A recent study published in the Journal of VitreoRetinal Diseases examined whether maternal asthma history was associated with retinopathy of prematurity (ROP) severity in preterm infants.
Let’s start with the basics.
ROP is a potentially vision-threatening retinal disease that develops when retinal blood vessels develop abnormally after early birth, severe cases can lead to scarring, retinal detachment, and permanent vision loss.
And while clinicians have long recognized that the strongest ROP risk factors are early gestational age and low birth weight, researchers have continued looking for additional prenatal and maternal factors that may help identify which infants are most likely to develop severe disease.
… which brings us to this new research?
Indeed. A recent study published in the Journal of VitreoRetinal Diseases examined whether maternal asthma history was associated with ROP severity in preterm infants.
The researchers found that infants born to mothers with asthma had higher odds of developing type 1 ROP, type 2 ROP, and ROP requiring treatment.
Now, why would maternal asthma matter for ROP?
Maternal asthma is relevant because asthma during pregnancy has been associated with adverse perinatal outcomes, especially when disease is more severe or poorly controlled.
Case in point: Prior research has linked maternal asthma severity and exacerbations with outcomes such as low birth weight, preterm birth, and small-for-gestational-age infants.
Because fetal oxygenation, placental function, inflammation, and infant growth may all influence neonatal outcomes, researchers wanted to know whether maternal asthma could also help predict severe ROP risk.
So what exactly did the researchers study?
The investigators performed a retrospective observational study using records from the University of Colorado ROP registry.
They reviewed infants screened for ROP between January 2006 and February 2024 and evaluated whether maternal asthma history was associated with several ROP outcomes, including:
- ROP stage
- ROP zone
- ROP type
- Need for treatment
The researchers used multinomial logistic regression to calculate odds ratios and performed multivariable analyses controlling for birth weight and gestational age.
Who participated in the study?
The study population came from the University of Colorado ROP registry, which included infants screened for ROP at participating Colorado institutions over an 18-year period.A total of 2,237 preterm infants met inclusion criteria based on birth weight and gestational age—and of those infants, 301 (13.5%) had mothers with a history of asthma.
Well, what did the researchers find?
Among infants with a maternal asthma history:
- 23 infants (7.6%) developed type 1 ROP
- 28 infants ( 9.3%) required treatment
After adjusting for birth weight and gestational age, maternal asthma remained associated with higher odds of more severe ROP outcomes.
Go on …
Compared with infants whose mothers did not have asthma, infants with maternal asthma history had:
- 2.39 higher odds of developing type 1 ROP
- 2.14 higher odds of developing type 2 ROP
- 1.87 higher odds of requiring treatment
In other words: Maternal asthma was associated with treatment-warranted ROP even after accounting for two of the most important baseline risk factors: birth weight and gestational age.
Why is that clinically important?
The findings matter because ROP screening already depends heavily on risk stratification—as current screening guidance for premature infants focuses largely on birth weight, gestational age, and clinical course.
And while those factors remain essential, this study suggests that maternal history may also provide useful context when clinicians are trying to identify infants who deserve especially close monitoring.
What might explain the association?
The study was not designed to prove why maternal asthma was linked with higher ROP risk, but there are biologically plausible possibilities:
- Asthma during pregnancy can affect maternal oxygenation, inflammation, and placental physiology
- Studies have also examined how maternal asthma may influence placental vascular function and fetal growth
Those pathways could theoretically affect retinal vascular development in preterm infants.
What else?
The authors also noted that inflammation may be relevant.
Prior studies have suggested that immune and inflammatory biomarkers may play a role in ROP risk, which could help explain why maternal inflammatory conditions deserve further attention.
Still, this remains a hypothesis. The current study found an association—not a confirmed mechanism.
Are there any limitations to keep in mind?
There are several important limitations.
First: This was a retrospective observational study, so it cannot prove that maternal asthma directly caused more severe ROP.
Second: Maternal asthma was identified through chart review, which means the analysis depended on documentation quality in clinical notes.
Third: The study did not fully characterize asthma severity, asthma control, medication adherence, or exacerbation frequency during pregnancy.
- That makes it difficult to determine whether the increased risk was related to asthma itself, uncontrolled disease, treatment patterns, or other associated factors
The findings also came from a single institutional registry, so additional studies in other populations will be needed to confirm whether the association holds more broadly.
What do the experts say?
The researchers concluded that maternal asthma was associated with treatment-warranted ROP in this Colorado cohort.
- Their findings suggest that maternal asthma history could eventually become part of a broader risk assessment for preterm infants, particularly if future studies validate the association in other settings.
But for now, the study supports a more cautious clinical interpretation: Infants born to mothers with asthma may deserve close ophthalmic attention, especially when other ROP risk factors are present.
Anything else worth noting?
One important point: This study should not be interpreted as a reason for pregnant patients to stop asthma treatment.
Rather, the unanswered question is whether better asthma control during pregnancy could reduce the risk of severe ROP in preterm infants.
This study raises that possibility, but it does not prove it.
And now for the take home.
This retrospective study found that preterm infants born to mothers with asthma had higher odds of developing type 1 ROP, type 2 ROP, and ROP requiring treatment.
The findings do not prove causation, and more research is needed to understand the mechanism. However, maternal asthma may represent an additional clinical clue when evaluating severe ROP risk in premature infants.