Michèle Hansen, a researcher and PhD student at the Telethon Institute for Child Health Research in Western Australia, said: "We found that twins conceived following ART treatment had a greater risk of adverse perinatal outcome, including preterm birth, low birthweight and death, compared with spontaneously conceived twins of unlike sex. ART twins had more than double the risk of perinatal death compared to ULS SC twins, although the risk was similar to that of all SC twins, including identical twins.
"ART twins stayed longer in hospital than ULS SC twins at the time of their birth: an average of 12 days compared with eight days. ART twins were four times more likely to be admitted to neo-natal intensive care than ULS SC twins, and were more likely to be admitted to hospital during the first three years of their life. After adjusting for confounding factors such as year of birth, maternal age, parity and so on, ART twins still had a nearly two-thirds higher risk of being admitted to neo-natal intensive care, and a higher risk of being admitted to hospital in their first three years of life, although this was only statistically significant in their second year, when their risk was nearly two-thirds higher."
Ms Hansen continued: "Couples undergoing fertility treatment should be aware that, in addition to the known increased perinatal risks associated with a twin birth, ART twins are more likely than spontaneously conceived twins to be admitted to neonatal intensive care and to be hospitalised in their first three years of life.
These results are an argument against implanting multiple embryos when doing in vitro fertilization (IVF). But many women opt for multiple embryo implants because they want to increase their chances of starting even a single pregnancy. Women in their mid 30s and later already hear a lot clock ticking and realize that time is not on their side. So rather than undergo a series of single embryo implantations they get more than one embryo implanted at once.
Development of better ways to test embryos to identify better embryos for implantation increase IVF success rates. These methods that boost success rates decrease the need for multiple embryo implantation. Also, better testing (genetic and otherwise) will identify embryos that have much lower odds of producing birth defects. So in time IVF combined with pre-implantation testing could become safer than pregnancies started the natural way
|Share |||Randall Parker, 2009 May 20 11:16 PM Biotech Reproduction|