Hello all, I keep seeing posts relating to sleep regression at 4 month and 6 months. My twins are 23 weeks / 15 weeks corrected age and have been pretty good sleepers but my girl is starting to be a lot more fussy, harder to settle and/or sleeps lighter and less some days. I'm wondering if this would be attributed to a 4 month sleep regression as they are nearly 4 months corrected age? Is sleep regression guaranteed at these month milestones, how long should I expect it to last and what can be done? Thanks x