Since in ICSI you’re using a needle and the sperm and egg fuse in a different fashion than they would in regular conception or IVF, does this change the genetics of the embryo from what they would have been if they fused naturally? Does the needle itself cause the DNA to recombine differently, possibly creating birth defects?
No. Recombination occurs when making eggs and sperm; not during fertilization.
It might affect the DNA. It’s also possible that people who resort to this procedure already have something wrong with their DNA, thus confounding the results.https://consumer.healthday.com/encyclopedia/fertility-19/infertility-news-412/intracytoplasmic-sperm-injection-icsi-646218.html
Although the medical research is not conclusive, in recent years a number of studies have shown that babies conceived through ICSI may have higher rates of certain birth defects and other problems. The risk of hypospadias – a birth defect that causes the urethral opening to be located in the underside of the penis – is higher in boys born through ICSI than in the general population. Also, because male infertility can be genetic, boys conceived through ICSI may inherit this condition and therefore have a higher chance of having fertility problems themselves as adults.
It has also been reported that ICSI babies have a four-fold increased risk of sex chromosome-linked genetic abnormalities that can result in various clinical syndromes.
A study of 5,138 Australian children showed that babies conceived through ICSI or IVF had twice as high of a risk of having a major birth defect as compared to babies that were conceived naturally. However, a study of 1,139 ICSI babies in Sweden showed that although ICSI babies had a slightly higher rate of minor or major birth defects, it was thought to be related to the higher rate of multiple and preterm births associated with fertility procedures, rather than to ICSI itself. Since there is not yet a consensus within the medical community, it’s probably safest to assume that the use of ICSI or any other assisted reproductive technology may carry a small risk of birth defect.
As for whether the ICSI procedure affects children’s learning skills, early research suggested that mental development may be slower among ICSI children. However, this study was small and has been refuted by several recent studies. Current research suggests that babies conceived through ICSI do not have a higher rate of learning disabilities. In 2005, the journal Pediatrics published a study of 1,423 five-year-old children from five European countries. The results showed that children conceived through ICSI or IVF did just as well as their naturally conceived peers on cognitive and motor development tests.
Some critics of the procedure argue that because it allows weaker sperm to fertilize eggs – rather than relying on natural selection to favor the hardiest sperm it may lead to genetic defects. However, even with a slight increase, these genetic conditions remain rare: researchers have stated risks ranging from minor birth defects in 1.2 percent of ICSI children to 4.1 percent for major birth defects. Some believe that the higher incidence of birth defects and other issues may be because couples who use ICSI tend to be older and may have other health issues.
That’s the confusing thing. It seems impossible to tell whether it’s one or the other. Would a damaged egg be too ruined to make it, or could it make it with compromised DNA?
Also - would some of the paternal mitochondria persist in ICSI? I’ve heard suggestions it might, but apparently there’s been no proof of it so far.