home
RSS
IVF may slightly increase mental retardation risk
A medical worker prepares to perform intracytoplasmic sperm injection (ICSI).
July 2nd, 2013
06:41 PM ET

IVF may slightly increase mental retardation risk

While new research finds no significant link between autism and singleton children conceived via in vitro fertilization (IVF), a slightly increased risk of mental retardation, or intellectual disability, was found following IVF treatment including intracytoplasmic sperm injection (ICSI).

ICSI involves the injection of a single sperm into an egg to fertilize it.  Researchers found when ICSI was used to overcome male infertility, the  risk for intellectual disability increased slightly compared to IVF without ICSI.

"The reasons (for an increased risk) could be the underlying infertility,” says Abraham Reichenberg, one of the study authors and a professor at Mt. Sinai School of Medicine in New York and King's College London.

“It could be something happening in the many steps that are involved in each of the treatments, or something that's happening later in the pregnancies, or all of them combined together.  It could be any one of those steps.  In any one of them it could go wrong." The increased risk was seen even in singleton births utilizing ICSI. However, the overall risk remains low.

There were about 91 children diagnosed with mental retardation (per 100,000 person follow-up years) when conceived by IVF using ICSI with ejaculated sperm and fresh embryos. That’s compared to about 61 children diagnosed using IVF without ICSI.

While no link was seen between autism and singleton children conceived via any form of IVF, study results did show a four-fold increase in the risk of autism in children conceived under the most severe forms of male infertility (in which sperm must be surgically extracted) compared to less severe forms of male infertility, but even that risk only showed up in twins.

"I think this study gives reassurance to both physicians and patients that there doesn't seem to be an association with IVF (and autism) in general," says Dr. Marcelle Cedars, professor at UCSF medical center in San Francisco.

"There may be a very small risk with some of the technologies used for male factor infertility and I think those are things that couples should be aware of, but I think that overall the study was reassuring and, despite the fact that couples frequently come to us and say 'I want twins, I want to transfer more embryos', I think this gives us more ammunition and more information to share with couples to try to encourage them to try to get pregnant with a singleton."

"The single embryo treatments are safer," Reichenberg says. “There are less birth complications, less pre-term births, the birth weight is better, all different neonatal outcomes are better in single embryos.”

The study, published Tuesday in the Journal of the American Medical Association (JAMA), tracked 2.5 million infants born in Sweden between 1982 and 2007, including 30,959 total infants conceived by all available types of IVF treatment.


soundoff (9 Responses)
  1. Mike

    The reason ought to be patently obvious. The fertilization technique can not accurately identify the genetic quality of individual sperm, resulting in forced fertilizations with inferior reproductive cells. This reduces the statistical probability of high genetic quality of offspring relative to the pairing itself. At least, I think so. Is it so hard to imagine that natural barriers and mechanisms of reproduction are there to ensure maximum quality of fertilization and thus increase long term species survival?

    July 2, 2013 at 21:06 | Report abuse | Reply
    • B

      Exactly what I was thinking.

      July 3, 2013 at 05:18 | Report abuse |
  2. André

    This is not surprising. Natural selection dictates that sperm have to compete to get to the egg. When we remove that very important evolutionary selection mechanism, more inferior sperm will make it through.

    July 3, 2013 at 03:10 | Report abuse | Reply
    • BubblySoup

      Actually, even if the selection is not perfect, the embryologist for ICSI select the best looking, faster going sperm to inject.

      July 8, 2013 at 23:42 | Report abuse |
  3. Adam

    I blame Jesus

    July 3, 2013 at 04:19 | Report abuse | Reply
  4. liss

    Agreed with Mike, it's unnatural, so these things may happen. Also, the couples undergoing IVF are typically older after they've exhausted all other attempts. Being older in general (older eggs and sperm) has it's own risks of defects, regardless of natural conceiving or IVF. People are waiting to they're older to have kids now days but it's not without it's own health risks.

    July 3, 2013 at 09:00 | Report abuse | Reply
    • IVFgirl

      No, the "majority" of patients undergoing IVF aren't older. There is a wide age difference in those undergoing IVF and to assume that someone is just old doesn't do justice for the millions of couples struggling to get pregnant in their 20's and 30's.

      July 8, 2013 at 12:33 | Report abuse |
  5. patriciaange

    Reblogged this on Sex and Relationships.

    July 6, 2013 at 06:37 | Report abuse | Reply
  6. BubblySoup

    I wonder if it have something to do with the placenta quality as well. There has been a recent study linking issue with the placenta (at a microscopic level) and autism... If we take in consideration IVF often happens in older women it may be a link. there too. They should check the placenta quality and add it to their result to see if some different conclusion may shows up.

    July 8, 2013 at 23:36 | Report abuse | Reply

Post a comment


 

CNN welcomes a lively and courteous discussion as long as you follow the Rules of Conduct set forth in our Terms of Service. Comments are not pre-screened before they post. You agree that anything you post may be used, along with your name and profile picture, in accordance with our Privacy Policy and the license you have granted pursuant to our Terms of Service.

Advertisement
About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.