In vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) has made a significant difference in the lives of thousands of couples facing infertility due to severe male factor — problems within the male reproductive system or the sperm, which account for 40% of all infertility cases. The process of injecting sperm into eggs at the time of in vitro fertilization was developed in 1992 and has now allowed for the birth of thousands of children whose parents would have otherwise not been able to conceive.

Since the IVF with ICSI procedure has a shorter track record, compared to a thirty year plus history for the IVF procedure, scientists and infertility specialists have been carefully monitoring children born utilizing IVF-ICSI. Prior studies of the genetic makeup of children born after being conceived via IVF-ICSI have reported that the risks of chromosomal abnormalities may be slightly increased as compared to natural conception. But these studies have been inconclusive.

However, a new study, presented at the annual meeting of the European Society for Human Reproduction and Embryology in Madrid, Spain this summer, prompted a collective sigh of relief. This extensive study involved 1,500 children from several European countries, who were followed up to age 5. The study was designed to examine both birth defects and mental development differences.

All the children underwent a thorough physical examination, including checking for birth defects, hearing and vision tests and psychological development. Although the rate of birth defects was slightly higher in the IVF-ICSI group at 5 years of age, there were no differences in language or physical skills, and no differences in behavior and temperament. The amount of difference seen in birth defect rates was not considered to be statistically significant enough to warrant concern. Moreover, the lack of difference in developmental skills was clearly an indication that IVF-ICSI children are expected to grow into thriving, healthy children.

The results of this study should be reassuring to parents of children conceived through IVF-ICSI, or those who are considering undergoing this procedure. The vast majority of children that result from the IVF-ICSI process do very well and show no major differences as compared to naturally conceived children.

If you are particularly interested more background and further details of this study, please read further

IVF-ICSI Study Details

In the general population, the risk of sex chromosome abnormalities is about 2 in every 1000 births (0.2%). With IVF-ICSI, the rate of sex chromosome abnormalities is estimated to be about 6 in every 1000 births (0.6%). These types of abnormal chromosomes can lead to a variety of defects but virtually all chromosomal abnormalities can be diagnosed by prenatal genetic testing (CVS or amniocentesis).

It is not certain that this increased risk is due to the injection procedure itself or whether it is due to the fact that the sperm of men with male factor infertility, being otherwise incapable of fertilization, has a higher percentage harboring chromosomal abnormalities. In fact, recent studies on the chromosomes from embryos created via IVF-ICSI have shown that abnormalities are primarily confined to embryos using sperm from men with the most severe forms of male infertility, usually sperm requiring surgical extraction from the testicles.

This new study focused not only on the sex chromosomal abnormalities but also on the mental development of children conceived with this method. (Prior studies had revealed conflicting results, some showing a slower development in a portion of the children and other studies finding no differences in mental and psychological development.)

Over 1,500 children from Britain, Belgium, Sweden, Denmark and Greece were followed up to age 5. Out of this total, 541 children were conceived through IVF-ICSI, 440 were conceived with IVF without ICSI and 542 were conceived naturally. The children underwent a thorough physical examination, including checking for birth defects, hearing and vision tests and psychological development. Although the rate of birth defects was slightly higher in the IVF-ICSI group (6.4% vs. 2.4%), at 5 years of age, there were no differences in language or physical skills, and no differences in behavior and temperament. The amount of difference seen in birth defect rates was not considered to be statistically significant enough to warrant concern. Moreover, the lack of difference in developmental skills was clearly a significant indication that IVF-ICSI children are expected to grow into thriving, healthy children.

At birth, IVF-ICSI children were similar in birth weight and maturity (only singleton births were included in the study). They were no more likely to have been in the neonatal intensive care unit and the Apgar scores (measuring general health at birth) were similar. However, children conceived with IVF-ICSI were more likely to have undergone mostly minor surgeries, such as kidney and urinary problems, and to have been hospitalized sometime in the first 5 years of life.

One potential explanation for the differences in the birth defects could also attributed to the mother’s age at conception, as there is clearly a trend towards slightly higher rates of birth defects with maternal age. Also, for unknown reasons, the IVF-ICSI mothers were more likely to have had illnesses during pregnancy. An additional problem with drawing conclusions from the birth defect data was pointed out by Dr. Arne Sunde, chairman of the ESHRE society. In this study, the control group of naturally conceived children was more likely to be skewed towards healthy children, as this group was recruited from mainstream schools. It is likely that some of the children with the most severe birth defects may not be enrolled in regular schools. More data is needed to confirm or refute these results.

Regarding the psychological development findings, one of the researchers of the study, Dr. Susan Golombok from the City University of London stated, “I think we can feel very reassured about children’s social, emotional, and cognitive development up to age 5. If they were doing all right up to age 5, you wouldn’t necessarily expect things to get worse as they grow older. By that time, they are starting school and if they are doing okay, there would be no particular reason to expect problems would suddenly start to manifest.”

Tags: Clinical Trials & Studies, ICSI, IVF - In Vitro Fertilization, Male Fertility

This entry was posted on Monday, September 1st, 2003 at 3:43 pm and is filed under Science Pulse. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.