Blood Estradiol level from transvaginal ultrasounds

Overview

Blood Estradiol Level from Transvaginal Ultrasounds

Keeping blood Estradiol level under control is crucial during fertility treatments in order to avoid risk of overstimulation. To this end blood samples are typically taken every one or two days.

As during fertility treatments Estradiol is mainly produced by the growing follicles, E2E allows physicians to estimate Estradiol level from number and size of the growing follicles as a result of transvaginal ultrasounds.

Fewer Blood Samples

for Treatment Cost Reduction

E2E enables reduction of the number of required blood samples during treatment to check that Estradiol level is below its safety threshold.

This contributes to reduce costs of fertility treatments.

Fewer Patient Visits

for Better Logistics and Higher Patient Comfort

As patients can perform transvaginal ultrasounds by themselves at home with portable devices (see for example Sonaura), E2E allows remote Estradiol estimation, thus enabling reduction of the number of patient visits per treatment.

This also contributes to reduce costs of fertility treatments and to increase patient comfort.

Reliable Individualised Estimations

E2E computes reliable individualised Estradiol estimations by taking into account patient external factors (for example, AFC, pathologies, treatment protocol in use).

Accuracy improves after any actual measurement. For most patient groups two measurements suffice to have fully reliable estimations.

Physiology of Estradiol Production during Fertility Treatments

Follicles growing in the ovary have the 3-layer structure shown in the figure. They consist in a fluid-filled Antrum, the Granulosa layer and the Theca layer.

During the Stimulation phase of a fertility treatment, Estradiol is mainly produced by the cells of the Granulosa layer of the growing follicles.

The diameter of the follicles, as measured from transvaginal ultrasounds, is the diameter of the Antrum (as granulosa and theca layers are not visible through ultrasounds).

Volume of the Granulosa Layer

It is known that the tickness of the Granulosa layer is constant during follicle growth (around $$45\mu m$$).

From this follows that the volume of the Granulosa layer can be easily estimated from the diameter of the Antrum using standard geometry arguments, assuming that the follicles have a spherical shape.

Retrospective Clinical Data

used for E2E Accuracy Estimation

Here we show experimental results on the accuracy assessment of the Estradiol estimations performed by E2E both when some actual Estradiol measurements are available for the patient at hand (patient-specific estimations) and when only information of the patient group is known (inter-patient estimations).

Experiments use retrospective clinical data on thousands of patients.

Data have been kindly provided by University Hospital of Zurich and Hannover Medical School (Paeon partners) as well as University Hospital of Lausanne and University Hospital of Basel as a result of networking activities.

The figure shows the accuracy achieved by the patient-specific Estradiol estimation performed by E2E. In particular, for each patient class, the figure shows the average Estradiol estimation error and the standard deviation on the patients in our database, when feeding the system with 2, 3 and 4 actual measurements of Estradiol blood level and number and size of follicles.

It can be seen that 3 actual measurements are enough to make Estradiol patient-specific estimation very accurate.

As expected, for some groups like the group consisting in women affected by PCOS, standard deviation is higher. This is in agreement with the fact that PCOS patients form a heterogeneous group with high inter-patient variability. It is also expected that standard deviation tends to increase as the number of follicles increases.