You have full access to this open access article. Fetal genital malformations represent a rare and heterogeneous group of congenital malformations of the disorders of sexual development DSD spectrum. A thorough literature review on the main topics in the prenatal approach towards DSD was conducted. First, a thorough overview on prenatal characteristics of the most common fetal genital malformations of ovaries, uterus and external genitalia, and second, a standardized approach for differential diagnosis in the presence of direct and indirect prenatal signs of DSDs.
This review is mainly directed towards the aspects of female genital malformations with aspects of male DSD explained as well to aid in the prenatal differential diagnosis. In prenatal diagnosis, suspicion of DSD may arise in addition to abnormalities detected in other organ systems than the external and internal genitalia. Whereas in the postnatal setting extensive guidelines exist that focus on diagnostic and treatment and quantitative scoring systems such as the external masculinization score and the Prader score are commonly used for the description of externa genitalia, there exist only few standardized protocols for the ultrasound approach of fetuses with genital malformations [ 1 , 2 , 3 , 4 , 5 ].
With this manuscript we will give an overview on the main topics in the prenatal approach towards DSD: First, a thorough overview on prenatal characteristics of the most common fetal genital malformations of ovaries, uterus and external genitalia, and second, we propose a standardized approach for differential diagnosis in the presence of direct and indirect prenatal signs of DSDs. Although this review is mainly directed towards the aspects of female genital malformations, in the setting of external genitalia, aspects of male DSD are explained as well to aid in the prenatal differential diagnosis.
The female reproductive system consists of the gonads, their internal ductal system and the external genitalia. Embryologic development starts in the first trimester with the embryonic anlage [ 6 ]. The gonads are formed as genital ridges. The germ cells migrate into the gonadal anlagen in the 6th week and the primary germ cords are formed. The uterine corpus develops from the cranial portion, the cervix from the middle two-fourths of the uterovaginal canal.
The cavitation of this vaginal plate is started by the 16th week and almost completed by the 19th week. The development of the external genitalia starts from the cloacal folds.
