A study of over 7.7 million children found that heart defects were around 36% more common in babies born after assisted reproduction.


Summary: A large study published in the European Heart Journal found that babies born through assisted reproductive technology, such as in vitro fertilization (IVF), have a 36% higher risk of being born with major congenital heart defects compared to naturally conceived babies. The study, which examined over 7.7 million children from Nordic countries, highlighted that the risk is particularly higher for multiple births. Researchers believe that underlying infertility factors in parents may contribute to this increased risk. Early detection of heart defects is crucial for timely treatment, as assisted reproductive technology becomes more common worldwide.

Key Takeaways:

  1. Higher Risk of Heart Defects: Babies conceived through assisted reproductive technology have a 36% higher risk of major congenital heart defects compared to those conceived naturally.
  2. Multiple Births Increase Risk: The risk of heart defects is even greater for multiple births resulting from assisted reproductive technology.
  3. Potential Link Between Infertility and Heart Defects: The study suggests a possible common factor linking infertility in parents and congenital heart defects in babies, regardless of the assisted reproductive technology method used (IVF, ICSI, or embryo freezing).

The risk of being born with a major heart defect is 36% higher in babies who were conceived after assisted reproductive technology, such as in vitro fertilization (IVF), according to results of a large study published in the European Heart Journal.

Researchers say the finding is important since congenital heart defects are the most common form of birth defects, and some of them are associated with life-threatening complications.

The study also shows that the increase in risk is particularly associated with multiple births which are more common in assisted reproduction.

“Previous research shows that there are increased risks for babies conceived with the help of assisted reproductive technology. These include preterm birth and low birth weight. We wanted to investigate whether the risk of heart defects was higher for babies born following assisted reproduction,” says professor Ulla-Britt Wennerholm from the University of Gothenburg in Sweden who led the study.

Study Overview and Scope 

The research included all liveborn children born in Denmark between 1994 and 2014, all children born in Finland between 1990 and 2014, those born in Norway between 1984 and 2015, and those born in Sweden from 1987 to 2015—more than 7.7 million in total.

Researchers compared data on babies born following assisted reproduction, including IVF, intracytoplasmic sperm injection (ICSI), and embryo freezing, with data on babies conceived naturally.

They assessed how many liveborn children in each group were diagnosed with a major heart defect or with a serious heart defect either in the womb or in the first year of life. They took into account other factors that can increase the risk of congenital heart defects, such as the child’s year of birth, country of birth, mother’s age at delivery, if the mother smoked during pregnancy, or if the mother had diabetes or heart defects.

Risk of Heart Defects in Assisted Reproduction

This showed that heart defects were around 36% more common in babies born after assisted reproduction, compared to babies conceived without such treatment (absolute risk 1.84% versus 1.15%). This risk was similar regardless of the type of assisted reproduction used (IVF or ICSI, fresh or frozen embryos). However, the risk was greater for multiple births following assisted reproduction compared to singleton births following assisted reproduction (2.47% versus 1.62%).

Wennerholm says in a release: “We already know that babies born after assisted reproductive technology have a higher risk of birth defects in general however, we have found a higher risk also in congenital heart defects, the most common major birth defect.

“The fact that the risk of heart defects is similar regardless of the type of assisted reproduction used may indicate that there is some common factor underlying infertility in parents and congenital heart disease in their babies.

“Congenital heart defects can be extremely serious requiring specialist surgery when babies are very young, so knowing which babies are at the greatest risk can help us diagnose heart defects as early as possible and ensure the right care and treatment are given. More and more people are conceiving with the help of assisted reproductive technology, so we might expect to see increases in cases of congenital heart defects worldwide.”

Commentary on Findings

In an accompanying editorial, Dr Nathalie Auger from the University of Montreal Hospital Research Centre in Canada and colleagues say: “Assisted reproductive technology is a popular intervention in reproductive medicine, with these procedures accounting for 2% to 8% of births depending on the country. While most neonates born after assisted reproductive technology are healthy, these procedures are not without risks.

“In one of the largest studies to date, the researchers found that assisted reproductive technology was associated with the risk of major heart defects diagnosed prenatally or up to one year of age.

“Patients who use assisted reproductive technology tend to differ from the general population. These patients may have underlying morbidities that affect both fertility and the risk of heart defects.”

ID 99787479 © Nata3081 | Dreamstime.com