Maternal Diabetes in Pregnancy Linked to High Refractive Error in Children's Eyes

By Linda Carroll

August 24, 2021

(Reuters Health) - Children of mothers who have diabetes before or during pregnancy are more likely to develop high refractive error eye disorders later in life, a new study suggests.

An analysis of data from more than 20,000 children in Denmark followed for as long as 25 years revealed that prenatal exposure to maternal diabetes was associated with a 39% increased risk of eye conditions such as nearsightedness, farsightedness and astigmatism compared with unexposed children, according to the results published in Diabetologia.

Maternal diabetes complications during pregnancy increased the risk even further (hazard ratio 2.05), versus children of mothers with diabetes but no diabetic complications (HR 1.18), the registry study found.

Our findings suggest that maternal diabetes during pregnancy is associated with an increased risk of high refractive error in offspring, in particular among those of mothers with diabetic complications," said Yongfu Yu, a researcher in the department of biostatistics at the School of Public Health at Fudan University in China and the department of clinical epidemiology at Aarhus University in Denmark, and Dr. Jiangbo Du, an associate professor in the department of epidemiology at the School of Public Health at the State Key Laboratory of Reproductive Medicine at Nanjing Medical University in China.

"Early ophthalmological screening should be recommended in offspring of mothers with diabetes diagnosed before or during pregnancy," Yu and Dr. Du said in an email. "As much of refractive error in young children is treatable, early identification and intervention can have a lifelong positive impact," they noted.

"Therefore, although the 39% increased risk observed in our study is a relatively low effect size, from a public health perspective, considering the high global prevalence of refractive errors, any tiny improvement in this low-risk preventable factor will contribute to a huge reduction in absolute incidence of refractive errors," the researchers said. "Thus, the value of early ophthalmological screening should be evaluated in offspring of mothers with diabetes, especially with diabetic complications, before or during pregnancy for their eyesight health in the future."

It's already known that hyperglycemia contributes to the development of high refractive error in adult diabetics, and that children born to mothers with gestational diabetes have increased rates of high refractive error, the authors note in their report.

To explore the possible impact of diabetes during pregnancy on child eye health, the researchers used Danish national registers, focusing on 2,470,580 live births in Denmark from 1977 to 2016. Follow-up started from birth and ended at the first occurrence of a high refractive error (RE) diagnosis, death, emigration, 31 December 2016, or offspring's 25th birthday, whichever came first.

Exposure included maternal diabetes during or before pregnancy (type 1 diabetes, type 2 diabetes and gestational diabetes).

During follow-up, 553 offspring of mothers with diabetes and 19,695 offspring of mothers without diabetes were diagnosed with high refraction errors (RE). Prenatal exposure to maternal diabetes was associated with increased risk of RE (HR 1.39). Standardized cumulative incidence in unexposed offspring at 25 years of age was 1.18%, and in exposed offspring, 1.90%.

The elevated risks were observed for hypermetropia (HR 1.37), myopia (HR 1.34), and astigmatism (HR 1.58).

The new study is "very interesting," said Dr. Tamiesha Frempong, an assistant professor of ophthalmology at the Icahn School of Medicine at Mount Sinai in New York City, and a pediatric ophthalmologist at the New York Eye and Ear Infirmary of Mount Sinai.

"We already knew that babies born to diabetic mothers, particularly women with type one diabetes can have problems with the optic nerve, which can result in inferior field loss, or blind spots," Dr. Frempong said. "In this study, when they compared the offspring of mothers with diabetes to those from mothers without diabetes, there was a tremendous difference."

Clinically, this means that babies with diabetic mothers should be examined early, Dr. Frempong said. If they have high RE, then they can be fitted with glasses which can help them attain normal vision, she added.

How early?

"I wouldn't necessarily put them on a newborn," Dr. Frempong said. "Babies see about 20/400 at birth. And they sleep a lot."

"But certainly by the time they are 6 months old you can put them in glasses," Dr. Frempong said.

SOURCE: Diabetologia, online August 17, 2021.