Umbilical artery waveforms in triplet and quadruplet pregnancies.

The incidence of abnormal umbilical waveforms in triplet and quadruplet pregnancies and its correlation with adverse pregnancy outcome was studied by a retrospective review of all our triplet and quadruplet pregnancies (1986-1993) with documented Doppler flow assessment. Obstetrical outcomes were analyzed in relation to abnormal umbilical artery waveforms. Nineteen triplet and 4 quadruplet pregnancies were studied. Of 73 fetuses, 6 had abnormal umbilical artery waveforms (8.2%). All abnormal waveforms were characterized by persistent absence of the end-diastolic velocities (AEDV). In comparing the abnormal and normal groups, significant differences were found in birth weights (910+/-433 vs. 1,724+/-434 g; p = 0.0004), small for gestational age rate [5/6 (83%) vs. 5/67 (7.5%); p = 0.0003], and perinatal mortality rate [3/6 (50%) vs. 2/67(3%); p = 0.001]. There were no differences in congenital anomalies, gestational age at birth, and neonatal intensive care admission. In conclusion, it seems that Doppler umbilical artery waveforms in multiple pregnancies were either normal or extremely abnormal (e.g. AEDV). AEDV was associated with adverse perinatal outcomes such as low birth weight, growth restriction and perinatal mortality.