Do human babies have gill slits while in the womb

I keep hearing this.
Is it true or false?

Truishly false ... or falsishly true

1) Gill slits is the wrong term. The word "gill" suggests a certain structure and/or function, and what human embryos have do not have the structure or function of gills.

2) Human embryos have pharyngeal slits. The word 'pharyngeal' only indicates location of the body, not structure or function.

“Soon, only a thin membrane, the branchial plate, separates the [ectodermal] groove from the [pharyngeal] pouch. If, and when, the branchial plate ruptures, a passageway is formed between the pharyngeal lumen and the exterior of the animal. This passageway is a pharyngeal slit. The slits may be permanent, as in fishes in which they are exits for respiratory water from the gills, or they are temporary, as in most tetrapods. … Pharyngeal slits are temporary if the animal is going to live on land. … In reptiles (including birds) and mammals, no gills develop in the [pharyngeal] pouches, and the [pharyngeal] slits are transitory. Of the five pouches that develop in chicks, the first three rupture to the exterior and close again. Only one or two of the more anterior pouches of mammals may rupture. Cervical fistulas occasionally seen in human beings are usually the result of the failure of the cervical sinus, housing the third and fourth slits, to close.”
(George C. Kent & Robert K Carr, Comparative Anatomy of the Vertebrates: Ninth Edition, McGraw Hill, 2001, p7)


That indicates that human embryos have transient pharyngeal slits; one or two open up and then close up quickly.



Note that it is not just embryos of humans that have these pharyngeal slits -- so too do the embryos of other mammals, birds, reptiles, amphibians, and fish. All of those other groups of animals descended from certain ancient fish, which is why they still have pharyngeal slits.

All of those animals - including humans (as embryos) - also have a postanal tail, which they inherited from certain ancient fish.