VOORHEESVILLE — On Friday, it became a felony to drive drunk in New York with a child in the car.

During a countywide blanket patrol for drunk drivers held the following night, Guilderland Police arrested the first driver to be charged under the new law.

Dr. Eileen Joyce, 52, an obstetrician/gynecologist from Voorheesville, was driving two adult passengers and a 7-year-old through Guilderland after leaving Proctor’s Theatre in Schenectady, according to Captain Curtis Cox, of the Guilderland Police.  Cox spoke on Monday at a press conference that, he explained, the department held in anticipation of media inquiry.

“What makes this significant is that the law was changed because of a tragedy,” Cox said, explaining that the circumstances of the Guilderland arrest were not unusual.

The Child Passenger Protection Act, better known as Leandra’s Law, was signed by Governor David Paterson in November.  It followed the October death of 11-year-old Leandra Rosado in an accident on the Henry Hudson Parkway — the woman who was driving the car was later charged with drunk driving and manslaughter.  Rosado’s father, Leonard, has since campaigned for stricter drunk-driving penalties.  The law makes driving with a blood-alcohol content higher than the legal limit of .08 when there is a person 15 years old or younger in the vehicle a felony.

Albany County ran its 77^th blanket patrol from 7 p.m. on Friday to 5 a.m. on Sunday.  It resulted in: 36 stops in Altamont, with no arrests; 39 stops in Guilderland, with one DWI arrest; 50 stops by the county sheriff’s department, with no arrests; and a total of 655 stops countywide, with one ticket for driving while ability impaired, eight arrests for driving while intoxicated, and three arrests for aggravated driving while intoxicated.

On Dec. 19, Joyce caught a Guilderland officer’s attention when she made an erratic movement near the intersection of routes 20 and 146 before continuing on Route 20, making several infractions, and then turning onto Route 155, Cox said.  Police stopped her near Nott Road.

“She was argumentative at first,” Cox said, and she then failed field sobriety tests.  Her blood-alcohol content was .14, according to a breath test, he said.

Since Joyce has been charged with a felony under the new law, she could face a fine up to $5,000 and a jail term of up to four years, Cox said.

First-time offenders charged with felony driving while intoxicated can sometimes plead down to a charge of driving while ability impaired, a violation, said Heather Orth, a spokesperson for the Albany County District Attorney’s office, but Leandra’s Law will allow defendants to plead down only to a misdemeanor DWI charge.

Since this is an ongoing case, Orth could not comment on whether or not Joyce’s occupation as a doctor would influence the kind of plea she might be offered.

If a doctor is convicted of a felony, the Office of Professional Medical Conduct “would be interested,” said Claire Pospisil, a spokeswoman for the state’s health department, when asked if a doctor could lose his or her license to practice if convicted of a felony.

Joyce did not return calls for comment and Joseph McCoy, the lawyer she retained this weekend, would not comment beyond saying, “I’ve always found that the Albany County DA’s office has treated people fairly.”