Errors in the measurement of endometrial depth using transvaginal sonography in postmenopausal women on tamoxifen: random error is reduced using saline instillation sonography.

OBJECTIVE: The endometrium in women on tamoxifen is often made irregular by small cysts. The aim of this study was to assess the accuracy and precision of the measurement of endometrial depth by transvaginal sonography. METHODS: The endometrial depth from endometrial biopsies obtained with the resectoscope in 15 women receiving tamoxifen was compared to the endometrial depth measured by TVS. The inter-observer variability was measured in 58 women. RESULTS: In those biopsies of sufficient quality to allow a measurement, the corresponding depth measurement obtained by ultrasound was up to 3 mm greater than the histological measurement. The interobserver variability for the measurement of endometrial depth using TVS was assessed in 58 postmenopausal women on tamoxifen. The interobserver variability deteriorated as the mean endometrial depth increased, probably because the increase in depth resulted from greater morphological changes within the endometrium such as cyst formation which resulted in an irregular endometrial/myometrial boundary. This may, however, be improved by performing saline instillation sonography. In a prospective study of 10 postmenopausal women, the interobserver variability was significantly greater during tamoxifen treatment compared to pretreatment. CONCLUSIONS: On the basis of the above, if uterine surveillance using TVS were to be offered to postmenopausal women on tamoxifen, then the procedure should be augmented by saline instillation sonography if the endometrial depth is > 4 mm, as this will improve the measurement precision and also identify intrauterine pathology.

Histological analysis of the uterine junctional zone as seen by transvaginal ultrasound.

OBJECTIVE: This study aimed to investigate the histology of the subendometrial halo, the junctional zone between the endometrium and myometrium. METHODS: Thirteen ex vivo uteri removed for treatment of menorrhagia were studied. In each case, the subendometrial halo, as seen by transvaginal ultrasound, was marked using a Nottingham breast location biopsy needle. A standard histological examination was performed. Full thickness blocks of the anterior uterine wall were taken and standard serial 5-micron tissue sections were prepared from each block. Subsequent morphometric analysis followed staining with Feulgen reagent, using a CAS 200D quantitative image analysis system. Additionally, anti-CD31, an antibody stain for vascular endothelium, was used. RESULTS: The histological examination showed the subendometrial halo to consist of apparently normal myometrium. Morphometric analysis demonstrated a greater total nuclear area in the subendometrial halo than the outer myometrium, but no difference in individual nuclear size between the two zones. CD31 stained a greater total area in the inner myometrium. CONCLUSIONS: These results suggest that the subendometrial halo is a distinct compartment of the myometrium comprising tightly packed muscle cells with an increased vascularity. Such architecture would increase the density of this tissue layer, altering its acoustic impedance, and account for its echopenic appearance on ultrasound.

Ultrasound evaluation of the uterine zonal anatomy during in-vitro fertilization and embryo transfer.

This study was designed to establish if ultrasound could detect differences in uterine zonal anatomy between conception and non-conception in-vitro fertilization (IVF)/embryo transfer cycles. A transvaginal ultrasound scan was performed on the day of down regulation (D0), on day 8 of ovulation induction (D8), on the day of human chorionic gonadotrophin (HCG) injection, at the time of oocyte retrieval, and at embryo transfer. Thicknesses of endometrium, junctional zone, myometrium and full thickness of the uterus were recorded for every patient and comparisons made at all the assessment points. Differences between measurements on D0 and all other measurements (temporal changes) and between every subsequent measurement (dynamic changes) were also compared. There were no statistically significant differences in endometrial thickness between pregnant and non-pregnant groups at any time. The diameter of the uterus increased during therapy and was significantly greater in the pregnant subset at the time of HCG injection, oocyte retrieval and embryo transfer (P < 0.02, 0.03 and 0.02 respectively). The myometrium was significantly thicker in the pregnant group on D0, on D8 and at HCG administration (P < 0.03, 0.004 and 0.02). There was a decrease in junctional zone thickness in both groups during the first week of ovulation induction, and on D8 the junctional zone in pregnant patients was significantly thinner (P < 0.04). The junctional zone became significantly thicker at embryo transfer in the pregnant group (P < 0.01). This was confirmed by significant temporal and dynamic changes at the time of oocyte retrieval and embryo transfer (P < 0.01, 0.0001 and P < 0.05, 0.01 respectively). In the patients who did not conceive, changes in the junctional zone were less pronounced. In conclusion, it was not possible to predict the likelihood of pregnancy from endometrial thickness at any time during the IVF cycle, but changes occurred in other uterine layers that were more pronounced in conception cycles. The responsiveness of the junctional zone seems to be associated with implantation, and its measurements at the time of downregulation and embryo transfer can be used to predict treatment outcome.

Uterine junctional zone contractions during assisted reproduction cycles.

This study was designed to assess junctional zone contractions (JZ) during cycles of in-vitro fertilization (IVF) and embryo transfer in oocyte donors exposed to a long protocol regime for ovarian stimulation. Real-time transvaginal ultrasound and advanced audio-visual and computer technology were used to evaluate the contraction pattern, frequency and velocity. At the time of down-regulation JZ contractions were not observed. After 7 days of superovulation all patients displayed cervico-fundal, fundo-cervical and random contractions. Cervico-fundal waves dominated the picture at the time of human chorionic gonadotrophin injection. However, the activity was strongest on the day of oocyte retrieval. At that time the percentage of opposing waves increased and fundo-cervical waves disappeared. The highest wave frequency and velocity (4.29+/-0.68 waves/min and 2.73+/-0.54 mm/s respectively) were observed at the time of oocyte retrieval. All patients had some JZ activity on days 2, 3 and 4 after oocyte retrieval but regular wave-like contractility gradually decreased and only single random movements were seen on day 4 after oocyte retrieval. In conclusion, JZ activity throughout the IVF cycle is more exaggerated when compared to the results reported from observations of the natural cycle but follows a similar pattern. This fact can probably be explained by the vastly different hormone levels. Higher JZ activity and correspondingly increased mobility of the endometrium may impair its receptivity and affect implantation.

Embryo transfer--can we learn anything new from the observation of junctional zone contractions?

To assess whether embryo transfer can alter junctional zone contractility, we studied the effect of easy and difficult mock transfers in 14 oocyte donors during in-vitro fertilization (IVF) cycles. An Echovist bolus (30 microl) was used to represent embryos and transfer medium. An 'easy' transfer was judged to be an atraumatic insertion of the catheter without touching the uterine fundus. A 'difficult' embryo transfer was mimicked by deliberately touching the uterine fundus twice with the soft end of the cannula. Transvaginal scan images were recorded, digitized and converted into five times normal speed to allow us to evaluate junctional zone contractility. Easy mock embryo transfers did not change endometrial mechanical activity. Echovist remained in the upper part of the uterine cavity and was not dispersed after 45 min. A difficult procedure generated strong random waves in the fundal area and waves from fundus to cervix which relocated the Echovist in six out of seven cases. We observed movements of the transfer bolus from the upper part of the uterus towards the cervix (four cases) and into Fallopian tubes (two patients). Our study confirms that the mechanical activity of the uterus is capable of relocating intrauterine embryos and that this activity depends on physical stimulation. Junctional zone contractions can be implicated in cases of IVF/embryo transfer failure or ectopic gestation.