I think there's more to it than that.

Prosecutors had argued that Jennifer Jorgensen was speeding, intoxicated and unbelted when she crossed into oncoming traffic in 2008 and hit another vehicle head-on, killing Robert and Mary Kelly. Jorgensen was eight months pregnant at the time.

She was acquitted of manslaughter in the deaths of the Kellys but convicted of recklessly causing her daughter’s death. (https://newyork.cbslocal.com/2015/10/22/jennifer-jorgensen-conviction-overturned/)

If she wasn't found guilty of killing the Kellys in a head on collision, driving the wrong way, and allegedly involving alcohol, there's something else going on here besides the unborn child, although it does make sense not to potentially criminalize pregnancy.