MILWAUKEE, WI (WISN/CNN) - An alarming statistic among babies, the number of newborns with congenital syphilis has reached a 20-year high in the United States.
Congenital syphilis is passed on by the mother during pregnancy or delivery.
According to the Centers for Disease Control and Prevention, the number of cases more than doubled from 2013 to 2017 when the recorded cases hit 918.
The CDC says this even outpaces the national increase of sexually transmitted diseases.
Arizona, California, Florida, Louisiana, and Texas accounted for 70 percent of the newborn syphilis cases.
Experts say they aren't surprised by the dramatic increase since the number of adults diagnosed with syphilis has been rising.
Eight out of 10 pregnant women who have untreated syphilis will pass it on in utero.
And that's what worries doctors.
If syphilis is left untreated, it could lead to stillbirth, a deadly infection for the infant and other medical issues.
The CDC recommends expectant mothers get screened early on in their pregnancy, then again around 28 weeks, and at delivery.
Syphilis can be easily treated with penicillin, which is safe for the fetus.