Comparison of transabdominal and transvaginal pelvic ultrasonography for ovarian follicle assessment in in vitro fertilisation.

The emergence of transvaginal ultrasound-guided oocyte retrieval provided an opportunity to review and improve the traditional transabdominal ultrasonic approach for follicular tracking in in vitro fertilisation (IVF). This technique requires a full bladder, which may cause extreme discomfort. Hence, to provide both effective and comfortable monitoring, we instituted a study comparing transabdominal and transvaginal ultrasonography, with regard to patient preference and follicular number, size and dominance, in patients undergoing IVF and gamete intrafallopian transfer (GIFT). Commencing usually on day 9 of the treatment cycle, 45 patients were scanned on 55 occasions, initially abdominally (with a full bladder) and subsequently vaginally, using a transvaginal 7.5 MHz sector transducer. Follicular number was identical in 78% of cases, with the majority of the remaining patients showing an extra follicle on vaginal assessment. There were no significant differences in overall or dominant follicular diameters with either technique. Overall, 85% unashamedly preferred the vaginal approach. We believe that tracking follicular development in IVF treatment cycles is efficient and popular using the vaginal sector transducer and accordingly have ceased all assessments using the abdominal probe. Subsequently, 450 follicle scans have been performed with virtually the unanimous approval of our patients.