Journal of Ultrasound in Medicine, Vol 4, Issue 12 633-639, Copyright © 1985 by American Institute of Ultrasound in Medicine
Visualization of the fetal genitalia by ultrasonography: a review of the literature and analysis of its accuracy and ethical implications
B. R. Elejalde, M. M. de Elejalde and T. Heitman
The results of the ultrasonographic determination of fetal gender in utero
in 722 fetuses (13-35 weeks' gestation) are described, demonstrating that
fetal genitalia can be seen in 60.5 per cent of those examined before the
eighteenth week, and in 100 per cent of those examined twice or once after
20 weeks of gestation. All errors (3.04 per cent) of gender assignment
occurred before the twenty-fourth week. When the fetus was examined for the
first time at 17 weeks, the genitalia were visualized and correctly
diagnosed in 282 males and 155 females; nine males and 13 females were
incorrectly diagnosed. Ultrasonographic determination of fetal gender in
utero is an integral part of the prenatal diagnosis of sex maldefinition,
testicular feminization, and campomelic dysplasia. It has proved to be a
reliable marker in determining whether each sac has been sampled in
multiple pregnancies (when each fetus is in a different sac) if
ultrasonographically assigned sex per twin corresponds to its karyotype.
The determination of fetal gender in utero by ultrasonography allows for
gender selection; some of its ethical implications are considered.