Infection caused by contamination from stagnant water in pipes and water hoses has been raised as an issue (George & Hobbs, 1990; Robb et al., 1991; Rawal et al. 1994). It is also thought that the warm temperature of the water may provide the ideal conditions for bacteria to multiply (Zanetti-Daellenbach et al. 2007) so increasing the chance of neonatal colonisation.
A small study undertaken in Germany specifically investigated the risk of fetal and maternal infection following a waterbirth (Fehervary et al., 2004). There were three phases in the study. In the first, they compared the outcomes for babies born in water (n = 34) with babies born on land (n = 36) and a third group whose mothers received water immersion in the first stage of labour. The results for the third group will not be discussed in this review. Consent was gained from the women who participated. Swabs were obtained from each baby’s ear and palate. In the waterbirth group 44% of the palate swabs and 9% of the ear swabs were negative compared with 53% palate and 11% ear swabs in the land birth group. In both groups the most common bacteria identified were Staphylococcus epidermidis, Escherichia coli, non-haemolytic streptococci. In both groups
Staphylococcus aureus and Candida albicans were also found occasionally. Corynebacteriaceae and Proteus spp. were only seen after a land birth. B streptococci and Citrobacter spp. were only identified from the waterbirth swabs. In a second part to their study the outcomes for 100 babies born in water were compared with 100 born on land. There were no significant differences between the groups. Three of the waterbirth babies were diagnosed with a bacterial infection and were treated with antibiotics compared with 2 of the land birth group. However, in two of the three waterbirth cases, the mother had prolonged pre-labour ruptured membranes (> 24 hours) compared with none in the land birth group. These women and their babies would be at increased risk of infection and require intravenous antibiotics during labour. However, it is not stated whether they were administered. The third phase of the study was to send a questionnaire six months after the birth to 100 women who had a waterbirth and 100 women who had a land birth. The authors do not explain whether these are the same women in phase two of the study. The response rate was 60% in the waterbirth group and 47% from the land birth women. The waterbirth women reported that 19 babies (31.7%) had suffered from an infection which included: 12 cases of common cold, varicella infection and non-specified infections. In the land birth group 13 babies (27.7%) had infections which included: 7 cases of common cold, 2 cases of otitis media, I case of conjunctivitis, 1 case of enteritis and 1 non-specified infection. The waterbirth babies suffered slightly more infection than the land birth babies.
A similar finding was obtained from another very small comparative study which was undertaken to assess the rates of colonisation and infection in mother and baby following a waterbirth (Hawkins, 1995). The sample was 16 women who gave birth in the pool and the next woman to give birth on land was used as a control. The 32 women and their babies were monitored for seven days for signs of infection. The neonatal swabs were obtained from the axilla, ears, umbilicus, and groin as soon as possible after the birth. When the 32 cases were analysed, it was noted that one baby was colonised with Pseudomonas aeruginosa in the ear and groin. At five days old further samples were taken from septic spots and Pseudomonas aeruginosa and Acinetobacter sp. were identified. The pre-use pool water sample was also noted to be contaminated with the same bacteria, so the pool was closed until the source of contamination was found. In the waterbirth group eight of the babies had the same organism as the mother: four had Staphylococcus epidermides and two had Escherichia coli cultured. In the control group, four babies had the same organism present as the mother: in three cases Staphylococcus epidermidis was present, one had Streptococcus faecalis, one had Enterobacter sp. During the seven day monitoring period, two waterbirth babies developed ‘sticky cords’. Culture of swabs showed one had Enterococcus faecalis and Escherichia coli present; this baby also developed a neck blister and Staphylococcus aureus was isolated. The second baby’s swabs showed Staphylococcus aureus. Hawkins (1995) does not explain whether women knew swabs were obtained from their baby or whether the babies whose swabs cultured bacteria were treated with antibiotics. The researcher concluded that babies who are born in water have a greater risk of colonisation with micro-
organisms. However, it is too small a study to determine whether this conclusion is correct because the results could have been obtained by chance.
However, Aird et al. (1997) when comparing 100 women who had a waterbirth with 100 who had a land birth found no cases of neonatal infection. Gilbert & Tookey (1999) in the large national survey concluded that they were neither able to confirm nor dismiss concerns about neonatal infection. Geissbuhler & Eberhard (2000) in their large prospective comparison of 2,014 waterbirths and 2,262 land births found that the neonatal infection rate was not significantly different between the groups (0.6% of waterbirth babies and 1.05% land births; p = >0.05). In fact the authors surmise that because the water is continually renewed while a woman is in the pool, the risk of infection is low. Unfortunately, the authors highlight a problem of missing neonatal data which may have impacted on the analysis. Brown (1998) reported an audit involving 541 women who used a birthing pool in a three year period. Two babies had sticky eyes, and ear swabs from two babies cultured Pseudomonas aeruginosa which would indicate a low incidence of neonatal infection (0.74%). However, Pseudomonas aeruginosa is found in stagnant water so it has to be presumed that the babies’ infection may be linked to the waterbirth and would not have occurred if born on land.
There is evidence that birth in water may protect a baby from bacterial colonisation. Zanetti-Daellenbach et. al. (2006a) investigated whether babies
born in water are at increased risk of colonisation by Group B streptococcus (GBS). Two groups of women were compared: one group which gave birth in water and the other group which used water immersion for the first stage of labour. The researchers screened the women for GBS towards the end of pregnancy and found that 31.25% of the women in the waterbirth group and 34.8% in the immersion group were GBS carriers (p = 0.854). A water sample was obtained when the women left the pool. There was a significant difference between the groups. In the waterbirth group 65% of water samples were positive compared with 25% in the immersion group (p = 0.022). Analysis of the neonatal pharyngeal swabs revealed that 15% were positive in the waterbirth group compared with 31% in the control group (p = 0.42). This was a small study but it would seem that even when water is significantly colonised with GBS after a waterbirth compared with water immersion, the baby does not appear to be at risk of acquiring the bacteria. In fact the authors conclude that waterbirth may protect the baby by providing a ‘wash out effect’ at delivery.
Support for this conclusion is provided by one Italian low-risk maternity unit, where 52% of babies are born in water. The unit audited 741 waterbirths to assess whether there is an increased risk of neonatal infection (Thoni et al., 2004). They obtained pool water samples before pool use and after delivery. They had a control group comprising babies born on land, but did not explain how the control group was chosen. Although bacteria were found in the pool water samples there was no increased risk of infection for the waterbirth babies 1.34% (n = 10) compared with 3.4% (n = 15) land babies.
Forde et al. (1999) matched women in a non-randomised prospective study. Ninety-five women used the pool but only 49 achieved a waterbirth. Samples of pool water were obtained before the women entered the pool and after the birth. One of the post-delivery samples did identify Staphylococcus aureus but the organism was not obtained on the neonatal swabs. Group B Streptococcus was cultured from a second post-delivery pool water sample and also from the baby’s ear swab. Coliforms were also isolated mainly from the first pre-entry to the pool sample and Bacillus sp. from the post-delivery samples but these appeared to cause no problems to the neonate. Pseudomonas aeruginosa has been cultured from a pool water sample obtained before the woman entered the pool (Brown, 1998) which probably indicates that the water was contaminated from stagnant water remaining in the pipes.
Waterbirths do not therefore seem to increase the risk of infection but there is enough conflicting information about the risk of neonatal infection following a waterbirth compared with a land birth to indicate that a large RCT is required to address this concern.