In this discussion, two epidemiological studies using two different designs are compared in terms of health outcomes. Araujo et al. (2025) used the cross-sectional approach to the HPV prevalence in Peru, while Shirvanifar et al. (2024) used the cohort design to explore the pregnancy outcomes in Sweden; both studies differed on designs, sampling, bias, and inferential strength. Study Design In a cross-sectional design, Araujo et al. (2025) studied the HPV study as it analyzed AUNA clinic in Peru (2018-2021) results from 68,714 women for the HPV test. This allowed a snapshot of disease status by region and age groups as well as an estimation of HPV prevalence in different regions and among age groups. On the other hand, the pregnancy outcome study by Shirvanifar et al. (2024) follows a cohort design using 1,973,638 singleton pregnancies in Sweden (2000-2020) for evaluating the pregnancy outcomes with respect to maternal BMI, such as gestational diabetes or pre-eclampsia. Longitudinal exposure-outcome analysis was most suited to this design. Benefits and Limitations Cross-sectional (HPV Study) The cost-efficient and ideal approach for generating hypotheses was used. Nevertheless, it lacked temporal data and, therefore, limited causal inference due to simultaneous exposure-outcome assessment. It may also miss rare conditions. Examples of suggested improvements are linked to longitudinal records. Cohort (Pregnancy Study)