Immigration and Customs Enforcement is ending its practice of automatically releasing pregnant women from detention, according to internal communications reviewed by The Daily Beast.

This is because of President Donald Trump’s executive order “Enhancing Public Safety in the Interior of the United States,” which requires stricter enforcement of immigration laws. Previously, the agency’s general practice was to release women from detention who were pregnant.

Now, pregnant women will only be able to get released if an ICE officer determines so on a case-by-case basis.

Pregnant women were still sometimes detained under the previous internal guidelines. Immigrants’ rights advocates say the practice is dangerous to women and to their unborn children, and that pregnant women are more likely to miscarry if they’re in detention than if they are free. This new policy means more pregnant women will spend time in detention.

“This new ICE policy memo confirms our fears that the government is continuing its barbaric policy of detaining pregnant women despite substantial evidence that detention of this particularly vulnerable population has been linked to serious health implications to the mother and unborn child and also constitutes a significant barrier to receiving a meaningful day in court,” said Katie Shepherd, who does legal advocacy for asylum-seeking women at the American Immigration Council.