{
  "abstract": "Introduction Climate change has led to extreme heat events, disproportionately affecting vulnerable populations. Heat stress during pregnancy is linked to adverse health outcomes, yet the biological mechanisms remain poorly understood. This research study aims to investigate the effect of environmental heat on maternal, fetal and infant health and examine the biological pathways linking heat stress to adverse pregnancy outcomes.Methods and analysis This prospective cohort study will recruit 6000 pregnant women from three districts in Sindh, Pakistan. Eligible participants ≥18 years old, will have a minimum of five scheduled visits from <14 weeks’ gestation and will be followed up to 12 months postpartum. Primary outcomes include low birth weight and small vulnerable newborns (SVN); secondary outcomes include preterm birth, small for gestational age (SGA), miscarriage, stillbirth, and composite maternal and neonatal morbidity and mortality. Fetal ultrasound scans with Doppler assessments will be performed at each visit to measure fetal growth, uteroplacental and fetoplacental circulation. Each woman’s heat exposure will be measured using wearable sensors and heat strain biomarkers. In a subset of 1000 women, maternal heart rate, skin temperature sleep patterns and physical activity will be monitored throughout pregnancy using wearable devices. Time-varying, distributed lag and non-linear models will examine associations between heat stress indices and pregnancy outcomes.Ethics and dissemination The study has received ethical approval from the Aga Khan University (AKU) (Ref: 26249) and the Pakistan National Bioethics Committee (Ref: 1065/23/1736). Written informed consent will be obtained from all participants before enrolment. Referral pathways to healthcare facilities will be established to ensure timely management of pregnancy complications. Findings will be disseminated through peer-reviewed publications, scientific conferences, and engagement with policymakers and public health stakeholders to inform climate-resilient maternal health strategies. Results will also be shared with participants and communities through meetings and informal sessions to raise awareness and support evidence-based heat adaptation.Trial registration number NCT01234567.",
  "authors": [
    {
      "affiliations": [
        "Institute for Global Health and Development, The Aga Khan University, Karachi, Sindh, Pakistan",
        "Department of Paediatrics and Child Health, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Jai K Das"
    },
    {
      "affiliations": [
        "Institute for Global Health and Development, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Asma Abdul Malik"
    },
    {
      "affiliations": [
        "Nuffield Department of Women’s & Reproductive Health, University of Oxford, Oxford, Oxfordshire, UK",
        "Oxford Maternal and Perinatal Health Institute, Green Templeton College, University of Oxford, Oxford, Oxfordshire, UK"
      ],
      "name": "Aris T Papageorghiou"
    },
    {
      "affiliations": [
        "Institute for Global Health and Development, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Suneel Piryani"
    },
    {
      "affiliations": [
        "Institute for Global Health and Development, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Mahnaz Ambareen"
    },
    {
      "affiliations": [
        "Department of Obstetrics and Gynaecology, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Nadeem Zuberi"
    },
    {
      "affiliations": [
        "Department of Obstetrics and Gynaecology, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Zaheena Islam"
    },
    {
      "affiliations": [
        "Department of Obstetrics and Gynaecology, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Nuruddin Mohammed"
    },
    {
      "affiliations": [
        "Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada"
      ],
      "name": "Narjis Fatima Hussain"
    },
    {
      "affiliations": [
        "Department of Medicine, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Zainab Samad"
    },
    {
      "affiliations": [
        "Department of Medicine, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Farhala M Baloch"
    },
    {
      "affiliations": [
        "Section of Pediatric Surgery, Department of Surgery, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Saqib Qazi"
    },
    {
      "affiliations": [
        "Institute for Global Health and Development, The Aga Khan University, Karachi, Sindh, Pakistan",
        "Department of Paediatrics and Child Health, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Arjumand Rizvi"
    },
    {
      "affiliations": [
        "Department of Paediatrics and Child Health, The Aga Khan University, Karachi, Sindh, Pakistan",
        "Centre of Excellence in Women and Child Heath, The Aga Khan University, Karachi, Pakistan"
      ],
      "name": "Imran Ahmed Chauhadry"
    },
    {
      "affiliations": [
        "Department of Paediatrics and Child Health, The Aga Khan University, Karachi, Sindh, Pakistan",
        "Nutrition Research Laboratory, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Junaid Iqbal"
    },
    {
      "affiliations": [
        "Division of Cardiothoracic Sciences, Sindh Institute of Urology and Transplantation, Karachi, Sindh, Pakistan"
      ],
      "name": "Shazia Samad Mohsin"
    },
    {
      "affiliations": [
        "Division of Cardiothoracic Sciences, Sindh Institute of Urology and Transplantation, Karachi, Sindh, Pakistan"
      ],
      "name": "Fatima Ali"
    },
    {
      "affiliations": [
        "Department of Obstetrics and Gynaecology, The Aga Khan University Hospital, Karachi, Sindh, Pakistan"
      ],
      "name": "Lumaan Sheikh"
    },
    {
      "affiliations": [
        "Nutrition Research Laboratory, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Kehkashan Begum"
    },
    {
      "affiliations": [
        "Nutrition Research Laboratory, The Aga Khan University, Karachi, Sindh, Pakistan"
      ],
      "name": "Rabia Zuberi"
    },
    {
      "affiliations": [
        "Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK"
      ],
      "name": "Simon Cousens"
    },
    {
      "affiliations": [
        "Nuffield Department of Women’s & Reproductive Health, University of Oxford, Oxford, Oxfordshire, UK",
        "Oxford Maternal and Perinatal Health Institute, Green Templeton College, University of Oxford, Oxford, Oxfordshire, UK"
      ],
      "name": "Stephen Kennedy"
    },
    {
      "affiliations": [
        "Institute for Global Health and Development, The Aga Khan University, Karachi, Sindh, Pakistan",
        "Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada"
      ],
      "name": "Zulfiqar Ahmed Bhutta"
    }
  ],
  "title": "Biological impacts of rising temperatures on maternal, fetal and newborn health: protocol for a cohort study (BIRTH-Cohort)",
  "uid": "c6c17ab0-2cb9-52cd-b142-ad1e30307228"
}