To investigate ultrasonic imaging characteristics and prognosis of fetal congenital cataract (CC).

From January 2018 to December 2021, a total of 7 cases of fetuses with CC (fetus 1-7) [six fetuses (fetus 1-6) were diagnosed as CC at gestational age of 23^{+ 4}-28 weeks by prenatal ultrasound in Department of Ultrasound, West China Second University Hospital, Sichuan University, and one fetus (fetus 7) was diagnosed as CC in another hospital at the gestational age of 30^{+ 1} weeks and was transferred to our hospital] were selected as research subjects. The ultrasonographic characteristics and prognosis of those 7 cases of CC fetuses were analyzed retrospectively.

①Ultrasonographic characteristics of fetal CC: fetal lens of 4 cases (fetus 1, 3, 5, 6) showed complete hyperechogenicity, 2 cases (fetus 3, 7) showed dot and sheet hyperechogenicity, and 1 case (fetus 2) showed annular hyperechogenicity. ②Pregnant mothers: all denied once exposure to radioactive substances, chemicals and other toxic and harmful substances during pregnancy. Lineal relation of two cases (fetus 3, 5) had a history of cataract. Pregnant mothers of three cases (fetus 1, 3, 6) were diagnosed with vaginitis during pregnancy, and pregnant mother of fetus 1 was diagnosed with vaginitis in the other hospital during early pregnancy and was treated with external application drugs (unknown of detail drugs), and pregnant mothers of fetus 3 and 6 did not receive any treatment for vaginitis. ③Fetal pregnancy outcome and prognosis: 5 cases (fetus 2, 3, 5, 7) were isolated CC, 2 cases (fetus 1, 4) were combined with other structural malformations. Six cases (fetus 1-6) were induced to terminate pregnancy, fetus 1 and 4 with multiple malformations underwent full exon sequencing analysis, and fetus 4 had COL4AI gene C. 268G>T variation which was a possible pathogenic variant associated with CC, no definite or possible pathogenic variation related to CC was found in fetus 1. The other 4 fetuses did not receive gene test. Fetus 7 was delivered by elective cesarean section at gestational age of 37 weeks, and CC operation was performed 4 weeks after birth.

Fetal CC is a kind of disease with abnormal lens development. Prenatal ultrasound shows complete hyperechogenicity, dot, sheet or ring hyperechogenicity. Prenatal ultrasound diagnosis of CC fetus can provide important information for prenatal consultation, early treatment for CC.