The treatment is almost beside the point.
As more families turn to medical science to fulfill the hope of parenthood, a large American study gently redirects our attention: it is not the path taken to conception, but the underlying terrain of parental fertility itself, that appears connected to subtle differences in how some children develop. Tracking over fifteen thousand mother-child pairs across the United States, researchers found small but measurable shifts in behavior and developmental traits among children born to parents who had struggled to conceive—shifts that persisted even when no fertility treatment had been used at all. The findings invite a deeper reckoning with what infertility may signal about the biological and environmental inheritance parents pass on, long before any medical intervention begins.
- Children born to parents with fertility challenges showed measurably higher rates of behavioral problems, autism-like traits, and ASD diagnoses—even when conceived without any treatment.
- Non-IVF fertility treatments were linked to higher ADHD odds, while IVF—the most scrutinized intervention—showed no clear neurodevelopmental association, complicating simple cause-and-effect narratives.
- The study's scale, spanning 15,382 mother-child pairs across 44 sites, finally gave researchers enough statistical power to separate the effects of infertility itself from the effects of the treatments designed to address it.
- Scientists now point toward the underlying conditions driving infertility—genetic, environmental, or biological—as the more likely source of these developmental differences, shifting focus away from treatment risk.
- The differences observed were small, not catastrophic, but their consistency across a large and diverse cohort suggests they are real signals worth continued investigation as fertility treatment becomes ever more common.
A large NIH-funded study has found that children born to parents who struggled to conceive show subtle but measurable differences in behavior and development—and that these differences appear rooted in the fertility challenges themselves, not in the treatments used to overcome them.
Researchers examined data from 15,382 mother-child pairs across 44 sites in the United States and Puerto Rico, tracking developmental outcomes from ages two to ten. Pregnancies were sorted by fertility history: infertility diagnoses, fertility treatments, repeated miscarriages, or simply longer-than-expected conception times. Children's outcomes were assessed through parent questionnaires and clinical diagnoses of autism spectrum disorder and ADHD.
The pattern that emerged was specific and consistent. Children of parents with fertility challenges scored higher on behavioral problem assessments, displayed more autism-like traits, and had elevated odds of an ASD diagnosis—even when conceived without any fertility treatment. This pointed away from medical intervention as the cause and toward something inherent in the parents' underlying fertility struggles.
A closer look at treatment types added nuance. Non-IVF treatments, such as ovulation-stimulating medications or intrauterine insemination, were associated with higher ADHD odds. IVF, by contrast, showed no clear neurodevelopmental link—a distinction that further supported the idea that the treatments themselves were not the driving factor.
Previous research had been too limited to disentangle infertility from its treatments. This study, published in JAMA Network Open, offered the scale needed to make that separation. Researcher Linda Kahn of NYU Langone Health stressed that the findings should not alarm families who pursued treatment, but rather direct scientific attention toward the genetic, environmental, or biological conditions that made treatment necessary in the first place.
A large study tracking thousands of American families has found that when parents struggle to conceive, their children show subtle but measurable differences in behavior and development—differences that appear to stem from the underlying fertility challenges themselves rather than from the treatments used to overcome them.
Researchers at the National Institutes of Health examined data from 15,382 mother-child pairs across 44 study sites in the United States and Puerto Rico, looking for connections between parental fertility history and how children developed between ages two and ten. The work was funded through the ECHO Program, an initiative designed to understand how environmental and biological factors shape childhood health. The team combined medical records with parent surveys to sort pregnancies into categories: those where parents had infertility diagnoses, those involving fertility treatments, those marked by repeated miscarriages, and those where conception simply took longer than expected. They then tracked children's behavioral and developmental outcomes using parent questionnaires and clinical diagnoses of autism spectrum disorder and attention-deficit/hyperactivity disorder.
The findings were striking in their specificity. Children born to parents who had faced fertility challenges showed measurably higher scores on behavioral problem assessments. They displayed more autism-like traits. They had higher odds of receiving an autism spectrum disorder diagnosis—and this pattern held true even when those children had been conceived without any fertility treatment at all. The association suggested something about the parents' underlying fertility struggles themselves, not the medical interventions, was connected to these developmental differences.
When the researchers looked at different types of treatment, a more nuanced picture emerged. Children conceived through non-IVF fertility treatments—such as medications to stimulate ovulation or intrauterine insemination—showed higher odds of an ADHD diagnosis compared to children conceived naturally. But in vitro fertilization, the most intensive and widely discussed fertility treatment, showed no clear connection to neurodevelopmental outcomes in this analysis. That distinction mattered. It suggested that the treatment itself was not the culprit; rather, something about the underlying conditions that made certain treatments necessary appeared to be the relevant factor.
The research fills an important gap. As fertility treatments have become more common, questions have mounted about their long-term effects on children. Previous studies had been too small or too limited to separate the effects of infertility itself from the effects of the treatments meant to address it. This analysis, drawing on data from a large and diverse cohort, allowed researchers to make that distinction with more confidence. The differences they found were small—not dramatic developmental delays or widespread diagnoses, but measurable shifts in behavior and traits that could accumulate over time.
Linda Kahn, a researcher at NYU Langone Health and part of the ECHO team, emphasized what the findings did not show: that infertility treatment itself was independently driving these outcomes. Instead, the evidence pointed toward the parents' underlying fertility problems—whether rooted in genetics, environmental exposures, or other biological factors—as the likely source of the associations. The study, published in JAMA Network Open, adds to a growing body of research suggesting that the treatments families choose to pursue parenthood are not themselves the cause of concern. The concern, if there is one, lies in the conditions that made treatment necessary in the first place.
Notable Quotes
The evidence suggests that infertility treatment itself is not independently associated with child neurodevelopment outcomes. Rather, the parents' underlying fertility problems—whether stemming from genetic, environmental, or other influences—are likely driving these associations.— Linda Kahn, PhD, ECHO researcher, NYU Langone Health
The Hearth Conversation Another angle on the story
Why does it matter whether the fertility challenges themselves, rather than the treatments, are driving these developmental differences?
Because it changes what we're actually worried about. If IVF or other treatments were causing problems, we'd need to reconsider how we use them. But if the underlying infertility is what's connected to these outcomes, then the real question becomes: what biological or environmental factors are affecting both the parents' fertility and the children's development?
So the parents and children might share something in common—genetically or otherwise?
Exactly. If a parent has a genetic condition affecting fertility, that same genetic factor could influence how their child's brain develops. Or if environmental exposures affected the parent's reproductive system, those same exposures might affect the child. The treatment is almost beside the point.
But the study did find that non-IVF treatments were linked to higher ADHD odds. Doesn't that suggest the treatment matters?
It's more complicated than that. Non-IVF treatments are often used for different types of fertility problems than IVF is. So you're not really comparing the treatment itself—you're comparing the underlying conditions that made different treatments necessary. The treatment is a marker, not the cause.
What about the families who used IVF? Should they feel reassured?
The data suggests they should, yes. IVF showed no clear association with neurodevelopmental outcomes. But the broader message is that all these families—whether they conceived naturally or with help—are dealing with underlying biological realities that may influence their children's development. The reassurance isn't that treatment is safe; it's that treatment isn't making things worse.