Last menstrual period versus ultrasound for pregnancy dating.
Barr
W B
WB
Department of Family Practice and Community Medicine and Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA 19104, USA. barrw@uphs.upenn.edu
Pecci
C C
CC
D000328:Adult; D005260:Female; D005306:Fertilization; D005865:Gestational Age; D006801:Humans; D008598:Menstruation; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D016216:Ultrasonography, Prenatal