July 2, 2003 -- Babies born with the assistance of the infertility treatments in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) don't face any more health problems than babies conceived by natural means, according to the longest-running study to date.
Researchers say the study provides the most comprehensive evidence so far that IVF and ICSI procedures are safe.
Fears Laid to Rest
"Overall, the results are reassuring and lay to rest the fears that have been expressed about the health and welfare of children conceived though IVF and ICSI," says researcher Christina Bergh, of Sahlgrenska University Hospital in Göteborg, Sweden, in a news release. Bergh presented the results of the study today at the annual meeting of the European Society of Human Reproduction and Embryology in Madrid, Spain.
IVF is a procedure in which women take drugs to stimulate egg production; eggs and sperm are collected and combined in a test tube or laboratory dish, and then inserted in her uterus to develop. ICSI involves directly injecting each collected egg with a single sperm by hand prior to inserting the fertilized egg into the woman's body.
The study involved 440 children conceived using IVF, 541 children conceived with ICSI, and 542 naturally conceived children and followed them until age 5. Researchers compared rates of problems experienced by the children in the following areas:
- Birth health and obstetrical complications
- Birth defects or malformations
- Family relationships
- Physical development
- Mental, psychological, and social development
No major differences in birth weight, growth, total IQ, motor development, and behavior problems or parental stress were found between the children conceived with infertility treatments and those conceived naturally.
But some minor differences were found in these areas:
- ICSI mothers and fathers were more committed to their role as parents than others.
- Hospital admission rates were slightly higher for ICSI and IVF babies than naturally conceived babies, although the rate of medical illnesses across the three groups was similar.
- The rate of birth defects was 6.2% and 4.1% for ICSI and IVF babies, respectively, compared with 2.4% among naturally conceived babies. The rates were statistically different only when comparing ICSI children with naturally conceived children, and not by IVF. These differences in malformations were also more commonly seen in boys than in girls. Researchers say all the birth defects were correctable and the children went on to be as normal and healthy as others.
Infertile Couples Are Different
Experts also say that the fact these couples experience more birth defects might reflect factors other than the safety of the procedures. Infertile couples are different than those who get pregnant naturally, and some of those things may predispose them to other problems.
For example, Brian Kaplan, MD, reproductive endrocrinologist at the Fertility Centers of Illinois, says infertile couples are already a high-risk group for birth defects and other congential problems for a number of reasons. They usually are older than the general population and are more likely to have multiple pregnancies, which are both known to increase the risk of abnormalities.
"But most important is that the men we have treated with this ICSI procedure are men with extremely low sperm counts," says Kaplan.
"The reason they might have low sperm counts is that they might have some chromosomal abnormality themselves, so you're really just transmitting into their progeny the problem that the husband has rather than the procedure itself causing the problem."
Jamie Grifo, MD, PHD, director of the division of reproductive medicine at the New York University School of Medicine, says it's also hard to study differences between babies conceived with infertility treatments and others.
"IVF babies are looked at and scrutinized much more carefully than naturally conceived babies," says Grifo. He says just the process of looking harder at babies conceived though assisted fertility techniques can reveal problems that might otherwise be ignored in the general population.
Although it's impossible to say IVF and ICSI are without risk because they're relatively new procedures, Both Kaplan and Grifo say the results of this and previous studies are as reassuring as they can possibly be.
"We don't know if there are risks with these technologies; we don't have reason to believe there are risks, but no one really knows. The only way to find out is wait a long time and look," says Grifo.
Because this study was done by people who do not perform IVF themselves, Grifo says it also carries more weight that those conducted by people with a vested interest in the procedure.
"This is the most reassuring data to date that if there are risks to these procedures they are so small that they almost not measurable in good studies. That's really the bottom line, so that's a good thing," Grifo tells WebMD.
In addition, Kaplan says the results are consistent with prior U.S. studies indicating this technology really does not create any increase in problems with the children. "I think these further studies, particularly from the European groups, adds to our armamentarium in being able to reassure patients that this is a safe technology," says Kaplan.
Researchers say further studies need to be done on even larger numbers of IVF and ICSI babies and over longer periods of time, but the current study appears to show the procedures themselves do not cause any long-term damage in the children.
"Nothing is risk-free," says Grifo. "Patients make choices. If there are risks, most patients are willing to take them because they are educated about the potential risks even though we don't know that they are any, patients still choose to do this stuff."