Prenatal care utilization in excess of recommended levels: trends from 1985 to 2004.

Indexes of prenatal care adequacy distinguish care that includes more than the recommended number of visits because extra visits may signal a high-risk pregnancy. Using Natality files from 1985 to 2004, the authors found such "superadequate" care increased from 19.5% of pregnancies in 1985 to 30.0% in 2004. Although there were dramatic changes in the demographics of childbearing over the same 20 years, those changes do not explain the increase in extra prenatal visits: Superadequate care increased within every stratum defined by maternal birthplace, race, age, education, gravidity, marital status, and multiple birth. Had the demographics of childbearing not changed since 1985, the superadequate rate would be just as high in 2004. Although randomized controlled trials have found that reduced visit schedules for low-risk women do not lead to worse maternal or perinatal outcomes, the cost-effectiveness of more intense visit schedules is not known.