Before the health crisis Ms. Perez said she had briefly entertained the idea of a home birth but never thought of it seriously.

Now, the pandemic “has changed labor and delivery as we once knew it.”

Some hospitals are making changes in response to the concerns of pregnant women and to protect their own staff.

Northwell Health, New York’s largest health care provider with obstetric units at 10 hospitals, said it was testing expectant mothers for the virus before they are admitted.

A mother who is infected but asymptomatic would be kept six feet away from her newborn except for breastfeeding. A mother showing symptoms would almost immediately be isolated from her child, said Dr. Nimaroff. “Unfortunately, the mom can’t bond with the baby,” he said.

“There are a number of pregnant patients who have certainly developed the infection and many patients do test positive,” he added. “Some obviously are very sick from corona.”

But, Dr. Nimaroff said, the hospital “is still a safe space to have a baby.”

In New York State, there are roughly 1,150 certified nurse-midwives, according to state figures. Most work in hospitals; a smaller number specialize in home births.

Only three-quarters of the states allow licenses for midwives to practice out-of-hospital deliveries. Some states, like West Virginia and Georgia, do not offer licenses, making midwifery essentially illegal. Other states, like New York, place restrictive rules on home births, including a requirement that midwives have a written practice agreement with a doctor or hospital.