Dollahite provides a review of research on LDS fertility; LDS fertility rates above average of non-religious and most other religious groups.
David C. Dollahite, Loren D. Marks, and Heather Howell Kelley, "Mormon Scholars and Mormon Families in Family Studies: A Brief Retrospective," Mormon Studies Review 4 (2017): 16-40
Mormon fertility rates have consistently stayed above the average of nonreligious groups and above those of most other religious groups. Although these rates remain well above the national average, they are gradually declining.