Study Overview: This study looks at how pregnancy affects women with cystic fibrosis (CF), especially focusing on lung function. Cystic fibrosis is a disease that causes mucus to build up in the lungs. The study will also look at the effects of special medicines called CFTR modulators, which help many people with CF breathe better.

About the Study: The study will take place at 40 different sites across the United States. Women will join the study during their first three months of pregnancy. Researchers will check on them every 3 months while they are pregnant, and then every 6 months for 2 years after they give birth. The study will measure their lung function and see how it's affected by the medicines they're taking.

• Time Commitment: Regular visits throughout pregnancy and for 2 years after.
• Participation: Open to pregnant women with CF in the Cystic Fibrosis Foundation Patient Registry.
• Risks: Observational, meaning no extra treatments or risks.

Note: There are no specific risks from participating, as the study is just observational (watching and recording), not testing any new treatments.