“There are beautiful things happening all the time in the midst of all this sadness,” said Sandra Bernstein, director of the Mother and Baby Care Center at Enloe Medical Center in Chico, which took on patients who had originally planned to deliver at the damaged hospital in Paradise.

Still, new and expecting mothers contend with unique health challenges during natural disasters, one of the biggest being the inability to find a safe place to give birth, said Dr. Nicole Smith, an assistant professor of obstetrics and gynecology at Harvard Medical School. Other concerns involve contaminated water, stress, trauma and depression.

As smoke contaminated the air, mothers feared for their babies’ health.

“I was afraid that the smoke would cause her asthma,” Ms. Tellez Flores, 24, said.

Like Ms. Tellez Flores, Kamber Wright, 31, was supposed to deliver in Paradise. When the fire began, Ms. Wright was less than a week away from her due date, asleep in the house she and her husband purchased recently. It took her more than four hours to drive from Paradise to Chico — time spent worrying that she’d go into labor as her house (and the baby’s jungle-themed nursery) turned to ash in the rearview mirror.

Her son, Grayson James, was born on Nov. 13.

“He’s too small to wear a mask,” Ms. Wright said. “We wrapped three blankets over the top of his car seat to really make sure no smoke would get to him.”