A study was released yesterday in the journal Human Reproduction about infertility therapies and the risk of cerebral palsy (CP). A lot of major news outlets jumped on the study, reporting that the risk of CP was more than doubled with IVF (in vitro fertilization).
Should you worry?
After reviewing the article myself and with a colleague, Dr. Ivan Huang who is a board certified reproductive endocrinologist (infertility doctor), it is hard to get overly excited because the article doesn’t add too much new information to the discussion. Although, in the investigator’s defense it is a larger study and more thorough look at the subject matter and these and confirmatory studies are always nice.
Researchers looked at a Danish registry for cerebral palsy. Many countries with universal health care maintain registries for all kinds of health conditions to track outcomes and refine therapies to eventually provide better health care (just another great benefit of universal health care). The investigators looked at more than 500,000 children and found that CP was more common among pregnancies that were the result of assisted reproduction. The rate of CP was almost doubled.
However, when all the data was analyzed the increase in CP was found to be related to either/or A) multiple pregnancy B) prematurity. So, women who conceived only one baby as a result of assisted productive techniques and made it to term (at least 37 weeks) were no more likely to have a baby with CP than women who conceived naturally. As my friend Dr. Huang says, “a healthy pregnancy is a healthy pregnancy.”
The biggest players in the study were multiple pregnancies and prematurity. Multiples are more likely to have CP, even when they deliver at term, and they are also more likely to deliver prematurely, and premature delivery is the biggest risk factor for CP. The rate of premature delivery was very high among the women who conceived a single baby with assisted techniques, 20.% versus 5.6% for those who conceived naturally. After all the data was analyzed, this study confirms that it’s not the actual process if IVF that increases the risk of CP, rather the consequences of IVF: multiples and prematurity.
Why are women who get pregnant with assisted reproductive techniques and only have one baby more likely to deliver prematurely? No one really knows, but it has been identified in many studies. There are lots of theories, but nothing concrete.
So what should you do if you need assisted reproductive technologies to get pregnant?
Find a clinic that has a low rate of multiples. I know, people think multiples are “fun” (have the whole family at once!), but if you want to have the lowest risk pregnancy with the best chance of the healthiest outcome, you want one baby. The CDC tracks Fertility Clinic Success Rates, click on the link and you can read about every clinic (the site even explains how to interpret the stats). This is VERY important because some clinics (and this happened more before this kind of public reporting) implanted WAY too many embryos or were a little too happy with the hormones to boost pregnancies rates, just throwing caution to the wind with multiples. Quadruplets or higher (and in some cases even triplets), unless they are identical, are almost always the result of a mismanaged infertility cycle. And yes, I wonder about that for my own pregnancy all the time. There are laws governing reproductive techniques in Europe – the pregnancy rates are the same, but they have far fewer multiples. Doctors here resist that kind of legislation, saying they will “self govern.” Of course, the two most obvious examples of how self- regulation has failed are “Jon and Kate plus eight” and “Octomom.” TLC has a whole spectrum of shows filled with the results of self-governing.
You should also be aware that you are at higher risk for delivering prematurely. Do everything that you can to stay healthy. Check out the preventing prematurity info on this site and talk with your OB about ways to reduce your risks.
Bottom line, if you need reproductive technologies to get pregnant, you need them to get pregnant. Just do your research. Chose your clinic based on hard data and be aware that your risk of delivering prematurely is higher, so find an OB who understands this fact. And remember, 80% of women who get pregnant with infertility therapies who have one baby don’t deliver prematurely, so the odds are still in your favor!
Oh, and the picture at the top? My son with CP breaking a board at Tae Kwon Do.