The number of children younger than 2 entering foster care in the metropolitan area has increased 40 percent in the past three years, according to a report released yesterday.

The report by the Metropolitan Washington Council of Governments underscored a shortage of foster care homes, which has resulted in some homes exceeding their licensed capacities.

In the District, some infants who were abandoned in hospitals by drug-addicted mothers have lived in the hospitals for months because of the shortage of foster homes.

Virginia Lt. Gov. Don Beyer, Del. Walter E. Fauntroy (D-D.C.) and Rep. Constance Morella (R-Md.) held a joint news conference yesterday to begin a Council of Governments regional foster parent recruitment campaign.

"We are here today to talk about hope," Beyer said. "The kind of hope borne of desperation. The hope of a child in need . . . . They require a few simple things: a warm bed, clean clothes, a hot meal, an understanding ear."

Last year, there were 4,269 children in foster homes in the metropolitan area, nearly half of them in the District. An additional 494 children were kept in group or residential care.

Since 1987, requests for foster care placement increased 15 percent in suburban Maryland, 9 percent in the District and 2 percent in Northern Virginia.

One of the most dramatic findings of the report showed that there were 400 more children 5 and younger entering foster care in 1989 than there were in 1987.

Last year, area social workers sought homes for 840 children younger than 2 and 760 children ages 2 to 5. Montgomery County exerienced a 77 percent increase in foster children younger than 2 in the past three years. While the number of additional foster homes needed varies with each jurisdiction, Jim Mable, a Montgomery County foster home recruiter, said his county is seeking between 250 and 300 new homes.

Area social service representatives blame the rise in infants and toddlers entering foster care on a variety of social problems, including homelessness, teenage pregnancies, economic hardships and substance abuse. Nationally, child welfare experts have attributed a growing crisis in their systems to an increase in neglected and abused children from families that abuse drugs.

In the District, up to half of the reported cases of child neglect and abuse has been attributed to illegal drugs and alcohol, and some social workers reported that more than half of their cases involved children whose parents were addicted to crack cocaine.

Fauntroy appealed yesterday for more residents to take children into their homes. Having completed an eight-week training course, Fauntroy said he will become a foster parent next week.