Studies Show Possible Autism Links to Fertility Drugs, In Vitro Fertilization and Pre-Term Birth

Two studies presented May 19 at the International Society for Autism Research meeting in Philadelphia indicate possible links between autism and fertility drugs, in vitro fertilization and pre-term birth.

In a Harvard School of Public Health study, women with infertility and who used ovulation drugs had twice as much chance of having a child with an autism spectrum disorder.

The study found that about 4% of women who took fertility drugs such as Clomid or gonadotropins had a child with autism, compared to 2% who had a child with autism but did not take fertility medications. That means that the great majority of children conceived after using fertility drugs did not develop an autism disorder.

Of about 3,900 mothers who took part in the Nurses’ Health Study II, about 34% of moms with an autistic child had used fertility drugs compared to about 24% without an autistic child, according to the study.

Kristen Lyall, ScD, the study’s lead author, said the findings are preliminary, involved a small group and needed to be confirmed by additional research. She noted that older women are more like to have fertility problems and to take ovulation-inducing drugs, and that prior research has found that older mothers are more likely to have autistic children.

In a second study presented at the Philadelphia meeting, Israeli researchers found an increased risk for autism in children whose mothers used in vitro fertilization in children who were born pre-term.

In that study, 10.2% of 461 children diagnosed with an autism disorder were conceived using in vitro fertilization. Among Israelis, about 3.5% of children are conceived in vitro. While 1% of Israeli children are born prematurely and have low birth weight, nearly 4% of kids with autism were born pre-term and nearly 5% had low birth weight.

Ditza Zachor, MD, the study’s lead author emphasized that the study is preliminary and more research is needed before a link between in vitro fertilization or prematurity and autism can be established.

For further information, click here to see a report on U.S. Department of Health & Human Services website,

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