Is the evidence on water birth just too murky?
In the summer of 1999, a woman delivered a 7.7-lb infant after 42 weeks of gestation. The birth took place in the woman’s home in Japan, and the baby was delivered in a bathtub of warm water. The woman had had an uneventful pregnancy, and the baby appeared to be perfectly normal.
Four days later, the infant developed fever and jaundice and was admitted to the hospital, where she was treated with phototherapy. She improved, but her symptoms recurred 3 days later, and she began to vomit. Eight days after birth, she suffered cardiopulmonary arrest and died. An autopsy revealed the cause of death to be legionellosis—infection with Legionella pneumonia. The most likely source was the bathtub in which she was born.43
Other case reports describe similar tragedies associated with water birth (among them, drowning, infection, and a snapped umbilical cord), but no randomized, clinical trial has systematically compared delivery in water with conventional land-based birth.
The death, morbidity, and lack of data so troubled members of the American Academy of Pediatrics that the Committee on Fetus and Newborn issued an advisory in 2005:
- The safety and efficacy of underwater birth for the newborn has not been established. There is no convincing evidence of benefit to the neonate but some concern for serious harm. Therefore, underwater birth should be considered an experimental procedure that should not be performed except within the context of an appropriately designed randomized clinical trial after informed parental consent.44
This statement contrasts the conclusion of the most recent Cochrane review of the subject, which found that, “Immersion in water during the first stage of labour significantly reduces women’s perception of pain and use of epidural/spinal analgesia.”45 The review also noted, however, that, “No trials could be located that assessed the immersion of women in water during the third stage of labour.”45
No studies have explored immersion in water during the third stage of labor.
What’s in that water?
Amy Tuteur, MD, an ObGyn who publishes a popular blog (“The Skeptical OB”), focused on the topic of water birth earlier this year. “What’s in the water at waterbirth?” she asks.46
To answer the question, Dr. Tuteur cites a 1999 study of 4,030 deliveries in water, which found that 35 infants suffered serious morbidity and three died—although it is unclear if any of the deaths were a direct result of water birth. “However, of the 32 survivors who were admitted to the NICU,” writes Dr. Tuteur, “13 had significant respiratory problems, including pneumonia, meconium aspiration, water aspiration, and drowning. Other complications attributable to water birth include five babies who had significant hemorrhage due to snapped umbilical cord. In all, 18 babies had serious complications directly attributable to waterbirth.”47
Dr. Tuteur also points to the poor quality of the water in birthing pools, arguing that it is “essentially toilet water.”46 “The water in a birth pool, conveniently heated to body temperature, the optimum temperature for bacterial growth, is a microbial paradise,” she writes.46 She cites a study of 1,500 water births that included analysis of the water found in the birthing pools (before anyone entered the water) and identified:
- coliforms in 21% of samples
- enterococcus in 19% of samples
- Escherichia coli in 10% of samples
- Legionella pneumophila in 12% of samples
- Pseudomonas aeruginosa in 11% of samples.48
After a special water filter was installed, contamination diminished but did not disappear completely.
Pools in the home setting were not the only ones implicated in contamination; some hospital pools also were affected.
What’s the bottom line?
The American College of Obstetricians and Gynecologists has yet to weigh in on the matter. Until it does, ObGyns may be wise to heed the words of Ruth Gilbert, MD, of the Centre for Paediatric Epidemiology and Biostatistics at the Institute of Child Health in London.
“Can delivery in water cause serious adverse outcomes?” she asks, rhetorically, it turns out.
“Undoubtedly, the answer is ‘yes.’”49 —JANELLE YATES, SENIOR EDITOR
The data we do have are difficult to interpret
Among the limitations of studies of home birth are:
- lack of follow-up after the delivery
- varying definitions of perinatal mortality internationally
- lack of clarity regarding the identity and education of delivering providers
- the fact that there are often “too few neonatal deaths from which to extrapolate reliable rate calculations.”16
One meta-analysis found a rate of intrapartum transfer ranging from 7.4% to 16.5%, and a rate of primary cesarean delivery of 1.4% to 17.7% (it was 13.8% to 28.25% in the “comparison group”).16