PRAGUE — Results of the longest follow-up study of children conceived through intracytoplasmic sperm injection are reassuring despite the finding that they have a significantly increased rate of two major malformations, reported Dr. Florence Belva, an investigator in the study.
“The absolute risk of major malformations should be interpreted with caution and may be due to our study design,” Dr. Belva reported in a press conference at the annual meeting of the European Society of Human Reproduction and Embryology.
Her study compared 150 8-year-old children conceived through intracytoplasmic sperm injection (ICSI) with 147 spontaneously conceived control children. The only demographic difference between the two groups was maternal age, which was significantly greater in the ICSI children, compared with controls (32 years vs. 30 years), said Dr. Belva, a pediatrician and research assistant at the Center for Medical Genetics, Vrije University in Brussels.
Parents were asked to complete detailed questionnaires about their children's medical histories, and the children underwent extensive physical examinations, which included a neurologic work-up.
The only difference found between the two groups was an increase in the rate of major malformations, defined as malformations causing functional impairment and/or requiring surgery. The rate was 10% in ICSI children and 3% in the control children, which translates into a relative risk of 2.9 for a major malformation in the ICSI group.
The differences in major malformations between the two groups were in the rate of naevus flammeus (two cases in the ICSI group, and none in the control group) and inguinal hernia requiring surgery (five cases in the ICSI group and one in the control group).
Dr. Belva said her finding of an increased rate of major malformations in ICSI children was consistent with those of other studies; however, she said, the 10% rate was higher than has been previously reported.
“This may be because we had stricter definitions of major malformation to make sure we did not miss anything. Also our follow-up of 8 years is the longest, because other studies only followed children to 5 years of age. We found additional malformations between 5 and 8 years, which would not have been included in the shorter studies,” she said.
These findings are reassuring for parents, as long as they are carefully explained, said Dr. Sherman J. Silber of the Infertility Center of St. Louis. “I am concerned that the public may think that ICSI children have three times the rate of all major malformations, when it is simply an increase in inguinal hernias,” he said.
Similarly, Dr. Joe Leigh Simpson noted the importance of putting the results in perspective. “In the United States our definition of major malformation is normally death, severe malfunction, or structural anomalies requiring surgery,” said the professor and chair of obstetrics and gynecology at Baylor College of Medicine in Houston.
Source: Dr. Weisman