Recently, there have been a couple of high-profile cases in which various Israeli rabbinical courts ruled that a given baby born through surrogacy would not be recognized as Jewish, or that their status is doubtful and that they should undergo a pro forma or precautionary conversion process to remove all questions.While each case requires individual examination, we’ll try to present the general rabbinic debate over surrogacy and why that has led to many difficult legal quandaries. Within Jewish law, fatherhood is established through the owner of the sperm. Thus, with sperm donation, the lineage of the child is established through the biological father, even as another man might take full responsibilities for raising the child (as is also the case in adoption). A “functional father” (i.e., a man raising the child) may have rights and obligations as a custodian, but the child’s personal status (for purposes of lineage, for example) is determined by the identity of the man who contributed the sperm.The case of ovum donation is more critical because Jewish status, according to traditional Jewish law, is transmitted through the mother. It is also more complicated, as one could argue that maternity may be determined at different stages of the reproductive process. This could be established at conception, at some given point during gestation, or at birth.Around the world, various countries have different standards on this question for a variety of purposes. For example, in the case of a child born abroad through surrogacy to American citizens, the United States recognizes its citizens as the legal custodians but does not grant automatic citizenship to the child, unless one of the parents has a genetic connection to the child. Countries also have distinct rules regarding what types of rights the gestational mother (i.e., the woman who carried the baby to term) has toward the baby and what types of contractual agreements (if any) will be enforced.BECAUSE OF these types of complexities, some decisors, like rabbis Eliezer Waldenburg and Moshe Sternbuch, believe that the entire process of ovum donation is unadvisable. Many disagree, and in any case, all understand that Jewish law must determine the status of children who have been born through this process.Like their secular counterparts, Jewish legal decisors in Israel and elsewhere have had an extended discourse regarding the status of children born through ovum donation under various arrangements.In one scenario, a Jewish Israeli opts to contract a legal agreement with a non-Jewish woman outside of the country (say, from Thailand or Ukraine) who provides the ovum and the womb. In this case, Israeli law will recognize the Israeli couple as the parents, but Jewish law treats the child as non-Jewish since no Jewish maternal partner contributed to the biological process. Such a child requires conversion by an authorized rabbinical court. Secular Israelis are not always aware of this requirement, while rabbinical courts are not always eager to convert children being raised in nonobservant homes, causing much confusion. Parents seeking a solution in these and other cases should consult with the AMI conversion program or ITIM’s Giyur K’Halacha network.A more complex debate emerged in cases in which the genetic mother (the ovum donor) and the gestational mother (the womb carrier) are not the same and only one is Jewish. Does Jewish identity get transmitted through the egg or within the birth process?A series of decisors, including rabbis Shaul Yisraeli, Nachum Rabinovitch and former Sephardi chief Rabbi Mordechai Eliyahu, asserted that the identity of the gestational mother determines the child’s status. As support for their opinion, they cited the Talmudic ruling that the child of a woman who converted during pregnancy does not need to convert, because the mother was Jewish at the time of parturition. They also cited Talmudic rulings that treat an embryo before the 40th day of gestation as “mere water,” i.e., legally insignificant. Eliyahu, moreover, was insistent that such a child not undergo pro forma conversion, because this process would inherently cast doubts on the status of others born from a Jewish gestational carrier.In contrast, Rabbi Avigdor Nebenzahl, former Ashkenazi chief Rabbi Shlomo Goren and current Jerusalem Chief Rabbi Shlomo Amar, among others, asserted that Jewish identity is determined by the ovum donor. Some cite aggadic passages in the Talmud that speak of the mother contributing certain physical characteristics or that human life begins at conception. Others assert that this is the logical conclusion from genetics, and that following the ovum donor will help keep track of lineage through DNA testing.When he served as Israel’s Sephardi chief rabbi, Amar insisted that pro forma conversions were not necessary for children of Jewish ovum donors, while bona fide conversions were entirely required for children of a Jewish gestational mother.In spite of his efforts, however, many decisors, including rabbis Shlomo Zalman Auerbach and Zalman Nehemiah Goldberg, maintained that there is no clear answer to this question, and that it is possible that both the gestational and genetic mothers play a role in determining Jewish identity. As such, they require the baby to undergo a conversion process in all cases in which only one of the participating mothers is Jewish.Cogent arguments may be made for all of these positions, yet ultimately a legal system must operate under clear and coherent standards.In theory, the Israeli Chief Rabbinate grand council could create some order amid this chaos, but there is too much internal rabbinic debate on this question. In the interim, it behooves the Chief Rabbinate to provide clear and unambiguous instructions regarding its policies and to make Israelis, secular and religious alike, aware of the options and pathways toward resolving their child’s status.The writer directs the Tikvah Overseas Students Institute and is a postdoctoral student at Bar-Ilan University law school. His book, A Guide to the Complex: Contemporary Halakhic Debates, won a National Jewish Book Award.