Acknowledgements
We thank Dr Chng Chai Kiat for his assistance in securing funding for this study, Dr Pui Ling Chay and Dr Rahul Nair for their help in oral examination and Dr Nisha Subash Chandran Suyien for providing useful comments to revise the manuscript draft. The continuous and skilful help of the home visitors and the clinical team from the National University Hospital and the K.K Women’s and Children’s Hospital, as well as the database and biostatistics teams, is deeply appreciated.