Six-month-old Sean Preston fell April 1 as his nanny was lifting him from the high chair and something in the chair snapped, Star magazine reported Tuesday. The infant slipped from her arms and fell, bruising his head on the floor, the magazine said.
People magazine and the Los Angeles Times also reported the incident on Wednesday.
Though a doctor examined the baby at the house, Spears and husband Kevin Federline took the baby to the emergency room to have him examined six days later, People said.
The magazine says Sean Preston had been rushed to the hospital a day earlier when his parents became alarmed at realizing he was sleeping more than usual.
Spears' attorney, Martin Singer, said in a statement that the hospital made a report to the Department of Children and Family Services as required by state law.
"DCFS immediately responded and determined there was no problem and no reason to open a formal investigation. They determined that the parents weren't involved in the injury and nothing was improper within the home," he said.
The Los Angeles DCFS and the Lost Hills sheriff's station declined to give details of Saturday's visit, and would not say if there was an ongoing investigation. DCFS public-affairs director Louise Grasmehr didn't return a phone message left Tuesday at her Los Angeles office. The department routinely refuses to discuss cases, citing confidentiality laws.
"It's a very standard, routine patrol request," Lt. Debra Glaskides said Tuesday. "We just roll out with them. We stood by, we took no action, no report or anything."
In February, DCFS visited Spears' home after publication of photographs showing the 24-year-old singer driving with then 4-month-old Sean Preston in her lap, rather than in a car seat as required by law.
Spears later apologized, saying she did it because of a "horrifying, frightful encounter with the paparazzi."
The incident even caught the attention of U.S. Transportation Secretary Norman Mineta.
"Recent photos of Britney Spears driving with her infant son on her lap are troubling," said Mineta, who chided Spears during a Feb. 13 Philadelphia event marking Child Passenger Safety Week. "And while Ms. Spears has acknowledged her mistake, her actions still send the wrong message to millions of her fans."