TIJUANA, Mexico — A growing number of expectant mothers are among the migrants coming in daily from Honduras, Guatemala, El Salvador — even Haiti — to more than 30 already overflowing shelters in Tijuana, Mexico.

“More women are arriving pregnant or with babies,” said pastor Gustavo Banda of the Embajadores de Jesús (Ambassadors of Jesus) church, which operates a shelter in Cañón del Alacrán (Scorpion’s Canyon) on the outskirts of Tijuana. “We have a lot of Haitian women and some Central American.”

Some women also get pregnant while they wait.

These pregnant women are here because the Trump administration’s “Remain in Mexico” program requires some U.S.-bound asylum applicants to register at ports of entry and then return to Mexican border cities to wait as their claims are processed.

It’s a period of great anxiety, if only because many want their children born in the United States. The U.S. Constitution guarantees that every child born on American soil automatically becomes a U.S. citizen. Mexico also offers birthright citizenship, but it's not exactly the same: A child born in Mexico, regardless of their parents' nationalities, automatically becomes a Mexican citizen when they turn 18.