Ultrasonic systolic blood pressure gradient between upper and lower limbs in normal term Chinese neonates

The determination of a normal pattern of systolic blood pressure (SBP) gradient between upper limbs (UL) and lower limbs (LL) in neonates is important in the diagnosis of the coarctation syndrome. The scarcity of studies of normal neonates and the conflict of opinion prompted us to evaluate this problem. The UL and LL systolic blood pressures of 100 normal term Chinese neonates were measured by the Doppler Ultrasonic method (Roche Arteriosonde 1020). Under resting condition, the majority (89%) of our neonates had a negative SBP gradient (LL greater than UL). The mean LL SBP (70.1 mmHg) was significantly higher than that of the UL (59.5 mmHg), p less than 0.001. Eleven out of 100 of our neonates had a positive (UL greater than LL) SBP gradient. Eight of these were less than 1 week old. None had a positive gradient of more than 20 mmHg. According to the results of our study, during the first week of life, normal neonates may have upper limb pressure greater than lower limb of up to 20 mmHg.