The miracle of modern medicine has reshaped the landscape of the human family. In high-income societies across the globe, the dream of parenthood is increasingly realized through the intervention of science, with assisted reproductive technology now accounting for an estimated 1% to 4% of all births. As procedures like in vitro fertilization and embryo transfer become a standard part of the journey toward starting a family, scientists have begun to turn their attention toward the long-term health of the children born through these remarkable methods. A new chapter in this exploration has emerged from a massive collaborative effort in Taiwan, where researchers have uncovered a subtle but significant pattern in the lives of children conceived through the help of technology.
A Question Lingering in the Air
For years, the scientific community has debated a puzzling question: does the way a child is conceived influence their immune system’s future? Specifically, researchers have looked at atopic diseases—a trio of conditions consisting of asthma, allergic rhinitis, and atopic dermatitis. These conditions are more than just minor inconveniences; childhood asthma, in particular, stands as the most prevalent chronic disease in children. It is a condition that burdens caregivers, reduces school attendance, and diminishes the overall quality of life for the youngest members of society.
The curiosity surrounding this topic is driven by the “developmental origins of health and disease” theory. This concept proposes that factors during the fetal stage can essentially program changes in how organs and tissues function later in life. If the earliest moments of existence take place in a laboratory setting rather than within the body, could those environmental differences leave a lasting mark? Previous studies offered a confusing mosaic of results. Some suggested a higher risk of asthma for children conceived via assisted reproductive technology, while others found no association at all. One 2024 report even found no link, while another suggested that any symptoms might remain mild until adulthood. To clear the fog of these mixed results, researchers knew they needed a perspective that only a massive sample size could provide.
Searching Through a Nation of Data
To find the truth, the research team looked toward the vast data pool of Taiwan, home to 23.5 million people. By weaving together information from the National Health Insurance Research Database, the Assisted Reproduction Database, and the Maternal and Child Health Database, they were able to build a monumental retrospective cohort analysis. They identified 13,957 children conceived through various forms of assisted reproductive technology—including in vitro fertilization, intracytoplasmic sperm injection, and several types of intrafallopian transfers—and matched them with 55,828 children conceived naturally.
The researchers were meticulous, matching the children on a 1:4 ratio based on maternal age, the sex of the newborn, and the month of birth to ensure a fair comparison. They then followed these children for years, tracking the development of the three major atopic conditions. On average, children in the assisted reproductive technology group were followed for nearly eight years for asthma and over five years for allergic rhinitis. This long-term view allowed the team to see how the health of these children unfolded as they grew from infants into students, providing a window into the lived reality of these families.
The Subtle Differences in the Beginning
As the researchers peeled back the layers of the data, they noticed that the two groups of families started their journeys from different baselines. Parents who utilized assisted reproduction were slightly more likely to have their own history of allergies; paternal history of allergic rhinitis was 26.4% in the technology group compared to 22.3% in the natural conception group. The pregnancies themselves often carried more complications. Gestational diabetes, preeclampsia, and eclampsia were more common among those using reproductive assistance.
The birth stories were different, too. A staggering 65.6% of children conceived via assisted reproductive technology were delivered via Cesarean section, compared to 42.0% of those conceived naturally. These children were also much more likely to be part of a multiple birth—30.5% versus a mere 2.0%. Consequently, they were more likely to be born early or at a lower weight. These early life variables created a complex backdrop for the researchers to analyze, as they sought to determine if the technology of conception itself was the driving factor behind later health outcomes.
A Pattern Emerges from the Numbers
When the final tallies were calculated, a clear signal emerged from the data. Even after adjusting for the various differences in parental health and birth circumstances, children conceived via assisted reproductive technology showed a higher risk of developing atopic diseases. The risk was not tied to one specific condition but spanned across the entire spectrum. Specifically, the researchers found an adjusted hazard ratio of 1.13 for asthma, 1.15 for allergic rhinitis, and 1.08 for atopic dermatitis.
The study also looked deeper into the specific types of technology used. They found that the use of intracytoplasmic sperm injection—a procedure where a single sperm is injected directly into an egg—did not seem to significantly change the risk estimates. However, the method of embryo transfer did play a role in one area. Children born from fresh embryo transfers carried a higher risk of allergic rhinitis compared to those born from frozen embryo transfers. Despite these nuances, the overarching theme remained consistent: the path to conception appeared to be linked to a child’s future allergic health.
The Echo of the Earliest Moments
In their final analysis, the researchers were unequivocal about what the data revealed. They concluded that “children conceived via assisted reproductive technology had a higher risk of developing asthma, allergic rhinitis, or atopic dermatitis than children conceived naturally.” This was not merely a statistical quirk but a sustained pattern across different models and conditions. The findings “supported an association between assisted reproductive technology conception and later atopic disease development across the outcomes evaluated.”
While the study provides a definitive link, it also opens the door to new mysteries. The researchers have called for further investigation into the underlying biological mechanisms that might be at play. They want to understand exactly how these early interventions might program the immune system for years to come. For now, the message is one of awareness and vigilance, urging a commitment to the long-term health monitoring of these children as they navigate the world.
Why This Discovery Matters
This research is vital because it provides clarity to millions of families and healthcare providers navigating the world of modern fertility. As assisted reproductive technology becomes a cornerstone of family building in high-income societies, understanding its long-term implications is essential for providing the best possible care for children. By identifying a higher risk for asthma and allergies, this study allows parents and doctors to be more proactive in monitoring respiratory health and skin conditions from an early age.
Furthermore, by utilizing such a massive and comprehensive dataset, the study resolves previous scientific contradictions and provides a more “convincing perspective” on how our earliest developmental stages can influence chronic disease. Ultimately, this work ensures that as we continue to push the boundaries of how life begins, we remain equally dedicated to understanding and supporting how that life flourishes in the years that follow.
More information
Yao-Chi Hsieh et al, Atopic Disease Development in Offspring Conceived via Assisted Reproductive Technology, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.51690
