Aquabirths Research Review: Better outcomes for women and babies when they labour and birth in water.

Aquabirths Canberra Birth Pool

Aquabirths Research Review: 

Title: “Maternal and perinatal outcomes amongst low risk women giving birth in water compared to six birth positions on land. A descriptive cross sectional study in a birth centre over 12 years”.

Authors: Hannah G. Dahlen, Helen Dowling, Mark Tracy, Virginia Schmied, Sally Tracy

Published in the journal ‘Midwifery’ (Link)

Review by Emma Ashworth

Background
One of the limitations of research is getting enough data to really represent reality. This piece of research into the safety of waterbirth used data which was collected over 12 years, and considered the births of over 6,000 women. This gives us a really good, clear picture of what the outcomes really are. What the researchers have discovered is invaluable information for those looking to support women and people with their decisions around labour and birth in water compared to labour and birth on land in different positions, and supports the ongoing evidence that waterbirth is extremely safe and is an excellent way to support physiological birth.

What was the research looking at?
This research compared multiple labour and birth positions on land and in water. The aim was to see what difference six birth positions on land, and birth in water, made to perineal trauma, postpartum haemorrhage (PPH) and five minute APGAR scores.

The land birth positions were on a birth stool, semi recumbent, kneeling/all fours, lateral, standing and squatting.

Where was the research undertaken?
This data for this paper came from 12 years of maternity notes in an alongside Australian birth centre. The birth centre was next to an obstetric unit, and during the period of time that was looked at 8,338 women laboured there, and of these, 6,144 gave birth in the birth centre, the rest being transferred to the obstetric unit. Only the data of those who gave birth at the birth centre are included in this paper. The interesting thing about this birth centre is that both midwives and obstetricians work there, with the obstetricians working on a private basis, although the risk profile of the women for both types of birth workers were the same.

How accurate was the data?
The data that was used in this research paper was described as “detailed descriptions of the birth positions women had assumed for the birth as well as recording; parity, length of first, second and third stage of labour, blood loss, accoucheur, perineal trauma, sutured or not sutured, shoulder dystocia, physiological or active third stage management, use of oxytocis for third stage and analgesia.”

What were the outcomes?

  • Perineal trauma

Water birth showed a lower rate of perineal trauma compared to all of the land birth positions, although only labour and birth on a birth stool reached statistical significance. The authors discuss this, pointing out that other research has shown that birth stools can lead to higher rates of perineal trauma, although a study in Sweden1 did not show this to be the case. The difference in the Sweden trial was that the women were encouraged to not stay on the birth stool for longer than about half an hour which may have lessened the risk of oedema, as oedema  may be caused by sitting in the same position for long periods, and it may lead perineal tissues to be more prone to injury.

  • Post partum haemorrhage (PPH)

Defined as blood loss over 1000mls, water birth led to lower rates of PPH compared to all of the land birth positions, although again only rates within the birth stool group were statistically significantly different. The authors concluded that the increased rates of PPH for those women who used a birth stool is likely to be caused by perineal damage rather than bleeding from the uterus. It is also harder to judge the loss of blood in the pool compared to in a land birth which may have led the waterbirth blood loss rates to have been under or over recorded.

  • APGAR scores

The APGAR outcome that was looked at was a score of less than or equal to 7. All of the land birth positions led to more APGAR scores of less than or equal to 7 compared to water birth, although the only position where this reached statistical significance is the semi recumbent position. This may have been caused by women being asked to move into this position if there was a concern about the labour, rather than the position itself causing the lowered scores.

Summary
Although outcomes for waterbirth were better than for land birth in all areas, these differences rarely led to statistical significance. However, this does show that the outcomes of waterbirth that were looked at in this paper (PPH, perineal trauma and APGAR scores less than or equal to 7) were at least as good, if not better, than all of the land birth positions that were considered.

We can therefore conclude from the data in this paper that labour and birth in water is at least as safe as labour and birth on land, when looking at the specific parameters considered in this research paper. This is helpful to midwives and doctors wishing to demonstrate the safety of waterbirth to their Trust, and to support more midwives and doctors to be trained in supporting labour and birth in water.

References:

Is water birth safe for women and midwives during Covid-19?

There has, very understandably, been a huge amount of concern about whether different maternity care practices increase the risk of transfer of Covid-19 between the woman giving birth and those caring for her. In some hospitals, the use of gas and air was stopped for a while, and in many, water births have not been supported for some time.

The two most commonly referred to concerns about Covid-19 and water birth were:

  • As virus particles have been found in faeces, could water birth increase the risk of faecal transmission?
  • Could water vapour in the pool room transmit virus particles more efficiently than in dry air?

It is also important to look at whether water birth can reduce the transmission of Covid-19. Does birthing in water reduce the risk of transmitting Covid-19 between birthing mother and midwife?

Consideration of theoretical risks of water birth with Covid-19

Let’s first look at the possible risks. According to the WHO1, Covid-19 is transmitted through a) droplets in the air (created by sneezes, coughs, breathing and so on) which can be breathed in by other people, and b) by the droplets landing on a surface which are then picked up, eg by someone putting their hand on them, followed by them transferring the virus particles to the face, allowing entry through the eyes, nose or mouth.

Although, according to WHO, there may be Covid-19 virus particles in faeces, only one study has been able to culture it and there have been no reports of faecal-oral transmission.2 Furthermore, faeces passed in the pool is immediately in contact with the chlorinated tap water and enveloped viruses such as Covid-19 are not able to survive for long in chlorinated water. It’s not clear from this WHO data how long it might survive in chlorinated water (it only refers to de-chlorinated water), nor how chlorinated the water needs to be (as the tap water’s chlorine does evaporate over time). However, even without this data it seems that provided that normal care is taken with the water and hand and body hygiene, there is a much lower chance of a midwife contracting Covid-19 from a birthing woman through the water compared to through the air. Furthermore, when the baby is born in the presence of faeces (which, of course, is a very common occurrence), the effect of dilution and washing of the mother’s genitals by the water may decrease the chance of transmission at the point of birth from woman to baby, but to date there is no evidence on this point.  However there is evidence that rates of the newborn contracting other infections such as staphyloccus and e-coli are no different in land and water births. This does not mean that Covid-19 would be the same, but the effect of dilution in the water is likely to be an important protective mechanism.3

The second question was whether Covid-19 could be more easily transmitted through the air within the possibly more humid environment of the pool room. The research on this, as with so much around Covid-19, is very minimal and contradictory. It also tends to look at humidity in terms of weather, not humidity inside a room. There is some evidence that increased humidity may make the virus harder to transmit, but other research says that this is not the case – but social distancing, natural when a woman is labouring in a pool of water, PPE and hand hygiene might have far more impact anyway.

Consideration of theoretical benefits of water birth with Covid-19

We have already considered that it is likely that if there is any possible faecal-oral transmission route, water birth will reduce the chance of this. In addition, we believe that there are other possible benefits to water birth in terms of reduction of potential transmission of Covid-19 between mother and midwives.

The birth pool, by its nature, means that for many labour positions there is a greater distance between the birthing woman and the midwife, which could help to reduce the chance of cross infection. The water surface is a large part of the space within the room, and virus landing on the water would not be a possible route for surface to face infection, unlike a maternity bed.

Using bed birth as a comparator it is possible to see water birth as being as safe as a land birth. In summary, when looking at the safety of water birth in the context of Covid-19, we must not lose sight of the benefits as well as the possible risks – and not take away this vital form of pain relief as a knee jerk reaction rather than thinking through the comparative risks of land and water birth, physiological and medicalised birth.

 

References:

  1. WHO: Water, sanitation, hygiene and waste management for the COVID-19 virus: https://apps.who.int/iris/bitstream/handle/10665/331305/WHO-2019-NcOV-IPC_WASH-2020.1-eng.pdf
  2. WHO on faecal-oral transmission: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-coronaviruses
  3. Fehervary et al, 2004, Water Birth: Microbiological Colonisation of the Newborn, Neonatal and Maternal Infection Rate in Comparison to Conventional Bed Deliveries: https://pubmed.ncbi.nlm.nih.gov/12955529/