Splenic artery: peak systolic velocity of normal fetuses.

OBJECTIVE

To establish a reference range of splenic artery peak systolic velocity 1(SpA-PSV) in the normal singleton pregnancies (14-40 weeks).

METHODS

A prospective descriptive study was conducted on uncomplicated singleton pregnancies with normal fetuses and accurate gestational age were recruited into the study. The Doppler measurements of SpA-PSV were performed by the experienced sonographers with the high-resolution machine (Aloka Prosound alpha-10, Tokyo, Japan, or Voluson E8, GE Healthcare, USA).

RESULTS

A total of 540 measurements were performed, ranging from 15 to 30 for each gestational week (GA). The best regression model between GA and SpA-PSV was observed to be linear function with an equation as follows: SpA-PSV (cm/s)=-1.433+1.186 (GA, weeks) (r2=0.573). The table of nomogram for various percentile ranges was constructed. The results show a continuous increase in SpA-PSV over the period from 14 to 40 weeks.

CONCLUSION

A nomogram for SpA-PSV for each GA during 14-40 weeks was constructed. This reference range may be a useful non-invasive tool in risk assessment for fetal anemia, especially due to homozygous alpha-thalassemia-1 or fetal isoimmunization.