EARLIEST ULTRASOUND FINDING OF IMPLANTATION

Purpose: Our purpose was to verify our earlier observation of an alter ed endometrial echo character during the periimplantation period, sign ifying the earliest detection of implantation by ultrasound. Methods: The transvaginal ultrasound study used a 7.5-MHz probe on day 6 follow ing preembryo transfer Results: Of 31 embryo transfers studied, 8 (25. 8%) were positive for this sign on day 6, whereas 9 patients later sho wed a gestational sac, giving an accuracy of this sign of 88.8% (8 of 9) Conclusions: The normal secretory-phase endometrium shows a typical , evenly distributed hyperechogenecity described earlier by Hackeloer (1). In some cases of proliferative phases, too, this echo pattern has been reported by others (2, 3), and observed by us in stimulated and unstimulated cycles, and has been named type A endometrium by Gonen et al. (4) Both these varieties are seen to have an even, unbroken outli ne at the anterior and posterior myometrial-endometrial interphase. We report what we believe to be the earliest ultrasound picture of impla ntation, resembling this variety of endometrial echo bur having an irr egular outline (Fig. 2).