EP20.04: Diagnostic indices of MCA PSV for fetal severe anemia in MCDA twin pregnancy

Abstract

To examine the diagnostic indices of fetal middle cerebral artery peak systolic velocity (MCA PSV) above 1.55 multiples of the median(MoM) Doppler velocimetry for the identification of fetal severe anemia in monochorionic diamniotic (MCDA) twin pregnancies. Study population consisted of 178 MCDA twin fetuses who underwent MCA PSV Doppler velocimetry within 7 days of delivery between gestational age (GA) of 24 and 38 weeks at Seoul National University Hospital between 2005 and February 2017. Fetuses with chromosomal abnormalities, major congenital anomalies or intrauterine demise were excluded. We examined the frequency of severe fetal anemia according to the presence of an increased fetal MCA PSV (≥1.55 MoM). Severe anemia was defined in the presence of hemoglobin concentration < 0.55 MoM in umbilical cord blood at the time of delivery. An increased MCA PSV (≥1.55 MoM) was present in 8.4% of study population and severe anemia was present in 2.2%. Diagnostic indices of an increased MCA PSV (≥1.55 MoM) for the identification of severe anemia were as follows: sensitivity 100% (4/4), specificity 93.7% (163/14), positive predictive value (PPV) 26.7% (4/15) and negative predictive value 100% (163/163). However, PPV at GA 30 weeks or more was only 12.5%, while that at GA less than 30 weeks was 42.9%. The sensitivity and specificity of an increased MCA PSV (≥1.55 MoM) for the identification of severe anemia in MCDA twin pregnancies are very high. However, PPV of that is much lower in cases with GA 30 weeks or more than in those with GA less than less than 30 weeks among MCDA twin pregnancies. EP20.04: Table 1. Middle cerebral artery peak systolic velocity (MCA PSV) Doppler velocimetry in the prediction of fetal severe anemia