Advancements in ultrasound assessment of fetal genitalia for accurate diagnosis and comprehensive counseling.

Advancements in ultrasound technology and the integration of cell-free DNA testing into standard prenatal screening services have made it more feasible to identify fetal sex at an early stage. Fetal sex determination through sonography relies on different factors, depending on the gestational stage. In the late second trimester, it is determined by directly visualizing the external genitalia. However, in the late first and early second trimesters, it primarily relies on the direction of the genital tubercle, known as the sagittal sign. Other sonographic landmarks, like the fetal scrotum, midline raphe of the penis, labial lines, uterus, descended testis, and the direction or origin of the fetal micturition jet in males, can aid in the fetal sex determination accuracy. However, malformed external genitalia can lead to inaccurate results. This article focuses on the sonographic determination of fetal sex during the late first trimester, early second trimester and late second trimester, utilizing both transvaginal and transabdominal ultrasound techniques. Additionally, we explore various elements that have contributed to the precision of fetal sex determination. While ultrasound examination of the external genitalia is typically sufficient, there are certain situations where it becomes crucial to identify the internal genitalia for precise prenatal diagnosis and thorough counseling. This paper aims at reviewing these situations in which the evaluation of the external genital organs is necessary, as well as the ways in which ultrasound can be used in the diagnosis of genital malformations. [ABSTRACT FROM AUTHOR]