Storage and disposal of embryos and gametes

A critical evaluation of ovarian tissue cryopreservation and grafting as a strategy for preserving the human female germline

Ovarian tissue freezing has been used successfully in animals and it has recently begun to be offered clinically to young women who have medical conditions with a high risk of sterility. Although no frozen human ovarian grafts have yet been returned to the donor and resulted in a pregnancy, there are many indications that this procedure should be feasible. Although live young have been derived from frozen grafts in several species, research should aim to make further improvements to the cryopreservation and grafting procedures to optimize follicle survival, and hence minimize the amount of tissue that needs to be collected, stored and returned. Ovarian tissue freezing, particular if used in combination with egg and embryo freezing, should allow a patient to safeguard their chance of becoming a parent later (Table 1). In cases where the patient has a systemic cancer or infection and malignant cells or viruses may be present in the systemic circulation and the gonadal tissue, ovarian tissue could be collected and frozen, but grafting is not currently recommended (Table 3).

Notification of infectious diseases by junior doctors in accident and emergency departments

OBJECTIVE

To assess the knowledge about notifiable infectious diseases by accident and emergency (A&E) senior house officers.

METHODS

A telephone questionnaire of senior house officers was carried out over a one week period at the end of their six month attachment in A&E departments in Northern Ireland.

RESULTS

81 (91%) of the senior house officers participated in the study; 23 (29%) realised that the doctor diagnosing the notifiable disease had a statutory duty to notify that disease; nine (11%) were aware there were three statutory lists in the United Kingdom. Knowledge about which infectious diseases require notification varied from 79/81 (98%) for meningococcal disease to 15/91 (19%) for methicillin resistant S aureus. Seventy nine (98%) of the doctors thought that a poster displayed in the A&E department would be helpful. There was no significant difference between duration of qualification and performance on the questionnaire (p = 0.2).

CONCLUSIONS

Despite varying experience, junior doctors in A&E do not know which infectious diseases are notifiable by statute. They felt that it would be helpful to have a poster in the A&E department listing the notifiable diseases of that region. To encourage accurate reporting, interregional variation between the statutory lists should be abolished and replaced by one nationally agreed list.

Cryopreservation of immature human oocytes and ovarian tissue: an emerging technology?

OBJECTIVE

To review the potential for cryopreserving immature follicles either in situ or after isolation from ovarian stroma and to consider the options for fertility by transplantation or in vitro follicle growth.

DESIGN

The problems of storing embryos and mature (metaphase II) oocytes were considered in light of the needs of patients to protect fertility before undergoing potentially sterilizing therapy for cancer. The evidence from the experimental biology literature showing that immature oocytes (prophase I) in primordial follicles can be cryopreserved successfully and transplanted to produce fertile eggs was reviewed. The review, which was compiled from MEDLINE and other bibliographic databases, is intended to emphasize the practical opportunities for this technology and the need for future research rather than to be a comprehensive treatment of the subject.

CONCLUSION(S)

The disappointing results obtained with the cryopreservation of oocytes at metaphase II and ethical concerns about embryo storage are giving impetus to the banking of ovarian tissue for patients who require conservation of fertility. The numbers of needy patients are growing as long-term survivorship after high-dose chemotherapy and bone marrow transplantation rises. More speculatively, if ovarian tissue banking becomes a proven effective method, young, healthy women may request storage of ovarian biopsy samples to keep their reproductive options open in midlife when oocyte fertility is declining. Although the cryotechnology is not yet perfected, the major question now is how to use the tissue most effectively after thawing. For the present, ovarian tissue cryopreservation is still at the experimental stage, but it holds the promise of valuable applications.

Management of involuntary childlessness

Any definition of involuntary childlessness has to consider the difference between sterility and subfertility. As the latter affects about 20-30% of all couples at least once in their lives, general practitioners (GPs) may be the first to be confronted with this problem. This review presents the most relevant diagnostic and therapeutic options in cases of female or male infertility, and discusses the new assisted reproductive technologies (such as insemination, in vitro fertilization, gamete transfer and intracytoplasmatic sperm injection) so that GPs may adequately inform their patients about these procedures and their risks and outcomes. Although controversial, involuntary childlessness and its clinical treatment seem to have a strong psychological impact on a couple's social, emotional and sexual life. Being available for discussion with childless couples and offering ongoing support may be the most important role for the GP in this context.

Avian exposure and risk of lung cancer in women in Missouri: population based case-control study

OBJECTIVE

To investigate the association, previously reported in three European studies, between ownership of pet birds and the risk of lung cancer.

DESIGN

A population based case-control study with a structured questionnaire administered by telephone.

SETTING

Missouri, a midwestern state in the United States with a population of about 5 million.

SUBJECTS

All newly diagnosed cases of primary lung cancer in women aged 30-84 years in Missouri from 1 January 1993 to 31 January 1994 reported to the state cancer registry were invited to participate (n = 652); and 629 population based controls.

MAIN OUTCOME MEASURES

Odds ratios were computed in relation to whether or not the study subject ever kept pet birds, the type of bird kept, and several measures of intensity or duration of exposure. Odds ratios were adjusted for smoking.

RESULTS

The odds ratio (95% confidence interval) for the development of lung cancer associated with keeping pet birds was 0.84 (0.65 to 1.09). The results were similar for the type of pet bird kept, the number of birds kept, the location of the bird in the house, and the duration of ownership.

CONCLUSION

The keeping of pet birds carries no excess risk for the development of lung cancer.