Possible Use of Doppler Velocimetry in the Detection of Discordant Growth of Twins

Overview

Objective:
To evaluate the clinical utility of Doppler velocimetry as a comprehensive test for the prediction of discordant twins.

Design:
Prospective clinical study.

Setting:
Department of Gynecology and Obstetrics, Charles University Hospital, Hradec Králové, Czech Republic.

Methods:
Biometrical measurements and Doppler velocimetry of umbilical artery (UA) and middle cerebral artery (MCA) were performed in twins in third trimester. Intertwin differences in biometrical parametres Δ BPD, Δ AC, Δ FL, Δ EFW and in pulsality indexes of studied vessels Δ UA a Δ MCA were expressed. Discordance was identified by the birth weight difference from 20%. Studied parameters were evaluated using ROC analysis.

Results:
Among the 63 sets of twins studied, 33 pars fulfilled the study criteria. 21 pars were bichorionic, 7 monochorionic and 5 with unknown chorionicity. Ten sets of twins were discordant (30.3%). The mean gestational age at delivery was 35.9±1.7 weeks. Overall the best discordancy predictor was Δ EFW with sensitivity and specificity values of 100% and 95.7%, respectively, for the cut-off value Δ EFW 17.9%. The more accurate one of doppler parameters was MCA, with sensitivity and specificity values of 85.7% and 77.9%, respectively, for the cut-off value Δ MCA 25%. UA had senzitivity and specificity 70% and 47.8 %, respectively, for most suitable cut-off value Δ UA 16.7%.

Conclusion:
It is possible to predict the discordant twins birth using middle cerebral artery Doppler velocimetry, but the EFW assessment remains the most accurate method. Umbilical artery Doppler velocimetry did not appeared as effective.

Key words:
ultrasonography, twin pregnancy, Doppler velocimetry, growth discordance