It's hard to miss the mysterious baby in Death Stranding, and it's only common sense to wonder about its place in the story and twisted world of the game.
Here is all the information we have been able to gather so far.
Death Stranding: Bridge Baby
The official name of the device containing the baby carried by Sam is 'Bridge Baby' commonly abbreviated as 'BB'. The babies used were extracted from the 'still mother', pregnant women in a vegetative state, kept alive in the capital Knot City.
The Baby Pod Bridge mimics the mother's womb, and is regularly updated with environmental data to better reproduce and synchronize the mother's physiological conditions. Without this device, the baby could not survive long. But even with all this, a Bridge Baby is only in service for an average of one year.
The interest of all this is to create a link between the world of the dead and the carrier of the Bridge Baby. This effect is called 'trance connection'. This link allows us to see supernatural entities called 'beached things' (or BTs), which have been stranded outside the world of the dead and have ended up in ours.
It also seems that the BB is involved in Sam's resurrection, after he has been devoured by the BTs. It's a vital device for surviving and travelling between different areas.
Higgs (the 'Man in the Golden Mask') — one of the primary antagonists — carries an alternative version of this device, but with a fetus inside and a red rather than orange light.
The character of Mama and her ghostly baby seem to be special cases and one of the few rare phenomenon that make BBs so useful.
Death Stranding: Interactions with the baby
You will be able to take care of the baby to some extent. For example, if you shake it too much or fall on your stomach, the baby will not like it and will start crying. You can then rock it using the motion sensor on the PS4 controller or one of the joysticks to calm it down.
Other interactions have been introduced, for example, after a delivery, Sam receives a harmonica that he can play for the baby who will then award you "likes".
Finally, when Sam crosses a hot spring, the baby also benefits from it indirectly when his pod floats. It's likely that many other interactions are on the agenda.
