Ethics, Social, Legal and Counselling Ovarian tissue cryopreservation: therapeutic prospects and ethical reflections

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1 RBMOnline - Vol 3. No Reproductive BioMedicine Online webpaper 2001/220 on web 18 September 2001 Ethics, Social, Legal and Counselling Ovarian tissue cryopreservation: therapeutic prospects and ethical reflections Rudy Van den Broecke was born 4 April He undertook medical studies at Ghent State University, Belgium before training in surgery, obstetrics and gynaecology at Westfälische Landesfrauenklinik Bochem, Germany, and Ghent University Hospital from 1982 to He was Consultant Gynaecologist at Onze-Lieve-Vrouwenziekenhuis Oudenaarde and then underwent more training in Gynaecological Oncology at Ghent University Hospital He is currently Consultant Gynaecologic Oncologist at Ghent University Hospital. His research interests include ovarian tissue banking and breast cancer. His nonprofessional interests are the War of the Roses and Richard III. Dr Rudy Van den Broecke Rudy Van den Broecke 1,4, Guido Pennings 3, Josiane Van der Elst 2, Jun Liu 2, Marc Dhont 1,2 1 Department of Gynaecologic Oncology, 2 Infertility Centre, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium 3 Department of Philosophy, Brussels Free University (VUB), Pleinlaan 2, 1050 Brussels, Belgium 4 Correspondence: Tel ; Fax ; rudy.vdb@pronet.b Abstract Along with improved survival, methods to preserve or restore the fertility potential of young women and children treated with cytotoxic chemotherapy or pelvic radiotherapy have been developed or are in the offing. Surgery, radiotherapy and chemotherapy can all impact on the future ovarian function, but patient and disease tailored application and use of preventive measures can limit ovarian damage. When the loss of reproductive ovarian function is unavoidable, different alternatives to preserve fertility or at least to restore the procreative potential are available. Creation of embryos by IVF, oocyte donation and cryopreservation of mature or immature oocytes are potential issues, the advantages and limitations of which are discussed. Recently, ovarian tissue cryopreservation has spurred interest in the medical literature as well as in the lay press as a method for preservation and restoring fertility. Considering the available data and current state of knowledge, we want to stress that this methodology is still in an experimental phase and we would like to caution against unwarranted enthusiasm of physicians and patients. The medical information preceding the informed consent should mention the actual uncertainties of this method. Moreover, the imperative character of the offer and in particular for paediatric oncological patients, the force of the moral rules that define parental obligations towards children should not be ignored. Keywords: cryopreservation, ethics, grafts, ovary Introduction Decisions that could influence the health or the future wellbeing of patients have to be critically scrutinized. If there is doubt about the real value of new techniques, further research should be conducted before application in human medicine is considered. Indications and limitations of new therapeutic strategies should be outlined before proposing them to patients. The efficacy of new techniques should be the subject of preclinical and clinical studies. When we apply this line of thought to ovarian tissue cryopreservation (OTC), we feel that the value of this newly introduced technique to preserve and restore fertility has not yet been sufficiently evaluated. As the survival rates of young cancer patients continue to improve (Boring et al., 1994), protection against iatrogenic infertility caused by cancer treatment has become an important issue. As reported by Meirow (1999), up to 70% of young women treated with aggressive chemotherapeutic drugs are estimated to have been rendered sterile as a consequence of the treatment. Furthermore, women who resume menstrual activity after treatment are at risk of developing premature menopause (Byrne et al., 1992). Ovarian tissue cryopreservation was therefore introduced as the ultimate technique for the preservation of primordial follicles with the aim of restoring patients fertility using their own gametes. While this might be a potential option for preserving female fertility, the ethical problems connected with the procedure at its present stage should not be ignored. For obvious reasons, patients at risk of losing their fertility will seek help at centres for reproductive medicine. The methodology of cryopreservation lies within the scope of every well-equipped laboratory for assisted reproduction. Moreover, commercial incentives may speed up offering the service on a large scale. These factors urge on a balanced and prudent application of the technology. Although there is a worldwide 179

2 Table 1. Best assessment of risk of infertility following treatment for childhood cancer by disease. Low risk <20%; high risk >80%; medium risk difficult to quantify. Risk of infertility Low Medium High Disease/treatment Acute lymphatic leukaemia Acute myeloid leukaemia Total body irradiation Wilm s tumour Hepatoblastoma Localized radiotherapy: Soft tissue sarcoma: stage 1 Osteosarcoma pelvic or testicular Germ cell tumours with Ewing's sarcoma Chemotherapy gonadal preservation and Soft tissue sarcoma 'conditioning' no radiotherapy Neuroblastoma for bone marrow transplant Brain tumour: surgery only; Non-Hodgkin lymphoma Hodgkin disease: cranial irradiation <24 Gy Hodgkin disease: alkylating agent-based therapy 'hybrid' therapy Soft tissue sarcoma: metastatic Brain tumour: craniospinal radiotherapy; cranial irradiation >24 Gy; chemotherapy 180 interest in OTC, we feel a strong sense of hesitation in proposing this technique to patients. Several centres have already started banking human ovarian cortical tissue of young oncological patients. Are these young women, or the parents of these children, well informed about the present status of our knowledge? Is it justified to raise hopes that may never be answered? Should we not give more attention to possible other means of preserving ovarian function, means which are less invasive and probably more cost-effective and easier to perform? Surely not every young female patient treated with chemotherapy or radiotherapy for neoplastic disease may be at risk of losing her fertility. Certainly in cases where paediatric patients are involved, an estimate of the infertility risk due to the treatment is mandatory (Table 1). Patient selection is therefore very important (Bahadur and Steele, 1996) next to the evaluation of other fertility-preserving methods. We wish to express our reservations regarding the indiscriminate use of ovarian tissue cryopreservation and hope to raise a thoughtful discussion with other colleagues working in the field to arrive at a consensus on the right indications and an unequivocal advice to our patients. Which patients are eligible for OTC? The decision to offer OTC to a young patient before undergoing anticancer treatment should only be taken after multidisciplinary evaluation. The advice of the oncologist of the subspecialty concerned is essential because the therapeutic modality will be crucial in estimating the probability of fertility loss. Surgical and gynaecological oncologists are well aware of the fact that although radical ablative surgery may have a welldefined role in the treatment of several pelvic malignancies, it will also end the reproductive life of the patient. Therefore new fertility-sparing techniques are being developed and studied in the surgical treatment of early stage cervical cancer (Dargent et al., 2000) and borderline ovarian tumours (Morris et al., 2000). In patients scheduled for pelvic radiotherapy, damage to the ovaries will depend on the age of the patient, the radiation field and the radiation dose administered to the gonads. Lushbaugh (1976) calculated that the total dose inducing menopause was 6 Gy in women aged 40 years, while it could go up to 20 Gy fractionated in prepubertal girls. Damewood and Grochow (1986) stated that a dose of 60 rads has no deleterious effects in most age groups and that doses of 150 rads do not appear to affect young women <30 years, while women >40 years are at risk for sterilization (1 Gy = 100 rad). They noted that women in all age groups exposed to rads experience menstrual problems, with permanent sterility in all women >40 years of age. Lateral transposition of the ovaries could significantly reduce the dose administered to the ovaries, although possible damage caused by scattered rays must be considered. However, even with the inverted Y radiation technique, which includes the ovaries within the inguinal field, lateral displacement of the ovaries to the area of the iliac crest reduces the dose administered to the gonads to only 9% of the total dose (Maguire, 1979). Shielding of the transposed ovaries with lead blocks may further reduce the dose administered to the organ. Patients treated with total body irradiation, however, cannot be protected from radiation damage and in these women ovarian tissue cryopreservation may well be the only option for fertility preservation. In fact, a lot of young girls treated with radiotherapy for childhood malignancies should not be considered for OTC because their risk of becoming amenorrhoeic due to the treatment is rather small if the necessary precautions to shield the ovaries are taken (Lushbaugh and Casarett, 1976). Chemotherapeutic drugs act primarily on dividing cells. Since most of the oocytes are in a resting state and do not undergo mitotic division, the toxic effect of the drugs on these primordial follicles is not yet fully understood. The elucidation of the molecular mechanism of cell damage by cytotoxic drugs could also lead to new insights in preventive measures (Perez et al., 1997). One possible explanation could be that these drugs cause damage to the pool of growing follicles in which cyclic recruitment is continuously going on (Abir et al., 1998). The cytotoxic drugs most harmful for ovarian function are alkylating agents such as cyclophosphamide. Cyclophosphamide damages both granulosa cells and oocytes in vitro (Ataya et al., 1988; Rahami-Ataya et al., 1988). Hodgkin disease is the most common malignancy in the population aged years (Glaser, 1994). The successful use of cytotoxic chemotherapy has led to the prolonged survival of almost 90% of young Hodgkin disease patients (Glaser, 1994). Due to the age-related decrease in the number of follicles, ageing ovaries are more sensitive to cytotoxic treatment. This

3 has been clearly demonstrated in patients treated for Hodgkin disease. Gradishar et al. (1988) suggested that female patients <25 years of age would not experience any significant therapyrelated dysfunction during the 5 10 years following completion of chemotherapy, while patients >25 years of age had a significantly higher risk of ovarian failure. In the case of germ cell tumours and early stage epithelial cancer of the ovary in young women, conservative surgery might be performed but as a consequence, medical oncologists will want to compensate the conservative surgical treatment by administering platinum-based chemotherapeutic combinations. Fortunately, however, recent data indicate that platinum-based regimens of multi-agent chemotherapy do not seem to affect the fertility potential (Bakri et al., 2000). Gonadotrophin-releasing hormone analogues before and during chemotherapy seem to be helpful to prevent or reduce the damage to the ovaries, but their role is still the subject of clinical studies (Blumenfeld et al., 1996). Anticancer treatment reduces the number of viable follicles. Hence, it is advisable to propose ovarian tissue cryopreservation only to patients with a presumed adequate follicular reserve, because further loss of follicles by the freezing thawing process and the grafting procedure should be anticipated. Although follicular reserve is difficult to estimate, the combination of the measurement of the ovarian volume in conjunction with an estimation of follicular density in an adequate biopsy could help to predict the basal fertility of the patient (Lass et al., 1997). Furthermore, possible damage to the uterus and the endometrium due to radiochemotherapy could further compromise the patients fertility (Levitt and Jenney, 1998). In practice, OTC should be reserved for young patients without pregnancy-compromising sequelae, provided no acceptable alternative fertility-preserving technique with a reasonable chance of fertility preservation can be offered. Which fertility preserving techniques can be offered? Creation of embryos for future replacement At a glance, creation of embryos by IVF and cryopreservation for later replacement appears an appealing solution for young adult women with a partner. In case of the single patient, IVF using donor spermatozoa might be contemplated. These options, however, are compounded not only by practical but also by ethical limitations. The efficiency of IVF and a fortiori the efficiency of replacement of cryopreserved embryos is rather low and unpredictable. Before embarking on this solution, the uncertain prospect should be discussed with the patient and a realistic estimation of her chances of getting pregnant should be discussed. In patients with oestrogensensitive tumours, the oestradiol surge during gonadotrophic stimulation could on theoretical grounds be a supplementary risk. Besides these practical limitations, the existence of embryos will inevitably impose a moral burden on both partners and may render their decision more difficult when the time for procreation has arrived. In some countries like the UK, a statutory storage limit may prove a factor to hasten family formation. Furthermore, legislation can impose the destruction of the cryopreserved embryos should the sperm donor withdraw his consent. The creation of embryos for single women using donor spermatozoa is compounded by an extra ethical dilemma. By having chosen to procreate as a single woman, the patient can either compromise her chances of establishing a future relationship or, when the embryo is not yet replaced, the future of the embryo when a future partner prefers to have his own children. Oocyte donation In case the patient loses all her reproductive potential through therapy, oocyte donation followed by IVF with spermatozoa from her partner is another option. This option is more difficult to achieve due to the shortage of donor oocytes. The use of oocytes from ovaries of aborted fetuses (Shushan and Schenker, 1994) or from ovaries removed from female-to-male transsexual patients (Van den Broecke et al., 2000) could serve as a possible source of donated ova, but the origin of the oocytes, apart from the ethical aspects, presumably will not be acceptable to the majority of patients. Cryopreservation of mature or immature oocytes Cryopreservation of mature or immature oocytes from various mammalian species, including humans, has had very limited success. It has been linked with spindle damage, zona hardening, parthenogenesis of oocytes, low oocyte survival after thawing and impaired embryonic development (Nugent et al., 1997). Indeed, only a few human pregnancies and births after IVF of frozen thawed oocytes have been reported (Porcu et al., 1998). In addition, possible implantation or developmental problems associated with male embryos formed from cryopreserved oocytes must be considered (Porcu et al., 1998) Nevertheless, it is conceivable that in the near future substantial progress will be made in the field of oocyte cryopreservation and oocyte maturation in vitro. It is, however, clear that the collection of oocytes should in no way delay the oncological treatment of the patient. Ovarian tissue cryopreservation Ovarian tissue cryopreservation followed by orthotopic transplantation has been shown to be effective, and live offspring has been obtained by this method in several animal species (Nugent et al., 1997). For human ovarian tissue, however, information is very scarce. Human cryopreserved ovarian tissue, transplanted to the subcutaneous space or to the kidney of immunological tolerant SCID mice, has been shown to survive and to remain susceptible to stimulation (Gook et al., 2001; Van den Broecke et al., 2001). One publication reports restoration of cyclicity in a woman after subcutaneous grafting of ovarian tissue (Grischenko et al., 1987). An accidental ovarian autograft resulting from a laparoscopic excision of an endometrial cyst proved viable and contained growing follicles (Marconi et al., 1997). Oktay et al. (2000) described a case in which laparoscopic transplantation of frozen-stored ovarian tissue in the ovarian fossa of a woman resulted in the growth of a 17 mm follicle under gonadotrophic stimulation. Revel et al. (2000) succeeded in the retrieval of immature oocytes from human ovarian cortex transplanted to nude mice and stimulated with human follicle stimulating hormone. Oktay et al. (2000) 181

4 182 showed that heterotopic autotransplantation of human ovarian tissue can result in antral follicle development associated with sub-normal normal oestradiol concentrations. Finally, Radford et al. (2001) reported the orthotopic reimplantation of cryopreserved ovarian cortical strips after high-dose chemotherapy for Hodgkin lymphoma, resulting in a decrease in FSH and LH with a concomitant increase in oestradiol and a 2 cm follicular structure. The patient had one menstrual period. Nine months after the implantation, her sex steroid concentrations had returned to the menopausal status. These observations inevitably give rise to the question: for what period of time does transplantation of cryopreserved ovarian cortical tissue prolong the fertility of the patient? Experimental data indicate that in the mouse model a normal reproductive lifespan is restored after grafting of cryopreserved ovaries (Candy et al., 2000). Further experimental work in humans is warranted to investigate this point. Until now, however, no human embryo has been created with oocytes recovered from OTC. Are there any risks involved in OTC? When performed at the time of a medically indicated laparotomy or a laparoscopy, an ovarian biopsy would not add to the patient s risk of complications. In case of an elective laparoscopic procedure, one should consider the additional surgical and anaesthetic risk to the patient. Even in skilled hands, laparoscopy has a complication rate of ~0.1%, consisting mainly of vascular, urological and gastroenterological damage caused by the insertion of the Verres needle or by the trocar (Jansen, 1997). Furthermore, it is uncertain whether ovarian biopsies are adequate for obtaining a sufficient amount of follicles. Although it might slightly increase the surgical risk, unilateral ovariectomy would be more appropriate to secure a large number of follicles. Another major concern of grafting cryopreserved ovarian tissue is the possibility of reintroducing malignant cells. Although the ovary is rarely affected by solid tumours or Hodgkin disease, the risk is significantly greater for blood-borne cancers such as leukaemia. Shaw et al. (1996) reported transmission of lymphoma cancer cells from donor to graft recipients with fresh and cryopreserved mouse ovarian tissue samples. Although the mouse lymphoma model may not be directly comparable with the human situation, this risk combined with the seriousness of the reintroduced disease is sufficient in our opinion to be careful in accepting patients with blood-borne cancers for OTC until more information regarding this issue is gathered. In the treatment of oestrogen sensitive cancers, the amenorrhoeic state could be of considerable value in the treatment (Namer and Ramaioli, 2000). When reimplanting viable steroid producing ovarian tissue, the therapeutic effect of the amenorrhoea might become reversed. Also, the genetic transmissibility of certain cancers must be considered (Anderlik and Lisko, 2000). Finally, an uncharted but crucial domain concerns the risk of genetic damage to the cryopreserved primordial follicles. One has to be attentive for possible point mutations and/or translocations caused by the cryopreservation process that could pass unnoticed to become apparent in later generations. The problem of consent and the imperative character of the offer When the offer is made for OTC, patients must, of course, consent to the intervention before it can be started. Providing the patient with objective information is extremely difficult, for the simple reason that much of the relevant information is not available at present. The lack of certainty about the possible use of the cryostored material in the future makes it highly likely that the message transferred to the patient is physiciandependent: those physicians who believe that the necessary techniques will be developed in the future will transmit a message of hope, the others will transmit their doubts. Still, it could be argued that similar uncertainties exist for other medical interventions. Patients should be informed of all the risks, benefits and uncertainties of the removal, storage and later use. It should be stressed that there is at present no reliable technology to use the frozen tissue and that the chances of success are equally uncertain (Newton, 1998; Bahadur et al., 2000). Physicians should be well aware of the unintended and even unwanted effects of the offer on the patient or the patient s parents. Regardless of the warnings included in the counselling, they may interpret the offer as a sure sign. A number of psychological mechanisms should be kept in mind when young women (or their parents) are counselled about the possibility to cryopreserve ovarian tissue. It may be thought that the offer of an additional option is always a good thing because it increases the freedom to choose. However, a freely offered choice may have a coercive effect due to the technological imperative. The offer of the possibility to preserve one s future fertility may take on an imperative character because of the anticipated decision regret (Tymstra, 1989). Psychologists have found that, in decision making, people are led by anticipation of the negative feelings that might arise if they find out later that they made the wrong decision. If I do not take the offer to store genetic material, I will have strong feelings of regret if I later want to have children of my own and if the technology is available to use my material. The chance of success of the technique is largely ignored in this reasoning. The psychological mechanism of decision regret is reinforced by an extended set of strong moral principles about parental responsibility when OTC is considered for minors. Good parents will do anything for the well-being of their child. Refusing a possible treatment option for one s child is seen as irresponsible parental behaviour by a large number of people. In addition, parents may have strong feelings of guilt. The child may later blame them for not having stored material. All these influences together make it highly unlikely that parents will ever reject the offer. On the other hand, the emphasis on the experimental nature of the intervention may trigger a different set of principles. In that case, there is a presumption against participation. Good parents do not submit their child to such a procedure. The challenge consists in finding the right balance to fit the special nature of ovarian freezing, i.e. an experimental procedure with the prospect of direct personal benefit for the child (Levine, 1986).

5 The stress on the experimental nature of the intervention should be accompanied by a clear distinction between the decision to store ovarian tissue and the decision to use the material for treatment later. Patients frequently regard freezing as a first step, which logically implies the following steps. In normal circumstances, this is a reasonable conclusion: if one does not intend to use the material, then why store it? Moreover, if the physician did not think that there was a chance of using the material, it is logical to suppose that he/she would not have proposed storage. The recent conflict in the UK between women who wanted to use their frozen eggs for procreation while the HFEA considered this practice as insufficiently safe shows this confusion. A final psychological consequence of cryopreservation should be mentioned. The availability of the cryopreserved material might also constitute a burden. Once ovarian biopsies are frozen, a decision has to be made about them. This initial act changes all later decisions by adding an option. The reticence demonstrated by people who have to decide about the disposition of their embryos shows us that the psychological weight of frozen material should not be underestimated. This argument applies to all cases, even if no additional surgical interventions are needed to obtain the material. On the other hand, beneficial effects may also follow from the offer. The offer and the storage of reproductive material may encourage and strengthen the patient and offer her a real link with the future. The stored ovarian tissue is a strong symbol of life: it not only expresses the firm belief that the patient will have a life after the cancer treatment but also that she will be able to create life. Anticipatory autonomy rights When cryostorage of ovarian tissue of children is considered, the procedure can be justified by referring to the anticipatory autonomy rights (Feinberg, 1994). The child has the right to decide whether or not to start a family but she cannot exercise her free choice until later when she is an autonomous adult. This right would be foreclosed by the absence of gametes. The decision by the parents to cryopreserve the ovarian tissue of their child can be justified as an act that keeps the option open until the time that the child can decide for herself. The children thus keep the future choice of using their gametes (Hewitt et al., 1998). This is a specific application of the principle that parents should consent to therapeutic and non-therapeutic interventions on their children when this intervention secures or improves the actual or prospective autonomy (Brown, 1982). Since reproduction is an important part of most people s life plan, parents can reasonably decide to maintain the possibility of genetic parenthood. However, the option is only kept open if it later proves to exist, i.e. when successful clinical application is possible. The use of the anticipatory autonomy rights to justify a medical intervention also has important implications for the extent of the parents right to dispose of the body material of their child. The decisional authority of the parents should be restricted to the decision to preserve the material up to the time that the child becomes an autonomous individual. From that moment on, the authority is transferred completely to the child from whom the genetic material is derived (Bahadur et al., 2000). The parental consent for storage is purely meant to preserve the autonomy of the child in the future. This means that when the child dies or becomes mentally incompetent, the only possible destinations for the frozen tissue are destruction or research followed by destruction. Donation for reproduction by third parties is excluded on two reinforcing rules: a person cannot donate the genetic material of another person, and a minor cannot donate his or her genetic material. Parents do not have the right to decide about the use of the material for procreation, since they cannot be considered as reproductive partners of the child (Pennings, 1996). When the child is considered mature and competent, her decision should be respected even if the parents and/or the treating physician hold a different opinion. The problem of obtaining consent from adolescent patients has recently been addressed by Bahadur et al., (2001). The competence is neither determined by the age of the child nor by the physical development. To avoid cheating, the decision about the competence should be made before anything is known about the opinion of the minor. It is often tempting to judge a child or adolescent as rational and competent if and only if she agrees with the adult. With the exception of the unavoidable borderline cases, it should be possible to reach a judgement about the capability of the child to participate in the decision making. Given the diminished life expectancy of cancer patients as a group, it is strongly recommended that a written advance directive is available at the time of freezing. This advance directive indicates the destination of the ovarian tissue if the patient dies or becomes incapable of varying or revoking her consent (Pennings, 2000). Since OTC is offered to preserve fertility, the storage period should be adapted to the individual circumstances of the patient in order to give her an adequate chance to decide about her family planning. It would be highly unreasonable to maintain a maximum storage period of 10 years if the material was stored when the patient was 14. Conclusion OTC should not be considered as a panacea for young female cancer patients needing radiotherapy or chemotherapy. The decision whether or not to freeze ovarian cortical tissue should be made on the basis of all the relevant factors including an estimation of the risk benefit ratio and on the evaluation of the patient s medical chart. The ultimate justification for offering OTC is the reasonable claim that this intervention is in the best interest of the young female. Given the uncertainty about the extent of the risks and benefits and the difficulty of predicting future improvements of the necessary technology, it is extremely important that patients and/or the patients parents are well informed and counselled before the decision. In this respect, registration of referral centres that offer OTC and the establishment of a database of the patients already treated and of the results achieved would be most useful. References Abir R, Fisch B, Raz A et al Preservation of fertility in women undergoing chemotherapy: current approach and future prospects. 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