Water contamination and the rate of infections for water births

A. Thoeni*, F. Ploner and N. Zech 2008

Department of Gynaecology and Obstetrics, District Hospital of Vipiteno, Northern-Italy 


Objective: The potential for increased risks of infection is an important concern with water births.

We performed microbiological analyses on water samples taken from birthing pools before and after water births, and compared the rate of neonatal infection arising after water births with that arising after conventional delivery.

Materials and Methods:

In this prospective observational study beginning in 2001, water from the delivery pool was analyzed to determine the prevailing microorganisms.

Two water samples were taken at each delivery.

The first sample (sample A) was taken after the tub was filled with tap water; the second sample (sample B) was taken after the delivery.

The high rate of water contamination with Legionella pneumophila and Pseudomonas aeruginosa led us to install a filter system (Aquasafe –FilterR) into the supply hose for the birthing pool to reduce the water contamination.

This intervention significantly reduced the total microbial loading and there was no longer evidence of Legionella pneumophila.

Furthermore, we determined the rate of neonatal infections in infants delivered in water and compared it with those delivered conventionally out of the water.


Samples were obtained from 300 out of a total of 1,625 water deliveries, which took place between 2001 and 2007. Before the installation of a filter system, 29% of the A-samples showed bacterial growth with Legionella pneumophila,
22% with Pseudomonas aeruginosa, 18% with enterococci, 32% with coliforms, and 8% with Escherichia coli.

After the installation of the filter system, the water contamination decreased considerably:
– there were no further signs of Legionella bacteria, and Pseudomonas aeruginosa was found in only 3% and coliforms in 13% of the samples, respectively.

By comparing the microbiological composition of the B-samples before and after installation of the filter system, we concluded that the intervention did not influence the microbial loading of the water, which occurred during and as a result of
the whole delivery phase.

The microbiological loading of the water in the birthing pool after it was filled may have partly originated from the insufficient cleaning and disinfections of the birthing pool and after changing the cleaning records there was no longer any evidence of a significant microbial count (unpublished data).

Of the B-samples, 82% contained large amounts of coliforms, 64% contained Escherichia coli with concentrations of up to 105 CFU/100 mL, and 8-12% contained Pseudomonas aeruginosa.

Staphylococcus aureus and Candida spp were also
present in moderate amounts.

The rate of neonates treated with antibiotics for suspected infection on the basis of clinical symptoms (tachypnoea, skin color) or laboratory findings (CRP rise, leukocytosis) was 1.05% after water births (17 out of 1,625) compared with
1.75% (20 out of 1,139) after conventional delivery (p<0.05).


Based on our results and the literature, water birth is a valuable alternative to traditional delivery when certain criteria are met and risk factors are excluded.

During water birth, faeces are discharged into the pool and the water is
contaminated with a variety of microorganisms.

However, contamination of the water with such microorganisms seems not to translate into an increased risk of neonatal infection.

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Watford General Hospital: Cleaning & disinfecting water birth pool and surrounding area

Watford General Hospital

Before use

The pool needs to be cleaned every 24 hours, as per instructions below. On completion The Pool Cleaning Record is signed by the member of staff performing the procedure.

Prior to each use and every 24 hours (to coincide with the daily pool cleaning), the pool taps need to be run for 2 minutes, as per water flushing guidelines.

After Use

1. Use the standard infection control precautions (plastic apron, disposable gloves and eye protection) when cleaning the pool. Ensure the area is well ventilated.

2. Remove any debris from the pool, using the sieve, before emptying the pool (to prevent debris blocking the pool outlet). Please ensure the thermometer has been removed from the pool prior to empyting the pool, in order not to block the pool outlet.

3. Use a non-abrasive detergeant to clean the pool of any further debris and blood; ensure the tap is cleaned first, so as not to transfer micro-organisms from the “dirty” pool area to the cleaner tap region. Please see guidance on cleaning sinks/basins and taps below. Rinse well with warm water.

4. Ensure the pool tap outlet is turned to “closed” prior to cleaning the pool tap and pool area with the chlorclean solution (2 tablets in 2 litres of cold water).

5. Clean the pool tap first prior to cleaning the pool with the chlorclean solution, as above.

6. When cleaning the pool itself, pour the chlorclean solution around the side of the pool. Using a clean disposable mop head/cloth, clean the surfaces of the pool and leave the solution in the pool for 10 minutes. Discard this mop head.

7. Open the tap outlet and empty the pool of the chlorclean solution.

8. Using cold water, rinse the tap then the pool to remove all traces of the chlorclean solution, to prevent any residue being left on the pool surface.

9. Dry the entire surface of the pool using a clean cloth or fresh disposable mop head. the pool is dried ensure the mop bucket asigned for cleaning the pool is cleaned and dried throroughly. Store it with the mop handle in room 8. Ensure all disposable mop heads used are disposed of in a yellow clinical waste bag.

11. Ensure the outside of the pool, window ledges, sink and its tap are cleaned with a chlorclean solution.

12. To clean the equipment (sieve, pool thermometer, mirror) used: wash and rinse these in warm water. Then soak for a minimum of 30 minutes in a chlorclean solution (2 chlorclean tablets in 2 litres of cold water), to cover equipment. After this, rinse and dry the equipment before placing these on a clean inco sheet on the top of the delivery box.

13. Finally, after the pool room has been restocked of equipment, towels, draw sheets etc, the floor is mopped using a chlorclean solution and a separate mop/bucket supplied by Medirest.

Guidance on cleaning of sinks/basins and taps in West Hertfordshire Hospitals NHS Trust
(to minimise risk of Pseudomonas aeruginosa)

Step 1 – cleaning the surrounding area

All basins, sinks and surrounding areas should e free from clutter and debris:

• Put on disposable gloves and apron
• Using a new disposable cloth and detergeant damp-clean the paper towel holder, then the soap dispenser, paying particular attention to theunderside of the soap dispensing unit, finishing with the nozzle.
• Then clean the underside of the sink/basin working from the higher level downwards.
• Carefully dispose of the cloth into the appropriate waste bag.
• Dry all surfaces with disposable cloth/towel as above.

Step 2 – Cleaning the wash-hand basin

• Using a new disposable cloth and sanitiser clean tap(s) first – start at the tap outlet end (do not put the cloth into the tap outlet), finish at the base and then clean tap handles.
• Then clean around the inside of the sink/basin from top rim of bowl, then overflow and waste outlet (do not put cloth into the overflow or waste outlet)
• Rinse as above
• Carefully dispose of cloth in appropriate waste bag.
• Dry all surfaces with disposable cloth/towel as above
• Dispose of gloves and apron in appropriate waste bag and decontaminate hands between the cleaning of each sink.