Washington (CNN) A pregnant woman apprehended Monday by Border Patrol in McAllen, Texas, delivered a stillborn baby later that same day at a local hospital, according to a Customs and Border Protection statement provided to lawmakers and obtained by CNN.

The statement cites "initial reports" that the woman was apprehended and Border Patrol agents determined she required medical attention and transported her to a local hospital where an examination revealed no fetal heartbeat. The woman then delivered a stillborn child.

Additional details were not immediately available, the release said. Authorities are not yet releasing the mother's identity and CBP vowed to conduct a "thorough review of the circumstances."

The growing humanitarian crisis on the southern border has gained urgency amid reports of overcrowding and poor conditions at migrant detention centers and an influx of apprehensions at the southern border. On Tuesday, concerns about the safety of migrants were further raised when a photograph depicting the drowned corpses of a father and young daughter attempting to cross the Rio Grande went viral.

Lawmakers cited the photo throughout the day amid votes to provide additional funding to assist with the swell of migrants.

Read More