That happened elsewhere also. It's because they stopped doing as many early / preventative C-sections, not primarily due to reduced stress. It points to the developed world likely doing too many unnecessary C-sections (for example they may do 9 that are unnecessary for every 1 that actually turns out to be required to save a life, however they'll take that trade-off in non-Covid times rather than risk additional deaths).
The C-sections spike the premature counts without any evidence that they're all required (it's strictly loose guesswork by the doctors in most cases, rather than being literally urgent; they have minimal fear of a C-section procedure today and liberally do them). This isn't uncommon, the developed world is frequently guilty of overdoing preventative & early detection medicine (we did it with mammograms, we did it with prostate cancer, and so on).
The C-sections spike the premature counts without any evidence that they're all required (it's strictly loose guesswork by the doctors in most cases, rather than being literally urgent; they have minimal fear of a C-section procedure today and liberally do them). This isn't uncommon, the developed world is frequently guilty of overdoing preventative & early detection medicine (we did it with mammograms, we did it with prostate cancer, and so on).