2020 updates by Cathy Bickel
Since gerbils do not appear visibly pregnant until the last few days of pregnancy and typically give birth quietly in the early morning, your first awareness of a pregnancy might be the soft chirp of hungry pink babies.
Should you have the privilege of seeing birth take place, observe quietly. It is seldom necessary for a mother gerbil to require assistance. If you do observe your female gerbil in labor for a very extended period of time, for more than 8 hours, a call to your vet is in order. Labor can be stalled by low calcium levels, which can be boosted by administering a slurry of a ground-up Tums or Rolaids with a bit of water. This is given orally in a syringe.
A female truly in danger will require a C-section, which is effectively a spay surgery. It is unlikely that most or any pups will survive a very extended labor, so brace yourself. But do seek help for the mother if she is in pain. This is one of the risks you accept as the owner of a breeding female. The chances of a mother gerbil needing surgery are, in my experience, less than 1%. Many long-time breeders will never see this complication.