title: Reply to Dr Jelsema.
authors.forename: Nir
authors.initials: N
authors.lastname: Melamed
authors.forename: Israel
authors.initials: I
authors.lastname: Meizner
mesh_terms: D018568:Crown-Rump Length; D005260:Female; D020567:Fetal Weight; D005333:Fetus / Q000033:anatomy & histology*; D006801:Humans; D011247:Pregnancy; D016216:Ultrasonography, Prenatal