Clinical And Pelvic Ultrasound Assessment Of The Growth And Development Of Normal Young Girls

Objective: To observe the morphology changes of pelvic reproductiveorgans in normal girls, the median reference range of multi-parameters wasobtained by using ultrasound technology. To assess the growth anddevelopmental status in various periods, growth index, secondary sexualcharacteristics, bone age were comprehensively analyzed.Method:274cases of normal young girls were randomly recruitedbetween July and August2011. The age range was between4.2-13.9years oldand average age was9.0±2.2（mean±SD）. The cases were considered asnormal if breast developmental age was after8years old, menarchal age wasafter10years old, the height and weight were within normal range （mean±2SD）, and bone age was within±1years old. Girls who suffer fromgynecological or endocrine disorders, severe weakness of the physicalcondition, urogenital malformations, pelvic pain, uterine or ovarian surgeryhistory were excluded from this study. We also measured height and weight,assessed breast Tanner stage, took X-rays of left wrist to assess Bone age withCHN method. Levels of follicle stimulating hormone （FSH）, luteinizinghormone （LH）, and estrogen （E₂） were evaluated by immunoassays.Transabdominal pelvic ultrasound was performed with the consent of bothsubjects and their parents. Ultrasonic parameters were measured andcalculated in which include uterine body and cervix length, width, thickness,volume, endometrial thickness, the ratio of uterine body/cervix thickness（FCR）, ovarian three dimensional size and volume, maximum follicle diameter,the number of follicles with diameter≥4mm. Two hundreds and seventy fournormal subjects were divided into five groups by chronologic age, and fourgroups by breast Tanner stages. Except11subjects without record of bone age,a total of263cases were divided into five groups by bone age. Statistical analysis was performed with SPSS13.0software. The data of non-normaldistribution were described by median （interquartile range）. Paired Wilcoxonsigned-rank test was used to compare left and right ovaries, P <0.05wasconsidered statistically significant. Kruskal-Wallis H test was used to comparegrowth index, hormone levels, the parameters of uterus and ovaries indifferent age groups, breast stage groups or bone age groups. Mann-WhitneyU test was used to do pairwise comparisons, the inspection level p=0.05/thenumber of comparison times. Line×list chi-square test was used to comparethe constituent ratio of ovarian follicular type in different age groups, breaststage groups or bone age groups. P<0.05was considered statisticallysignificant. Four table chi-square test was used to do pairwise comparisons, p<0.05/number of comparison times was considered statistically significant.Curve fitting including cubic curve, quadratic curve and exponential curvewere used to show the inner relationship between growth index, bone age andultrasonic parameter. The curve forms with the largest coefficient ofdetermination （R2） were selected as the best fit curve. The correlation indexwas calculated and the regression equation of the best-fit curve was obtained.P<0.05was considered statistically significant for the curvilinear regressionrelationship of two variables. Spearman rank correlation was used to accessthe relationship between sex hormone levels, breast stage and ultrasonicparameters. P<0.05, the correlation relationship was considered statisticallysignificant between two variables.Results:1Ultrasonic parameters show that there was no significant differencebetween left and right ovaries. All data were obtained and interpreted bytaking the average values.2Height, weight and sex hormone levels elevated with the increase ofchronologic age, breast developmental stage or bone age. In chronologic andbone age group, LH level remained relatively stable before eight and thenstarted to rise after8-year-old. The level of FSH, E₂remained relatively stablebefore10and started to rise after10. There was a significant difference between the LH levels before and after10years old. In the breast stage group,the level of LH rose and pairwise comparisons were statistically significant;FSH and E₂progressively increased from breast stage I to III, but nosignificant difference between stage III and IV-V （P>0.05）.3The length, width, thickness, volume of uterine body and cervixremained relatively stable before8years old or stage I, no increase was foundto be correlated with the growth of chronologic age and bone age. The medianlength, width, thickness, volume of uterine body was1.6-1.7cm,1.1-1.2cm,0.6-0.7cm, and0.6-0.7cm³respectively. The median length, width, thickness,volume of uterine cervix was1.5-1.7cm,1.0cm,0.6cm,0.4-0.5cm³,respectively. Endometrial lining was not displayed. After8years old or stageII of the breast, the size of the uterine body and cervix began to increasegradually with the growth of chronologic age and bone age. Endometriumbegan to proliferate. After10years old, the size of the uterus increased rapidlyand the endometrium displayed from linear to strip gradually. The shape of theuterus began to change.4The length, width, thickness and volume of ovary remained relativelystable before8years old or stage I, no correlated increase with the growth ofchronologic age and bone age. The median length, width, thickness, volume ofovary was2.0-2.3cm,1.2-1.4cm,0.8-0.9cm,1.0-1.5cm³respectively. TheConstituent ratio of follicles with diameter≥4mm and number≥4in eitherside of the ovary was approximately40%. After8years old or stage II of thebreast, the size of the ovary began to increase gradually with the growth ofchronologic age and bone age, showing statistically significant differencescompared with data of8years old before. After10years old, the ultrasonicparameters of the ovary increased rapidly, the diameter and number offollicles increased at the same time. The Constituent ratio of follicles withdiameter≥4mm and number≥4in either side of the ovary was larger than80%.5The size of uterus and ovaries, the thickness of endometrium, maximumfollicular diameter showed curve relationship in chronologic age, bone age,height and weight, respectively, the best form of curve fitting was cubic curve. Bone age was showed to be most closely related to the ultrasonic parametersof uteri and the ovaries. Statistically significant correlations were observedbetween the level of sex hormone, breast stages and the size of the uteri andthe ovaries, the thickness of endometrium, maximum follicular diameter. Thebest correlation was between breast stages and ultrasonic parameters above.Among the levels of sex hormone, LH was showed be best correlated withultrasonic parameters above.Conclusion: All tested parameters showed that the development of pelvicreproductive organs was closely related to the chronologic age, bone age,physical growth and breast development. The size and morphology of thepelvic reproductive organs may reflect the growth and developmental status ofgirl. Pelvic ultrasound combined with clinical indicators may be used tocomprehensively assess the growth and development status of normallydeveloped girls. Our studies provide basic data for clinical diagnosis andtreatment of endocrine diseases.