Male-to-female gender ratio in fetuses with increased nuchal translucency.
OBJECTIVE
To describe gender distribution in fetuses with increased nuchal translucency (NT) measurements.


METHODS
All fetuses with mild (2.5-2.9 mm) and moderate (3.0-3.5 mm) NT enlargement at 12.0-12.6 weeks gestation were studied. The Z test for proportions was used to compare the gender distribution of this study group to that of all babies born at Roosevelt Hospital in 2008, and to compare the gender distributions of the subgroups.


RESULTS
5109 patients received screening at 12.0-12.6 weeks gestation. 44 fetuses had mild and 28 had moderate enlargement, with a male-to-female ratio of 3.8:1.0, much higher than the 1.06:1.0 ratio among total births at Roosevelt Hospital in 2008 (p < 0.0001). Male-to-female ratio was 7.8:1.0 in fetuses with mild and 1.8:1.0 with moderate NT enlargement (p = 0.03). Among fetuses with mild NT enlargement, 3 males had aneuploidy; among those with moderate enlargement, 6 fetuses had aneuploidy, 3 males and 3 females. Seven pregnancies with aneuploidy were voluntarily terminated. All pregnancies carried to term were healthy.


CONCLUSIONS
More males than females had mild NT enlargement on first-trimester screening, but unless aneuploidy was detected they had normal birth outcomes. A slightly larger NT may be normal in males, while indicating possible fetal abnormalities in females.
Department of Obstetrics and Gynecology, St. Luke's-Roosevelt Hospital Center, New York 10019, USA.
Manal El
ME
Daouk
Lois
L
Brustman
Oded
O
Langer
Andrzej
A
Lysikiewicz
D000782:Aneuploidy; D005260:Female; D005333:Fetus / Q000502:physiology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D059785:Karyotype; D008297:Male; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011261:Pregnancy Trimester, First; D017678:Sex Distribution; D012744:Sex Ratio; D016216:Ultrasonography, Prenatal