Public Release: 

Study allays fears about the physical and psychological development of ICSI children

European Society of Human Reproduction and Embryology

Lausanne, Switzerland: Children born with the help of intracytoplasmic sperm injection (ICSI) appear to be developing normally, despite earlier concerns about their physical and psychological development, according to American researchers.

Dr Gianpiero Palermo, from the Center for Reproductive Medicine and Infertility at Cornell University, USA, told the European Society of Human Reproduction and Embryology annual meeting at Lausanne today (Monday 2 July) that the majority of ICSI children they had studied appeared to be developing well with no significant delays in their cognitive abilities, socio-emotional development or their motor skills.

Amongst the small proportion of children who needed a follow-up evaluation, half had come from multiple pregnancies which carry their own risks, both in terms of medical complications at birth and the natural stresses on parents who have to learn to cope with not just one new baby but two, or possibly more, at the same time.

Dr Palermo, who first developed the ICSI technique in 1991, said: "Our study shows that ICSI children do develop normally. While the response rate from parents in our study was relatively low, and later evaluations are still needed, these data argue for the safety of the ICSI procedure."

Dr Palermo and his team sent questionnaires out to 411 ICSI families and 357 IVF families, representing a total of 601 ICSI and 514 IVF children aged between two and a half and three and a half years old. From these, 91 (22%) ICSI and 50 (14%) IVF families completed at least one questionnaire. The number of multiple pregnancies, the sex of the children and the maternal age was similar for each group. The questionnaires asked about the pregnancy, the children's behaviour, social skills and development, and parental stress levels.

Previous studies of ICSI children had brought up a number of concerns about the nature of the ICSI technique itself, the effects it might have on babies, and the development of ICSI children. Dr Palermo said: "There were concerns that the ICSI procedure is more invasive than previous assisted reproductive technologies because it involves manipulation of sperm and eggs at the point of conception.

"There were concerns that the resulting zygote would not be as healthy or viable, because the natural steps of fertilization are bypassed, and more specifically, because this introduces a sperm head with a complement of acrosomal enzymes1 that in natural fertilization have already been discarded."

He said that initial studies suggested that there might be an increased risk of mild delays in development at one year of ICSI children compared with children conceived by routine IVF or naturally, and that there might be a slight increase in the transmission of paternal sex chromosomal defects. However subsequent studies have concluded that ICSI children are performing normally, and that the prevalence of congenital and chromosomal abnormalities was no higher than those found in the general population. Dr Palermo's study supports these findings.

Where the study found that ICSI children were not performing so well and fell into the "at risk" group, this usually turned out to be due to an unwillingness of the children to perform the requested tasks, or, in the majority of cases, because the parents had not answered all the questions, thereby giving a lower estimate of how their child performed.

He said: "So far, ICSI has been able to help well over 30,000 couples worldwide affected with male factor infertility to have children. While the invasiveness of ICSI itself has not shown itself to have any bearing on the incidence of malformations or abnormal development so far, we feel that it is our duty as infertility treatment providers to monitor the development of these children, generated by this sophisticated technique, at least until their reproductive age."

He continued: "We would like to continue to follow these children at age five where they are in pre-school or first grade. This would give us a better understanding of their progress, especially of the children that are in the 'at risk' category." In addition, Dr Palermo and his team will be working on ways to encourage more ICSI and IVF families to take part in the study.


Abstract no: O-058


1 Acrosomal enzymes are the enzymes contained in the head of the sperm which break down the cell membrane of the egg so that the sperm can gain entry.

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