small litter trend?

[Donna Anastasi]

I placed a dove-black gerbil pair with a friend and in their first
litter one large, healthy pup was birthed; unfortunately he died at a
few days (I'd guess unable to maintain body heat -- right?).

A second litter is due shortly,
What is the chances that this second litter (and future litters) will be
very small too?

Please answer soon, as I'm going to recommend if it's another one pup
(or two) litter that they keep the nest box in place to help the pup
maintain its temperature.

Thanks!  Donna A.