New Delhi, Nov 1 : Children born to mothers who had Covid-19 while pregnant may be at a high risk of suffering from developmental disorders, including speech delays, autism, and motor disorders, by the time they turn 3 years old, according to new research.

Researchers from the Mass General Brigham in the US explained that these may be due to immune activation during pregnancy, which disrupts normal foetal brain development.

'These findings highlight that Covid-19, like many other infections in pregnancy, may pose risks not only to the mother, but to foetal brain development,' said Andrea Edlow, Maternal-Foetal Medicine specialist in the Department of Obstetrics and Gynaecology at Mass General Brigham. The findings, published in the journal Obstetrics and Gynecology, are based on an analysis of 18,124 live births during the peak Covid window of March 2020 to May 2021.

The team studied 18,124 mother-child pairs. Among the 861 children whose mothers were SARS-CoV-2-positive during pregnancy, 140 (16.3 per cent) received a neurodevelopmental diagnosis by 3 years of age, compared with 1,680 (9.7 per cent) of the 17,263 remaining children from SARS-CoV-2-negative pregnancies.

After adjusting for other influencing factors, SARS-CoV-2 infection during pregnancy was associated with 29 per cent higher odds of a neurodevelopmental condition in children.

The investigators also found that males were at higher risk than females. Risk was greatest when infection occurred during the third trimester of pregnancy.

The study also supported the importance of trying to prevent Covid infection in pregnancy, particularly when public trust in vaccines -- including the Covid-19 vaccine -- is being eroded.

While reducing risk is important, 'the overall risk of adverse neurodevelopmental outcomes in exposed children likely remains low,' said co-senior author Roy Perlis, of the Mass General Brigham Department of Psychiatry.

/IANS