another from certain danger. This rule is not quoted by either the Shulchan Aruch or Rema. According to Sema and Pitchai Teshuva, the Talmud Bavli disputes the Yerushalmi's premise and the halacha follows the Bavli. See also Teshuvot Radbaz, no. 627 (It is forbidden to endanger oneself to save another. One who does is a chassid shoteh - a foolish pious person). Others permit (but don't require) self-endangerment if the person to be rescued is a superior talmid chacham etc. but prohibit such endangerment if the rescuer is greater. Pitchai Teshuvah Y.D. 252:1 in name of Teshuvot Yad Eliyahu, no. 43. L'halacha, we permit altruistic volunteering regardless of the rescuer's status but don't compel it. See Igrot Moshe Y.D. II, 174:4 (kidney transplant) and Aruch HaShulchan C.M. 421:4 (cautioning, however, that one should not be overly protective and cautious of one's safety in declining to render assistance). For further discussion, see Nishmat Avraham Y.D. 156:4 and 252:1.

33. Even according to the Yerushalmi cited by Beit Yosef, there would probably be no obligation to put oneself in danger here for the Yerushalmi imposes the obligation only if it is a relative certainty that rescue will be successful. In view of the small percentage of implanted IVF embryos that are brought to term, the prospects of rescue are at best safek. [CHECK]

34. See R. Pirutinsky, Sefer HaBrit 266:6 (Mekor U'Biur Halacha) for a complete discussion.

35. See Mishna Berurah 331:24 citing this as the position of "most acharonim". If the milah does take place, however, one is of course obligated to be mechallel shabbat to extricate the child from sakkana. Id.

36. Tashbetz I, no. 21 quoted in Beit Yosef Y.D. 268; Birchai Yosef Y.D. 262; Maharsham V, no. 7; Yabea Omer V, Y.D. no. 23.

37. Shach, Y.D. 266:18; Magen Avraham, 331:9; Eliyahu Rabba, 331:10; Noda B'Yehuda II, Y.D. 166; Chacham Tzvi, Teshuvot Nosefot no. 9; Mishna Berurah 331:73; Shemirat Shabbat K'Hilchata 32:(96). See also Nishmat Avraham Y.D. 262:3 who quotes Rabbi Shlomo Zalman Auerbach to the same effect.

38. Some opinions prohibit this because of the prohibition against generating pikuach nefesh situations. Others prohibit this merely because it is improper to cause unnecessary pain and suffering over shabbat. According to the latter understanding, this halacha would have no relevance to the pikuach nefesh issue under discussion here.

39. A more subtle analysis lends further support to this argument. If destruction of a fertilized ovum is prohibited, it is not because it is a "life" but because it is an organism that has the potential to develop into life. It is its future existence, not its present reality, that is the predicate for justifying the obligations of hatzala. The "sin" of destruction is not abortion or feticide; rather it is the failure to bring to fruition a certain potential. That failure exists whether the fertilized ovum is discarded or whether the egg is never retrieved in the first place. Limiting oocyte retrieval to a small number of eggs does not eliminate the vice or evil that is being condemned and therefore, there is no logical reason why such limitation should be halachically mandated. [Would this be true even in cases of certainty?]