Evaluating the association between household water, sanitation and hygiene (WASH) and selected placenta-related complications in The Gambia, Kenya and Mozambique

Abstract Placenta-related complications such as pre-eclampsia, small-for-gestational-age (SGA) and stillbirth contribute significantly to maternal and perinatal mortality globally, with the highest burden in low– and middle-income countries (LMICs). The potential impact of inadequate access to household water, sanitation, and hygiene (WASH) on these outcomes has not been quantified. This study investigates the association between household WASH conditions and pre-eclampsia, stillbirth and SGA in The Gambia, Kenya, and Mozambique, where access to safe WASH services remains a challenge. This study is nested within the PRECISE (PREgnancy Care Integrating Translational Science, Everywhere) study, a prospective observational cohort including 5,745 unselected pregnant women. Multivariate logistic regression analysis was used to test the associations between household WASH and pre-eclampsia, SGA or stillbirth. Compared to women with piped water in their homes, those relying on other improved water sources had higher odds of experiencing selected placenta-related complications (adjusted odds ratio (aOR) 1.36 [95% confidence interval (CI) 1.18, 1.57], p < 0.001). Country-specific analyses revealed differences across settings. In both The Gambia (1.52 [1.03, 2.24], p = 0.034) and Kenya (1.29 [1.04, 1.59], p = 0.019), the use of other improved water sources was associated with increased odds of selected placenta-related complications. Unimproved sanitation, compared with improved sanitation, was associated with increased odds of selected placenta-related complications in Mozambique (1.35 [1.02, 1.80], p = 0.038). The findings highlight the role of household-level WASH conditions as potential risk factors for placenta-related complications. Even when water sources are improved, contamination can occur during collection, transport and storage, while unimproved sanitation can increase pathogen exposure. These results underline the need for targeted WASH interventions to reduce pregnancy-related risks. Addressing these gaps could significantly reduce the prevalence of placenta-related complications, contributing to improved maternal and neonatal health outcomes in LMICs. Future research should explore the mechanisms linking WASH to pre-eclampsia, SGA and stillbirth and other placenta-related complications, and assess the effect of comprehensive WASH interventions. Competing Interest Statement The authors have declared no competing interest. Funding Statement Funding The PRECISE Network is funded by the UK Research and Innovation Grand Challenges Research Fund GROW Award scheme (grant number: MR/P027938/1). PRECISE-DYAD is funded by the NIHR–Wellcome Partnership for Global Health Research Collaborative Award, reference 217123/Z/19/Z. The laboratory analysis in Kenya and Mozambique for the COVID-19 studies was funded by periCOVID Africa, part of the EDCTP2 program supported by the European Union (grant no: RIA2020EF-2926). The PRECISE cohort extension in Kenya after January 2022 was funded by the Office of The Director, National Institutes of Health, the National Institute of Biomedical Imaging and Bioengineering, the National Institute of Mental Health and the Fogarty International Center of the National Institutes of Health under award number U54TW012089. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Research Ethics Committee of King's College London, United Kingdom, gave ethical approval for this work (approval references HR-17/18-7855 and HR-20/21-19714). The Joint Ethics Committee of The Gambia Government and the Medical Research Council Unit The Gambia, The Gambia, gave ethical approval for this work (approval references SCC 1619 and SCC 22843). The Research and Ethics Committee of Aga Khan University Hospital, Nairobi, Kenya, gave ethical approval for this work (approval references 2018/REC-74 and 2021/IERC-08). The Institutional Bioethics Committee of the Centro de Investigacao em Saude de Manhica, Manhica, Mozambique, gave ethical approval for this work (approval reference CCI/044/OUT/2024). The National Bioethics Committee for Health (Comite Nacional de Bioetica para a Saude) of the Ministry of Health, Maputo, Mozambique, gave ethical approval for this work (approval references 545/CNBS/18 and 655/CNBS/20). All participants provided written informed consent before taking part in the study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability The data that support the findings of this study are available from the Research Programme Manager MLV, marie-laure.volvert{at}kcl.ac.uk, on reasonable request. The guidelines for data and sample access requests for the PRECISE network can be found here: https://precisenetwork.org/precise/data-and-sample-access/