Ultrasound evaluation of fetal gender at 12-14 weeks.
OBJECTIVE
The aim of this study was to assess the feasibility and accuracy of fetal gender assignment by transabdominal ultrasound at 12-14 weeks of gestation.


METHODS
Fetal gender assessment was performed in 1222 singleton pregnancies. In all fetuses the crown-rump length (CRL) was measured and the genital area of the fetus was examined in the mid-sagittal plane. The result of ultrasound examination was compared to the phenotypic sex of the newborn after delivery.


RESULTS
The feasibility as well as accuracy in determining gender increased with growing fetal CRL. At CRL < 50 mm (gestational age < 11+4) the feasibility was 39.1% and accuracy 30.5% (40.9% in male gender vs 24.3% in female gender). At CRL 50-54.9 mm (gestational age 11+4 to 12+0) the feasibility was 63.5% and accuracy 75.0% (89.1% in male gender vs 66.7% in female gender). At CRL 55-59.9 mm (gestational age 12+0 to 12+2) the feasibility was 90.5% and accuracy 96.6% (99.1% in male gender vs 93.5% in female gender). At CRL ≥ 60 mm (gestational age ≥ 12+2) the feasibility was 97.4% and accuracy 100.0% (100.0% in male gender vs 100.0% in female gender).


CONCLUSIONS
Fetal gender may reliably be determined when CRL ≥ 60 mm (gestational age ≥ 12+2). Male gender may already be reliably determined when CRL ≥ 55 mm (gestational age ≥ 12+0). If CRL < 50 mm (gestational age < 11+4) the gender cannot be reliably predicted.
Department of Obstetrics and Gynecology, University Hospital Olomouc, Czech Republic. marek@lubusky.com
Marek
M
Lubusky
Martina
M
Studnickova
Ales
A
Skrivanek
Katherine
K
Vomackova
Martin
M
Prochazka
D005240:Feasibility Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008297:Male; D011247:Pregnancy; D012727:Sex Characteristics; D016216:Ultrasonography, Prenatal / Q000379:methods