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Gender bias in the disposition of frozen embryos
FERTILITY AND STERILITY威 VOL. 76, NO. 6, DECEMBER 2001 Copyright ©2001 American Society for Reproductive Medicine Published by Elsevier Science Inc. Printed on acid-free paper in U.S.A.
Gender bias in the disposition of frozen embryos Sigal Klipstein, M.D.,a,b Richard H. Reindollar, M.D.,a,b Meredith M. Regan, Sc.D.,a and Michael M. Alper M.D.a,b Beth Israel Deaconess Medical Center, Boston, and Boston IVF, Waltham, Massachusetts
Objective: To examine the gender differences found among couples when choosing the disposition of their frozen embryos. Design: Retrospective chart review. Setting: University affiliated in vitro fertilization (IVF) center. Patients: Couples undergoing their first cycle of assisted reproductive technology (ART). Intervention(s): None. Main Outcome Measure(s): Choice of disposition of gametes and embryos. Result(s): Gender bias is found when couples choose the dispositon of their frozen embryos, but not when they choose the disposition of their gametes. Conclusion(s): Gender bias was found in couples who made decisions regarding the disposition of their frozen embryos. (Fertil Steril威 2001;76:1181– 4. ©2001 by American Society for Reproductive Medicine.) Key Words: Frozen embryo, gender bias, disposition
Received October 23, 2000; revised and accepted June 18, 2001. Reprint requests: Sigal Klipstein, M.D., Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, East Campus, Room K317, 330 Brookline Avenue, Boston, Massachusetts 02215 (FAX: 617667-5011; E-mail: sklipste@caregroup. harvard.edu). a Beth Israel Deaconess Medical Center. b Boston In Vitro Fertilization. 0015-0282/01/$20.00 PII S0015-0282(01)02889-8
Technological advances in the field of infertility are evolving much more rapidly than our ability to analyze their implications. The availability of cryopreservation of excess embryos has created unique situations in reproductive decision-making. By separating fertilization and implantation in time and space, a new set of choices has emerged for couples wishing to reproduce. The initial decision to form an embryo and the subsequent decision to allow it to develop have been separated. With the advent of embryo freezing, the decision to create embryos may occur moments to years before the decision to allow them to develop. Infertility centers have recognized the potential issues inherent in embryo freezing, and have instituted consent forms for the disposition of these embryos. Couples are requested to make choices regarding the fate of their unused frozen embryos if death of one partner, separation or divorce were to occur. Shultz (1) states that, with regard to reproductive technologies: “whenever subdivision occurs, choices emerge.” In the case of frozen embryos, couples that initially contract for the creation of embryos may undergo life-chang-
ing events such as divorce or death. These potential changes may affect their desires toward the disposition of their stored embryos. As stated by Dehmel (2), “freezing embryos . . . allows for delay between donation and implantation . . . time for a party to change his or her mind about completing the process through implantation.” The decision to create embryos is customarily made jointly by a couple. At a later date, the couple may disagree on the ultimate disposition of these embryos. Gender differences are evident when investigating how men and women view their gametes and their embryos. The purpose of this paper is to retrospectively review choices made by couples on the disposition of their frozen embryos, and to contrast these with choices couples make for the disposition of their unfertilized gametes.
MATERIALS AND METHODS All patients undergoing assisted reproductive technology (ART) cycles at Boston IVF are required to fill out a form titled: Consent Form for Disposition of Embryos, Eggs and 1181
Sperm. This form asks couples whether they want to cryopreserve excess embryos that may be produced during the course of their ART. Couples were asked to decide how they wanted to dispose of the frozen embryos in the event that the female died, the male died, or both members of the couple died. They had the opportunity to choose to donate or discard the embryos in all cases. In the case of female death, they had the ability to elect to return the embryos to the male’s new partner. In the case of male death, they were able to choose to return the embryos to the body of the female. A very small percentage (1%) chose other options. These were not included in the results, as they did not affect the outcomes of the analysis. Furthermore, couples were asked to choose the disposition of their embryos in the event that they became separated or divorced. They were able to choose among four options: donate the embryos to another couple, discard the embryos, return the embryos to the body of the female, or return the embryos to the body of the male’s new partner. Finally, the couples were asked whether they would give permission for the use of excess unfertilized oocytes and sperm for laboratory testing. Each couple jointly completed this form before their first ART cycle. Forms were renewed each year, or earlier at the couple’s request. Institutional Review Board approval for this project falls under Boston IVF protocols that allow for retrospective chart review. A retrospective chart review of the responses of all patients undergoing their first cycle of ART at our infertility center between January and June of 1998 was undertaken. There were a total of 393 cycles during this time period, of which 385 (98%) were available for review. Of these 385 cycles, 101 cycles resulted in 509 embryos frozen. In those couples for which embryos were cryopreserved, 67% had between one and five, 22% had between six and nine, and only 11% had 10 or more. The distribution of decisions within a scenario was compared using 2 test for equal proportions. Decisions across/ between different scenarios were compared using McNemar’s test for paired proportions with an exact P value. For each scenario, decisions were compared among subgroups of couples defined by type of infertility (female factor, male factor, unexplained) and by parity (0 vs. 1⫹) using 2 or Fisher’s exact test. The differences in male and female age by decision were assessed using the Kruskal–Wallis test.
RESULTS The mean (⫾SD) age of women was 36 ⫾ 4.5 years (range 20 – 46), and that of men was 37 ⫾ 6.2 years (range 20 – 68). A subgroup analysis looking at the ages of females and males showed no significant differences between age of either parent and decisions regarding frozen embryo disposition. The percentage of couples agreeing to donate unused sperm for laboratory research was not different from those 1182 Klipstein et al.
Gender bias and frozen embryos
TABLE 1 Embryo disposition with death of male or female, or both. Disposition method Donate Discard Return Other Total
Female death
Male death
Both male and female death
22% 59% 18% ⬍1% 100%
9% 32% 58% ⬍1% 100%
35% 64% NA ⬍1% 100%
NA ⫽ not applicable. Klipstein. Gender bias in frozen embryo disposition. Fertil Steril 2001.
agreeing to donate unused oocytes (62% vs. 66%, P⫽.26). Furthermore, couples were concordant in their decisions to allow or refuse donation for research of excess gametes. Although 58% of couples agreed to allow for experimentation with both oocytes and sperm, 30% declined experimentation with either oocytes or sperm. In total, a full 88% of couples were concordant in their decision to allow or decline testing of their excess male and female gametes. Only 12% of couples were discordant in their decisions toward the testing of excess male and female gametes. The vast majority of couples (96%) chose to freeze any excess embryos created during their first ART cycle. The authors next looked at what couples decide to do with any “surplus” frozen embryos that they may create. This data is presented in Table 1. Couples differed significantly in their decisions to donate, discard or return the embryos, depending upon whether the male, female or both partners were to die (P⬍.001 for all three comparisons). In the case that the female were to die, embryos were most likely to be discarded, whereas in the case that the male were to die, the embryos were most likely to be returned to the body of the female. Interestingly, in the case of female death, the couple was more likely to choose to donate the embryos than to allow the male to have control over their disposition. Conversely, in the case of male death, most couples chose to allow the female to be able to return the embryos to her body. In the unfortunate situation that both members of the couple were to die, couples were more willing to donate their frozen embryos than if only one were to die (P⬍.001). Of those couples who chose to discard the embryos in the case of female death, 8% would donate the embryos if both parents were to die. Similarly, of those couples that chose to discard the embryos in the case of male death, 6% would donate the embryos if both members of the couple were to die (P⫽.016). Finally, couples were asked to choose the disposition of the embryos in the event that they became separated or divorced. The data is presented in Table 2. Vol. 76, No. 6, December 2001
DISCUSSION
TABLE 2 Embryo disposition in the event of divorce. Donate Discard Return embryo to the body of the female Return embryo to the body of the male’s new partner Other method
17% 58% 22% 1% 2%
This is the first report in the literature to look at gender bias in reproductive choices toward frozen embryos. In this study, each couple had to mutually agree on the answers to the questions on the embryo disposition consent forms. This was done before the embryos were available for cryopreservation. Among these couples, gender differences were readily apparent.
Klipstein. Gender bias in frozen embryo disposition. Fertil Steril 2001.
In the case of divorce, most couples chose to completely discard their frozen embryos over all other options, including donating them to another infertile couple (P⬍.001). In those couples that chose to return the embryos to the body of the female or the male’s new partner in the case of death of one member of the couple, 47% would discard the embryos in the case of divorce (P⬍.001). For those couples that chose neither to donate nor to discard the embryos, 22% would return frozen embryos to the original female if the male died, but only 1% would return the embryos to the male’s new partner if the female died. Finally, the percentage of couples who chose to discard the embryos in the case of female death were not different from those choosing to discard the embryos in the case of divorce (59% vs. 58). Next, the authors looked at associations between decisions toward frozen embryo disposition and other factors. P values of comparisons are summarized in Table 3. Decisions generally did not differ depending on the type of infertility. The only exception to this was when looking at male vs. female factor infertility, there was a statistically significant difference for the decision when both died (P⫽.041). There were no statistically significant differences in male or female age by decision type. For all decisions, there was a difference depending on parity (P⬍.05) for each decision. In all cases, couples in which the female was parous were more likely to discard frozen embryos than couples in which the female was nulliparous.
In attempting to foresee future events, couples in this study tended to revert to traditional gender-based societal roles. Gender differences were apparently absent when couples made decisions regarding their gametes. Once the gametes united, the decisions were much more likely to follow established societal gender patterns. In cases for which control of the embryos could be transferred to either the male or the female, it was the female who preferentially received decision-making authority over the couples’ unified gametes. This is interesting in light of the fact that males and females did not view their unfertilized gametes differently, as evidenced by their concordant decisions toward the disposition of their unfertilized eggs or sperm. One limitation of this study was that couples filled out the consent forms together. It would be enlightening to compare the answers men and women give when pondering these issues as individuals, unencumbered by the need to come up with a mutual decision, and uninfluenced by one another. In the case of the death of one partner, gender differences appeared. The disposition chosen for the frozen embryos depended upon the gender of the partner who died. In the case of death of the female, the majority of couples chose to discard the embryos. Conversely, in the case that the male were to die, the majority of couples chose to return the embryos to the body of the female. Interestingly, almost half of couples (47%) who chose to return the embryos to the woman or the man’s new partner in the case of the death of one of them, would rather discard the embryos in the case of divorce. Perhaps this represents a decision on the part of couples to remove as yet unborn children from the equation
TABLE 3 P value comparisons of couples’ decisions with age, parity, and type of infertility. Decision Experiment with excess oocytes Experiment with excess sperm Female death Male death Death of both male and female Divorce a
Primary indicationa
Male age
Female age
Parity
.119 .094 .114 .127 .042 .263
.637 .645 .484 .199 .836 .254
.517 .421 .602 .098 .903 .063
.031 .031 .016 .055 .001 .041
Male, female, unexplained.
Klipstein. Gender bias in frozen embryo disposition. Fertil Steril 2001.
FERTILITY & STERILITY威
1183
in the case that their status as a decision-making unit were to be disrupted. In the case of divorce, 22% of couples chose to return the embryos to the body of the female, while only 1% picked the option of returning the embryos to the body of the male’s new partner. Clearly, the present state of reproductive affairs allows women to more easily bring their frozen embryos to fruition than men. One wonders if couples are choosing based on logistics, or rather on the assumption that it is more appropriate for potential children to be reared by their mothers than by their fathers. Women seem to be given more say in the disposition of these embryos. This occurs even though at the time of their formation, the genetic makeup of these embryos is most often a contribution of both partners. Approximately the same percentage of couples would discard embryos if the female member of the couple were to die (59%), as would choose to return the embryos to the body of the female if the male were to die (58%), these two numbers not being statistically different. This likely reflects the tendency in our society for mothers to raise children. This may be further elucidated when looking at couples’ choices in the event that both of them were to die. In such a situation, 64% chose to discard the embryos, just above the 59% who would choose to discard the embryos in the event of the female’s death. Neither type of infertility nor age of either partner had any significant impact on decision making regarding disposition of frozen embryos. Only parity significantly impacted decision-making. In all cases, couples that already had at least one child would rather discard than donate frozen embryos. It would appear that couples that have already had the experience of raising a child prefer not to delegate this task to others. In a world where conception and implantation are separated, this gender inequality is somewhat artificial. The frozen embryo contains virtually equal parts maternal and paternal DNA. Indeed, men and women consider their unfertilized genetic material equally, at least as deduced by their similar answers when asked if they would allow for experimentation of their excess gametes. Once the gametes unite, the resulting embryo is seen in a different light. In this study, the majority of couples allowed their female members to lay greater claim to these fertilized entities. In the “natural” state, such a choice does not exist. Unassisted by reproductive technologies, couples have no choice beyond allowing the pregnancy to continue or terminating it. The decision to allow conception and implantation are one and the same, and once conception has occurred, the female has more decision-making authority by virtue of the fact that it is her body that is nourishing the growing embryo.
1184 Klipstein et al.
Gender bias and frozen embryos
In the case of frozen embryos, this decision exists in a state of suspended animation, able to be delayed for an as yet undetermined period of time. Clearly, when looking at reproductive choices pragmatically, it is logistically easier for a woman to bring a frozen embryo to maturity. Even so, men do have a means of bringing frozen embryos into the world, be it by contracting with surrogates or implanting these embryos into their new partners. If in fact men believe that surrogacy is an unrealistic option, they may not choose to have control over the couples’ embryos. If surrogacy were to become commonplace, men might be more likely to desire this option, and request control over the disposition of the embryos. Perhaps women see embryos as babies, and men see them more as gametes. It is also possible that women bond sooner to embryos than do men. If this is true, men may not have as strong an attachment to the embryos. This may cause men to be more likely than women to relinquish authority over embryo disposition. Such gender differences warrant further study. Finally, society associates more with single motherhood than with single fatherhood. The courts continue to award custody preferentially to women in cases of divorce. Additionally, children living in single-parent homes are much more likely to live with their mothers than with their fathers. Couples may continue to perpetuate this gender bias when choosing the disposition of their frozen embryos. The choice of embryo disposition is unique to couples undergoing ART. The separation of the desire to conceive from the implantation process has created new and unique choices for couples. Long-held traditional views in concert with biological differences continue to shape couples’ decisions regarding their embryos. As more options become available to couples, it is possible that their choices regarding the disposition of frozen embryos will become more balanced.
Acknowledgments: The authors thank Doria Harris, Ph.D. for her help in preparing this manuscript.
References 1. Shultz MM. Reproductive technology and intent-based parenthood: an opportunity for gender neutrality, Wisconsin Law Review 1990;297– 398. 2. Dehmel JM. To have or not to have: whose procreative rights prevail in disputes over dispositions of frozen embryos?, Connecticut Law Review 1995;1377–1405.
Vol. 76, No. 6, December 2001
Gender bias in the disposition of frozen embryos Sigal Klipstein, M.D.,a,b Richard H. Reindollar, M.D.,a,b Meredith M. Regan, Sc.D.,a and Michael M. Alper M.D.a,b Beth Israel Deaconess Medical Center, Boston, and Boston IVF, Waltham, Massachusetts
Objective: To examine the gender differences found among couples when choosing the disposition of their frozen embryos. Design: Retrospective chart review. Setting: University affiliated in vitro fertilization (IVF) center. Patients: Couples undergoing their first cycle of assisted reproductive technology (ART). Intervention(s): None. Main Outcome Measure(s): Choice of disposition of gametes and embryos. Result(s): Gender bias is found when couples choose the dispositon of their frozen embryos, but not when they choose the disposition of their gametes. Conclusion(s): Gender bias was found in couples who made decisions regarding the disposition of their frozen embryos. (Fertil Steril威 2001;76:1181– 4. ©2001 by American Society for Reproductive Medicine.) Key Words: Frozen embryo, gender bias, disposition
Received October 23, 2000; revised and accepted June 18, 2001. Reprint requests: Sigal Klipstein, M.D., Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, East Campus, Room K317, 330 Brookline Avenue, Boston, Massachusetts 02215 (FAX: 617667-5011; E-mail: sklipste@caregroup. harvard.edu). a Beth Israel Deaconess Medical Center. b Boston In Vitro Fertilization. 0015-0282/01/$20.00 PII S0015-0282(01)02889-8
Technological advances in the field of infertility are evolving much more rapidly than our ability to analyze their implications. The availability of cryopreservation of excess embryos has created unique situations in reproductive decision-making. By separating fertilization and implantation in time and space, a new set of choices has emerged for couples wishing to reproduce. The initial decision to form an embryo and the subsequent decision to allow it to develop have been separated. With the advent of embryo freezing, the decision to create embryos may occur moments to years before the decision to allow them to develop. Infertility centers have recognized the potential issues inherent in embryo freezing, and have instituted consent forms for the disposition of these embryos. Couples are requested to make choices regarding the fate of their unused frozen embryos if death of one partner, separation or divorce were to occur. Shultz (1) states that, with regard to reproductive technologies: “whenever subdivision occurs, choices emerge.” In the case of frozen embryos, couples that initially contract for the creation of embryos may undergo life-chang-
ing events such as divorce or death. These potential changes may affect their desires toward the disposition of their stored embryos. As stated by Dehmel (2), “freezing embryos . . . allows for delay between donation and implantation . . . time for a party to change his or her mind about completing the process through implantation.” The decision to create embryos is customarily made jointly by a couple. At a later date, the couple may disagree on the ultimate disposition of these embryos. Gender differences are evident when investigating how men and women view their gametes and their embryos. The purpose of this paper is to retrospectively review choices made by couples on the disposition of their frozen embryos, and to contrast these with choices couples make for the disposition of their unfertilized gametes.
MATERIALS AND METHODS All patients undergoing assisted reproductive technology (ART) cycles at Boston IVF are required to fill out a form titled: Consent Form for Disposition of Embryos, Eggs and 1181
Sperm. This form asks couples whether they want to cryopreserve excess embryos that may be produced during the course of their ART. Couples were asked to decide how they wanted to dispose of the frozen embryos in the event that the female died, the male died, or both members of the couple died. They had the opportunity to choose to donate or discard the embryos in all cases. In the case of female death, they had the ability to elect to return the embryos to the male’s new partner. In the case of male death, they were able to choose to return the embryos to the body of the female. A very small percentage (1%) chose other options. These were not included in the results, as they did not affect the outcomes of the analysis. Furthermore, couples were asked to choose the disposition of their embryos in the event that they became separated or divorced. They were able to choose among four options: donate the embryos to another couple, discard the embryos, return the embryos to the body of the female, or return the embryos to the body of the male’s new partner. Finally, the couples were asked whether they would give permission for the use of excess unfertilized oocytes and sperm for laboratory testing. Each couple jointly completed this form before their first ART cycle. Forms were renewed each year, or earlier at the couple’s request. Institutional Review Board approval for this project falls under Boston IVF protocols that allow for retrospective chart review. A retrospective chart review of the responses of all patients undergoing their first cycle of ART at our infertility center between January and June of 1998 was undertaken. There were a total of 393 cycles during this time period, of which 385 (98%) were available for review. Of these 385 cycles, 101 cycles resulted in 509 embryos frozen. In those couples for which embryos were cryopreserved, 67% had between one and five, 22% had between six and nine, and only 11% had 10 or more. The distribution of decisions within a scenario was compared using 2 test for equal proportions. Decisions across/ between different scenarios were compared using McNemar’s test for paired proportions with an exact P value. For each scenario, decisions were compared among subgroups of couples defined by type of infertility (female factor, male factor, unexplained) and by parity (0 vs. 1⫹) using 2 or Fisher’s exact test. The differences in male and female age by decision were assessed using the Kruskal–Wallis test.
RESULTS The mean (⫾SD) age of women was 36 ⫾ 4.5 years (range 20 – 46), and that of men was 37 ⫾ 6.2 years (range 20 – 68). A subgroup analysis looking at the ages of females and males showed no significant differences between age of either parent and decisions regarding frozen embryo disposition. The percentage of couples agreeing to donate unused sperm for laboratory research was not different from those 1182 Klipstein et al.
Gender bias and frozen embryos
TABLE 1 Embryo disposition with death of male or female, or both. Disposition method Donate Discard Return Other Total
Female death
Male death
Both male and female death
22% 59% 18% ⬍1% 100%
9% 32% 58% ⬍1% 100%
35% 64% NA ⬍1% 100%
NA ⫽ not applicable. Klipstein. Gender bias in frozen embryo disposition. Fertil Steril 2001.
agreeing to donate unused oocytes (62% vs. 66%, P⫽.26). Furthermore, couples were concordant in their decisions to allow or refuse donation for research of excess gametes. Although 58% of couples agreed to allow for experimentation with both oocytes and sperm, 30% declined experimentation with either oocytes or sperm. In total, a full 88% of couples were concordant in their decision to allow or decline testing of their excess male and female gametes. Only 12% of couples were discordant in their decisions toward the testing of excess male and female gametes. The vast majority of couples (96%) chose to freeze any excess embryos created during their first ART cycle. The authors next looked at what couples decide to do with any “surplus” frozen embryos that they may create. This data is presented in Table 1. Couples differed significantly in their decisions to donate, discard or return the embryos, depending upon whether the male, female or both partners were to die (P⬍.001 for all three comparisons). In the case that the female were to die, embryos were most likely to be discarded, whereas in the case that the male were to die, the embryos were most likely to be returned to the body of the female. Interestingly, in the case of female death, the couple was more likely to choose to donate the embryos than to allow the male to have control over their disposition. Conversely, in the case of male death, most couples chose to allow the female to be able to return the embryos to her body. In the unfortunate situation that both members of the couple were to die, couples were more willing to donate their frozen embryos than if only one were to die (P⬍.001). Of those couples who chose to discard the embryos in the case of female death, 8% would donate the embryos if both parents were to die. Similarly, of those couples that chose to discard the embryos in the case of male death, 6% would donate the embryos if both members of the couple were to die (P⫽.016). Finally, couples were asked to choose the disposition of the embryos in the event that they became separated or divorced. The data is presented in Table 2. Vol. 76, No. 6, December 2001
DISCUSSION
TABLE 2 Embryo disposition in the event of divorce. Donate Discard Return embryo to the body of the female Return embryo to the body of the male’s new partner Other method
17% 58% 22% 1% 2%
This is the first report in the literature to look at gender bias in reproductive choices toward frozen embryos. In this study, each couple had to mutually agree on the answers to the questions on the embryo disposition consent forms. This was done before the embryos were available for cryopreservation. Among these couples, gender differences were readily apparent.
Klipstein. Gender bias in frozen embryo disposition. Fertil Steril 2001.
In the case of divorce, most couples chose to completely discard their frozen embryos over all other options, including donating them to another infertile couple (P⬍.001). In those couples that chose to return the embryos to the body of the female or the male’s new partner in the case of death of one member of the couple, 47% would discard the embryos in the case of divorce (P⬍.001). For those couples that chose neither to donate nor to discard the embryos, 22% would return frozen embryos to the original female if the male died, but only 1% would return the embryos to the male’s new partner if the female died. Finally, the percentage of couples who chose to discard the embryos in the case of female death were not different from those choosing to discard the embryos in the case of divorce (59% vs. 58). Next, the authors looked at associations between decisions toward frozen embryo disposition and other factors. P values of comparisons are summarized in Table 3. Decisions generally did not differ depending on the type of infertility. The only exception to this was when looking at male vs. female factor infertility, there was a statistically significant difference for the decision when both died (P⫽.041). There were no statistically significant differences in male or female age by decision type. For all decisions, there was a difference depending on parity (P⬍.05) for each decision. In all cases, couples in which the female was parous were more likely to discard frozen embryos than couples in which the female was nulliparous.
In attempting to foresee future events, couples in this study tended to revert to traditional gender-based societal roles. Gender differences were apparently absent when couples made decisions regarding their gametes. Once the gametes united, the decisions were much more likely to follow established societal gender patterns. In cases for which control of the embryos could be transferred to either the male or the female, it was the female who preferentially received decision-making authority over the couples’ unified gametes. This is interesting in light of the fact that males and females did not view their unfertilized gametes differently, as evidenced by their concordant decisions toward the disposition of their unfertilized eggs or sperm. One limitation of this study was that couples filled out the consent forms together. It would be enlightening to compare the answers men and women give when pondering these issues as individuals, unencumbered by the need to come up with a mutual decision, and uninfluenced by one another. In the case of the death of one partner, gender differences appeared. The disposition chosen for the frozen embryos depended upon the gender of the partner who died. In the case of death of the female, the majority of couples chose to discard the embryos. Conversely, in the case that the male were to die, the majority of couples chose to return the embryos to the body of the female. Interestingly, almost half of couples (47%) who chose to return the embryos to the woman or the man’s new partner in the case of the death of one of them, would rather discard the embryos in the case of divorce. Perhaps this represents a decision on the part of couples to remove as yet unborn children from the equation
TABLE 3 P value comparisons of couples’ decisions with age, parity, and type of infertility. Decision Experiment with excess oocytes Experiment with excess sperm Female death Male death Death of both male and female Divorce a
Primary indicationa
Male age
Female age
Parity
.119 .094 .114 .127 .042 .263
.637 .645 .484 .199 .836 .254
.517 .421 .602 .098 .903 .063
.031 .031 .016 .055 .001 .041
Male, female, unexplained.
Klipstein. Gender bias in frozen embryo disposition. Fertil Steril 2001.
FERTILITY & STERILITY威
1183
in the case that their status as a decision-making unit were to be disrupted. In the case of divorce, 22% of couples chose to return the embryos to the body of the female, while only 1% picked the option of returning the embryos to the body of the male’s new partner. Clearly, the present state of reproductive affairs allows women to more easily bring their frozen embryos to fruition than men. One wonders if couples are choosing based on logistics, or rather on the assumption that it is more appropriate for potential children to be reared by their mothers than by their fathers. Women seem to be given more say in the disposition of these embryos. This occurs even though at the time of their formation, the genetic makeup of these embryos is most often a contribution of both partners. Approximately the same percentage of couples would discard embryos if the female member of the couple were to die (59%), as would choose to return the embryos to the body of the female if the male were to die (58%), these two numbers not being statistically different. This likely reflects the tendency in our society for mothers to raise children. This may be further elucidated when looking at couples’ choices in the event that both of them were to die. In such a situation, 64% chose to discard the embryos, just above the 59% who would choose to discard the embryos in the event of the female’s death. Neither type of infertility nor age of either partner had any significant impact on decision making regarding disposition of frozen embryos. Only parity significantly impacted decision-making. In all cases, couples that already had at least one child would rather discard than donate frozen embryos. It would appear that couples that have already had the experience of raising a child prefer not to delegate this task to others. In a world where conception and implantation are separated, this gender inequality is somewhat artificial. The frozen embryo contains virtually equal parts maternal and paternal DNA. Indeed, men and women consider their unfertilized genetic material equally, at least as deduced by their similar answers when asked if they would allow for experimentation of their excess gametes. Once the gametes unite, the resulting embryo is seen in a different light. In this study, the majority of couples allowed their female members to lay greater claim to these fertilized entities. In the “natural” state, such a choice does not exist. Unassisted by reproductive technologies, couples have no choice beyond allowing the pregnancy to continue or terminating it. The decision to allow conception and implantation are one and the same, and once conception has occurred, the female has more decision-making authority by virtue of the fact that it is her body that is nourishing the growing embryo.
1184 Klipstein et al.
Gender bias and frozen embryos
In the case of frozen embryos, this decision exists in a state of suspended animation, able to be delayed for an as yet undetermined period of time. Clearly, when looking at reproductive choices pragmatically, it is logistically easier for a woman to bring a frozen embryo to maturity. Even so, men do have a means of bringing frozen embryos into the world, be it by contracting with surrogates or implanting these embryos into their new partners. If in fact men believe that surrogacy is an unrealistic option, they may not choose to have control over the couples’ embryos. If surrogacy were to become commonplace, men might be more likely to desire this option, and request control over the disposition of the embryos. Perhaps women see embryos as babies, and men see them more as gametes. It is also possible that women bond sooner to embryos than do men. If this is true, men may not have as strong an attachment to the embryos. This may cause men to be more likely than women to relinquish authority over embryo disposition. Such gender differences warrant further study. Finally, society associates more with single motherhood than with single fatherhood. The courts continue to award custody preferentially to women in cases of divorce. Additionally, children living in single-parent homes are much more likely to live with their mothers than with their fathers. Couples may continue to perpetuate this gender bias when choosing the disposition of their frozen embryos. The choice of embryo disposition is unique to couples undergoing ART. The separation of the desire to conceive from the implantation process has created new and unique choices for couples. Long-held traditional views in concert with biological differences continue to shape couples’ decisions regarding their embryos. As more options become available to couples, it is possible that their choices regarding the disposition of frozen embryos will become more balanced.
Acknowledgments: The authors thank Doria Harris, Ph.D. for her help in preparing this manuscript.
References 1. Shultz MM. Reproductive technology and intent-based parenthood: an opportunity for gender neutrality, Wisconsin Law Review 1990;297– 398. 2. Dehmel JM. To have or not to have: whose procreative rights prevail in disputes over dispositions of frozen embryos?, Connecticut Law Review 1995;1377–1405.
Vol. 76, No. 6, December 2001