This table is a supplement to the Evidence Based Birth® article on waterbirth, which you can read in full here, and download as a PDF here.
What rare adverse events have been seen in case reports?
A number of researchers have published case reports of individual infants who have had adverse effects possibly caused by waterbirth—and in some cases definitely caused by waterbirth.
The authors of the ACOG/AAP opinion statement relied almost solely upon case reports to describe waterbirth as dangerous. However, case reports are considered the lowest level of medical evidence.
It’s important to understand that there are different types of case reports. When a case report is formally published as a peer-reviewed article in a scientific journal, it is called a case study. Case studies are used to describe a rare event in great detail so that other health care professionals can learn from that rare event. However, some case reports are published as letters to the editor. These brief letters to the editor are not peer-reviewed. They often lack enough detail to get a clear picture of what really happened.
The pros of case reports are that they allow us to take an in-depth look (or brief look, in the case of letters to the editor) at a rare event. We can learn lessons from the case study that can help us improve the quality of care for women and infants in the future.
The main drawback of case reports is that they are not a systematic research study. Case reports are considered one of the lowest levels of research evidence. When researchers publish a case report of a rare event, there is no way for us to know how often an event like that has occurred. Also, some of the case reports about waterbirth are incomplete—they barely give us any information about the type of care the woman and infant received during the waterbirth.
To help you understand the case reports that have been published on waterbirth, I have made a table below with their findings. To read more details about the case reports, you can download the annotated bibliography here: https://gum.co/waterbirth
Table: Case Reports on Waterbirth
|Type of Report
|The cases took place in Austria, England, and Sweden
|This magazine article described 3 stories about newborn drownings: 1) The parents did not remove the infant from the water until 25 minutes after the birth, 2) An infant was born on dry land but still inside the membranes, and the parents did not know how to remove the infant from the membranes, 3) A baby died after a home waterbirth attended by 2 experienced midwives. The baby showed no signs of stress during labor, but was born with severe respiratory distress and made breathing movements as it came up to the surface.
|This article was not a case report but was a magazine story.It was cited as case report evidence of two “waterbirth drownings” in the Pinette et al. 2004 review article entitled the “Risks of underwater birth,” published in the American Journal of Obstetrics and Gynecology.
|A male infant was born at term and developed a Pseudomonas blood infection after a hospital waterbirth. Culture samples from the birthing tub, filling hose, taps, exit hose, and disposable lining of the tub all grew Pseudomonas. Within two days he made a complete recovery, and he was discharged after being treated with antibiotics for seven days.
|The authors stated that there should be regular laboratory testing of birthing tubs and strict infection control policies. Before this case, their hospital policy was to wash the system with hot water and detergent and allow it to dry after each birth. Now, they take cultures from the birthing tub system after each water birth, keep the filling and exit hoses short, and heat-disinfect the hoses after each use.
|Letter to the editor
|After a waterbirth, the newborn had some difficulty breathing and a seizure. A laboratory work-up revealed hyponatremia (low sodium levels). It was thought that the hyponatremia may have been due to inhaling fresh water.
|No other details were provided about the infant or the birth.
|A male infant was born at 38 weeks in a waterbirth in a disinfected outdoor hot tub at home, attended by a midwife. He was admitted to the NICU shortly after birth for respiratory distress. Chest x-ray showed fluid in the lungs, and he was intubated at 16 hours of age and received 3 doses of surfactant, after which his breathing improved. Cultures of a specimen from his trachea grew “scant but pure growth” of Berkholderia picketti, an organism usually found in water. The Berkholdia picketti was not present in any cultures of the hospital water. Cultures later taken from the tub in which the infant was born grew Berkholderia picketti. The infection did not spread to the baby’s bloodstream. He remained on a ventilator for 5 days, had 14 days of antibiotics, and his symptoms resolved completely.
|The infant’s final diagnosis was aspiration pneumonia, which contributed to a surfactant deficiency, and incidental colonization of the trachea with B picketti. The organism was not the cause of the respiratory symptoms—however, the fact that the same rare organism was present in the tub and present in his trachea “is compelling evidence that he aspirated tub water during the delivery.”
|Letter to the editor
|A female infant who was born in the water at 37 weeks gestation, attended by a CNM. At age 19 days, the infant presented with a one-week history of yellow drainage from the right ear. The infant was alert, vigorous, and had no fever or any other signs of illness. The ear drum was ruptured and the culture was positive for Pseudomonas and rare E coli. The infant’s blood cultures were positive for Pseudomonas. The infant received two weeks of intravenous antibiotics and had a normal follow-up one month after completion of therapy.
|It is not clear whether the facility was a hospital or birth center. No culture or lab samples were available from the birthing tub where the infant was born. The facility closed before this letter to the editor was written.
|A 23 year old mother took a 30-minute tub bath at term. Later that day she gave birth to a male infant, on land. At 11 days, the baby was not feeding well, was lethargic, and had seizures. He was diagnosed with Pseudomonas aueroginosa meningitis and underwent immediate treatment with antibiotics. At nine months of age, he has normal psychomotor development. Pseudomonas bacteria cultured from the shower tubing at home were genetically identical to bacteria present in the infant’s cultures.
|This was not a waterbirth, although it is cited as a complication of waterbirth in the Pinette et al. (2004) review article published in the American Journal of Obstetrics and Gynecology. It is impossible to tell if the infant was contaminated because of the mother’s tub bath before giving birth or if he was contaminated at some other point prior to developing meningitis at 11 days of age.
|Four infants who experienced complications from water birth and were transferred to their facility:
|It is not clear whether the infants were born at home or in the hospital, and it is possible that several of the births were unattended. The authors provided no information on whether safety procedures were followed during the waterbirth; for example, it is not known how long the infants were submerged in the water before being lifted up to the surface. They also did not report water temperature.
|Letter to the editor
|Only the first two cases appear to be related to water birth. The authors did not present the cases thoroughly. It is not known whether the cases reported are directly due to the water birth, or if standard safety procedures were followed. No other details about these births were provided, including whether or not the infants recovered.
|A 42-week infant girl was born unassisted (no midwife present) in a bathtub in her home. The home was installed with “ever-ready” hot water system in which hot water is always circulating through the plumbing. The infant had a normal assessment at birth but developed a fever and jaundice on day 4 of life. She was admitted to the hospital for phototherapy and discharged the next day. On day seven the infant was vomiting and had a fever, and the next day she stopped breathing. She was transported to the emergency room, where she was unable to be resuscitated. An autopsy showed Legionella lung disease. In an environmental investigation, the bathtub laboratory tests were positive for numerous Legionella.
|The authors attribute this case to the 24-hour “always ready” bathing system. In these systems, the same water is used over and over for days or months, and kept at a warm temperature. Even though the water may be filtered, heated, chemically disinfected, or have UV light disinfection, some organisms may survive. The water may be clean enough for normal bathing, but it is not clean enough for drinking or use by newborn infants.
|A newborn developed Legionella pneumonia 7 days after a hospital waterbirth.
|The entire hot water supply of the hospital was positive for Legionella, and the bacteria were present in very high numbers.
|A 40-week gestation infant developed respiratory distress after a hospital waterbirth. The baby did not need resuscitation at birth, but at one hour he was grunting and was admitted to the NICU with respiratory distress. A chest x-ray showed changes consistent of aspirating water. The infant made a complete recovery.
|The authors did not report whether standard safety procedures were followed during the waterbirth.
|A 42-week gestation infant died of meconium aspiration and Pseudomonas pneumonia after a home waterbirth.
|The Pseudomonas infection was thought to have come from the birthing pool, although no laboratory tests were done on the pool or water.
|The authors described three drownings: two after waterbirth and one after a shower birth. In all three cases, the drownings were likely intentional, although investigators were not able to prove it. All three women had hidden pregnancies, had no prenatal care, had unassisted births, and one of the women did not even know she was pregnant when she birthed into the tub.
|These were criminal cases in which mothers were thought to have intentionally drowned their newborns.
|A female infant was born at 40 weeks and 4 days via a planned waterbirth at home. The mother had diarrhea and a low-grade fever for one week before giving birth. She had a bowel movement in the water prior to the baby’s birth. The infant was healthy until 4 days of age when she developed a fever, was hospitalized, and diagnosed with sepsis and adenovirus. The infant’s condition grew worse and she died shortly after the parents decided to withdraw medical support. Autopsy results showed adenoviral pneumonia, bleeding in the colon, and multi-organ failure.
|Newborn adenovirus infections are very rare and few cases have ever been described. It is thought that the mother typically transfers immune protection for adenovirus to the fetus through the placenta, which is why newborns do not usually get this illness. The authors propose that this newborn’s infection was transmitted during the waterbirth since the mother had an infectious bowel movement (diarrhea) in the water bath immediately prior to delivery. Because the water was heavily contaminated, this increased the newborn’s risk of contact with the virus.
|Systematic review of all case reports of umbilical cord tears during waterbirth
|The authors reviewed all published cases of waterbirth umbilical cord tearing. An umbilical cord tear is also called umbilical cord “snap,” “rupture,” or “avulsion.” Based on their review, they estimated that there are about 3.1 umbilical cord snaps per 1,000 waterbirths. Out of all the cases of umbilical cord snap, about 23% lead to NICU admission, 13% lead to the need for a newborn blood transfusion, and there have been no reports of any long-term harmful effects.
|The authors provided a list of guidelines that can be used to prevent and treat umbilical cord tears. It is impossible to compare the rates of umbilical cord tears between waterbirth and land birth because researchers have not recorded how often cord tearing occurs during land births.