title: The effect of fetal gender on nuchal translucency at 10-14 weeks of gestation.
abstract: Recent data have suggested that fetal nuchal translucency (NT) is affected by fetal gender. We investigated the size of this effect in 12 189 unselected pregnancies with known normal outcomes that had undergone NT measurements between 10 and 14 weeks of gestation. NT increased with gestation and was converted to multiples of the median (MoM) for the gestational day. The median NT MoM (95% CI) for female fetuses was 0.98 (0.97-0.99). This was significantly lower than that of the male fetuses (1.03; range 1.02-1.04) (p<0.0005; Wilcoxon rank-sum test). The gender difference was not observed at 10 weeks but was observed from 11 weeks onwards. There is no obvious explanation for the above findings.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Tsan Yuk Hospital, Hong Kong, China. yhlam@hkucc.khu.hk
authors.forename: Y H
authors.initials: YH
authors.lastname: Lam
authors.forename: M H
authors.initials: MH
authors.lastname: Tang
authors.forename: C P
authors.initials: CP
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: Sin
authors.forename: R
authors.initials: R
authors.lastname: Tang
authors.forename: H S
authors.initials: HS
authors.lastname: Wong
authors.forename: S F
authors.initials: SF
authors.lastname: Wong
mesh_terms: D000328:Adult; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006723:Hong Kong; D006801:Humans; D008297:Male; D008499:Medical Records; D009333:Neck / Q000000981:diagnostic imaging* / Q000196:embryology*; D011247:Pregnancy; D012016:Reference Values; D012189:Retrospective Studies; D012723:Sex; D016216:Ultrasonography, Prenatal