NEWBORNS IN MOVIES/TV

They can't have a movie crew sit around a maternity ward and wait for a baby to be born, it would probably cost too much. 

The following is an answer I found:

Yes. In California, infants can start working when they’re 15 days old, provided that they (or their parents) have a work permit and a note from a licensed physician. According to the California labor code, the note must attest that the child was not born prematurely, was of normal birth weight, and is, in the doctor’s opinion, “physically capable of handling the stress of filmmaking.” Also, the child’s lungs, eyes, heart, and immune system must be “sufficiently developed to withstand the potential risks.”



In some states, like New Mexico, West Virginia, and Wyoming, there are no age restrictions on acting gigs. That means babies can make their screen debuts as soon as their umbilical cords are cut. California’s standards are stricter. Along with outlawing infants under 2 weeks old, it’s also a violation of state law to cast preemies. That practice was outlawed in California in 1998 due to protestations from child-labor advocates and the Screen Actors Guild. According to a 1996 Washington Post story, for example, one child advocate alleged that 1-month-old twins who were born two months premature had been slathered with cream cheese and jelly for a birth scene. (Screen Actors Guild guidelines do cover condiment usage. Grape, red currant, and cherry jelly can be used to simulate birth-related fluids. Strawberry, raspberry, and K-Y jellies are a no-no, for fear of allergic reactions.)



There are a slew of other regulations outlining what film crews can and can’t do with a baby. In California, infants under 6 months are allowed on-set for two hours a day, but their actual workday can’t exceed 20 minutes. For every three children of ages between 15 days and 6 weeks, there must be one nurse and one studio teacher; California law also requires that a parent or guardian be in attendance. Most productions set up trailers equipped with cribs where babies remain with their parents, guardians, and nurses before their scenes.



Where do these babies come from? Like everyone else in Tinseltown, babies have agents and managers. The most desirable infant actors come in sets of two or three—using twins or triplets means a production can film for 40 or 60 minutes a day instead of 20, or that a cranky baby can be swapped out for a more compliant twin. And what are these young pups paid? According to a SAG spokesperson, infants are typically hired as “background actors” and receive a day rate of $126. If an agent or parent bargains for the child to be paid as a principal performer, the rate increases to $737 per day.



Bonus Explainer: Can newborns be in the Screen Actors Guild? Yes. Most parents don’t bother signing up their newborns, though, because children under 4 are protected under the same terms as a SAG contract even if they aren’t union members.