A group of nearly 200 aid and advocacy organizations are calling on Customs and Border Protection to issue formal regulations around how pregnant women and new mothers are detained.

Calls for reform took off in 2020, after a 27-year-old asylum seeker from Guatemala went into labor while in custody Chula Vista Border Patrol Station that February.

According to a complaint filed by the ACLU's San Diego chapter, the women partially gave birth to her baby while holding onto a trash can for support, before being taken to the hospital. The complaint alleges she was denied a shower at the hospital and returned to CBP custody with her new baby a few days later.

The incident was also highlighted by a group of U.S. senators, who also called for reforms.

In the new letter sent this month, advocacy groups and medical professionals say despite those efforts, the agency has failed to adopt a clear and consistent policy to limit detaining pregnant and postpartum women, and nursing mothers.

They cite more incidents that have been documented since, including a pregnant asylum seeker who remained in CBP custody in Yuma for 16 days before being released to her U.S. sponsors. Another woman went into labor and was nearly separated from her young daughter.