Short bi-iliac distance in prenatal Ullrich-Turner syndrome

The purpose of the present study is to evaluate the bi-iliac distance and the caudo-cranial position of the iliac bones in Ullrich-Turner syndrome (UTS) fetuses compared to recently published standards for normal fetuses. Whole-body radiographs in antero-posterior projections of 24 UTS fetuses (crown-rump lengths, 106-220 mm) were included in the study. From each radiograph, two horizontal (outer and inner bi-iliac distances) and two vertical (caudocranial) positions compared to the vertebral column were measured to estimate the position of the iliac bones. The present investigation revealed that both the outer and inner bi-iliac distances were significantly shorter in UTS fetuses than in normal fetuses. We also found that for the inner bi-iliac distance, the growth rate in UTS fetuses was significantly lower than in normal fetuses. This finding suggests not only a lesser growth but also a different growth pattern compared to normal fetuses. Regarding the caudo-cranial position of the iliac bones compared to the lower vertebral column, there was no significant difference for the lower caudo-cranial position, but the upper caudo-cranial position was significantly lower in UTS fetuses than in normal fetuses. The bi-iliac distance and the iliac bone position have not previously been described in Ullrich-Turner syndrome fetuses. (C) 2002 Wiley-Liss, Inc.