Leung Vivian Yee-fong, Chu Winnie Chiu-wing, Metreweli Constantine
Diagnostic Radiology and Organ Imaging Department, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
J Pediatr. 2009 Jan;154(1):116-20. doi: 10.1016/j.jpeds.2008.06.032.
To establish a nomogram of fetal hydronephrosis index (HI) (anteroposterior diameter of renal pelvis divided by urinary bladder volume) at different gestational ages, to serve as a new reference for antenatal ultrasound examination, and to avoid overestimation of fetal hydronephrosis due to transient effect of a distended fetal bladder.
504 uncomplicated singleton pregnancies from 20 to 38 weeks' gestation were included. In each fetus, the maximum anteroposterior diameters of both renal pelves were measured on transverse view of fetal kidneys. Urinary bladder volume was calculated using the ovoid volume formula. HI was derived accordingly.
Values of HI vary significantly at different trimesters of pregnancy. HI was much higher (mean = 0.1543) from 20 to 27 weeks' gestation, and its value decreased significantly (mean = 0.0253) from 28 to 38 weeks' gestation (P < .05, independent-sample t test). As gestational age increased, HI decreased (R(2) = 0.5921).
HI is easy to be measured and can be used as a new physiological reference for assessment of fetal hydronephrosis by eliminating the confounding effect of a full fetal bladder. The change in values of HI throughout gestation supports the clinical importance of a nomogram for this new index.
建立不同孕周胎儿肾盂积水指数（HI）（肾盂前后径除以膀胱容积）的列线图，作为产前超声检查的新参考指标，避免因胎儿膀胱扩张的短暂影响而高估胎儿肾盂积水情况。
纳入504例妊娠20至38周的单胎妊娠且无并发症的孕妇。对每个胎儿，在胎儿肾脏横断面上测量双侧肾盂的最大前后径。使用椭圆体积公式计算膀胱容积。据此得出HI。
HI在妊娠不同孕期差异显著。妊娠20至27周时HI值高得多（均值 = 0.1543），而妊娠28至38周时其值显著下降（均值 = 0.0253）（P < 0.05，独立样本t检验）。随着孕周增加，HI降低（R² = 0.5921）。
HI易于测量，通过消除胎儿膀胱充盈的混杂影响，可作为评估胎儿肾盂积水的新生理参考指标。HI在整个孕期的数值变化支持了该新指标列线图的临床重要性。
