This wariness has further alerted reproductive specialists to the medicolegal nightmares that can result from holding life on ice. If statistics compiled at the Jones Institute by Jake Mayer, director of the embryology lab there, can be taken as representative, the bulk of embryos are held for two or three years before being thawed for use in IVF attempts. So Tucker's tally looks about right. Clinics already spend a good deal of time and effort ensuring that frozen embryos suffer no damage. Ethical and legal considerations have driven most programs to install backup liquid-nitrogen and power systems and to hone procedures for wheeling embryos to safety in case of fire or natural disasters.
Couples are often extremely reluctant to okay disposal.
Dorothy Greenfeld, Yale University psychotherapist and former president of the American Society for Reproductive Medicine's Mental Health Professional Group, points out that patients are not the only ones who become emotionally invested. It seems that the staff in clinics may become more attached to these embryos than the couples do. But they're of human origin, so one can be sympathetic with lab directors who are reluctant to thaw them. Apparently, some workers delay or refuse to thaw embryos even when given explicit consent to do so. Caplan argues that labs, having created an overabundance of embryos, can solve the problem easily by setting a strict time limit on cryo-preservation and hewing to it.