Healthy People 2010, measure 16-6a.
56 Pregnant women receiving prenatal care in the first trimester, United States, 2002, by
Centers for Disease Control and Prevention, National Center for Health Statistics, National Vital Statistics System—Natality.
Number of live births.
Number of mothers receiving prenatal care in the first trimester (three months) of pregnancy.
A description of the primary measurement used to determine the fetus' gestational age—the interval between the first day of the last normal menstrual period (LMP) and the birth— has been published by the NCHS.