The research looked at over 300,000 South Australian births, 1986 – 2002, which included 6,163 births resulting from assisted reproductive technology (ART) and in which physicians reported information concerning birth defects to a state registry. The team discovered that 8.3% of the children whose conception was assisted in some way developed a birth defect, versus 5.8% who conceived naturally and spontaneously, said the LA Times. The use of ART was linked to a 28% increased risk for giving birth to a baby with a birth defect including, “cardiovascular, musculoskeletal, urogenital, and gastrointestinal abnormalities and cerebral palsy,” said the researchers.
The team also assessed risks by ART type, such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). As we’ve explained, IVF, a process that has been in use for several decades, involves an egg fertilized by sperm in a lab. ICSI involves fertilization of an egg via injection of a single sperm and has long been the main method used to overcome male infertility. If successful fertilization occurs, the embryo is then placed into the female via IVF. Fertilization, not necessarily pregnancy, rates are relatively high when ICSI is employed.
The new study’s raw data indicated that IVF was linked with a 26% increased risk in birth defects; the possibility of random chance could not be ruled out after statistical adjustments were made. With ICSI, however, a 57% increased risk of giving birth to a baby with a birth defect was seen, versus babies born to fertile women, even when accounting for demographic and other significant factors, said the LA Times. The risk actually increased to 66% in cases in which fresh embryos were used; the risk of birth defects was not significantly higher when frozen embryos were used, versus fertile women, the researchers found.
The team speculated that the embryo freezing and thawing process could be eliminating embryos naturally prone to developing a birth defect, explained the LA Times. Meanwhile, increased birth defect risks were see in intrauterine insemination, gamete intrafallopian transfer, and home use of the drug, Clomid (clomiphene citrate).
Women who previously attempted conception via ART, but who did not conceive and then became pregnant on their own, were 25% likelier to give birth to a baby with a birth defect versus women with no infertility history. Women with a history of infertility, but who never tried ART and who became pregnant on their own, were 29% likelier to give birth to a baby with a birth defect. The team speculated that these findings could be traced, in part, to home use of Clomid, which has been seen in a prior Danish study, said the LA Times.
We just wrote that other research, published in the journal Fertility and Sterility, revealed that babies conceived through certain fertility techniques are at about a one-third increased risk for being born with a birth defect, versus babies conceived naturally. Other studies on which we’ve written have indicated that IVF babies seem to experience an increased risk for childhood cancer, versus babies conceived naturally, according to prior Swedish research; that birth defect risks appeared to be twice as high in babies conceived via fertility treatment, versus babies conceived naturally, according to French scientists; that women who undergo IVF or ICSI and who become pregnant, experience an increased risk of giving birth to a stillborn baby, according to Danish scientists; that use of IVF or ICSI to conceive appears to increase the odds of Y-chromosome defects or microdeletions in male offspring, according to Chinese researchers; and that prior research linked ARTs with low birth weight, pre-term delivery, cerebral palsy, and major birth defects.
Some researchers believe that such therapies may prompt gene mutations.