Dr. Marla Shapiro: Most babies born by IVF not at higher risk of birth defects
Published Tuesday, May 8, 2012 9:33AM EDT
Last Updated Monday, June 11, 2012 1:35PM EDT
We have made great advances in fertility treatments with newer reproductive technology. The question is whetherthese infertility treatments lead to a greater number of birth defects?
A study just released in the New England Journal of Medicine looked at data collected on more then 6,100 births that were achieved using assistive reproductive technology in Australia. The study looked at more than 300,000 births as a comparator, looking for differences in the outcome of birth defects associated with infertility treatments compared to those that were not assisted in any way.
Generally, women who used reproductive technologies were older and more likely to not have any children, were white and less likely to live in disadvantaged areas. These women in the assisted technologies were also more likely to have a stillbirth and be delivered by C-section. Their children also had a lower mean birth weight.
The results showed that for any kind of assisted reproduction, the risk of any birth defect was 8.3%. Unassisted pregnancies saw a rate of 5.8%. The kinds of defects seen included cleft palate and congenital disease of the heart, gastrointestinal musculoskeletal, urogenital and cerebral palsy.
If the kinds if assisted technologies were looked at, the breakdown showed:
Risk of Birth Defect
IVF ( in vitro fertilization) 7.2%
ICSI (intracytoplasmic sperm injection) 9.9%
Clomiphene Citrate 3fold increase
The authors note that in the case of IVF, the increased risk could be associated with parental factors such as the age or weight of the patient. However ,these confounders were not seen with ICSI and the risk remained higher.
We cannot exclude that perhaps what led to infertility in the first place could be the cause independent of treatment. For example, in ICSI, where a single sperm is injected into an egg, it could be the DNA of the sperm itself. It is also noted that women with a history of infertility and previous assistance who now did not undergo assistance also have a higher increase of children with birth defects. A history of infertility without any treatment also showed an increase in risk.
As well, when looking at reproductive assistance with fresh and frozen embryo, there was a difference as well. Frozen embryos did not show the increase risk in birth defects that fresh embryos did and that might be because a developmentally abnormal embryo might not survive the thawing process.
It should also be noted that reproductive technologies have only gotten better and perhaps present day data would show lower risk outcomes.