Follow-up of children conceived from cryopreserved embryos

Few reports have been published on the follow-up of children born after embryo cryopreservation. These present reassuring data but lack the methodology for definitive conclusions about the physical and psychological development of children conceived with this technique. Paediatric follow-up studies are difficult to organise, especially when choosing a well-matched control group. There are ethical problems with singularising these children by enrolling them into specific medical and psychological studies. Studies are troubled by unstandardised tools, multiple observers, poor matching criteria, poor follow-up rates, and insufficient power for the outcome measures, absence or inappropriate control group and insensitive tools of assessment. Adequate malformation studies on these children have not been performed. A birth registry needs to be established. Overall the wellbeing of these children is satisfactory. Continuing follow-up needs to be performed in countries performing embryo cryopreservation. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.