• Water filters in birth tubs

    Water hygiene and safety in water births

    Where warm water, prolonged stagnation, and complex plumbing systems intersect, significant hygiene challenges can arise. From an infection prevention perspective, the microbiological quality of water used in birthing tubs is critical to safeguarding both mother and newborn – particularly because both are physiologically immunocompromised immediately after delivery.

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    Across Germany in Europe, birthing tubs with volumes of approximately 700 liters (≈185 gallons) are commonly used, with water temperatures maintained between 32–37°C (89.6–98.6°F).

    These conditions – warm water, extended holding times, and complex water systems – can promote the proliferation of opportunistic pathogens such as Pseudomonas aeruginosa and Legionella spp.

    During labor and immediately postpartum, both mother and newborn are at increased risk of infection. Healthcare personnel may also be exposed. Continuous monitoring of water quality and implementation of appropriate infection prevention measures are therefore essential.

    Infection risks in water births

    Clinical studies have demonstrated that birthing tub water can be microbiologically contaminated both before and after delivery.

    Pre-delivery samples have shown contamination with:

    • Legionella spp.
    • Pseudomonas spp.
    • Enterococci

    Post-delivery samples frequently show significantly increased contamination with:

    • Coliform bacteria
    • Escherichia coli

    This increase is primarily due to maternal bodily fluids entering the water during labor.

    Additional studies have shown that Point-of-Use filtration systems can significantly reduce contamination with waterborne pathogens such as Legionella and Pseudomonas.

    Case reports, including those documented by UK public health authorities, highlight that prolonged storage of warm water in birthing pools can lead to severe infections in neonates, including Legionella-associated disease.

    Comparative clinical analyses have also indicated:

    • Higher rates of puerperal fever in mothers after water birth
    • Increased inflammatory markers in newborns

    These findings underline that tap water itself can represent a relevant infection source, particularly when:

    • Warm water is stored prior to use
    • Biofilms develop in pipes, fittings, or hoses
    • Cleaning and disinfection are inadequate
    • Routine microbiological monitoring is lacking

    Regulatory requirements and recommendations

    Germany and Switzerland in Europe

    In Germany, infection prevention in water births is guided by German Society of Hospital Hygiene (DGKH) recommendations, German Society of Gynaecology and Obstetrics e.V. (DGGG) clinical guidelines and national legislation (IfSG).

    Key recommendations include:

    • Permanently installed water supply systems
    • No overflow systems or air jets
    • Connection to hot water circulation systems
    • Regular microbiological testing (at least quarterly)
    • Documentation of results
    • Use of terminal bacterial filters if contamination is detected
    • Strict adherence to filter replacement intervals
    • Proper sterilization of cleaning equipment

    Swiss hospital guidelines further emphasize that water outlets and moist environments may serve as reservoirs for Pseudomonas aeruginosa. Therefore, regular descaling, thermal disinfection, and microbiological testing are essential.

    Evidence-based clinical practice

    United Kingdom in Europe

    In the United Kingdom, water birth is an established component of maternity care and is supported by national guidelines (NICE – National Institute for Health and Care Excellence). For low-risk pregnancies, water immersion during labor is actively recommended as an option. Large cohort studies conducted in National Health Service (NHS) settings have demonstrated that water birth is not associated with increased maternal or neonatal risk when strict clinical protocols are followed.

    However, UK public health authorities clearly emphasize that safety depends on robust infection prevention and water management practices, particularly with regard to Legionella control.

    Special attention is given to:

    • Avoiding pre-filled or pre-heated birthing tubs
    • Preventing water stagnation
    • Ensuring rigorous cleaning and disinfection protocols
    • Monitoring water systems and hygiene parameters

    Infection prevention perspective

    United States

    In the United States of America, there are no uniform national regulations specifically governing water births. However, infection prevention requirements are derived from:

    • CDC water management guidance
    • ASHRAE Standard 188 (Legionella control)
    • AWHONN clinical recommendations

    Healthcare facilities are expected to implement facility-wide water management programs to reduce risks associated with opportunistic pathogens in building water systems.

    Point-of-Use water filters as a preventive measure

    Only water meeting potable water standards and free of pathogenic microorganisms should be used in birthing tubs. Even when baseline water quality is compliant, sterile filtration provides an additional and highly effective layer of protection.

    European studies have demonstrated:

    • Complete elimination of Legionella spp.
    • Significant reduction of Pseudomonas spp.

    The i3 FIVE inline filter enables filtration directly at the point of water supply to the birthing tub, reducing the risk of exposure to waterborne pathogens.

    The i3 ONE Point-of-Use water filter provides an additional level of protection in clinical settings, particularly for:

    • Handwashing stations
    • Water outlets used for neonatal care

    Conclusion

    Water birth can be a safe option when performed under controlled clinical conditions. However, the combination of warm water, potential stagnation, and complex water systems creates a relevant and preventable infection risk.

    The integration of structured hygiene protocols, water management strategies, and sterile filtration represents a critical component of modern infection prevention in obstetric care.

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    We are happy to provide further information and personalized consultation on sterile filtration solutions – non-binding and free of charge. Contact us for more information.

    References

    • Committee Opinion No. 679 Summary: Immersion in Water During Labor and Delivery (November 2016). Obstetrics & Gynecology 128(5):p 1198-1199. | DOI: 10.1097/AOG.0000000000001765

      Lenzen-Schulte, Martina. Nabelschnurverletzungen: Wassergeburten nicht ohne Risiken für Mutter und Kind (Mai 2023). Deutsches Ärzteblatt Ausgabe 24/2023, Deutsches Ärzteblatt International.
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      Evidence Based Birth. The Evidence on: Waterbirth (Originally published on July 8, 2014, and updated on February 14, 2024 by Rebecca Dekker, PhD, RN.). View source

      Hirslanden Gruppe. (o. D.). Wassergeburt im Krankenhaus.
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      Zanetti-Dällenbach R, Holzgreve W, Hösli I, Maertens A. Wassergeburt – ein Infektionsrisiko für Mutter und Kind? (2005). Speculum – Zeitschrift für Gynäkologie und Geburtshilfe 2005; 23 (1)(Ausgabe für Schweiz), 22-22. Speculum – Zeitschrift für Gynäkologie und Geburtshilfe 2005; 23 (1) (Ausgabe für Österreich), 22-26. View source

      Länder-Arbeitskreis zur Erstellung von Hygieneplänen nach § 36 IfSG. Rahmen-Hygieneplan für Entbindungseinrichtungen (Geburtshäuser/Entbindungsheime) (Juni 2005).
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      Bovbjerg ML, Cheyney M, Caughey AB. Maternal and neonatal outcomes following waterbirth: a cohort study of 17 530 waterbirths and 17 530 propensity score-matched land births (2022 May). BJOG. 129(6):950-958. doi: 10.1111/1471-0528.17009. Epub 2021 Dec 1. PMID: 34773367; PMCID: PMC9035022.

      Rabieri J, Uerlings V, Diebold C. Wassergeburt: Hygiene und Kontraindikationen (April 2020, Gültig bis: 31.12.2026). Luzerner Kantonsspital. View source

      Österreichisches Hebammengremium (März 2022). Qualitätssicherung der Hebammenhilfe im außerklinischen Bereich Version 3.0. View source

      Robert Koch-Institut. Wassergeburt – mobile Gebärwannen (Juli 2014). View source

      Johannes O. Geburtshaltungen und Wassergeburt (August 2015). Springer Medizin.
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      Thöni A, Moroder L, Mayr S. Die Kontamination des Wassers und die Infektionsrate bei der Wassergeburt (2007). Z Geburtshilfe Neonatol 2007; 211 – PO_02_11 DOI: 10.1055/s-2007-1002914
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      AG Ver- und Entsorgung der DGKH. Leitlinie: Hygienisches Management bei Wasserentbindungen (Dezember 2002). Deutsche Gesellschaft für Krankenhaushygiene. View source

      Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e.V., Deutsche Gesellschaft für Hebammenwissenschaft. S3-Leitlinie “Die vaginale Geburt am Termin” Version 1.0 (Dezember 2020). AWMF-Register Nr. 015/083. View source

      Additional information from United Kingdom (Europe):

      National Institute for Health and Care Excellence (NICE). (2023). Intrapartum care (NG235).
      Public Health England. (2014). Legionnaires’ disease and birthing pools.

      Royal Cornwall Hospitals NHS Trust. (n.d.). Waterbirth and the use of water during labour – Clinical guideline.

      NHS Borders. (n.d.). Pool use in labour and birth – Clinical guideline.
      Milton Keynes University Hospital NHS Foundation Trust. (2022). Water birth guideline.

      Additional information from United States:

      Centers for Disease Control and Prevention (CDC). (2021). Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings.

      ASHRAE. (2018). Standard 188: Legionellosis: Risk Management for Building Water Systems.
      Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN). (2016). Immersion in water during labor and birth (Position Statement).