Excessive use of a single donor? And inadvertent consanguinity

Sperm donor limits that control for the 'relative' risk associated with the use of open-identity donors

The majority of countries that support the use of donor insemination (DI) in artificial reproductive technology (ART) limit the number of children born from one donor. The setting of these donor limits, though intended to control for the risk of inadvertent half-sibling unions between the offspring of anonymous donors, actually have no evidence base. Controlling for the risk of inadvertent half-sibling unions may soon become unnecessary due to the increasing world-wide use of open-identity sperm donors and the revocation of donor anonymity in many countries. With the shift from anonymous to open-identity donation, the central issue is not the risk of genetic abnormality from inadvertent half-sibling consanguinity; it is the psycho-social impact of the multiple use of open-identity sperm donors. Despite this, the jurisdictions that allow or mandate the use of open-identity donors continue to observe existing limits that do not consider nor specifically control for the psycho-social impact of the multiple use of open-identity sperm donors. It is proposed that: (i) conservative interim donor limits be placed on the multiple use of open-identity donors, while research into the psycho-social impact of disclosure is undertaken to inform the establishment of evidence-based limits; and (ii) the existing limits in jurisdictions where anonymity is still commonly practiced or protected could be raised, if an updated mathematical model was used for calculating evidence-based anonymous donor limits.

A review of mathematical models used to determine sperm donor limits for infertility treatment

OBJECTIVE

To review mathematical models used to determine sperm donor limits for infertility treatment and to consider the need to develop a new, internationally recognized and applicable model for calculating limits.

DESIGN

Literature review.

SETTING

Models for determining sperm donor limits were identified through bibliographic databases.

PATIENT(S)

Published models.

INTERVENTION(S)

Variables used in the models were defined, evaluated, and assessed for relevancy and applicability.

MAIN OUTCOME MEASURE(S)

Relevance and applicability of model variables used to predict the number of consanguineous matings, probability of unwitting sibling mating and contribution to F (coefficient of inbreeding).

RESULT(S)

Models found to be outdated and inadequate for the present-day.

CONCLUSION(S)

Many countries have introduced limits to the number of offspring each anonymous sperm donor can father but these limits vary considerably. Published models for calculating sperm donor limits are in need of improvement and it is recommended that an enhanced, internationally applicable formula be developed for calculating acceptable limits. Moreover, it is recommended that further research be undertaken into the social and familial consequences of the revocation of sperm donor anonymity and the implications for the setting of sperm donor limits.