Two babies born via water delivery in Arizona developed the infection, which can grow and spread in unsterilized water.

Brand new baby born via natural home water birth
Credit: John Carleton/Getty Images

A water birth may sounds like a gentle way to welcome your newborn to the world. But now comes the news that babies born this way may be at risk of contracting Legionnaires' disease—a serious and potentially life-threatening form of pneumonia—after two infants in Arizona delivered via water birth developed the infection just days after they were born.

The cases were apparently unrelated and both babies recovered after being hospitalized and treated with antibiotics. But this is a scary piece of news nonetheless. Because while infections among infants born in heated birthing pools are rare, Legionella bacteria thrive in warm water and can grow in places like water storage tanks and pipes.

According to a new report released by the CDC, in both of the cases in question, there were big gaps in infection prevention. In the first case, the baby was delivered by a midwife on January 6 in a tub filled with tap water, then rushed to the ER the following day in severe respiratory distress with low blood oxygen levels. The tub had been cleaned with vinegar and water before being filled with tap water immediately before delivery. But tap water is not sterile, and since Legionella can grow and spread in plumbing systems, the bacteria managed to find its way into the baby's lungs even though no water had been swallowed.

The second newborn was delivered by a different midwife on April 5 in a rented, jetted Jacuzzi tub heated to 98 degrees for a week—an optimal temperature for the bacteria to grow. Three days after the birth, the baby developed a fever of 101 degrees that lasted two days, a subsequent chest X-ray revealed cloudy spots in the lungs, and the bacterial infection was later confirmed to be Legionella.

Water births have been growing in popularity over the last decade or so. But while the American College of Obstetricians and Gynecologists (ACOG) said in a revised opinion last fall that there are a few pros to undergoing early stages of labor in a birthing pool—shorter labor being one of them— it added that water delivery has no proven benefits to women or babies and may even pose a risk of serious health problems for the newborn, which is why it is not recommended by the organization.

To protect the health and safety of the mother and the baby during labor, ACOG provides recommendations for facilities that offer water birth or water immersion in the first stage of labor, including following infection control procedures, maintaining and cleaning all tubs and immersion pools, and having a plan in place for how to move women from the tub if complications arise.

For more information about the risks for Legionella infection for women choosing water immersion for labor or birth, check out this online handlbook developed by Arizona health officials.

Hollee Actman Becker is a freelance writer, blogger, and mom of two who writes about parenting and pop culture. Check out her website holleeactmanbecker.comfor more, and then follow her on Instagram and Twitter.