Study On A Diagnostic Model For Girls With Idiopathic Precocious Puberty

Objective : To establish a diagnosis model of Idiopathic central precocious puberty(ICPP)based on pelvic ultrasound,bone age(BA)and basic gonadotropin,To explore the best timing for Gn RH stimulation test.Method:The study included 167 girls with prematurely developed breasts whose first diagnosis age was less than 9 years old and whose Tanner breast development stage II,From January 2016 to May 2018.69 girls with Luternizing hormone(LH)peak value ? 5 IU/L and LH peak / Follicle-stimulating hormone(FSH)peak value ? 0.6 were selected as ICPP group(n = 69),and the rest were Premature Thelarche(PT)group(n = 98).The clinical data,hormone,BA and pelvic ultrasound parameters of the two groups of girls were compared.The receiver operating characteristic(ROC)curve was established and the parameters with differences between the ICPP and PT groups.A multi-index joint diagnosis model was established by binary Logistic regression analysis.Results:1.There was no significant difference in Chronological age,height,weight,BMI and FCR between ICPP group and PT group(P>0.05);2.Compared with the PT group,the ICPP group showed older bone age,higher basic LH,FSH and LH/FSH,larger volume of uterus and ovary,longer diameter of uterus and maximum follicle,more follicles ?4mm,thicker endometrium and vaginal wall,and significant differences between the two groups(P<0.05);3.The prediction equation was successfully established: Y=-13.287 + 1.787 × uterine length + 1.251 × basic LH+1.093 × BA,the AUC was 0.854,the cut-off value was-0.81,the sensitivity was 75.4%,and the specificity was 83.7%.Conclusion:The prediction equation has more diagnostic value for girls with ICPP than single parameter.After the girls with prematurely developed breasts passed the basic clinical examination,the uterine length,basic LH and BA were brought into the prediction model,if the predicted results <-0.81,it is recommended to make regular clinical observation.If the predicted results >-0.81,it is necessary to make a definite diagnosis by Gn RH stimulation test.