The Preembryo in Halacha

Rabbi Yitzchok Breitowitz

The development of new reproductive technologies over the past 15 or so years has offered great hope to many infertile couples. Along with the blessings they bring, however, these technologies are also a source of major ethical dilemmas. For the Jew whose every decision is guided by the Davar Hashem, it is the halacha to which he or she must turn. The specific topic of this paper concerns the halachic status of the preembryo, a particular configuration of human cells that did not really exist in externalized form until the advent of in-vitro fertilization (IVF) in the late 1970's.¹

In-vitro fertilization may exist in various forms but at its simplest, it involves the extraction of immature eggs (oocytes) from a woman's ovaries, the placement of those eggs in a petri dish which is supplied with nutrients, the obtaining of sperm from a donor, the fertilization of the egg in the dish, the transplantation of the fertilized ovum into the woman's uterus (usually at the 48-72 hour developmental stage)². If all goes well, the embryo will implant and a pregnancy will ensue and be detectable within 10-14 days after the transfer. Since the procedure was first introduced in 1978, over 25,000 IVF babies have been born. The average take-home baby rate is 17%; 19% for women under 39, 66% for older women. "Preembryo" is the term often used for a fertilized ovum that has not yet been transferred into a uterus.

Although in the natural course of ovulation, a woman's ovaries release only one egg at a time, the modern IVF procedure involves the extraction of multiple oocytes to raise the probability of successful fertilization.³ As a consequence, there may be several eggs that are fertilized. Multiple eggs may be transferred for implantation; cryopreserved for future use in another reproductive cycle; donated to other infertile couples; used for experimentation and research; destroyed; allowed to thaw; or just kept in storage which will effectively result in their destruction after the passage of time. At least under American law, all of these options are legal possibilities though the locus of dispositional authority in the event of disagreement has not been definitely identified.

The existence of literally thousands of preembryos in freezers raises difficult problems. What happens if both or any one of the gamete (egg or sperm) donors die? What if they get divorced? Are frozen embryos "children" subject to a custody determination or marital property? Do preembryos have inheritance rights? In light of the Jewish restrictions on abortion, must all preembryos be implanted? May they be donated? In the event of a donation (whether permissible or not), who does halacha regard as the parents? Must thawed preembryos be buried? Are they considered "human life" for purposes of chillul shabbos, etc.? What about yibum? A number of these issues have been discussed extensively; some have not.

After briefly outlining the general principles governing IVF, this article will proceed to analyze seven specific problem areas: (1) may "surplus" preembryos be destroyed; (2) may such preembryos be utilized for experimentation and research and subject to what limitations; (3) may such preembryos be donated to other infertile couples, Jewish or non Jewish; (4) may a Jewish couple utilize a donated preembryo of Jewish or non Jewish origin in their own IVF protocol; (5) does the halachic system recognize a right of compensation to the gamete providers if preembryos are wrongfully destroyed without their consent; (6) do preembryos have inheritance rights and do they "count" for purposes of yibum, chalitza, and pidyon haben; (7) who has ultimate decisional authority over preembryos if husband and wife are divorced, deadlocked, or dead. To facilitate comparison to the secular legal system, an Appendix to this article describes the status of the preembryo under American law.⁴

Needless to say, no statements in this article are intended to be psak halacha.

I. General Considerations on the Use of IVF Technology

The halachic literature on assisted reproductive technologies is quite large and cannot be fully surveyed here. Much of it concerns artificial insemination where either husband or donor sperm is inserted vaginally or into the uterus.⁵ Many of the halachic concerns with AIH, particularly those involving the methods by which sperm is procured, apply equally to in-vitro fertilization.⁶

Subject to careful supervision of the physician, waiting periods, and exploration of alternatives, AIH is generally regarded as a halachically permissible procedure through which paternity can be established and the mitzva of p'ru v'revu or at least lashevet can be fulfilled.⁷ By and large, most poskim have assimilated IVF to AIH and have permitted its utilization subject to the same limitations.⁸ A notable exception is Rabbi Eliezer Waldenberg who maintains that IVF is an impermissible procedure and even ex post facto one does not fulfill the mitzva of p'ru u'revu.⁹ He argues that IVF is more problematical than AIH in a number of distinct respects: (1) Unlike AIH where all sperm is deposited into the vagina or uterus, IVF only transfers the fertilized ova with the rest of the sperm discarded, thus violating the edict against hashchatat zera; (2) One does not fulfill the mitzva of procreation where fertilization occurs outside of the womb. This independently creates a violation of hashchatat zera; (3) There is neither a paternal or maternal¹⁰ relationship with an IVF-offspring. Rabbi Moshe Sternbuch¹¹ also denies paternal identity in cases of IVF and consequently, prohibits the practice as violative of hashchatat zera. R. Yehuda Gershuni¹² agrees with Rabbis Sternbuch and Waldenberg that there is no paternal bond between a sperm donor and an externalized embryo even if later brought to term but he nonetheless permits the procedure; since IVF does in fact result in the creation of a physical human being albeit one that is not halachically related to the genetic parents, it is a fulfillment of the prophetic statement, "He did not create the world to be void but he formed it so that it would be settled" [lashevet yatzara] (Isaiah 45:18). R. Gershuni argues that even the mere fulfillment of lashevet is enough to prevent the emission of the seed from being levatala.

As noted, Rabbis Waldenberg, Sternbach, and Gershuni are decidedly in the minority. Virtually all contemporary poskim have concluded, first, that the egg and sperm providers do have a parental relationship with an IVF - generated offspring; second, that the procedure if undertaken for procreation by an otherwise infertile couple¹³ does not violate the prohibitions against hashchatat zera; third, that one may fulfill from any resulting offspring either the mitzva of p'ru u'revo or at the very least, the "lesser" mitzva of lashevet.¹⁴ These will be the assumptions on which this paper is predicated.¹⁵

II. May Surplus Preembryos Be Destroyed?

In the early days of IVF, this was an especially pressing concern. Before the development of freezing techniques, there was no way to store preembryos for future use. Whatever ova were not implanted during this particular cycle would inevitably be discarded. As a result, some halachic authorities permitted IVF procedures only if all fertilized eggs were implanted. Since, however, the implantation of five, six, or seven preembryos could severely jeopardize the prospects of a successful pregnancy, this also meant that only a small number of eggs could be extracted (typically no more than four). This sharply reduced the prospects of successful fertilization in the dish necessitating repetitive IVF attempts. Insurance plans commonly did not cover IVF after two or three attempts, thereby rendering IVF a less effective procedure for Orthodox Jews.

Two technological developments have rendered these concerns less pressing. First, the development of preembryo freezing means that fertilized ova can be stored for use at a future date. Second, use of specialized ova penetration techniques (such as drilling) allows for a greatly increased probability of fertilization even with a smaller number of eggs. Nevertheless, while the practical issues are less pressing, they have not gone away; the theoretical problems of alternative disposition remain: must a fertilized egg be transferred in an attempt to achieve a pregnancy?

a) Abortion

Issues concerning the destruction of embryonic or fetal life fall within the halachic strictures against abortion. The basic guidelines concerning abortion have been detailed in a number of places and will not be repeated here.¹⁶ Briefly, however, a number of principles bear repeating:

1. The killing of a fetus is not a capital crime, at least for a Jew.

2. Notwithstanding its exclusion from the death penalty, the vast majority of halachic authorities regard killing a fetus as a violation of Torah law. A small minority views the prohibition as purely rabbinic.¹⁷

3. The violation of feticide is committed not only by the person actually performing the procedure but, according to R. Auerbach, also by the woman who hires the physician and makes herself available for the operation. At the very least, making oneself available for an abortion would violate the prohibition of lifnei ivair - aiding and abetting a transgression whether the physician is Jewish or not.¹⁸

4. The source of the Torah prohibition is subject to disagreement.

Some opinions view abortion as form of murder [retzicha], albeit one that does not carry the death penalty similar to the case of killing a tereifah where there is a transgression of lo tirtzach without its corresponding punishment. Others view abortion as falling within the prohibition of hashchatat zera (destruction of seed) in that it wastefully destroys that which could potentially blossom into life. A third view treats "abortion" as an unjustified act of chavala ("wounding"). Within this view, there are some that regard the "chavala" in terms of the mother and others that regard the prohibited chavala as being done to the fetus. A final view would prohibit abortion as being inconsistent with the affirmative obligations to protect and preserve life and well-being, an obligation derived from "lo taamod al dam rayecha" or "hashavat aveida".

5. The halachic theory for the prohibition would determine which extenuating circumstances may amount to a proper justification, i.e., if the issur is retzicha, abortion can be sanctioned only if the fetus qualifies as a rodef. General considerations of pikuach nefesh would not suffice. At the other extremes, considerations of chavala may be set aside by lesser concerns. Hashchatat zera and hatzala can be arguably set aside for pikuach nefesh even where the fetus does not qualify as a rodef but nothing short of pikuach nefesh would suffice.

6. The foregoing refers to abortions performed by Jews (whether to Jewish or non-Jewish fetuses).¹⁹ Abortion performed by non-Jews (whether to Jewish or non-Jewish fetuses) is a capital offense under the Seven Laws of Noach. There is considerable discussion and debate whether Noachides may perform abortions even where there is pikuach nefesh or the baby is a rodef.²⁰

b) Abortion Prior to Forty Days

The Talmud records in a number of instances that fetal development prior to the 40th day is considered "mere water". Thus, a miscarriage within 40 days carries no tumat leidah nor does it necessitate the bringing of a korban. A widowed bas cohen who was married to a yisrael is allowed to eat the terumah in her father's house for forty days following her husband's demise because even if she is pregnant, the ubar doesn't count as an entity of disqualification. Based on those teachings, some poskim have concluded there is no issur of hapala within 40 days.²¹

To the extent there is an absolute heter to abort a pre-40 days embryo, there would certainly be a dispensation to destroy or discard a preembryo (regardless of how many days may have passed from fertilization) since its development has certainly not progressed to the 40-day point. In truth, however, the 40-day limit is subject to much disagreement. The argument that an embryo of less than 40 days is "mere water" is relevant to the abortion issue only if abortion is predicated either on its being murder, i.e., the taking of existing life or on its being chavala of the embryo - arguably, one cannot "wound" that which does not have the status of an existing person. The forty-day cut off is clearly irrelevant insofar as chavala of the mother is concerned. It is equally irrelevant on hashchatat zera grounds - after all, destruction of sperm is prohibited even prior to fertilization.

Moreover, the affirmative obligations of hatzala based on "lo taamod al dam rayecha" and "hashavat aveida" may apply at all stages of embryonic development. There is a disagreement among the rishonim if one is permitted to desecrate shabbat or otherwise violate the Torah in order to save or prolong the life of a fetus where the mother's life is not endangered.²² According to some authorities, the dispensation of "V'chai Bahem" applies only to autonomous lives. The Baal Hilchot Gedolot seems to concede that the verse "V'chai Bahem" does not cover a fetus but maintains that the potential for life and future observance of mitzvot triggers the rationale of "Better that one shabbat be violated so that many other shabbatot (may) be kept." The Behag apparently utilizes this concept as a justification for pikuach nefesh independent of the verse "and they shall live by them." Ramban makes clear that according to Behag, no distinction should be drawn between pre-40 day and post. It is the potential for human life, not its actualization, that justifies the dispensation of pikuach nefesh. The final decision is in accordance with the Behag. Moreover, even according to those who dispute Behag, it is arguable that there may indeed be a mitzva of "lo taamod" and "hashavat gufo" even towards a fetus and even before the fortieth day but this obligation does not fall within the parameters of pikuach nefesh when such obligations conflict with other prohibitions such as shabbat. In the absence of such a conflict, all might concede the duty of hatzala. Be it as it may, however, according to the Behag, one can clearly be mechallel shabbat for a fetus less than 40 days old. It would be incongruous and illogical to permit and apparently mandate the violation of shabbat in order to save a life that one is in fact permitted to extinguish. Thus, unless chillul shabbat be termed optional, a right to chillul shabbat for life preservation should inescapably lead to a prohibition against the taking of such life.²³ Note, however, that most assuredly the converse is not necessarily true; the inability to be mechalel shabbat does not automatically suggest that active termination is permitted.

Conceding, however, that abortion within 40 days is not retzicha or chavala of the child does permit consideration of other factors and mitigating circumstances that would otherwise be ignored. Thus, genetic defects or medical reasons falling short of rodef or pikuach nefesh, such as serious genetic conditions (e.g.,Tay-Sachs), may justify abortion. (What about rape, incest?)

c) Abortion Prior to Forty Days Under Noachide Law

The source of the Noachide ban on abortions is the verse "Shofeich Dam HaAdam B'Adam Damo Yishafech" (Genesis ____) which is interpreted as meaning, "He who spills the blood of a man [person] within a man [person], his blood shall be spilled." As the Talmud points out, a "person within a person" aptly describes a fetus.²⁴ Since, however, the Noachide prohibition is premised on there being a "person" and an embryo less than 40 days does not have the status of "personhood", some poskim have concluded that there is no Noachide ban on feticide within 40 days;²⁵ Noachides are enjoined only against the taking of actual life (even fetal), not potential life. The latter could be proscribed only under hashchatat zera, a nullification of p'ru u'revu, chavala of the mother or as a violation of the affirmative duty to "desecrate one Sabbath so that he may keep many Sabbaths." None of these obligations pertains to non Jews.

This psak gives rise to two questions: Could a Jew perform an abortion on a Noachide if the embryo is less than 40 days? Could a Jewish woman procure such an abortion by the expedient of utilizing a non Jewish physician?

The answer to the first question appears to be in the affirmative. While a Jew may not take the life of a non Jew, there is no positive duty of protecting future life. Nor is there the problem of lifnei ivair in aiding and abetting the woman in obtaining the abortion since the non Jew herself is not commanded with the affirmative obligations of hatzala. Thus, notwithstanding the fact that a Jewish physician could normally not abort the fetus of a non Jew, he would be permitted to abort a Noachide fetus of less than 40 days even according to the authorities that prohibit such an abortion for a Jew.²⁶

The answer to the second question, however, is in the negative. It is indeed true that insofar as the non Jew is concerned, aborting any embryo within 40 days is halachically permissible whether the embryo is Jewish or non Jewish. However, given the fact that the abortion prohibition is triggered not only by the one performing the procedure but by the woman who makes herself available and hires the physician, the obligation to preserve and protect even potential Jewish life would preclude her acquiesence in the procedure.

In short, whatever leniencies may exist under Noachide law for the termination of a pregnancy less than 40 days old would not extend to a Jewish woman enlisting the assistance of non Jews. [At the very least, this would also be prohibited rabbinically under the rubric of amira l'akum but in all probability would involve a direct violation of "lo taamod" and "hashavat gufo", certainly according to the Behag and possibility even according to those who differ with the Behag concerning chillul shabbat.]

d) Preembryo Disposition

A preembryo should certainly be entitled to no more halachic protection than a pre-40 day implanted embryo and there are logical grounds to afford it less. Thus, if genetic testing uncovers a defect which would justify abortion of a pre-40 day embryo, destruction of the preembryo may be similarly permitted. A number of contemporary poskim have gone further and have allowed the virtual indiscriminate discard of "surplus" embroys even where actual abortion of a transplanted "less than 40 day" embryo would not be justified.²⁷

Without in any way intending to issue a psak, it would appear that the validity of this leniency should depend on the reasons why abortions are genreally prohibited. Because a preembryo is outside a woman's body, there is obviously no issue of chavala of the mother. Since the preembryo is not in an environment in which it will be able to be brought to term and live, it arguably does not have the status of a living being even according to those who might accord such status to an implanted embryo before 40 days. Thus, neither retzicha nor chavala of the embryo would be implicated. It is not likely that destruction of a preembryo could be regarded as a chavala since there is no existing living being which is being "wounded." It has also been suggested that regardless of the 40 day rule, until there is implantation within a human being, no human life can be said to exist.²⁸ (It might also be added that since the preembryo is microscopic, not visible to the unaided human eye, the Torah does not invest its existence with any halachic significance.)²⁹

To the extent abortion restrictions rest on hashchatat zera considerations, however, those concerns should apply equally to the preembryo. As noted, many authorities refuse to equate abortion of any embryo or fetus with the sin of hashchatat zera arguing that the latter is violated only at the time of seminal emission and not after an ovum has been fertilized.

The fundamental question is not whether there is a sin to destroy preembryos which at best may only be life in potential not actualization but rather whether there is a mitzva to preserve them. What about considerations of "lo taamod", "hashavat gufo", "vechai bahem", "mutav sheyechallel shabbat achat v'al yechallel shabbatot harbai"? Do these concepts impose an affirmative obligation to sustain the "life" of a preembryo and compel its implantation? Assuming there is no hashchatat zera issue, the matter is not clear. I have already mentioned the halachic view of the Behag and the argument of Chavot Yair that whenever there is a dispensation for chillul shabbat, there is a duty to affirmatively sustain life and a corresponding prohibition not to diminish it.

A recent responsum of R. Shmuel Wozner of B'nai Brak has ruled that even according to the Behag, one may not be mechallel shabbbat on behalf of a preembryo.³⁰ Since the justification of chillul shabbat is based not on the presence of actual human life (since mayim be'alma) but only on its potential, where the potential for realization is very remote or improbable (as is the present percentage of successful IVF pregnancies brought to term), the dispensation for chillul shabbat or other transgression of the Torah is not present. If we understand this ruling to suggest that there are no affirmative obligations to sustain preembryo life, the surplus embryos may indeed be discarded with impunity for any reason. If, however, as is more likely, R. Wozner's ruling is limited to conflicts with other prohibitions but in the absence of such conflict, there would indeed be an obligation to protect potential life, then one could not automatically assume the unlimited right to discard unwanted preembryos.³¹

I would suggest, however, an alternative basis of leniency. It must be kept in mind that what is involved in preembryo disposition is not necessarily active destruction but simply allowing them to thaw out or disintegrate in storage. Thus, we are not dealing with active homicide (retzicha b'yadaim) but simply omitting to affirmatively act - the sin is shev v'al taaseh on hatzala. Moreover, for reasons of meyim bealma, even active destruction would at worst be violative only of the affirmative duty to protect potential life, i.e., under no circumstances would it be retzicha. Certainly, from the perspective of the husband and wife, they are at worst authorizing the cessation of affirmative activity that would culminate in embryo transfer and implantation.

Assuming that in the abstract there is a mitzva to sustain life based on "lo taamod", "hashavat gufo", "vechai bahem", or "mutav sheyechallel", at what cost? The halacha is very clear that one need not endanger one's life in order to preserve or protect even the existing life of another.³² While it is permitted and perhaps encouraged to do so, there is no duty.³³ It is also clear that pregnancy and parturition are life-threatening conditions that justify chillul shabbat. Thus, a woman should not be halachically compelled to receive a fertilized ovum in order to possibly preserve its life because through that process she would be endangering her own. Accordingly, fertilized eggs do not have to be implanted.

Admittedly, this argument might prove too much. After all, it is a crystal clear that a healthy woman may not abort a viable pregnancy merely because pregnancy and childbirth per se are life threatening experiences. Because these experiences are normal, common and natural and the risk of danger in ordinary course is low, the life of the fetus must be respected. Moreover, although a woman is technically not obligated in the mitzva of pr'v u'revu, she certainly could not insist on contraception or abstinence on the grounds that pregnancy per se is a dangerous condition. The obligations and responsibilities of the marital bond including onah, lashevet yatzara, and the duty to facilitate the husband's mitzva of pru v'revu all combine to negate the elements of sakkana which at best is remote and infrequent. Similarly, the existence of a concrete nefesh (embryo or fetus after 40 days) precludes such reliance. Where, however, the prospects of hatzala are in themselves extremely remote, perhaps even remote dangers may justify inaction. Insofar as onah and lashevet are concerned, these obligations do not require consent to an IVF procedure nor would it require her to complete the procedure once begun. [Onah can also be waived by mutual consent.] In the absence of countervailing concerns, therefore, the woman's claim of sakkana at least in the context of a preembryo should be given credence. (What about within 40 days? Is this only an argument for not implanting but not to destroy?)

The conclusions that emerge from this analysis are a bit unusual:

(1) all extracted eggs that are fertilized should be implanted;

(2) the wife would have the right to refuse implantation;

(3) if the wife is willing, the husband would have no right to abort the process;

(4) if wife says no, it is questionable whether the embryos must be discarded or whether they can be donated. While logic would support the latter, the alternative of donation is not accepted by most poskim addressing the matter.

e) The Propriety of Initiating the Procedure

A final question: given the fact that a woman has the right to refuse the receipt of fertilized eggs on grounds of sakkana, is it proper to perform or authorize an IVF procedure which may result in more preembryos than the woman is willing to receive either now or later? Must the IVF protocol be structured so that only a very limited eggs are retrieved to guarantee that all fertilized eggs will be "rescued"? While freezing for later implantation minimizes the problem, it does not eliminate it. If, for example, twenty eggs are retrieved and six are fertilized, a woman may be unwilling to have all the embryos implanted even over a period of several years.

Without coming to a definitive conclusion, this question may be connected to a well-known dispute between the Ramban and the Baal HaMaor. In Talmudic times, babies needed warm water after circumcision. If the brit was taking place on Shabbat the water had to be prepared before Shabbat because it is only a machshir milah - something necessary for the brit but not part of the actual ceremony. If one did circumcise a baby and then the water spilled, it is clear that one would be allowed to boil water for pikuach nefesh. But what if the water spilled before the milah? Is one allowed to perform the brit knowing that a situation of sakkana will thereby be generated necessitating the desecration of Shabbat or is it preferable to defer the milah until the next day? Baal HaMaor rules the milah should be postponed while Ramban rules that the mitzva that is incumbent to be performed should be performed even with the knowledge that a situation of pikuach nefesh will be generated.³⁴ While the precise dispute of Ramban and Baal HaMaor is not explicitly addressed in the Shulchan Aruch, the halachic consensus follows Baal HaMaor and necessitates that the milah be deferred.³⁵

If we may extrapolate from shabbat to other areas, the governing principle appears to be that one is not allowed to engage in conduct [which may be permissible in and of itself] with the knowledge that a situation of pikuach nefesh necessitating transgression will be thereby generated. Applying this to the disposal of surplus embryos, while the in vitro fertilization may be halachically permissible in and of itself - donation of eggs is not problematical and the emission of sperm was for procreative purposes and not levatala - it would be halachically improper to utilize the procedure in such a manner that there are likely to be surplus fertilized eggs that will then have to be discarded. Even if halacha permits those eggs to be discarded once they are generated (because of considerations of maternal health and pikuach nefesh), it would be improper to generate them. In effect, therefore, unless the mother is willing to have fertilized ova cryopreserved for future use, oocyte extraction would have to be limited to the number of eggs that the mother is able and willing to have implanted.

The analogy to brit milah and shabbat may not be exact. Circumcising on shabbat in the absence of warm water will inevitably necessitate chillul shabbat by virtue of pikuach nefesh; because of this certainty, Baal HaMaor rules that the milah should be delayed. By contrast, the extraction of multiple eggs will not necessarily result in transgression. Presumably, even according to Behag the mitzvot of hatzala, lo taamod, hashavat aveida etc. come into effect only upon fertilization. It is quite possible that out of a total of eight, ten, or twelve eggs, only one or two (or none) may be fertilized. It is possible, of course, that multiple fertilizations may occur thereby necessitating their disposal, but since this is only a possibility, not a certainty, the parties are permitted and indeed encouraged to proceed in any way that will enhance the efficacy of the procedure regardless of what the later consequences might be.

This conclusion - distinguishing between certainty and possibility - finds support in another law of milah on Shabbat. Chazal had a tradition that for the first three days following milah (according to some, only the third day) the child's health may be especially precarious permitting the violation of Shabbat because of pikuach nefesh. Some poskim have concluded that it is improper to perform a milah on Thursday or Friday (unless it is a bris performed on eighth day) since this may necessitate chillul shabbat.³⁶ The majority of poskim rule, however, that Thursday or Friday milah is permitted and it is in fact improper to delay the performance of a mitzva.³⁷ While it is indeed true that purely elective surgery should not be performed after Wednesday because of the mere possibility of shabbat having to be violated,³⁸ such possibilities carry no weight where a mitzva is being performed.

As between a mitzva like milah where only the certainty of desecration warrants postponement and an optional medical procedure where even the possibility of chillul shabbat necessitates rescheduling, IVF falls somewhere in the middle. On one hand, the obligations of p'ru v'revu and lashevet have never been understood as compelling resort to any type of surgical procedure to achieve procreation. At the same time, most poskim do consider the offspring produced from IVF as having a familial bond to the biological parents. The father either fulfills p'ru v'revu or at least the prophetic injunction of lashevet. As such, the kiyum hamitzva that one may attain, by analogy to milah shelo bizmana, may be sufficiently great that one may be permitted to pursue whatever avenues carry the greatest prospects of success even if there is a possibility (not a certainty) that pikuach nefesh will be invoked to violate prohibitions, i.e., disposal of surplus eggs.

In fact, one might argue that to the extent IVF is permissible only because the sperm is procured for purposes of reproduction, the prohibitions of hashchatat zera require, not only permit, that IVF be implemented in a manner most likely to produce a successful pregnancy and minimize the need for repetitive semen procurement. Since multiple egg retrieval greatly increases the chances for success, its utilization may actually be preferable notwithstanding the "risk" of surplus embryos that will not be implanted.³⁹