A U.S. Border Patrol facility in Texas came under new scrutiny Saturday after a teenage mother was found there with a premature baby.

Immigrant advocates expected the facility in the U.S.-Mexico border city of McAllen to allow doctors inside to conduct health assessments, but it was not immediately clear whether those assessments took place.

The 17-year-old mother was from Guatemala and had an emergency cesarean section in Mexico in early May before crossing the border with the baby in June, said Hope Frye, a volunteer with an immigrant advocacy group.

The mother was in a wheelchair in extreme pain when legal advocates found her this week with the tiny baby. The advocates believe the baby belonged at a hospital neonatal unit.

The number of arriving migrants that border patrol agents are dealing with is overwhelming, and they need more funding, according to officials with the administration of President Donald Trump.

The teenage mother is one of more than 56,000 children apprehended at the border since October without their parents, a group the government calls "unaccompanied minors." The government apprehended more than 11,000 in May, a big increase from the previous month.

The children are processed by Customs and Border Protection officials and then transferred to the custody of a separate federal agency, the Health and Human Services Department. The children are held in facilities around the U.S. alongside other unaccompanied children, and the government is running out of space to hold them.

The children are supposed to be released from the facilities to relatives or sponsors, but critics have said the administration has imposed restrictions that are keeping the children in custody for lengthy periods.

In some cases, teenagers arrive in the U.S. pregnant or with newborn babies, creating medical issues as they are detained.

Trump administration officials have said Central American adults dangerously put their children in the hands of smugglers who transport them to the U.S., exposing them to violence and in some cases sexual assault.

Former Department of Homeland Security Secretary Kirstjen Nielsen told lawmakers last year that girls over the age of 10 are given pregnancy tests after they arrive in the U.S.