Cold water swimming has increased in popularity in recent years, with risks and benefits increasingly well documented. Now a first-of-its-kind study has focused specifically on the safety of the pastime during pregnancy - and is taking steps to fill the gap in evidence.
The research aimed to answer questions related to the impact of water temperature on the mother and fetal development, as well as whether water quality could harm the baby.
Comprising a group of cold water and exercise physiologists, and specialists in fertility, obstetrics, neonatology, midwifery, water epidemiology and public health, the research team set about finding evidence from existing studies to answer questions that women had asked.
They found just six published studies worldwide relating to pregnant people and cold water swimming and of that number, no study had taken place in a large enough group to offer significant insight, with the studies highlighting large gaps in knowledge.
The new research, published in the journal Lifestyle Medicine, contains a list of expert-led recommendations for pregnant people, based on the expertise of the authors involved.
Carmel Lawless, who lives in Plymouth, enjoyed cold water swimming, and planned to continue the pastime when she became pregnant in 2022. However, the lack of research meant she felt guilt every time she went - so she welcomed the new study and future plans.
She said: "There are so many physical and mental health benefits to sea swimming that I didn't want to stop but I felt guilty and irresponsible every time I entered the water. It was reassuring yet frustrating that I - along with others seeking to swim outdoors during pregnancy - were all being told to abstain not necessarily because it was too dangerous but because there wasn't enough evidence of what the risks might be.
"More research would enable us to have open conversations with healthcare professionals, make informed decisions and minimise the risk to ourselves and our children."
This paper provides an overview of the available evidence and offers practical guidance for those who are pregnant or considering cold water swimming during pregnancy.
Dr Heather Massey, University of Portsmouth's School of Psychology, Sport, and Health Science
Dr Heather Massey , from the University of Portsmouth's School of Psychology, Sport, and Health Science , has been researching the effects of outdoor swimming for several years . She said: "As outdoor swimming continues to rise in popularity, we've received numerous inquiries about pregnancy and cold water swimming. This paper provides an overview of the available evidence and offers practical guidance for those who are pregnant or considering cold water swimming during pregnancy."
The recommendations include advice to only swim in cold water during pregnancy if a person is a regular cold water swimmer before pregnancy; do not swim alone; and avoid cold water swimming altogether if blood pressure is raised or very low.
The authors highlight that these are informed, consensus-led expert opinions in the absence of specific studies, and underline the need for further research.
Dr Malika Felton, Senior Lecturer in Health and Exercise Physiology at Bournemouth University , said: "Living and working by the coast in Bournemouth, we can see the popularity of cold water swimming increasing year by year and therefore it is unsurprising that women who are getting pregnant have many questions about whether it is safe to continue this activity during their pregnancy.
"At this stage with the existing knowledge, we are not recommending pregnant women start cold water swimming if they have no previous experience, but if women are already taking part in cold water swimming or immersion then this work outlines the suggested extra considerations to be aware of should they continue to participate during pregnancy."
The authors highlight that these are informed, consensus-led expert opinions in the absence of specific studies, and underline the need for further research.
Professor Mike Tipton MBE , co-founder of the University of Portsmouth's Extreme Environments Lab (EEL) , said: "This review is an important first step in establishing what is known and what advice can be given to those wanting to continue their open cold water swimming pastime during pregnancy. We have formed a research group, SWIMHER, to try and advance this area and the quality of the advice that can be provided."
The study was co-authored by researchers from the University of Plymouth, University of Portsmouth; Bournemouth University; University College London; Royal Sussex County Hospital; University Hospitals Sussex; Scottish Environment Protection Agency; Brighton and Sussex Medical School; the Bluetits Chill Swim Ltd, and Chelsea and Westminster NHS Foundation Trust.
