Women across Latin America have been convicted of killing their newborn babies, but the evidence against them included a forensic test that was being used in the era of the Mayflower. LA Times foreign correspondent Leila Miller wrote about how an unreliable test rooted in antiquity is still being relied on to put women behind bars today. Miller joined host Lisa McRee on “LA Times Today.”   

The flotation test has been in use for at least 400 years, but, Miller said, it is an outdated and flawed way to see if a baby died in the womb.

“It’s a test to determine whether a baby was born dead or alive. What you do is you take the baby’s lung and place it in a container of water. And you see whether it floats or not. If it floats, that supposedly means there was air in the lung and the baby took a breath. If is sinks, that means there was no air in the lungs and the baby was born dead,” Miller explained.  

The test has been disputed for two centuries. One reason is that there are other reasons that a baby’s lungs might have air in them.

“It can happen for a number of reasons. It can happen because of decomposition gases that formed inside the newborn. It can happen when the newborn’s chest was squeezed, when it was coming through the birth canal. Or it could have been because someone gave the newborn CPR,” Miller said. 

One woman Miller spoke to did not even know she was pregnant when she suddenly gave birth into a latrine. She gave birth and then fainted. At the hospital, she was arrested for killing her child, whom prosecutors later said had been born alive because of a positive float test. Activists have been trying to free women who were jailed because of the test.

“There have been exonerations. I looked at a few cases where women were exonerated after their attorneys appealed to a judge and told the judge to take a second look at how the float test had been used. So, the defense attorneys made the case that the float test was unreliable, but that it had been relied upon to say that the baby had been born alive,” Miller said. “Forensic pathologists largely agree that the float test can’t be used alone. That more tests need to be done. If the float test is used, more tests need to be done with the float test to determine whether a baby was born dead or alive.”

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CORRECTION: The story has been updated to more accurately describe an unexpected childbirth by a woman who spoke with Miller. (Aug. 11, 2022)