The Changes Of Sonographic Characteristics In Partial Hydatidiform Mole In The First Trimester Over The Time

Objective: Due to the high rate of misdiagnosis and omission diagnosis of partial hydatidiform mole(PHM)in the first trimester,it is extremely challenging to accurately early diagnosis of PHM.We investigated the changes in sonographic characteristics of PHM over time,improved our understanding of early PHM,and looked for ultrasound indicators with diagnostic predictive value by examining the ultrasound characteristics of PHM at different gestational ages and comparing them with the ultrasound images of normal pregnant women during the same time period.Methods: This retrospective study was performed on 83 patients(140pre-operational ultrasound files)with PHM pathologically proven in Women’s Hospital,School of Medicine,Zhejiang University from January 2010 to January2020.According to the gestational age at the time of the ultrasound examination,the PHM group was divided into five groups: 42-55 days group,56-69 days group,70-83 days group,84-97 days group,and >98 days group.The ultrasound characteristics,such as embryonic sac morphology,chorionic bump,villus thickness change characteristics,and the accuracy of ultrasound diagnosis at various gestational ages were then examined.The ultrasound data of normal pregnancies delivered in Women’s Hospital,School of Medicine,Zhejiang University from August 2021 to October 2021 were matched with the PHM ultrasound data according to gestational age ≥2:1,and the differences in embryo sac length,germ length,and villus thickness between the two images were analyzed.A total of 245 normal pregnancies(297ultrasound data)were included in the study.Results: The diagnostic rate was positively correlated with gestational age(P<0.05),and the younger the gestational age,the lower the diagnostic rate of ultrasound for PHM,with the diagnostic rate of the 42-55 days group being 0.0%.Of the 145 PHM ultrasound reports,the diagnostic rate was 33.8%(49/145),and the misdiagnosis rate was 66.2%(96/145).Uterine volume,germ length,embryo sac shape,embryo sac length,villus thickness,and the number of vesicular were positively correlated with gestational age(P< 0.05);in contrast,septa within the embryo sac and ovarian cysts were negatively correlated with gestational age(P <0.05).Vesicles were present in most cases of PHM,with the earliest day of occurrence being 51 days and the number <5 accounting for only 10.6%(2/19)in the early 42-55 day group.And the number of vesicles ≥5 was 71.0%(103/145).The earliest time a chorionic bump was discovered was 51 days.They were visible in21.4%(31/145)of PHM and quite common in the 56-69 day group and the ≥98 day group,28.6%(10/35)and 25.0%(4/16),respectively.Embryo sac morphology was more common in the 42-55 days group with type 0(42.1%,8/19)and type 1(42.1%,8/19),in the 56-69 days group and 70-83 days group with type 1(48.6%,47.2%),and in the 84-97 days group and ≥98 days group with type 2(51.3%,56.2%).Except the84-97 day group,the villus thickness values in the PHM group were consistently higher than those in the normal group and were significantly different(P< 0.05).According to ROC curve analysis,the AUC of villus thickness for various time periods was 0.925(95%CI,0.872-0.979),0.698(95% CI,0.581-0.814),and 0.518(95% CI,0.388-0.649),in that order.The best cut-off values were 0.655,0.990,1.115,and 2.010,respectively,with sensitivity of 68.4%,80.0%,55.6%,and 33.3% and specificity of 91.8%,94.6%,80.6%,and 88.5% for the 42-55,56-69,70-83,and84-97 days groups.Conclusion: PHM is not characterized by typical ultrasound features in the first trimester and has a high rate of misdiagnosis.The morphology of the embryo sac has a positive correlation with gestational age,and morphological changes such as the morphology of the embryo sac,the delicate structures of the internal wall of the embryo sac,and the chorionic bump are valuable for the diagnosis of PHM.One of the key characteristics in the diagnosis of PHM is villus thickening,which can be used to confirm the diagnosis before the onset of early typical ultrasonography signs such as an abundance of vesicles(snowstorm effect).