Babies born between 32 and 37 weeks of pregnancy are considered preterm. The Growth Tracker and Development Tracker tools within the app will be adjusted based on the number of weeks early up until 2 years of age. At the end of 2 years, the app no longer adjusts for preemies.
To turn on preemie mode in the app, go to the app's Settings > Birthday. There is a "switch" to turn on preemie mode and you can enter your due date.
To turn off preemie mode at any time, you can turn off this switch.