What are the true risks of in vitro fertilization?
Often thought as “the great equalizer”, the internet is information-laden. However, not all sources are equitable. Deciphering amongst myth, opinion and truth, particularly in the field of Assisted Reproductive Technologies (ART) can be complicated and equally frustrating.
When one is contemplating whether IVF is suitable for their circumstance, it is important to understand true risks. These data were by Sutcliffe et. Al. Outcome of assisted reproduction. Lancet 2007; 370: 351-9.
The greatest risk is multiple births. Yes, there has most definitely been an increase in the number of twins and higher order multiples (triplets and quadruplets) over the initial years of instituting these technologies. In 2007, our governing body , ASRM (American Society of Reproductive Medicine), published guidelines with regard to the number of embryos recommended for transfer. However, prior to this publication, a move to reduce the number of embryos transferred had started. As a result, the twin rate, and in particular, higher-order multiple-rate has decreased.
A second concern is that the miscarriage rate seems to be slightly increased when compared to spontaneously conceived pregnancy. It is possible that this increase may be biased partially. It may be that with IVF, exact timing is monitored; therefore, those women who have transient demonstrations of pregnancy hormone (biochemical pregnancies) may be registered whereas in naturally-conceived pregnancies, the woman may not even have realized that she was transiently-pregnant. Or, perhaps, IVF made it possible to achieve a pregnancy that may not have occurred naturally.
Thirdly, there seems to be a slight increase in numeric sex-chromosome abnormalities with injecting of the sperm into the oocyte (ICSI) (0.6% vs 0.2%).
However, it must be noted that to be a medical candidate for ICSI, there is often an underlying issue regarding subfertility at the level of sperm function. Therefore, these same issues causing the infertility, may very well play a part in how the chromosomes come together to form the developing embryo. It should be noted that there are other medical conditions that have much higher predispositions to such chromosomal rearrangements. In particular, a women with Diabetes Mellitus demonstrates a greater of an offspring with such an issue in comparison to the minute risk of ICSI (<1%).
Risks of preeclampsia, slightly smaller infants and pre term delivery increase. In part, these risk increases may be related directly to multiple gestation. For instance, twins are more likely to deliver earlier and be slightly smaller than their singleton counterpart.
It is important also to look at the long term data regarding how ART babies fair.
Neurodevelopmentally mature-term babies born after ART progress equally as well as those children that are the result of a spontaneously conceived pregnancy. To those couples who are candidates for IVF, the benefits of ART greatly outweigh the risks and may be the only chance to have a baby.