Endometrial thickness, morphology, vascular penetration and velocimetry in predicting implantation in an in vitro fertilization program.

A total of 96 women undergoing in vitro fertilization (IVF) treatment were studied on the day of human chorionic gonadotropin (hCG) administration by transvaginal ultrasonography with color and pulsed Doppler ultrasound. We assessed endometrial thickness, endometrial morphology, presence or absence of subendometrial or intraendometrial color flow, intraendometrial vascular penetration and subendometrial blood flow velocimetry on the day of hCG administration and related the results to pregnancy rates. The overall pregnancy rate was 32.3% (31/96) and there was no significant difference between the pregnant and non-pregnant groups with regard to endometrial thickness, subendometrial peak systolic blood flow velocity (Vmax) or subendometrial pulsatility index (PI). The pregnancy rates based on endometrial morphology were not significantly different, being 17.6% (3/17), 33.3% (2/6) and 35.6% (26/73) for types A (hyperechoic), B (isoechoic) and C (triple-line) endometria, respectively. In eight (8.3%) patients, subendometrial color flow and intraendometrial vascularization were not detected. This absence of blood flow was associated with failure of implantation (p < 0.05). The pregnancy rates related to the zones of vascular penetration into the subendometrial and endometrial regions were: 26.7% (4/15) for Zone 1 (subendometrial zone), 36.4% (16/44) for Zone 2 (outer hyperechogenic zone) and 37.9% (11/29) for Zone 3 (inner hypoechogenic zone), and were not significantly different. Of cycles with type A endometrium, 23.5% (4/17) had absent subendometrial color, which was greater than the frequency of absent color in the type C endometrium (4.1%, p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)