More than 5 million children have been born worldwide after in vitro fertilization since the first one, Louise Brown, was born in 1978 in the United Kingdom.
Many millions more children have been born after less-invasive fertility treatments, such as ovulation induction, in which fertility drugs stimulate ovulation, and intrauterine insemination (IUI), in which sperm that have been washed and concentrated are placed directly in the uterus.
Scientists, and, likely, some parents, have wondered whether the manipulation of sperm and eggs might affect the health of children born after fertility treatments.
Two newly published studies by Danish researchers should reassure to parents who have turned to or are considering fertility treatments to help expand their families.
One report, in the October 2016 issue of the journal Fertility and Sterility, focused on about 5,000 singleton (not twins, triplets, etc.) babies born from 1990 to 1992 in Aarhus, the second-largest city in Denmark. Of those babies, 210 were born as a result of fertility treatments, 334 were born to parents who conceived naturally but had tried to get pregnant for more than a year, a sign of below-normal fertility, and 1,827 were born to parents who reported that the pregnancy was unplanned.
The researchers, using questionnaires and information from Danish national registries (unlike the United States, Scandinavian countries collect detailed information about their citizens’ health and health care via dozens of registries), tracked how well the children did in school up to age 19.
After accounting for other factors that could have an effect, such as parental age and education level and whether the mothers smoked or drank alcohol while pregnant, the scientists found no connection between fertility treatments, below-normal fertility, or whether a pregnancy was planned and children’s school performance and IQ at age 19.
“The results of the present study add to the growing body of reassuring evidence establishing fertility treatment as safe procedures” with regard to children’s development, the scientists concluded.
Another team of Danish scientists added more reassuring evidence, this time about children’s risk of type 1 diabetes, with a study in the December 2016 issue of Fertility and Sterility.
This study involved all singleton births in Denmark from 1995 to 2003—a total of about 565,000 children. Of that total, about 15,000 children were conceived by ovulation induction or intrauterine insemination, while about 8,500 were conceived by IVF or intracytoplasmic sperm injection, or ICSI, in which a single sperm is injected directly into an egg in the laboratory.
By looking at prescriptions filled for insulin up to 2013, the researchers identified about 2,000 cases of type 1 diabetes out of the 565,000 children in the study. Overall, after accounting for such factors as whether the parents themselves had type 1 diabetes before the birth, they found no connection between fertility treatments and children’s risk of developing type 1 diabetes.
They did find that children conceived after ovulation induction or intrauterine insemination with follicle-stimulating hormone had a higher risk of type 1 diabetes. However, they wrote, that could have been due to chance, given that only four of the 368 children born after either of those fertility treatments was diagnosed with type 1 diabetes.