Answer:
Longitudinal study design
Step-by-step explanation:
A longitudinal study design is a type of research design that has to do with observation of same variables repeatedly over a period of time. A longitudinal study can be over a shirt period of time or a long period.
This researcher is interested in collecting data on perinatal circumstances and he is collecting data from these persons at different times of their life. When they are 10, 18 and when they are 35.