The Role of Transv aginal Duplex Doppler Ul tra Sonography in Early Detection of Tubal Pregnancy,TAREK R. ABBAS, HESHAM F.A. ABOU SENNA and HOSAM El-DIN G. MOHAMMAD
Abstract
Introduction: Ectopic pregnancy is not recognized in 5- 23% of all cases using state-of-the-art diagnostic procedures.
Aim of the Work: To evaluate the role of transvaginal duplex Doppler ultra sonography in early detection of tubal pregnancy.
Material and Methods: Blood flow in tubal arteries was measured using a trans-vaginal duplex Doppler ultra-sonography system. A 3.5 MHz Doppler transducer coupled to a 5 MHz imaging transvaginal sector probe was used to detect flow characteristics in the tubal branch of the uterine artery. This was performed in 3400 patients.
Results: There was a significant increase in the blood flow on the tubal gestation side (p<0.0001, z =-4.08). This between-side difference was determined using qualitative frequency shift analysis. The mean reduction in the resistance index on the side with the ectopic pregnancy as compared to the contralateral side was 15.6%.
These changes appear to be due to trophoblast invasion. Between-side differences showed no dependence on gestational age (between gestational weeks 4 and 12 post menstruation). We compared these data with those from the control group (early viable intrauterine pregnancy and early intrauterine pregnancy failure).
In the control group, the impedance to flow, expressed as 'resistance index', showed no significant between-side difference. All control groups had significantly higher mean resistance index values than the ectopic pregnancy side, but did not differ from the contralateral side of the ectopic preg-nancy group. The advantages of this new method in diagnosing ectopic pregnancy are early detection, non-invasively and immediate results.
Conclusion: With this non-invasive method, the experi-enced investigator can identify within minutes patients at enormous risk of ectopic pregnancy out of a group of unse-lected women. The examination can be performed under almost any circumstances and has good patient compliance.