Ductus arteriosus flow velocity patterns were studied in 298 women between 9 and 25 weeks of gestation using transvaginal or transabdominal Doppler ultrasound. Technically acceptable recordings were first obtained at 11 weeks resulting in 231 women for further analysis. Ductal waveforms show a significant change in shape from early pregnancy to mid‐pregnancy, in that end‐diastolic velocities are absent until 13 weeks, are present in 50% at 15 weeks and are present in all cases from 17 weeks. Regression analysis demonstrated a statistically significant linear increase with advancing gestational age for all flow velocity parameters except for the pulsatility index which remained stable during the entire study period. Copyright

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doi.org/10.1046/j.1469-0705.1992.02060397.x, hdl.handle.net/1765/93529
Ultrasound in Obstetrics and Gynecology
Department of Gynaecology & Obstetrics

Brezinka, C., Huisman, T.W.H., Stijnen, T., & Wladimiroff, J. (1992). Normal Doppler flow velocity waveforms in the fetal ductus arteriosus in the first half of pregnancy. Ultrasound in Obstetrics and Gynecology, 2(6), 397–401. doi:10.1046/j.1469-0705.1992.02060397.x