Good point @NotBadConsidering
At the time of a medically-enforced separation, a newborn would cry for his or her mother. This will probably not cause long-term trauma should they be reunited, but at the time the baby would cry and the mother, if conscious, would be desperate to soothe her fresh-from-the-womb newborn baby. The father, a partner, a grandparent or a nurse would obviously try to soothe the child and provide comfort and the baby would eventually tire and settle. That situation is far from ideal, but it is necessary to prioritise - possibly life saving - medical treatment.
Those who have experienced this personally would be unlikely to remember how it felt or how they screamed as we don’t form memories that early, but parents or grandparents may remember better and could recall how a baby wouldn’t settle unless close to the mother, close enough to smell her perhaps. Depending on the trauma and worry at the time it could be also traumatic for them too.
My child was held as I passed out from blood loss…upon consciousness I felt a very strong physical need not only to hold my baby right now but to also breastfeed, having no prior experience of this. My baby did not cry, I assume due to the shock of suddenly being outside of my body rather than inside (which is common, with lengthy births especially babies can also exit very tired out) but our enforced medical separation was minutes, not hours or days and I can only describe the physical reaction I had as primal or animalistic. I would even say it was something beyond instinct, it’s difficult to describe.
I don’t know why the mother/baby dyad would be any different for a surrogate-born baby. Does a baby know they are being grown and birthed by a woman who has agreed to be a surrogate mother? Any study exploring this would need to create a control group to prove the findings and as a PP said, this would be unethical.
Why wouldn’t a study be done where newborns are taken from their mothers and given to strangers (human babies don’t build emotional bonds with the providers of the gametes they were conceived with) to form a control group for a study on surrogate born babies? Why is it considered unethical - is it because the bond between mother and child is widely understood, has been studied for decades (Bowlby etc) and it would be considered cruel to artificially withdraw a mother from her child and a child for his or her mother, for the purposes of a study?