BACKGROUND: Natrelle 410 implants (Allergan, Inc., Irvine, CA) are approved in the United States for breast augmentation, reconstruction, and revision. OBJECTIVES: To assess the risk of nipple and skin sensation changes and lactation issues in subjects receiving implants for primary breast augmentation and ascertain whether differences based on incision site exist. METHODS: We used 410 Continued Access study data to assess safety and effectiveness of devices implanted via inframammary or periareolar incision sites. Subjects were evaluated preoperatively and at 4 weeks, 6 months, and annually up to 10 years postoperatively. Lactation issues and nipple and skin sensation changes (hypersensitivity/paresthesia, loss of sensation) were assessed. RESULTS: The inframammary and periareolar cohorts comprised 9217 and 610 implanted devices, with mean follow-up of 4.1 years (range, 0-10.1 years) and 4.8 years (range, 0-10.1 years), respectively. In the inframammary cohort, risk of first occurrence of nipple sensation changes was 0.3% (95% CI: 0.2-0.5) at week 4 and month 6, and 0.4% (0.3-0.7) at year 10. Risk of skin sensation changes was 0.0% (95% CI: 0.0-0.2) at week 4, 0.1% (0.0-0.2) at month 6, and 0.1% (0.0-0.3) at all subsequent time points. No nipple or skin changes occurred in the periareolar cohort. Incidence of lactation issues was similar to that reported in postpartum women who did not have breast implants. CONCLUSIONS: We found that the risk of nipple or skin sensation changes and lactation issues is low and provide long-term safety and effectiveness data on subjects receiving implants for primary breast augmentation. LEVEL OF EVIDENCE 3: Therapeutic.