University of Oxford - National Perinatal Epidemiology Unit (NPEU), Mahatma Gandhi Institute of Medical Sciences, Gauhati Medical College Hospital, Srimanta Sankaradeva University of Health Sciences, Tezpur Medical College and Hospital, Fakhruddin Ali Ahmed Medical College and Hospital (FAAMCH), Mahatma Gandhi Institute of Medical Sciences, Jorhat Medical College and Hospital, Fakhruddin Ali Ahmed Medical College and Hospital (FAAMCH), Banaras Hindu University (BHU) - Institute of Medical Science (IMS), Silchar Medical College and Hospital (SMCH), Nazareth Hospital, Makunda Christian Leprosy and General Hospital, Gauhati Medical College Hospital, Assam Medical College (AMC), Dr Lal PathLabs - National Reference Laboratory, Dr Lal PathLabs - National Reference Laboratory, University of Oxford - National Perinatal Epidemiology Unit, University of Oxford - Department of Population Health, Imperial College London - Department of Haematology, University of Oxford - John Radcliffe Hospital, University of Oxford - National Perinatal Epidemiology Unit, University of Oxford - MRC Population Health Research Unit, University of Oxford - National Perinatal Epidemiology Unit and University of Oxford - National Perinatal Epidemiology Unit