Me: My guess along with the researcher is that when the embryo chosen to be used for fertilization, the people at the clinic happened to choose the best, largest, healthiest looking one to use. It is strange that females had the most pronounced effects.
IVF births result in taller children: NZ study October 14, 2010 Children born using in-vitro fertilisation (IVF) are likely to be taller than their naturally conceived counterparts, New Zealand researchers have found.
The study by Auckland University’s Liggins Institute found IVF children conceived from fresh, rather than frozen, embryos were about 2.6 centimetres (1.02 inches) taller than non-IVF children by the age of six. The research, which examined about 200 children, found the height difference was statistically significant, even after adjusting for variables such as the parents’ height. Liggins Institiute director Wayne Cutfield said the phenomenon was most striking in girls. “At this stage, we don’t know what the catalyst for that is,” he told Radio NZ on Thursday. Cutfield said appeared IVF children from fresh embyros had a different hormone profile to regular children, which could promote growth. This could be caused by the drugs mothers took to induce ovulation during the conception process or by the culture medium the embryos were developed in for 36 hours before being transferred to the womb, he said. Cutfield said another possibility was that medical workers simply picked the largest, most developed embryos because they were most likely to survive the IVF process. He said the study showed the need for more research into children born through IVF, which has assisted in up to four million births globally over the past 32 years. “There’s been remarkable little research done on IVF children,” he said. “There’s been several studies that have looked at intelligence and cognitive function that havent shown any differences with IVF. This is the first study that’s looked very precisely at growth resultation and metabolism.” Cutfield was sceptical about previous studies suggesting IVF children were more prone to conditions such as asthma and arthritis, saying the finding could be explained by other factors. “Within the IVF cohort, children are more likely to be born particularly small at birth, they are more likely to be born premature, there are more likely to be twins and triplets,” he said. “They’re all groups of children who are likely to have greater health problems and you need to be able to adjust for that.” British scientist Bob Edwards, whose pioneering work made possible the birth of the first IVF baby Louise Brown in 1978, was awarded the Nobel Prize for Medicine this month. (c) 2010 AFP
From News Medical…
Taller kids with IVF: Study
Published on October 13, 2010 at 10:13 PM ·
By Dr Ananya Mandal, MD
A new study has found that children born via IVF are typically taller than those born naturally. Newborn IVF babies created from a fresh embryo transferred back into the mother, also tended to be about 190g lighter than naturally conceived children.
The study was led by Dr. Mark Green from the University of Auckland’s Liggins Institute and is one of its kind. “There’s been four million children born from IVF … we wanted to see what the long-term implications were,” he said.
His study showed that babies conceived with fresh, as opposed to thawed, embryos, were on average up to 2.6cm taller than children born without assisted conception. The team looked at healthy, pre-pubescent children aged between four and 11, of which 72 were born from IVF using fresh embryos, 43 IVF children from frozen embryos and 94 naturally conceived children. Height difference was more prominent in girls they found. Dr Green said, “We’ve got no real hypothesis on why that might be, we do know that a lot of different things affect males and females in utero.”
Dr. Green explained, “We don’t know the reasons for the height difference…But can I suggest that it may have something to do with the hormones that are given to the mother to stimulate the ovary in fresh embryo transfer…Fresh embryos are usually of a better quality than frozen embryos which may be a contributing factor to differences in height in the resulting children.”
He suggested that more research into IVF born babies was needed to understand the effects. “We need more long-term studies because we know some of the later diseases, such as diabetes and cardiac disease, can be affected by events that happen during gestation, and they don’t really occur till the 40s or 50s,” Dr Green said.
The research was presented at The Fertility Society of Australia’s annual scientific meeting in Adelaide, on Wednesday.