The investigators will follow 146 new parents of children \<5 years of age at 18 participating US adult CF centers to assess the primary outcome of percent predicted forced expiratory volume in one second (ppFEV1) up to 5 years after becoming a parent. A prospective approach will capture the immediate and long-term impact of the use of the highly effective CFTR modulator ETI (elexacaftor/tezacaftor/ivacaftor) by \~90 percent of US adults with CF. By combining objective health measures and participant surveys, the investigators can comprehensively assess the psychosocial impacts of parenthood and explore the interplay between the parenting role and physical and mental health. The investigators anticipate identifying modifiable factors that may ameliorate negative health impacts of parenthood. The investigators will conduct hypothesis-generating, semi-structured dyadic interviews with a subset of parents and their key supports (partner/family/friend) to inform future interventions. The investigators have selected qualitative methodology to avoid preconceived theories/hypotheses.
