A lawsuit filed by Nathan and Reggan Koopmeiners in Kenosha County Circuit Court names the company, Care.com, and Sarah Gumm as defendants.
Gumm is jailed in Lake County, Illinois, where she is charged with first-degree murder in the 2012 death of 3-month-old Rylan Koopmeiners. Gumm is accused of causing a head injury that resulted in the baby's death at her home in Waukegan, Illinois.
The Koopmeiners allege Care.com, of Waltham, Massachusetts, failed to reveal that Gumm had a court record, including two citations for drunken driving, even though they paid for the background check.
Care.com issued a statement in response to a request for comment.
"While we remain deeply saddened by these events, we cannot comment on matters of ongoing litigation," the company said.
The wrongful death lawsuit alleges Gumm was under the influence of alcohol when the baby's head injury occurred. The child suffered a skull fracture and cranial hemorrhaging and died July 27, 2012, from blunt force trauma, according to an autopsy.
Gumm's attorney Jed Stone he understands why the Koopmeiners would "thrash about" looking for justice, but said Gumm did not intentionally cause the baby's death.
"The loss of a child is unimaginable. The loss of an infant child is heartbreakingly unimaginable," Stone said Friday. But that doesn't mean Gumm is a killer, he added.
Stone said he is in ongoing discussions to resolve the criminal case short of a trial in September.