Clinical and Experimental Obstetrics & Gynecology (CEOG) is published by IMR Press from Volume 47 Issue 1 (2020). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with S.O.G.
Reference ranges and standard percentile-curves for the doppler indices RI and SID ratio of the fetal middle cerebral artery. Color doppler measurements in a perinatal centre
Purpose: To perform reference ranges and standard percentile-curves for the Doppler indices resistance index (RI) and systolic/dyastolic (SID) ratio of the fetal middle cerebral artery, periodical color dopplersonographic measurements of 70 pregnant women in the 3rd trimester of pregnancy were done. Methods: 600 Doppler flow measurements of the fetal middle cerebral artery between 28 and 40 weeks of gestation were performed. The patients had no previous obstetric complications, no apparent medical problems and no complications in pregnancy and labor. Percentiles curves were performed for the RI and the SID ratio from the 10th percentile up to the 90th percentile. Results: In the 3rd trimester of pregnancy fetal cerebral circulation shows an increase of the diastolic component and simultaneous decrease in cerebral resistance. The average SID ratio in week 29 is 8.0, in week 34 6.0 and in the 40th week 3.5. The RI decrement is from 0.88 to 0.67. Other groups demonstrated similar ranges however absolute data are different. Conclusion: The increase in the diastolic component in the middle cerebral artery of the last third of the pregnancy demands reference ranges by using percentile curves. Knowledge of the reference range helps to discriminate between a normal fetal situation and disease. Because of different absolute ranges in the literature each perinatal centre should develop their own data.