Preimplantation genetic diagnosis (PGD) - in which doctors remove a cell from three-day-old embryos to look for genetic disease - appears to pose no harm to babies, Belgian researchers report.
The procedure, first introduced in 1990, analyses fertilised eggs for genetic problems prior to implantation in the mother's womb, as happens in in vitro fertilisation (IVF). But experts have worried that the procedure might pose a long-term safety risk to offspring, the BBC reported.
In the study, researchers at Brussels' Free University say that 563 of the 583 babies in the study that underwent PGD were born alive - a rate that matches that of conventional IVF or another fertility procedure called ICSI, where sperm is injected into the egg.
PGD babies also had comparable birth weights to infants who did not receive the procedure, and the rate of birth defects or malformations was also similar between PGD, IVF and ICSI children at two months and two years of age.
The findings were published at a meeting of the European Society of Human Genetics.
"I'm very reassured and not at all surprised by these latest results," Dr Alan Handyside, a spokesman for the British Fertility Society and one of the scientists who developed PGD in the 1980s, told the BBC. But he said longer-term data were still needed to confirm the procedure's safety.
In a related study, Danish researchers reporting at the same meeting said that non-invasive screening in early pregnancy can cut Down syndrome births by 50 percent. They used a combination of ultrasound examination of the foetal neck ("nuchal translucency") and maternal blood tests to assess the presence of the disorder. The test is usually carried out at between 11 and 14 weeks of gestation.
Beginning in 2004, Denmark's National Board of Health recommended routine use of the combination test. Implementation of the guidelines has reduced the number of Danish children born with Down syndrome, according to a team at the Kennedy Institute in Glostrup.
"When we looked further at the history of children born with Down syndrome, we found that their mothers had declined the offer of screening, or had taken it up too late in pregnancy," lead researcher Dr Karen Brondum-Nielsen said in a statement. – (HealthDayNews)
Tissue typing used on embryos