Taken from Reddit:
"Ok I just had a thought while watching this trailer. Every person has a literal baby inside them. That is why when the dude is getting sucked up into the void he uses a knife on his chest. He is aiming to kill the baby not himself. He would have used the knife to the eye for a more instant death. The baby is almost like a parasite in many ways. It needs a host to survive. The other baby in the tank is on a form of life support because it was extracted from another human host. The void also needs the babies as sustenance but needs them alive. Maybe the strands are a form of umbilical cord. Quick thoughts of this really unique game."
He tried to shoot himself in the head first though, so not sure that holds up.