We performed 77 Doppler blood flow studies of the umbilical artery in 45 foetuses with malformations and/or chromosomal abnormalities. 20 foetuses had chromosomal abnormalities and 34 records of the second and third trimester were analysed. In 25 foetuses with malformations, but without chromosomal abnormalities, 43 investigations were performed between 21st and 40th weeks of gestation. In the second trimester, 3 of 11 foetuses with chromosomal abnormalities had an absence of enddiastolic flow velocities, whereas the other foetuses had pulsatility indices within the range for foetuses with a normal karyotype. In the third trimester, 7 of 10 foetuses with chromosomal abnormalities had pathological Doppler findings. Four cases had absent or reversed enddiastolic (ARED) flow velocities. Altogether 10 of 13 foetuses beyond the 19th weeks of gestation had pathological Doppler findings (sensitivity = 77%). The structure and the function of the placenta is influenced by the abnormal karyotype, which is demonstrated by pathological Doppler findings. Only 3 of 43 investigations in foetuses with malformations but normal karyotype, showed abnormal PI values and there was no case of ARED flow. In a group of 24 foetuses with ARED flow, 6 foetuses had chromosomal abnormalities. All foetuses with malformations and ARED flow had an abnormal karyotype. Prenatal chromosome analyses of foetuses with suspicious sonographic findings, revealed a rate of 29% chromosomal abnormalities, nearly all of them with a maternal age under 35 years. Whereas Doppler sonography cannot exclude chromosomal abnormalities before the 20th weeks of gestation, there is a good correlation between chromosomal abnormalities and abnormal Doppler findings later on.(ABSTRACT TRUNCATED AT 250 WORDS)
Pulsed Dopplersonography of the umbilical artery was performed in 155 singleton high-risk pregnancies without malformations or chromosomal abnormalities. 59 foetuses were classified as foetuses with intrauterine growth retardation (IUGR). 46 of them had a birth weight below the tenth percentile. In 20 cases the pulsatility index (PI) was elevated (sensitivity: 44%). In all there were 50 neonates with a birth weight below the tenth percentile, 46 of whom were detected by biometry (sensitivity: 92%). 8 dystrophic neonates with a biometry that revealed IUGR were compromised by perinatal asphyxia. In six cases operative delivery was necessary and two cases with reversed diastolic flow ended in intrauterine foetal death. 7 of those foetuses had an elevated PI. The sensitivity of Dopplersonography in this group was 88%, the negative predictive value 97%. The positive predictive value with regard to a dystrophic neonate can be improved from 78% to 91%, if compared with biometry alone. Summing up, Dopplersonography of the umbilical artery can distinguish very well between IUGR foetuses at risk of perinatal morbidity or mortality and those IUGR foetuses with sufficient placental circulation who are, therefore, not at risk.
In a group of 810 singleton pregnancies without malformations or chromosomal abnormalities blood flow velocity wave forms of the umbilical artery were recorded in the third trimester by means of a pulsed duplex Doppler system. We calculated the pulsatility index (PI). 133 newborn with a birthweight below the 10th centile were classified as small-for-gestational-age (SGA) (prevalence: 16%). The sensitivity of the test (elevated PI) for these neonates is 52% and the specificity 97%, the positive predictive value is 78% and the negative predictive value 91%. Therefore, Doppler Sonography of the umbilical artery is not an appropriate screening test to identify SGA babies prenatally. The results for jeopardized SGA babies (caesarean section because of pathological CTG traces, transfer to the neonatal intensive care unit) are much better. 31 out of 133 belonged to that group. For these foetuses, the sensitivity of the test is 94% and the negative predictive value 97%. Hence, Doppler Sonography of the umbilical artery allows very well to identify the endangered SGA foetuses on the one hand and to exclude foetal jeopardy with a normal PI on the other.
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