J Clin Ultrasound zyxwvutsrq 21:3-8, January 1993 zyxwvuts 0 1993 by John Wiley zyxwvutsrq & Sons, Inc. CCC 0091-2751/93/0103-06 The Assessment of Normal Early Pregnancy by Transvaginal Color Doppler Ultrasonography Ash Kurjak, MD, PhD,* Gordon Crvenkovic, MD,* Aida Salihagic, MD, PhD,t Ivica Zalud, MD,* and Mladen Miljan, MD* Abstract: Transvaginal color Doppler was performed in 198 volunteer pregnant women whose menstrual age ranged from the fifth to the twelfth week. In all patients an attempt was made to obtain signals from both uterine arteries, peritrophoblastic/ retroplacental vessels, umbilical arteries, fetal aorta, intracranial vessels, and corpus luteum flow. With the combination of color and pulsed Doppler transvaginal sonography, detec- tion of vascular structures was greatly facilitated and the amount of time for exami- nation significantly reduced. Flow velocity waveforms were measured and results were analyzed by calculation of the Resistance Index. During the early stage of pregnancy, we were able to locate both uterine arteries in all cases and continuous diastolic shift signal was found. Flow in the peritrophoblas- tic/retroplacental area was observed with an overall success rate of 94%. Blood flow in the umbilical artery and fetal aorta was visualized by color Doppler starting from the seventh week. Intracranial blood flow could be visualized starting from the tenth week in some cases. Diastolic flow in these vessels was detectable starting from the twelfth week. Corpus luteum flow was found in 148 cases (75%) and the Resistance Index decreased as pregnancy progressed 0 1993 by John Wiley & Sons, Inc. Indexing Words: Transvaginal sonography - Color Doppler * Early pregnancy . Blood flow Remarkable hemodynamic changes occur in the maternal circulation during pregnancy, the most prominent being the continuous growth and de- velopment of the uteroplacental and fetoplacen- tal circulation.',' The role of fetal and uteroplacental blood flow study is now well established in obstetrical man- agement. Abnormalities in fetal peripheral cir- culation can be used as an important diagnostic parameter for the assessment of fetal ~ t a t u s ~ - ~ However, until now, there has been no reli- able way to obtain noninvasive measurements of embryonal- fetal blood flow. The combination of high-quality B-mode image, pulsed wave, and From the *Ultrasonic Institute, University of Zagreb, WHO Collaborating Center for Diagnostic Ultrasound, and tDe- partment of Physiology, University of Zagreb, Zagreb, Croatia. For reprints contact Asim Kujak, MD, PhD, Ultra- sonic Institute, University of Zagreb, Sveti Duh 64, Zagreb, Croatia. color Doppler ultrasound modalities in the same vaginal probe allows superb simultaneous visu- alization of anatomic structures and blood flow. This approach provides new insight into dynamic processes of embryonal- fetal and uteroplacental blood It is the purpose of this study to evaluate ma- ternal pelvic and embryonal-fetal blood flow be- tween the fifth and the twelfth menstrual week of normal pregnancy by the transvaginal color Doppler ultrasound technique. MATERIAL AND METHODS Transvaginal color Doppler (TVCD) sonography was performed on 198 volunteer pregnant women whose menstrual age (MA) ranged from 5 weeks to 12 weeks (Table 1). They were recruited from patients scheduled for termination of preg- nancy on request. All examined patients had 3