Teaching first trimester uterine sizing.
D005260:Female; D005865:Gestational Age; D006801:Humans; D008961:Models, Structural; D009774:Obstetrics / Q000193:education*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D013663:Teaching / Q000379:methods*; D014463:Ultrasonography; D014599:Uterus / Q000033:anatomy & histology*