Faculty Bibliography

OBJECTIVE: To evaluate the significance of cardiac activity on endovaginal ultrasound in embryos up to 10 mm in size. METHODS: Ninety-six women with positive urinary pregnancy tests had vaginal probe ultrasound examinations at the first clinical visit. All had discernible embryos between 1-10 mm in greatest length. The presence or absence of discernible cardiac activity was recorded. None of the subjects had any antecedent bleeding. All were available for follow-up until delivery or completion of a failed pregnancy. RESULTS: Seventy-four women had cardiac activity present at the initial study and 22 did not. Eighty-one delivered healthy newborns and 15 had early pregnancy failure. All embryos that ultimately proved normal showed cardiac activity by the time they were 4 mm in size. However, absence of detectable cardiac activity in embryos of 3 mm or less was still associated with a 41% continuation rate. CONCLUSIONS: Cardiac activity is present in normal embryos before it can be detected on ultrasound. There are variations in the type and frequency of ultrasound equipment, maternal anatomical characteristics (obesity, coexisting fibroids, uterine version), and in the visual acuity of observers. Nevertheless, we conclude that in our hands, the absence of cardiac activity in embryos measuring 4 mm or more is reliably associated with embryonic death. In contrast, the lack of cardiac activity in embryos of 3 mm or less is nondiagnostic and may warrant follow-up study in 3-5 days

Endovaginal ultrasound scanning is not merely a subset of conventional ultrasonography as practiced today. It should not be reserved for the imaging specialist. Its unique characteristics allow its incorporation into the overall routine gynecologic examination

New endovaginal probes will result in many investigators reexamining the crown-rump length data first generated with static arm and abdominal real-time scanners. As new tables are produced, only through better understanding of the anatomy of early embryos can we realize what we are actually seeing and measuring (or at least attempting to measure). Furthermore, as we try to correlate early embryonic size with gestational age, we realize that the crown-rump measurement is not applicable in principle or in nomenclature when the embryo is less than 18 mm long. When first seen, the embryo is relatively straight; a measurement of its size is best described as 'greatest length.' As the embryo curves into a C-shaped, tadpolelike structure, the greatest measurement along the long axis is actually a neck-rump measurement. Further unfolding of the head and regression of the tail finally allow an accurate crown-rump measurement (at about 18 mm) as we have used it for almost two decades. Early embryonic stages and characteristics are reviewed and methods of measurement of early embryonic size are explained

Endometrial sampling is the mainstay of management of the postmenopausal patient with uterine bleeding. Thirty women with postmenopausal bleeding were studied prospectively. Before endometrial sampling, a vaginal probe ultrasonographic examination was performed. Eleven patients demonstrated a thin 'pencil line' endometrial echo in which the maximum anteroposterior thickness on the long axis view was less than or equal to 5 mm. All eleven patients had minimal tissue obtained on biopsy and a pathology report of 'tissue insufficient for diagnosis.' Seventeen patients had an echogenic endometrium greater than or equal to 6 mm. Pathology reports of their samples revealed tissue insufficient for diagnosis (two cases), proliferative endometrium (six), secretory endometrium (three), hyperplastic endometrium (three), polyp (two), and endometrial cancer (one case). Two additional patients had no endometrial echo visualized because of associated myomas. These findings suggest (1) that the absence of significant endometrial tissue (echo less than or equal to 5 mm) on vaginal ultrasonography in cases with postmenopausal bleeding is uniformly associated with tissue insufficient for diagnosis, and (2) when endometrial thickness is greater than or equal to 6 mm the histologic diagnosis should be determined in the pathology laboratory

The orientation of the sonographer performing a transvaginal scan is currently based on a concept of anatomical planes, which is customary in transabdominal sonography. We challenge this concept and propose a different approach altogether based on focusing on target organs rather than anatomic planes. The problem of orientation in transvaginal sonography stems from the following: (1) There is a very short distance between the relatively high-frequency transvaginal transducer-probe and the scanned area; a close-up image is generated encompassing a single organ or only part of it. (2) The scanning angle is initially perpendicular to that of abdominal sonography. (3) Transvaginal sonography is an endocavitary dynamic scanning technique. According to the experience in our department (30,000 examinations during the past 4 years) and in two other medical centers, best results from the transvaginal ultrasonographic examination are achieved when the operator searches for every specific organ as the main target, without resorting to pelvic 'planes.' The guidelines for targeted organ scanning and the associated change in orientation are reported together with the limitations. Targeted organ scanning without resorting to 'planes' helps the operator to resolve the problem of orientation during the transvaginal ultrasonographic examination, and to simplify the procedure to a great extent

Vaginal ultrasonography, by virtue of its excellent resolution, has resulted in changing our concepts about early pregnancy both in normal and abnormal gestations. The purpose of this report is to examine the clinical application of this technique in abnormal early pregnancy. Pathologic pregnancy ultimately will prove to be either (1) an ectopic pregnancy or (2) an intrauterine gestation that may be destined to failure. (A third group, fetuses with anomalies, will be dealt with elsewhere). Vaginal sonography has enhanced very early pathologic diagnosis in pregnancy because of its ability to image things previously not seen with such clarity, and because the scanning process can be carried out at the time of pelvic examination when the clinical indication is first encountered.